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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

Browse Source 
Conflicts:
	arch/sh/kernel/vmlinux.lds.S
This commit is contained in:
Paul Mundt
2009-09-16 13:48:32 +09:00
parent a6f15ade97 0cb583fd28
commit ea88023b34
3897 changed files with 316200 additions and 138946 deletions
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2
Documentation/00-INDEX
View File

@@ -82,6 +82,8 @@ block/
- info on the Block I/O (BIO) layer.
blockdev/
- info on block devices & drivers
btmrvl.txt
- info on Marvell Bluetooth driver usage.
cachetlb.txt
- describes the cache/TLB flushing interfaces Linux uses.
cdrom/

77
Documentation/RCU/RTFP.txt
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@@ -743,3 +743,80 @@ Revised:
RCU, realtime RCU, sleepable RCU, performance.
"
}
@article{PaulEMcKenney2008RCUOSR
,author="Paul E. McKenney and Jonathan Walpole"
,title="Introducing technology into the {Linux} kernel: a case study"
,Year="2008"
,journal="SIGOPS Oper. Syst. Rev."
,volume="42"
,number="5"
,pages="4--17"
,issn="0163-5980"
,doi={http://doi.acm.org/10.1145/1400097.1400099}
,publisher="ACM"
,address="New York, NY, USA"
,annotation={
Linux changed RCU to a far greater degree than RCU has changed Linux.
}
}
@unpublished{PaulEMcKenney2008HierarchicalRCU
,Author="Paul E. McKenney"
,Title="Hierarchical {RCU}"
,month="November"
,day="3"
,year="2008"
,note="Available:
\url{http://lwn.net/Articles/305782/}
[Viewed November 6, 2008]"
,annotation="
RCU with combining-tree-based grace-period detection,
permitting it to handle thousands of CPUs.
"
}
@conference{PaulEMcKenney2009MaliciousURCU
,Author="Paul E. McKenney"
,Title="Using a Malicious User-Level {RCU} to Torture {RCU}-Based Algorithms"
,Booktitle="linux.conf.au 2009"
,month="January"
,year="2009"
,address="Hobart, Australia"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/urcutorture.2009.01.22a.pdf}
[Viewed February 2, 2009]"
,annotation="
Realtime RCU and torture-testing RCU uses.
"
}
@unpublished{MathieuDesnoyers2009URCU
,Author="Mathieu Desnoyers"
,Title="[{RFC} git tree] Userspace {RCU} (urcu) for {Linux}"
,month="February"
,day="5"
,year="2009"
,note="Available:
\url{http://lkml.org/lkml/2009/2/5/572}
\url{git://lttng.org/userspace-rcu.git}
[Viewed February 20, 2009]"
,annotation="
Mathieu Desnoyers's user-space RCU implementation.
git://lttng.org/userspace-rcu.git
"
}
@unpublished{PaulEMcKenney2009BloatWatchRCU
,Author="Paul E. McKenney"
,Title="{RCU}: The {Bloatwatch} Edition"
,month="March"
,day="17"
,year="2009"
,note="Available:
\url{http://lwn.net/Articles/323929/}
[Viewed March 20, 2009]"
,annotation="
Uniprocessor assumptions allow simplified RCU implementation.
"
}

34
Documentation/RCU/UP.txt
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@@ -2,14 +2,13 @@ RCU on Uniprocessor Systems
A common misconception is that, on UP systems, the call_rcu() primitive
may immediately invoke its function, and that the synchronize_rcu()
primitive may return immediately. The basis of this misconception
may immediately invoke its function. The basis of this misconception
is that since there is only one CPU, it should not be necessary to
wait for anything else to get done, since there are no other CPUs for
anything else to be happening on. Although this approach will -sort- -of-
work a surprising amount of the time, it is a very bad idea in general.
This document presents three examples that demonstrate exactly how bad an
idea this is.
This document presents three examples that demonstrate exactly how bad
an idea this is.
Example 1: softirq Suicide
@@ -82,11 +81,18 @@ Quick Quiz #2: What locking restriction must RCU callbacks respect?
Summary
Permitting call_rcu() to immediately invoke its arguments or permitting
synchronize_rcu() to immediately return breaks RCU, even on a UP system.
So do not do it! Even on a UP system, the RCU infrastructure -must-
respect grace periods, and -must- invoke callbacks from a known environment
in which no locks are held.
Permitting call_rcu() to immediately invoke its arguments breaks RCU,
even on a UP system. So do not do it! Even on a UP system, the RCU
infrastructure -must- respect grace periods, and -must- invoke callbacks
from a known environment in which no locks are held.
It -is- safe for synchronize_sched() and synchronize_rcu_bh() to return
immediately on an UP system. It is also safe for synchronize_rcu()
to return immediately on UP systems, except when running preemptable
RCU.
Quick Quiz #3: Why can't synchronize_rcu() return immediately on
UP systems running preemptable RCU?
Answer to Quick Quiz #1:
@@ -117,3 +123,13 @@ Answer to Quick Quiz #2:
callbacks acquire locks directly. However, a great many RCU
callbacks do acquire locks -indirectly-, for example, via
the kfree() primitive.
Answer to Quick Quiz #3:
Why can't synchronize_rcu() return immediately on UP systems
running preemptable RCU?
Because some other task might have been preempted in the middle
of an RCU read-side critical section. If synchronize_rcu()
simply immediately returned, it would prematurely signal the
end of the grace period, which would come as a nasty shock to
that other thread when it started running again.

20
Documentation/RCU/checklist.txt
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@@ -11,7 +11,10 @@ over a rather long period of time, but improvements are always welcome!
structure is updated more than about 10% of the time, then
you should strongly consider some other approach, unless
detailed performance measurements show that RCU is nonetheless
the right tool for the job.
the right tool for the job. Yes, you might think of RCU
as simply cutting overhead off of the readers and imposing it
on the writers. That is exactly why normal uses of RCU will
do much more reading than updating.
Another exception is where performance is not an issue, and RCU
provides a simpler implementation. An example of this situation
@@ -240,10 +243,11 @@ over a rather long period of time, but improvements are always welcome!
instead need to use synchronize_irq() or synchronize_sched().
12. Any lock acquired by an RCU callback must be acquired elsewhere
with irq disabled, e.g., via spin_lock_irqsave(). Failing to
disable irq on a given acquisition of that lock will result in
deadlock as soon as the RCU callback happens to interrupt that
acquisition's critical section.
with softirq disabled, e.g., via spin_lock_irqsave(),
spin_lock_bh(), etc. Failing to disable irq on a given
acquisition of that lock will result in deadlock as soon as the
RCU callback happens to interrupt that acquisition's critical
section.
13. RCU callbacks can be and are executed in parallel. In many cases,
the callback code simply wrappers around kfree(), so that this
@@ -310,3 +314,9 @@ over a rather long period of time, but improvements are always welcome!
Because these primitives only wait for pre-existing readers,
it is the caller's responsibility to guarantee safety to
any subsequent readers.
16. The various RCU read-side primitives do -not- contain memory
barriers. The CPU (and in some cases, the compiler) is free
to reorder code into and out of RCU read-side critical sections.
It is the responsibility of the RCU update-side primitives to
deal with this.

10
Documentation/RCU/rcu.txt
View File

@@ -36,7 +36,7 @@ o How can the updater tell when a grace period has completed
executed in user mode, or executed in the idle loop, we can
safely free up that item.
Preemptible variants of RCU (CONFIG_PREEMPT_RCU) get the
Preemptible variants of RCU (CONFIG_TREE_PREEMPT_RCU) get the
same effect, but require that the readers manipulate CPU-local
counters. These counters allow limited types of blocking
within RCU read-side critical sections. SRCU also uses
@@ -79,10 +79,10 @@ o I hear that RCU is patented? What is with that?
o I hear that RCU needs work in order to support realtime kernels?
This work is largely completed. Realtime-friendly RCU can be
enabled via the CONFIG_PREEMPT_RCU kernel configuration parameter.
However, work is in progress for enabling priority boosting of
preempted RCU read-side critical sections. This is needed if you
have CPU-bound realtime threads.
enabled via the CONFIG_TREE_PREEMPT_RCU kernel configuration
parameter. However, work is in progress for enabling priority
boosting of preempted RCU read-side critical sections. This is
needed if you have CPU-bound realtime threads.
o Where can I find more information on RCU?

7
Documentation/RCU/rcubarrier.txt
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@@ -170,6 +170,13 @@ module invokes call_rcu() from timers, you will need to first cancel all
the timers, and only then invoke rcu_barrier() to wait for any remaining
RCU callbacks to complete.
Of course, if you module uses call_rcu_bh(), you will need to invoke
rcu_barrier_bh() before unloading. Similarly, if your module uses
call_rcu_sched(), you will need to invoke rcu_barrier_sched() before
unloading. If your module uses call_rcu(), call_rcu_bh(), -and-
call_rcu_sched(), then you will need to invoke each of rcu_barrier(),
rcu_barrier_bh(), and rcu_barrier_sched().
Implementing rcu_barrier()

23
Documentation/RCU/torture.txt
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@@ -76,8 +76,10 @@ torture_type The type of RCU to test: "rcu" for the rcu_read_lock() API,
"rcu_sync" for rcu_read_lock() with synchronous reclamation,
"rcu_bh" for the rcu_read_lock_bh() API, "rcu_bh_sync" for
rcu_read_lock_bh() with synchronous reclamation, "srcu" for
the "srcu_read_lock()" API, and "sched" for the use of
preempt_disable() together with synchronize_sched().
the "srcu_read_lock()" API, "sched" for the use of
preempt_disable() together with synchronize_sched(),
and "sched_expedited" for the use of preempt_disable()
with synchronize_sched_expedited().
verbose Enable debug printk()s. Default is disabled.
@@ -162,6 +164,23 @@ of the "old" and "current" counters for the corresponding CPU. The
"idx" value maps the "old" and "current" values to the underlying array,
and is useful for debugging.
Similarly, sched_expedited RCU provides the following:
sched_expedited-torture: rtc: d0000000016c1880 ver: 1090796 tfle: 0 rta: 1090796 rtaf: 0 rtf: 1090787 rtmbe: 0 nt: 27713319
sched_expedited-torture: Reader Pipe: 12660320201 95875 0 0 0 0 0 0 0 0 0
sched_expedited-torture: Reader Batch: 12660424885 0 0 0 0 0 0 0 0 0 0
sched_expedited-torture: Free-Block Circulation: 1090795 1090795 1090794 1090793 1090792 1090791 1090790 1090789 1090788 1090787 0
state: -1 / 0:0 3:0 4:0
As before, the first four lines are similar to those for RCU.
The last line shows the task-migration state. The first number is
-1 if synchronize_sched_expedited() is idle, -2 if in the process of
posting wakeups to the migration kthreads, and N when waiting on CPU N.
Each of the colon-separated fields following the "/" is a CPU:state pair.
Valid states are "0" for idle, "1" for waiting for quiescent state,
"2" for passed through quiescent state, and "3" when a race with a
CPU-hotplug event forces use of the synchronize_sched() primitive.
USAGE

7
Documentation/RCU/trace.txt
View File

@@ -191,8 +191,7 @@ rcu/rcuhier (which displays the struct rcu_node hierarchy).
The output of "cat rcu/rcudata" looks as follows:
rcu:
rcu:
rcu_sched:
0 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=10951/1 dn=0 df=1101 of=0 ri=36 ql=0 b=10
1 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=16117/1 dn=0 df=1015 of=0 ri=0 ql=0 b=10
2 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=1445/1 dn=0 df=1839 of=0 ri=0 ql=0 b=10
@@ -306,7 +305,7 @@ comma-separated-variable spreadsheet format.
The output of "cat rcu/rcugp" looks as follows:
rcu: completed=33062 gpnum=33063
rcu_sched: completed=33062 gpnum=33063
rcu_bh: completed=464 gpnum=464
Again, this output is for both "rcu" and "rcu_bh". The fields are
@@ -413,7 +412,7 @@ o Each element of the form "1/1 0:127 ^0" represents one struct
The output of "cat rcu/rcu_pending" looks as follows:
rcu:
rcu_sched:
0 np=255892 qsp=53936 cbr=0 cng=14417 gpc=10033 gps=24320 nf=6445 nn=146741
1 np=261224 qsp=54638 cbr=0 cng=25723 gpc=16310 gps=2849 nf=5912 nn=155792
2 np=237496 qsp=49664 cbr=0 cng=2762 gpc=45478 gps=1762 nf=1201 nn=136629

22
Documentation/RCU/whatisRCU.txt
View File

@@ -136,10 +136,10 @@ rcu_read_lock()
Used by a reader to inform the reclaimer that the reader is
entering an RCU read-side critical section. It is illegal
to block while in an RCU read-side critical section, though
kernels built with CONFIG_PREEMPT_RCU can preempt RCU read-side
critical sections. Any RCU-protected data structure accessed
during an RCU read-side critical section is guaranteed to remain
unreclaimed for the full duration of that critical section.
kernels built with CONFIG_TREE_PREEMPT_RCU can preempt RCU
read-side critical sections. Any RCU-protected data structure
accessed during an RCU read-side critical section is guaranteed to
remain unreclaimed for the full duration of that critical section.
Reference counts may be used in conjunction with RCU to maintain
longer-term references to data structures.
@@ -785,6 +785,7 @@ RCU pointer/list traversal:
rcu_dereference
list_for_each_entry_rcu
hlist_for_each_entry_rcu
hlist_nulls_for_each_entry_rcu
list_for_each_continue_rcu (to be deprecated in favor of new
list_for_each_entry_continue_rcu)
@@ -807,19 +808,23 @@ RCU: Critical sections Grace period Barrier
rcu_read_lock synchronize_net rcu_barrier
rcu_read_unlock synchronize_rcu
synchronize_rcu_expedited
call_rcu
bh: Critical sections Grace period Barrier
rcu_read_lock_bh call_rcu_bh rcu_barrier_bh
rcu_read_unlock_bh
rcu_read_unlock_bh synchronize_rcu_bh
synchronize_rcu_bh_expedited
sched: Critical sections Grace period Barrier
[preempt_disable] synchronize_sched rcu_barrier_sched
[and friends] call_rcu_sched
rcu_read_lock_sched synchronize_sched rcu_barrier_sched
rcu_read_unlock_sched call_rcu_sched
[preempt_disable] synchronize_sched_expedited
[and friends]
SRCU: Critical sections Grace period Barrier
@@ -827,6 +832,9 @@ SRCU: Critical sections Grace period Barrier
srcu_read_lock synchronize_srcu N/A
srcu_read_unlock
SRCU: Initialization/cleanup
init_srcu_struct
cleanup_srcu_struct
See the comment headers in the source code (or the docbook generated
from them) for more information.

2
Documentation/arm/SA1100/ADSBitsy
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@@ -40,4 +40,4 @@ Notes:
mode, the timing is off so the image is corrupted. This will be
fixed soon.
Any contribution can be sent to nico@cam.org and will be greatly welcome!
Any contribution can be sent to nico@fluxnic.net and will be greatly welcome!

2
Documentation/arm/SA1100/Assabet
View File

@@ -240,7 +240,7 @@ Then, rebooting the Assabet is just a matter of waiting for the login prompt.
Nicolas Pitre
nico@cam.org
nico@fluxnic.net
June 12, 2001

2
Documentation/arm/SA1100/Brutus
View File

@@ -60,7 +60,7 @@ little modifications.
Any contribution is welcome.
Please send patches to nico@cam.org
Please send patches to nico@fluxnic.net
Have Fun !

4
Documentation/arm/SA1100/GraphicsClient
View File

@@ -4,7 +4,7 @@ For more details, contact Applied Data Systems or see
http://www.applieddata.net/products.html
The original Linux support for this product has been provided by
Nicolas Pitre <nico@cam.org>. Continued development work by
Nicolas Pitre <nico@fluxnic.net>. Continued development work by
Woojung Huh <whuh@applieddata.net>
It's currently possible to mount a root filesystem via NFS providing a
@@ -94,5 +94,5 @@ Notes:
mode, the timing is off so the image is corrupted. This will be
fixed soon.
Any contribution can be sent to nico@cam.org and will be greatly welcome!
Any contribution can be sent to nico@fluxnic.net and will be greatly welcome!

4
Documentation/arm/SA1100/GraphicsMaster
View File

@@ -4,7 +4,7 @@ For more details, contact Applied Data Systems or see
http://www.applieddata.net/products.html
The original Linux support for this product has been provided by
Nicolas Pitre <nico@cam.org>. Continued development work by
Nicolas Pitre <nico@fluxnic.net>. Continued development work by
Woojung Huh <whuh@applieddata.net>
Use 'make graphicsmaster_config' before any 'make config'.
@@ -50,4 +50,4 @@ Notes:
mode, the timing is off so the image is corrupted. This will be
fixed soon.
Any contribution can be sent to nico@cam.org and will be greatly welcome!
Any contribution can be sent to nico@fluxnic.net and will be greatly welcome!

2
Documentation/arm/SA1100/Victor
View File

@@ -9,7 +9,7 @@ Of course Victor is using Linux as its main operating system.
The Victor implementation for Linux is maintained by Nicolas Pitre:
nico@visuaide.com
nico@cam.org
nico@fluxnic.net
For any comments, please feel free to contact me through the above
addresses.

75
Documentation/arm/Samsung-S3C24XX/CPUfreq.txt Normal file
View File

@@ -0,0 +1,75 @@
S3C24XX CPUfreq support
=======================
Introduction
------------
The S3C24XX series support a number of power saving systems, such as
the ability to change the core, memory and peripheral operating
frequencies. The core control is exported via the CPUFreq driver
which has a number of different manual or automatic controls over the
rate the core is running at.
There are two forms of the driver depending on the specific CPU and
how the clocks are arranged. The first implementation used as single
PLL to feed the ARM, memory and peripherals via a series of dividers
and muxes and this is the implementation that is documented here. A
newer version where there is a seperate PLL and clock divider for the
ARM core is available as a seperate driver.
Layout
------
The code core manages the CPU specific drivers, any data that they
need to register and the interface to the generic drivers/cpufreq
system. Each CPU registers a driver to control the PLL, clock dividers
and anything else associated with it. Any board that wants to use this
framework needs to supply at least basic details of what is required.
The core registers with drivers/cpufreq at init time if all the data
necessary has been supplied.
CPU support
-----------
The support for each CPU depends on the facilities provided by the
SoC and the driver as each device has different PLL and clock chains
associated with it.
Slow Mode
---------
The SLOW mode where the PLL is turned off altogether and the
system is fed by the external crystal input is currently not
supported.
sysfs
-----
The core code exports extra information via sysfs in the directory
devices/system/cpu/cpu0/arch-freq.
Board Support
-------------
Each board that wants to use the cpufreq code must register some basic
information with the core driver to provide information about what the
board requires and any restrictions being placed on it.
The board needs to supply information about whether it needs the IO bank
timings changing, any maximum frequency limits and information about the
SDRAM refresh rate.
Document Author
---------------
Ben Dooks, Copyright 2009 Simtec Electronics
Licensed under GPLv2

119
Documentation/btmrvl.txt Normal file
View File

@@ -0,0 +1,119 @@
=======================================================================
README for btmrvl driver
=======================================================================
All commands are used via debugfs interface.
=====================
Set/get driver configurations:
Path: /debug/btmrvl/config/
gpiogap=[n]
hscfgcmd
These commands are used to configure the host sleep parameters.
bit 8:0 -- Gap
bit 16:8 -- GPIO
where GPIO is the pin number of GPIO used to wake up the host.
It could be any valid GPIO pin# (e.g. 0-7) or 0xff (SDIO interface
wakeup will be used instead).
where Gap is the gap in milli seconds between wakeup signal and
wakeup event, or 0xff for special host sleep setting.
Usage:
# Use SDIO interface to wake up the host and set GAP to 0x80:
echo 0xff80 > /debug/btmrvl/config/gpiogap
echo 1 > /debug/btmrvl/config/hscfgcmd
# Use GPIO pin #3 to wake up the host and set GAP to 0xff:
echo 0x03ff > /debug/btmrvl/config/gpiogap
echo 1 > /debug/btmrvl/config/hscfgcmd
psmode=[n]
pscmd
These commands are used to enable/disable auto sleep mode
where the option is:
1 -- Enable auto sleep mode
0 -- Disable auto sleep mode
Usage:
# Enable auto sleep mode
echo 1 > /debug/btmrvl/config/psmode
echo 1 > /debug/btmrvl/config/pscmd
# Disable auto sleep mode
echo 0 > /debug/btmrvl/config/psmode
echo 1 > /debug/btmrvl/config/pscmd
hsmode=[n]
hscmd
These commands are used to enable host sleep or wake up firmware
where the option is:
1 -- Enable host sleep
0 -- Wake up firmware
Usage:
# Enable host sleep
echo 1 > /debug/btmrvl/config/hsmode
echo 1 > /debug/btmrvl/config/hscmd
# Wake up firmware
echo 0 > /debug/btmrvl/config/hsmode
echo 1 > /debug/btmrvl/config/hscmd
======================
Get driver status:
Path: /debug/btmrvl/status/
Usage:
cat /debug/btmrvl/status/<args>
where the args are:
curpsmode
This command displays current auto sleep status.
psstate
This command display the power save state.
hsstate
This command display the host sleep state.
txdnldrdy
This command displays the value of Tx download ready flag.
=====================
Use hcitool to issue raw hci command, refer to hcitool manual
Usage: Hcitool cmd <ogf> <ocf> [Parameters]
Interface Control Command
hcitool cmd 0x3f 0x5b 0xf5 0x01 0x00 --Enable All interface
hcitool cmd 0x3f 0x5b 0xf5 0x01 0x01 --Enable Wlan interface
hcitool cmd 0x3f 0x5b 0xf5 0x01 0x02 --Enable BT interface
hcitool cmd 0x3f 0x5b 0xf5 0x00 0x00 --Disable All interface
hcitool cmd 0x3f 0x5b 0xf5 0x00 0x01 --Disable Wlan interface
hcitool cmd 0x3f 0x5b 0xf5 0x00 0x02 --Disable BT interface
=======================================================================
SD8688 firmware:
/lib/firmware/sd8688_helper.bin
/lib/firmware/sd8688.bin
The images can be downloaded from:
git.infradead.org/users/dwmw2/linux-firmware.git/libertas/

5
Documentation/connector/Makefile
View File

@@ -9,3 +9,8 @@ hostprogs-y := ucon
always := $(hostprogs-y)
HOSTCFLAGS_ucon.o += -I$(objtree)/usr/include
all: modules
modules clean:
$(MAKE) -C ../.. SUBDIRS=$(PWD) $@

33
Documentation/connector/cn_test.c
View File

@@ -19,6 +19,8 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#define pr_fmt(fmt) "cn_test: " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
@@ -27,18 +29,17 @@
#include <linux/connector.h>
static struct cb_id cn_test_id = { 0x123, 0x456 };
static struct cb_id cn_test_id = { CN_NETLINK_USERS + 3, 0x456 };
static char cn_test_name[] = "cn_test";
static struct sock *nls;
static struct timer_list cn_test_timer;
void cn_test_callback(void *data)
static void cn_test_callback(struct cn_msg *msg)
{
struct cn_msg *msg = (struct cn_msg *)data;
printk("%s: %lu: idx=%x, val=%x, seq=%u, ack=%u, len=%d: %s.\n",
__func__, jiffies, msg->id.idx, msg->id.val,
msg->seq, msg->ack, msg->len, (char *)msg->data);
pr_info("%s: %lu: idx=%x, val=%x, seq=%u, ack=%u, len=%d: %s.\n",
__func__, jiffies, msg->id.idx, msg->id.val,
msg->seq, msg->ack, msg->len,
msg->len ? (char *)msg->data : "");
}
/*
@@ -63,9 +64,7 @@ static int cn_test_want_notify(void)
skb = alloc_skb(size, GFP_ATOMIC);
if (!skb) {
printk(KERN_ERR "Failed to allocate new skb with size=%u.\n",
size);
pr_err("failed to allocate new skb with size=%u\n", size);
return -ENOMEM;
}
@@ -114,12 +113,12 @@ static int cn_test_want_notify(void)
//netlink_broadcast(nls, skb, 0, ctl->group, GFP_ATOMIC);
netlink_unicast(nls, skb, 0, 0);
printk(KERN_INFO "Request was sent. Group=0x%x.\n", ctl->group);
pr_info("request was sent: group=0x%x\n", ctl->group);
return 0;
nlmsg_failure:
printk(KERN_ERR "Failed to send %u.%u\n", msg->seq, msg->ack);
pr_err("failed to send %u.%u\n", msg->seq, msg->ack);
kfree_skb(skb);
return -EINVAL;
}
@@ -131,6 +130,8 @@ static void cn_test_timer_func(unsigned long __data)
struct cn_msg *m;
char data[32];
pr_debug("%s: timer fired with data %lu\n", __func__, __data);
m = kzalloc(sizeof(*m) + sizeof(data), GFP_ATOMIC);
if (m) {
@@ -150,7 +151,7 @@ static void cn_test_timer_func(unsigned long __data)
cn_test_timer_counter++;
mod_timer(&cn_test_timer, jiffies + HZ);
mod_timer(&cn_test_timer, jiffies + msecs_to_jiffies(1000));
}
static int cn_test_init(void)
@@ -168,8 +169,10 @@ static int cn_test_init(void)
}
setup_timer(&cn_test_timer, cn_test_timer_func, 0);
cn_test_timer.expires = jiffies + HZ;
add_timer(&cn_test_timer);
mod_timer(&cn_test_timer, jiffies + msecs_to_jiffies(1000));
pr_info("initialized with id={%u.%u}\n",
cn_test_id.idx, cn_test_id.val);
return 0;

119
Documentation/connector/connector.txt
View File

@@ -5,10 +5,10 @@ Kernel Connector.
Kernel connector - new netlink based userspace <-> kernel space easy
to use communication module.
Connector driver adds possibility to connect various agents using
netlink based network. One must register callback and
identifier. When driver receives special netlink message with
appropriate identifier, appropriate callback will be called.
The Connector driver makes it easy to connect various agents using a
netlink based network. One must register a callback and an identifier.
When the driver receives a special netlink message with the appropriate
identifier, the appropriate callback will be called.
From the userspace point of view it's quite straightforward:
@@ -17,10 +17,10 @@ From the userspace point of view it's quite straightforward:
send();
recv();
But if kernelspace want to use full power of such connections, driver
writer must create special sockets, must know about struct sk_buff
handling... Connector allows any kernelspace agents to use netlink
based networking for inter-process communication in a significantly
But if kernelspace wants to use the full power of such connections, the
driver writer must create special sockets, must know about struct sk_buff
handling, etc... The Connector driver allows any kernelspace agents to use
netlink based networking for inter-process communication in a significantly
easier way:
int cn_add_callback(struct cb_id *id, char *name, void (*callback) (void *));
@@ -32,15 +32,15 @@ struct cb_id
__u32 val;
};
idx and val are unique identifiers which must be registered in
connector.h for in-kernel usage. void (*callback) (void *) - is a
callback function which will be called when message with above idx.val
will be received by connector core. Argument for that function must
idx and val are unique identifiers which must be registered in the
connector.h header for in-kernel usage. void (*callback) (void *) is a
callback function which will be called when a message with above idx.val
is received by the connector core. The argument for that function must
be dereferenced to struct cn_msg *.
struct cn_msg
{
struct cb_id id;
struct cb_id id;
__u32 seq;
__u32 ack;
@@ -55,92 +55,95 @@ Connector interfaces.
int cn_add_callback(struct cb_id *id, char *name, void (*callback) (void *));
Registers new callback with connector core.
Registers new callback with connector core.
struct cb_id *id - unique connector's user identifier.
It must be registered in connector.h for legal in-kernel users.
char *name - connector's callback symbolic name.
void (*callback) (void *) - connector's callback.
struct cb_id *id - unique connector's user identifier.
It must be registered in connector.h for legal in-kernel users.
char *name - connector's callback symbolic name.
void (*callback) (void *) - connector's callback.
Argument must be dereferenced to struct cn_msg *.
void cn_del_callback(struct cb_id *id);
Unregisters new callback with connector core.
Unregisters new callback with connector core.
struct cb_id *id - unique connector's user identifier.
struct cb_id *id - unique connector's user identifier.
int cn_netlink_send(struct cn_msg *msg, u32 __groups, int gfp_mask);
Sends message to the specified groups. It can be safely called from
softirq context, but may silently fail under strong memory pressure.
If there are no listeners for given group -ESRCH can be returned.
Sends message to the specified groups. It can be safely called from
softirq context, but may silently fail under strong memory pressure.
If there are no listeners for given group -ESRCH can be returned.
struct cn_msg * - message header(with attached data).
u32 __group - destination group.
struct cn_msg * - message header(with attached data).
u32 __group - destination group.
If __group is zero, then appropriate group will
be searched through all registered connector users,
and message will be delivered to the group which was
created for user with the same ID as in msg.
If __group is not zero, then message will be delivered
to the specified group.
int gfp_mask - GFP mask.
int gfp_mask - GFP mask.
Note: When registering new callback user, connector core assigns
netlink group to the user which is equal to it's id.idx.
Note: When registering new callback user, connector core assigns
netlink group to the user which is equal to it's id.idx.
/*****************************************/
Protocol description.
/*****************************************/
Current offers transport layer with fixed header. Recommended
protocol which uses such header is following:
The current framework offers a transport layer with fixed headers. The
recommended protocol which uses such a header is as following:
msg->seq and msg->ack are used to determine message genealogy. When
someone sends message it puts there locally unique sequence and random
acknowledge numbers. Sequence number may be copied into
someone sends a message, they use a locally unique sequence and random
acknowledge number. The sequence number may be copied into
nlmsghdr->nlmsg_seq too.
Sequence number is incremented with each message to be sent.
The sequence number is incremented with each message sent.
If we expect reply to our message, then sequence number in received
message MUST be the same as in original message, and acknowledge
number MUST be the same + 1.
If you expect a reply to the message, then the sequence number in the
received message MUST be the same as in the original message, and the
acknowledge number MUST be the same + 1.
If we receive message and it's sequence number is not equal to one we
are expecting, then it is new message. If we receive message and it's
sequence number is the same as one we are expecting, but it's
acknowledge is not equal acknowledge number in original message + 1,
then it is new message.
If we receive a message and its sequence number is not equal to one we
are expecting, then it is a new message. If we receive a message and
its sequence number is the same as one we are expecting, but its
acknowledge is not equal to the acknowledge number in the original
message + 1, then it is a new message.
Obviously, protocol header contains above id.
Obviously, the protocol header contains the above id.
connector allows event notification in the following form: kernel
The connector allows event notification in the following form: kernel
driver or userspace process can ask connector to notify it when
selected id's will be turned on or off(registered or unregistered it's
callback). It is done by sending special command to connector
driver(it also registers itself with id={-1, -1}).
selected ids will be turned on or off (registered or unregistered its
callback). It is done by sending a special command to the connector
driver (it also registers itself with id={-1, -1}).
As example of usage Documentation/connector now contains cn_test.c -
testing module which uses connector to request notification and to
send messages.
As example of this usage can be found in the cn_test.c module which
uses the connector to request notification and to send messages.
/*****************************************/
Reliability.
/*****************************************/
Netlink itself is not reliable protocol, that means that messages can
Netlink itself is not a reliable protocol. That means that messages can
be lost due to memory pressure or process' receiving queue overflowed,
so caller is warned must be prepared. That is why struct cn_msg [main
connector's message header] contains u32 seq and u32 ack fields.
so caller is warned that it must be prepared. That is why the struct
cn_msg [main connector's message header] contains u32 seq and u32 ack
fields.
/*****************************************/
Userspace usage.
/*****************************************/
2.6.14 has a new netlink socket implementation, which by default does not
allow to send data to netlink groups other than 1.
So, if to use netlink socket (for example using connector)
with different group number userspace application must subscribe to
that group. It can be achieved by following pseudocode:
allow people to send data to netlink groups other than 1.
So, if you wish to use a netlink socket (for example using connector)
with a different group number, the userspace application must subscribe to
that group first. It can be achieved by the following pseudocode:
s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
@@ -160,8 +163,8 @@ if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
}
Where 270 above is SOL_NETLINK, and 1 is a NETLINK_ADD_MEMBERSHIP socket
option. To drop multicast subscription one should call above socket option
with NETLINK_DROP_MEMBERSHIP parameter which is defined as 0.
option. To drop a multicast subscription, one should call the above socket
option with the NETLINK_DROP_MEMBERSHIP parameter which is defined as 0.
2.6.14 netlink code only allows to select a group which is less or equal to
the maximum group number, which is used at netlink_kernel_create() time.

62
Documentation/connector/ucon.c
View File

@@ -30,18 +30,24 @@
#include <arpa/inet.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <getopt.h>
#include <linux/connector.h>
#define DEBUG
#define NETLINK_CONNECTOR 11
/* Hopefully your userspace connector.h matches this kernel */
#define CN_TEST_IDX CN_NETLINK_USERS + 3
#define CN_TEST_VAL 0x456
#ifdef DEBUG
#define ulog(f, a...) fprintf(stdout, f, ##a)
#else
@@ -83,6 +89,25 @@ static int netlink_send(int s, struct cn_msg *msg)
return err;
}
static void usage(void)
{
printf(
"Usage: ucon [options] [output file]\n"
"\n"
"\t-h\tthis help screen\n"
"\t-s\tsend buffers to the test module\n"
"\n"
"The default behavior of ucon is to subscribe to the test module\n"
"and wait for state messages. Any ones received are dumped to the\n"
"specified output file (or stdout). The test module is assumed to\n"
"have an id of {%u.%u}\n"
"\n"
"If you get no output, then verify the cn_test module id matches\n"
"the expected id above.\n"
, CN_TEST_IDX, CN_TEST_VAL
);
}
int main(int argc, char *argv[])
{
int s;
@@ -94,17 +119,34 @@ int main(int argc, char *argv[])
FILE *out;
time_t tm;
struct pollfd pfd;
bool send_msgs = false;
if (argc < 2)
out = stdout;
else {
out = fopen(argv[1], "a+");
while ((s = getopt(argc, argv, "hs")) != -1) {
switch (s) {
case 's':
send_msgs = true;
break;
case 'h':
usage();
return 0;
default:
/* getopt() outputs an error for us */
usage();
return 1;
}
}
if (argc != optind) {
out = fopen(argv[optind], "a+");
if (!out) {
ulog("Unable to open %s for writing: %s\n",
argv[1], strerror(errno));
out = stdout;
}
}
} else
out = stdout;
memset(buf, 0, sizeof(buf));
@@ -115,9 +157,11 @@ int main(int argc, char *argv[])
}
l_local.nl_family = AF_NETLINK;
l_local.nl_groups = 0x123; /* bitmask of requested groups */
l_local.nl_groups = -1; /* bitmask of requested groups */
l_local.nl_pid = 0;
ulog("subscribing to %u.%u\n", CN_TEST_IDX, CN_TEST_VAL);
if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
perror("bind");
close(s);
@@ -130,15 +174,15 @@ int main(int argc, char *argv[])
setsockopt(s, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &on, sizeof(on));
}
#endif
if (0) {
if (send_msgs) {
int i, j;
memset(buf, 0, sizeof(buf));
data = (struct cn_msg *)buf;
data->id.idx = 0x123;
data->id.val = 0x456;
data->id.idx = CN_TEST_IDX;
data->id.val = CN_TEST_VAL;
data->seq = seq++;
data->ack = 0;
data->len = 0;

105
Documentation/feature-removal-schedule.txt
View File

@@ -6,6 +6,35 @@ be removed from this file.
---------------------------
What: PRISM54
When: 2.6.34
Why: prism54 FullMAC PCI / Cardbus devices used to be supported only by the
prism54 wireless driver. After Intersil stopped selling these
devices in preference for the newer more flexible SoftMAC devices
a SoftMAC device driver was required and prism54 did not support
them. The p54pci driver now exists and has been present in the kernel for
a while. This driver supports both SoftMAC devices and FullMAC devices.
The main difference between these devices was the amount of memory which
could be used for the firmware. The SoftMAC devices support a smaller
amount of memory. Because of this the SoftMAC firmware fits into FullMAC
devices's memory. p54pci supports not only PCI / Cardbus but also USB
and SPI. Since p54pci supports all devices prism54 supports
you will have a conflict. I'm not quite sure how distributions are
handling this conflict right now. prism54 was kept around due to
claims users may experience issues when using the SoftMAC driver.
Time has passed users have not reported issues. If you use prism54
and for whatever reason you cannot use p54pci please let us know!
E-mail us at: linux-wireless@vger.kernel.org
For more information see the p54 wiki page:
http://wireless.kernel.org/en/users/Drivers/p54
Who: Luis R. Rodriguez <lrodriguez@atheros.com>
---------------------------
What: IRQF_SAMPLE_RANDOM
Check: IRQF_SAMPLE_RANDOM
When: July 2009
@@ -206,24 +235,6 @@ Who: Len Brown <len.brown@intel.com>
---------------------------
What: libata spindown skipping and warning
When: Dec 2008
Why: Some halt(8) implementations synchronize caches for and spin
down libata disks because libata didn't use to spin down disk on
system halt (only synchronized caches).
Spin down on system halt is now implemented. sysfs node
/sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
spin down support is available.
Because issuing spin down command to an already spun down disk
makes some disks spin up just to spin down again, libata tracks
device spindown status to skip the extra spindown command and
warn about it.
This is to give userspace tools the time to get updated and will
be removed after userspace is reasonably updated.
Who: Tejun Heo <htejun@gmail.com>
---------------------------
What: i386/x86_64 bzImage symlinks
When: April 2010
@@ -235,31 +246,6 @@ Who: Thomas Gleixner <tglx@linutronix.de>
---------------------------
What (Why):
- include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files
(superseded by xt_TOS/xt_tos target & match)
- "forwarding" header files like ipt_mac.h in
include/linux/netfilter_ipv4/ and include/linux/netfilter_ipv6/
- xt_CONNMARK match revision 0
(superseded by xt_CONNMARK match revision 1)
- xt_MARK target revisions 0 and 1
(superseded by xt_MARK match revision 2)
- xt_connmark match revision 0
(superseded by xt_connmark match revision 1)
- xt_conntrack match revision 0
(superseded by xt_conntrack match revision 1)
- xt_iprange match revision 0,
include/linux/netfilter_ipv4/ipt_iprange.h
(superseded by xt_iprange match revision 1)
- xt_mark match revision 0
(superseded by xt_mark match revision 1)
- xt_recent: the old ipt_recent proc dir
(superseded by /proc/net/xt_recent)
@@ -394,15 +380,6 @@ Who: Thomas Gleixner <tglx@linutronix.de>
-----------------------------
What: obsolete generic irq defines and typedefs
When: 2.6.30
Why: The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t)
have been kept around for migration reasons. After more than two years
it's time to remove them finally
Who: Thomas Gleixner <tglx@linutronix.de>
---------------------------
What: fakephp and associated sysfs files in /sys/bus/pci/slots/
When: 2011
Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
@@ -468,3 +445,27 @@ Why: cpu_policy_rwsem has a new cleaner definition making it local to
cpufreq core and contained inside cpufreq.c. Other dependent
drivers should not use it in order to safely avoid lockdep issues.
Who: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
----------------------------
What: sound-slot/service-* module aliases and related clutters in
sound/sound_core.c
When: August 2010
Why: OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
(14) and requests modules using custom sound-slot/service-*
module aliases. The only benefit of doing this is allowing
use of custom module aliases which might as well be considered
a bug at this point. This preemptive claiming prevents
alternative OSS implementations.
Till the feature is removed, the kernel will be requesting
both sound-slot/service-* and the standard char-major-* module
aliases and allow turning off the pre-claiming selectively via
CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss
kernel parameter.
After the transition phase is complete, both the custom module
aliases and switches to disable it will go away. This removal
will also allow making ALSA OSS emulation independent of
sound_core. The dependency will be broken then too.
Who: Tejun Heo <tj@kernel.org>

100
Documentation/filesystems/gfs2-uevents.txt Normal file
View File

@@ -0,0 +1,100 @@
uevents and GFS2
==================
During the lifetime of a GFS2 mount, a number of uevents are generated.
This document explains what the events are and what they are used
for (by gfs_controld in gfs2-utils).
A list of GFS2 uevents
-----------------------
1. ADD
The ADD event occurs at mount time. It will always be the first
uevent generated by the newly created filesystem. If the mount
is successful, an ONLINE uevent will follow. If it is not successful
then a REMOVE uevent will follow.
The ADD uevent has two environment variables: SPECTATOR=[0|1]
and RDONLY=[0|1] that specify the spectator status (a read-only mount
with no journal assigned), and read-only (with journal assigned) status
of the filesystem respectively.
2. ONLINE
The ONLINE uevent is generated after a successful mount or remount. It
has the same environment variables as the ADD uevent. The ONLINE
uevent, along with the two environment variables for spectator and
RDONLY are a relatively recent addition (2.6.32-rc+) and will not
be generated by older kernels.
3. CHANGE
The CHANGE uevent is used in two places. One is when reporting the
successful mount of the filesystem by the first node (FIRSTMOUNT=Done).
This is used as a signal by gfs_controld that it is then ok for other
nodes in the cluster to mount the filesystem.
The other CHANGE uevent is used to inform of the completion
of journal recovery for one of the filesystems journals. It has
two environment variables, JID= which specifies the journal id which
has just been recovered, and RECOVERY=[Done|Failed] to indicate the
success (or otherwise) of the operation. These uevents are generated
for every journal recovered, whether it is during the initial mount
process or as the result of gfs_controld requesting a specific journal
recovery via the /sys/fs/gfs2/<fsname>/lock_module/recovery file.
Because the CHANGE uevent was used (in early versions of gfs_controld)
without checking the environment variables to discover the state, we
cannot add any more functions to it without running the risk of
someone using an older version of the user tools and breaking their
cluster. For this reason the ONLINE uevent was used when adding a new
uevent for a successful mount or remount.
4. OFFLINE
The OFFLINE uevent is only generated due to filesystem errors and is used
as part of the "withdraw" mechanism. Currently this doesn't give any
information about what the error is, which is something that needs to
be fixed.
5. REMOVE
The REMOVE uevent is generated at the end of an unsuccessful mount
or at the end of a umount of the filesystem. All REMOVE uevents will
have been preceeded by at least an ADD uevent for the same fileystem,
and unlike the other uevents is generated automatically by the kernel's
kobject subsystem.
Information common to all GFS2 uevents (uevent environment variables)
----------------------------------------------------------------------
1. LOCKTABLE=
The LOCKTABLE is a string, as supplied on the mount command
line (locktable=) or via fstab. It is used as a filesystem label
as well as providing the information for a lock_dlm mount to be
able to join the cluster.
2. LOCKPROTO=
The LOCKPROTO is a string, and its value depends on what is set
on the mount command line, or via fstab. It will be either
lock_nolock or lock_dlm. In the future other lock managers
may be supported.
3. JOURNALID=
If a journal is in use by the filesystem (journals are not
assigned for spectator mounts) then this will give the
numeric journal id in all GFS2 uevents.
4. UUID=
With recent versions of gfs2-utils, mkfs.gfs2 writes a UUID
into the filesystem superblock. If it exists, this will
be included in every uevent relating to the filesystem.

98
Documentation/filesystems/nfs.txt Normal file
View File

@@ -0,0 +1,98 @@
The NFS client
==============
The NFS version 2 protocol was first documented in RFC1094 (March 1989).
Since then two more major releases of NFS have been published, with NFSv3
being documented in RFC1813 (June 1995), and NFSv4 in RFC3530 (April
2003).
The Linux NFS client currently supports all the above published versions,
and work is in progress on adding support for minor version 1 of the NFSv4
protocol.
The purpose of this document is to provide information on some of the
upcall interfaces that are used in order to provide the NFS client with
some of the information that it requires in order to fully comply with
the NFS spec.
The DNS resolver
================
NFSv4 allows for one server to refer the NFS client to data that has been
migrated onto another server by means of the special "fs_locations"
attribute. See
http://tools.ietf.org/html/rfc3530#section-6
and
http://tools.ietf.org/html/draft-ietf-nfsv4-referrals-00
The fs_locations information can take the form of either an ip address and
a path, or a DNS hostname and a path. The latter requires the NFS client to
do a DNS lookup in order to mount the new volume, and hence the need for an
upcall to allow userland to provide this service.
Assuming that the user has the 'rpc_pipefs' filesystem mounted in the usual
/var/lib/nfs/rpc_pipefs, the upcall consists of the following steps:
(1) The process checks the dns_resolve cache to see if it contains a
valid entry. If so, it returns that entry and exits.
(2) If no valid entry exists, the helper script '/sbin/nfs_cache_getent'
(may be changed using the 'nfs.cache_getent' kernel boot parameter)
is run, with two arguments:
- the cache name, "dns_resolve"
- the hostname to resolve
(3) After looking up the corresponding ip address, the helper script
writes the result into the rpc_pipefs pseudo-file
'/var/lib/nfs/rpc_pipefs/cache/dns_resolve/channel'
in the following (text) format:
"<ip address> <hostname> <ttl>\n"
Where <ip address> is in the usual IPv4 (123.456.78.90) or IPv6
(ffee:ddcc:bbaa:9988:7766:5544:3322:1100, ffee::1100, ...) format.
<hostname> is identical to the second argument of the helper
script, and <ttl> is the 'time to live' of this cache entry (in
units of seconds).
Note: If <ip address> is invalid, say the string "0", then a negative
entry is created, which will cause the kernel to treat the hostname
as having no valid DNS translation.
A basic sample /sbin/nfs_cache_getent
=====================================
#!/bin/bash
#
ttl=600
#
cut=/usr/bin/cut
getent=/usr/bin/getent
rpc_pipefs=/var/lib/nfs/rpc_pipefs
#
die()
{
echo "Usage: $0 cache_name entry_name"
exit 1
}
[ $# -lt 2 ] && die
cachename="$1"
cache_path=${rpc_pipefs}/cache/${cachename}/channel
case "${cachename}" in
dns_resolve)
name="$2"
result="$(${getent} hosts ${name} | ${cut} -f1 -d\ )"
[ -z "${result}" ] && result="0"
;;
*)
die
;;
esac
echo "${result} ${name} ${ttl}" >${cache_path}

2
Documentation/filesystems/seq_file.txt
View File

@@ -46,7 +46,7 @@ better to do. The file is seekable, in that one can do something like the
following:
dd if=/proc/sequence of=out1 count=1
dd if=/proc/sequence skip=1 out=out2 count=1
dd if=/proc/sequence skip=1 of=out2 count=1
Then concatenate the output files out1 and out2 and get the right
result. Yes, it is a thoroughly useless module, but the point is to show

99
Documentation/flexible-arrays.txt Normal file
View File

@@ -0,0 +1,99 @@
Using flexible arrays in the kernel
Last updated for 2.6.31
Jonathan Corbet <corbet@lwn.net>
Large contiguous memory allocations can be unreliable in the Linux kernel.
Kernel programmers will sometimes respond to this problem by allocating
pages with vmalloc(). This solution not ideal, though. On 32-bit systems,
memory from vmalloc() must be mapped into a relatively small address space;
it's easy to run out. On SMP systems, the page table changes required by
vmalloc() allocations can require expensive cross-processor interrupts on
all CPUs. And, on all systems, use of space in the vmalloc() range
increases pressure on the translation lookaside buffer (TLB), reducing the
performance of the system.
In many cases, the need for memory from vmalloc() can be eliminated by
piecing together an array from smaller parts; the flexible array library
exists to make this task easier.
A flexible array holds an arbitrary (within limits) number of fixed-sized
objects, accessed via an integer index. Sparse arrays are handled
reasonably well. Only single-page allocations are made, so memory
allocation failures should be relatively rare. The down sides are that the
arrays cannot be indexed directly, individual object size cannot exceed the
system page size, and putting data into a flexible array requires a copy
operation. It's also worth noting that flexible arrays do no internal
locking at all; if concurrent access to an array is possible, then the
caller must arrange for appropriate mutual exclusion.
The creation of a flexible array is done with:
#include <linux/flex_array.h>
struct flex_array *flex_array_alloc(int element_size,
unsigned int total,
gfp_t flags);
The individual object size is provided by element_size, while total is the
maximum number of objects which can be stored in the array. The flags
argument is passed directly to the internal memory allocation calls. With
the current code, using flags to ask for high memory is likely to lead to
notably unpleasant side effects.
Storing data into a flexible array is accomplished with a call to:
int flex_array_put(struct flex_array *array, unsigned int element_nr,
void *src, gfp_t flags);
This call will copy the data from src into the array, in the position
indicated by element_nr (which must be less than the maximum specified when
the array was created). If any memory allocations must be performed, flags
will be used. The return value is zero on success, a negative error code
otherwise.
There might possibly be a need to store data into a flexible array while
running in some sort of atomic context; in this situation, sleeping in the
memory allocator would be a bad thing. That can be avoided by using
GFP_ATOMIC for the flags value, but, often, there is a better way. The
trick is to ensure that any needed memory allocations are done before
entering atomic context, using:
int flex_array_prealloc(struct flex_array *array, unsigned int start,
unsigned int end, gfp_t flags);
This function will ensure that memory for the elements indexed in the range
defined by start and end has been allocated. Thereafter, a
flex_array_put() call on an element in that range is guaranteed not to
block.
Getting data back out of the array is done with:
void *flex_array_get(struct flex_array *fa, unsigned int element_nr);
The return value is a pointer to the data element, or NULL if that
particular element has never been allocated.
Note that it is possible to get back a valid pointer for an element which
has never been stored in the array. Memory for array elements is allocated
one page at a time; a single allocation could provide memory for several
adjacent elements. The flexible array code does not know if a specific
element has been written; it only knows if the associated memory is
present. So a flex_array_get() call on an element which was never stored
in the array has the potential to return a pointer to random data. If the
caller does not have a separate way to know which elements were actually
stored, it might be wise, at least, to add GFP_ZERO to the flags argument
to ensure that all elements are zeroed.
There is no way to remove a single element from the array. It is possible,
though, to remove all elements with a call to:
void flex_array_free_parts(struct flex_array *array);
This call frees all elements, but leaves the array itself in place.
Freeing the entire array is done with:
void flex_array_free(struct flex_array *array);
As of this writing, there are no users of flexible arrays in the mainline
kernel. The functions described here are also not exported to modules;
that will probably be fixed when somebody comes up with a need for it.

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Copyright (C) 2002-2008 Sentelic Corporation.
Last update: Oct-31-2008
==============================================================================
* Finger Sensing Pad Intellimouse Mode(scrolling wheel, 4th and 5th buttons)
==============================================================================
A) MSID 4: Scrolling wheel mode plus Forward page(4th button) and Backward
page (5th button)
@1. Set sample rate to 200;
@2. Set sample rate to 200;
@3. Set sample rate to 80;
@4. Issuing the "Get device ID" command (0xF2) and waits for the response;
@5. FSP will respond 0x04.
Packet 1
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
BYTE |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
1 |Y|X|y|x|1|M|R|L| 2 |X|X|X|X|X|X|X|X| 3 |Y|Y|Y|Y|Y|Y|Y|Y| 4 | | |B|F|W|W|W|W|
|---------------| |---------------| |---------------| |---------------|
Byte 1: Bit7 => Y overflow
Bit6 => X overflow
Bit5 => Y sign bit
Bit4 => X sign bit
Bit3 => 1
Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
Bit1 => Right Button, 1 is pressed, 0 is not pressed.
Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X Movement(9-bit 2's complement integers)
Byte 3: Y Movement(9-bit 2's complement integers)
Byte 4: Bit3~Bit0 => the scrolling wheel's movement since the last data report.
valid values, -8 ~ +7
Bit4 => 1 = 4th mouse button is pressed, Forward one page.
0 = 4th mouse button is not pressed.
Bit5 => 1 = 5th mouse button is pressed, Backward one page.
0 = 5th mouse button is not pressed.
B) MSID 6: Horizontal and Vertical scrolling.
@ Set bit 1 in register 0x40 to 1
# FSP replaces scrolling wheel's movement as 4 bits to show horizontal and
vertical scrolling.
Packet 1
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
BYTE |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
1 |Y|X|y|x|1|M|R|L| 2 |X|X|X|X|X|X|X|X| 3 |Y|Y|Y|Y|Y|Y|Y|Y| 4 | | |B|F|l|r|u|d|
|---------------| |---------------| |---------------| |---------------|
Byte 1: Bit7 => Y overflow
Bit6 => X overflow
Bit5 => Y sign bit
Bit4 => X sign bit
Bit3 => 1
Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
Bit1 => Right Button, 1 is pressed, 0 is not pressed.
Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X Movement(9-bit 2's complement integers)
Byte 3: Y Movement(9-bit 2's complement integers)
Byte 4: Bit0 => the Vertical scrolling movement downward.
Bit1 => the Vertical scrolling movement upward.
Bit2 => the Vertical scrolling movement rightward.
Bit3 => the Vertical scrolling movement leftward.
Bit4 => 1 = 4th mouse button is pressed, Forward one page.
0 = 4th mouse button is not pressed.
Bit5 => 1 = 5th mouse button is pressed, Backward one page.
0 = 5th mouse button is not pressed.
C) MSID 7:
# FSP uses 2 packets(8 Bytes) data to represent Absolute Position
so we have PACKET NUMBER to identify packets.
If PACKET NUMBER is 0, the packet is Packet 1.
If PACKET NUMBER is 1, the packet is Packet 2.
Please count this number in program.
# MSID6 special packet will be enable at the same time when enable MSID 7.
==============================================================================
* Absolute position for STL3886-G0.
==============================================================================
@ Set bit 2 or 3 in register 0x40 to 1
@ Set bit 6 in register 0x40 to 1
Packet 1 (ABSOLUTE POSITION)
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
BYTE |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
1 |0|1|V|1|1|M|R|L| 2 |X|X|X|X|X|X|X|X| 3 |Y|Y|Y|Y|Y|Y|Y|Y| 4 |r|l|d|u|X|X|Y|Y|
|---------------| |---------------| |---------------| |---------------|
Byte 1: Bit7~Bit6 => 00, Normal data packet
=> 01, Absolute coordination packet
=> 10, Notify packet
Bit5 => valid bit
Bit4 => 1
Bit3 => 1
Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
Bit1 => Right Button, 1 is pressed, 0 is not pressed.
Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
Bit3~Bit2 => X coordinate (ypos[1:0])
Bit4 => scroll up
Bit5 => scroll down
Bit6 => scroll left
Bit7 => scroll right
Notify Packet for G0
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
BYTE |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
1 |1|0|0|1|1|M|R|L| 2 |C|C|C|C|C|C|C|C| 3 |M|M|M|M|M|M|M|M| 4 |0|0|0|0|0|0|0|0|
|---------------| |---------------| |---------------| |---------------|
Byte 1: Bit7~Bit6 => 00, Normal data packet
=> 01, Absolute coordination packet
=> 10, Notify packet
Bit5 => 0
Bit4 => 1
Bit3 => 1
Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
Bit1 => Right Button, 1 is pressed, 0 is not pressed.
Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: Message Type => 0x5A (Enable/Disable status packet)
Mode Type => 0xA5 (Normal/Icon mode status)
Byte 3: Message Type => 0x00 (Disabled)
=> 0x01 (Enabled)
Mode Type => 0x00 (Normal)
=> 0x01 (Icon)
Byte 4: Bit7~Bit0 => Don't Care
==============================================================================
* Absolute position for STL3888-A0.
==============================================================================
Packet 1 (ABSOLUTE POSITION)
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
BYTE |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
1 |0|1|V|A|1|L|0|1| 2 |X|X|X|X|X|X|X|X| 3 |Y|Y|Y|Y|Y|Y|Y|Y| 4 |x|x|y|y|X|X|Y|Y|
|---------------| |---------------| |---------------| |---------------|
Byte 1: Bit7~Bit6 => 00, Normal data packet
=> 01, Absolute coordination packet
=> 10, Notify packet
Bit5 => Valid bit, 0 means that the coordinate is invalid or finger up.
When both fingers are up, the last two reports have zero valid
bit.
Bit4 => arc
Bit3 => 1
Bit2 => Left Button, 1 is pressed, 0 is released.
Bit1 => 0
Bit0 => 1
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
Bit3~Bit2 => X coordinate (ypos[1:0])
Bit5~Bit4 => y1_g
Bit7~Bit6 => x1_g
Packet 2 (ABSOLUTE POSITION)
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
BYTE |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
1 |0|1|V|A|1|R|1|0| 2 |X|X|X|X|X|X|X|X| 3 |Y|Y|Y|Y|Y|Y|Y|Y| 4 |x|x|y|y|X|X|Y|Y|
|---------------| |---------------| |---------------| |---------------|
Byte 1: Bit7~Bit6 => 00, Normal data packet
=> 01, Absolute coordinates packet
=> 10, Notify packet
Bit5 => Valid bit, 0 means that the coordinate is invalid or finger up.
When both fingers are up, the last two reports have zero valid
bit.
Bit4 => arc
Bit3 => 1
Bit2 => Right Button, 1 is pressed, 0 is released.
Bit1 => 1
Bit0 => 0
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
Bit3~Bit2 => X coordinate (ypos[1:0])
Bit5~Bit4 => y2_g
Bit7~Bit6 => x2_g
Notify Packet for STL3888-A0
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
BYTE |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
1 |1|0|1|P|1|M|R|L| 2 |C|C|C|C|C|C|C|C| 3 |0|0|F|F|0|0|0|i| 4 |r|l|d|u|0|0|0|0|
|---------------| |---------------| |---------------| |---------------|
Byte 1: Bit7~Bit6 => 00, Normal data packet
=> 01, Absolute coordination packet
=> 10, Notify packet
Bit5 => 1
Bit4 => when in absolute coordinates mode (valid when EN_PKT_GO is 1):
0: left button is generated by the on-pad command
1: left button is generated by the external button
Bit3 => 1
Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
Bit1 => Right Button, 1 is pressed, 0 is not pressed.
Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: Message Type => 0xB7 (Multi Finger, Multi Coordinate mode)
Byte 3: Bit7~Bit6 => Don't care
Bit5~Bit4 => Number of fingers
Bit3~Bit1 => Reserved
Bit0 => 1: enter gesture mode; 0: leaving gesture mode
Byte 4: Bit7 => scroll right button
Bit6 => scroll left button
Bit5 => scroll down button
Bit4 => scroll up button
* Note that if gesture and additional button (Bit4~Bit7)
happen at the same time, the button information will not
be sent.
Bit3~Bit0 => Reserved
Sample sequence of Multi-finger, Multi-coordinate mode:
notify packet (valid bit == 1), abs pkt 1, abs pkt 2, abs pkt 1,
abs pkt 2, ..., notify packet(valid bit == 0)
==============================================================================
* FSP Enable/Disable packet
==============================================================================
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
BYTE |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
1 |Y|X|0|0|1|M|R|L| 2 |0|1|0|1|1|0|1|E| 3 | | | | | | | | | 4 | | | | | | | | |
|---------------| |---------------| |---------------| |---------------|
FSP will send out enable/disable packet when FSP receive PS/2 enable/disable
command. Host will receive the packet which Middle, Right, Left button will
be set. The packet only use byte 0 and byte 1 as a pattern of original packet.
Ignore the other bytes of the packet.
Byte 1: Bit7 => 0, Y overflow
Bit6 => 0, X overflow
Bit5 => 0, Y sign bit
Bit4 => 0, X sign bit
Bit3 => 1
Bit2 => 1, Middle Button
Bit1 => 1, Right Button
Bit0 => 1, Left Button
Byte 2: Bit7~1 => (0101101b)
Bit0 => 1 = Enable
0 = Disable
Byte 3: Don't care
Byte 4: Don't care (MOUSE ID 3, 4)
Byte 5~8: Don't care (Absolute packet)
==============================================================================
* PS/2 Command Set
==============================================================================
FSP supports basic PS/2 commanding set and modes, refer to following URL for
details about PS/2 commands:
http://www.computer-engineering.org/index.php?title=PS/2_Mouse_Interface
==============================================================================
* Programming Sequence for Determining Packet Parsing Flow
==============================================================================
1. Identify FSP by reading device ID(0x00) and version(0x01) register
2. Determine number of buttons by reading status2 (0x0b) register
buttons = reg[0x0b] & 0x30
if buttons == 0x30 or buttons == 0x20:
# two/four buttons
Refer to 'Finger Sensing Pad PS/2 Mouse Intellimouse'
section A for packet parsing detail(ignore byte 4, bit ~ 7)
elif buttons == 0x10:
# 6 buttons
Refer to 'Finger Sensing Pad PS/2 Mouse Intellimouse'
section B for packet parsing detail
elif buttons == 0x00:
# 6 buttons
Refer to 'Finger Sensing Pad PS/2 Mouse Intellimouse'
section A for packet parsing detail
==============================================================================
* Programming Sequence for Register Reading/Writing
==============================================================================
Register inversion requirement:
Following values needed to be inverted(the '~' operator in C) before being
sent to FSP:
0xe9, 0xee, 0xf2 and 0xff.
Register swapping requirement:
Following values needed to have their higher 4 bits and lower 4 bits being
swapped before being sent to FSP:
10, 20, 40, 60, 80, 100 and 200.
Register reading sequence:
1. send 0xf3 PS/2 command to FSP;
2. send 0x66 PS/2 command to FSP;
3. send 0x88 PS/2 command to FSP;
4. send 0xf3 PS/2 command to FSP;
5. if the register address being to read is not required to be
inverted(refer to the 'Register inversion requirement' section),
goto step 6
5a. send 0x68 PS/2 command to FSP;
5b. send the inverted register address to FSP and goto step 8;
6. if the register address being to read is not required to be
swapped(refer to the 'Register swapping requirement' section),
goto step 7
6a. send 0xcc PS/2 command to FSP;
6b. send the swapped register address to FSP and goto step 8;
7. send 0x66 PS/2 command to FSP;
7a. send the original register address to FSP and goto step 8;
8. send 0xe9(status request) PS/2 command to FSP;
9. the response read from FSP should be the requested register value.
Register writing sequence:
1. send 0xf3 PS/2 command to FSP;
2. if the register address being to write is not required to be
inverted(refer to the 'Register inversion requirement' section),
goto step 3
2a. send 0x74 PS/2 command to FSP;
2b. send the inverted register address to FSP and goto step 5;
3. if the register address being to write is not required to be
swapped(refer to the 'Register swapping requirement' section),
goto step 4
3a. send 0x77 PS/2 command to FSP;
3b. send the swapped register address to FSP and goto step 5;
4. send 0x55 PS/2 command to FSP;
4a. send the register address to FSP and goto step 5;
5. send 0xf3 PS/2 command to FSP;
6. if the register value being to write is not required to be
inverted(refer to the 'Register inversion requirement' section),
goto step 7
6a. send 0x47 PS/2 command to FSP;
6b. send the inverted register value to FSP and goto step 9;
7. if the register value being to write is not required to be
swapped(refer to the 'Register swapping requirement' section),
goto step 8
7a. send 0x44 PS/2 command to FSP;
7b. send the swapped register value to FSP and goto step 9;
8. send 0x33 PS/2 command to FSP;
8a. send the register value to FSP;
9. the register writing sequence is completed.
==============================================================================
* Register Listing
==============================================================================
offset width default r/w name
0x00 bit7~bit0 0x01 RO device ID
0x01 bit7~bit0 0xc0 RW version ID
0x02 bit7~bit0 0x01 RO vendor ID
0x03 bit7~bit0 0x01 RO product ID
0x04 bit3~bit0 0x01 RW revision ID
0x0b RO test mode status 1
bit3 1 RO 0: rotate 180 degree, 1: no rotation
bit5~bit4 RO number of buttons
11 => 2, lbtn/rbtn
10 => 4, lbtn/rbtn/scru/scrd
01 => 6, lbtn/rbtn/scru/scrd/scrl/scrr
00 => 6, lbtn/rbtn/scru/scrd/fbtn/bbtn
0x0f RW register file page control
bit0 0 RW 1 to enable page 1 register files
0x10 RW system control 1
bit0 1 RW Reserved, must be 1
bit1 0 RW Reserved, must be 0
bit4 1 RW Reserved, must be 0
bit5 0 RW register clock gating enable
0: read only, 1: read/write enable
(Note that following registers does not require clock gating being
enabled prior to write: 05 06 07 08 09 0c 0f 10 11 12 16 17 18 23 2e
40 41 42 43.)
0x31 RW on-pad command detection
bit7 0 RW on-pad command left button down tag
enable
0: disable, 1: enable
0x34 RW on-pad command control 5
bit4~bit0 0x05 RW XLO in 0s/4/1, so 03h = 0010.1b = 2.5
(Note that position unit is in 0.5 scanline)
bit7 0 RW on-pad tap zone enable
0: disable, 1: enable
0x35 RW on-pad command control 6
bit4~bit0 0x1d RW XHI in 0s/4/1, so 19h = 1100.1b = 12.5
(Note that position unit is in 0.5 scanline)
0x36 RW on-pad command control 7
bit4~bit0 0x04 RW YLO in 0s/4/1, so 03h = 0010.1b = 2.5
(Note that position unit is in 0.5 scanline)
0x37 RW on-pad command control 8
bit4~bit0 0x13 RW YHI in 0s/4/1, so 11h = 1000.1b = 8.5
(Note that position unit is in 0.5 scanline)
0x40 RW system control 5
bit1 0 RW FSP Intellimouse mode enable
0: disable, 1: enable
bit2 0 RW movement + abs. coordinate mode enable
0: disable, 1: enable
(Note that this function has the functionality of bit 1 even when
bit 1 is not set. However, the format is different from that of bit 1.
In addition, when bit 1 and bit 2 are set at the same time, bit 2 will
override bit 1.)
bit3 0 RW abs. coordinate only mode enable
0: disable, 1: enable
(Note that this function has the functionality of bit 1 even when
bit 1 is not set. However, the format is different from that of bit 1.
In addition, when bit 1, bit 2 and bit 3 are set at the same time,
bit 3 will override bit 1 and 2.)
bit5 0 RW auto switch enable
0: disable, 1: enable
bit6 0 RW G0 abs. + notify packet format enable
0: disable, 1: enable
(Note that the absolute/relative coordinate output still depends on
bit 2 and 3. That is, if any of those bit is 1, host will receive
absolute coordinates; otherwise, host only receives packets with
relative coordinate.)
0x43 RW on-pad control
bit0 0 RW on-pad control enable
0: disable, 1: enable
(Note that if this bit is cleared, bit 3/5 will be ineffective)
bit3 0 RW on-pad fix vertical scrolling enable
0: disable, 1: enable
bit5 0 RW on-pad fix horizontal scrolling enable
0: disable, 1: enable

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Intel(R) TXT Overview:
=====================
Intel's technology for safer computing, Intel(R) Trusted Execution
Technology (Intel(R) TXT), defines platform-level enhancements that
provide the building blocks for creating trusted platforms.
Intel TXT was formerly known by the code name LaGrande Technology (LT).
Intel TXT in Brief:
o Provides dynamic root of trust for measurement (DRTM)
o Data protection in case of improper shutdown
o Measurement and verification of launched environment
Intel TXT is part of the vPro(TM) brand and is also available some
non-vPro systems. It is currently available on desktop systems
based on the Q35, X38, Q45, and Q43 Express chipsets (e.g. Dell
Optiplex 755, HP dc7800, etc.) and mobile systems based on the GM45,
PM45, and GS45 Express chipsets.
For more information, see http://www.intel.com/technology/security/.
This site also has a link to the Intel TXT MLE Developers Manual,
which has been updated for the new released platforms.
Intel TXT has been presented at various events over the past few
years, some of which are:
LinuxTAG 2008:
http://www.linuxtag.org/2008/en/conf/events/vp-donnerstag/
details.html?talkid=110
TRUST2008:
http://www.trust2008.eu/downloads/Keynote-Speakers/
3_David-Grawrock_The-Front-Door-of-Trusted-Computing.pdf
IDF 2008, Shanghai:
http://inteldeveloperforum.com.edgesuite.net/shanghai_2008/
aep/PROS003/index.html
IDFs 2006, 2007 (I'm not sure if/where they are online)
Trusted Boot Project Overview:
=============================
Trusted Boot (tboot) is an open source, pre- kernel/VMM module that
uses Intel TXT to perform a measured and verified launch of an OS
kernel/VMM.
It is hosted on SourceForge at http://sourceforge.net/projects/tboot.
The mercurial source repo is available at http://www.bughost.org/
repos.hg/tboot.hg.
Tboot currently supports launching Xen (open source VMM/hypervisor
w/ TXT support since v3.2), and now Linux kernels.
Value Proposition for Linux or "Why should you care?"
=====================================================
While there are many products and technologies that attempt to
measure or protect the integrity of a running kernel, they all
assume the kernel is "good" to begin with. The Integrity
Measurement Architecture (IMA) and Linux Integrity Module interface
are examples of such solutions.
To get trust in the initial kernel without using Intel TXT, a
static root of trust must be used. This bases trust in BIOS
starting at system reset and requires measurement of all code
executed between system reset through the completion of the kernel
boot as well as data objects used by that code. In the case of a
Linux kernel, this means all of BIOS, any option ROMs, the
bootloader and the boot config. In practice, this is a lot of
code/data, much of which is subject to change from boot to boot
(e.g. changing NICs may change option ROMs). Without reference
hashes, these measurement changes are difficult to assess or
confirm as benign. This process also does not provide DMA
protection, memory configuration/alias checks and locks, crash
protection, or policy support.
By using the hardware-based root of trust that Intel TXT provides,
many of these issues can be mitigated. Specifically: many
pre-launch components can be removed from the trust chain, DMA
protection is provided to all launched components, a large number
of platform configuration checks are performed and values locked,
protection is provided for any data in the event of an improper
shutdown, and there is support for policy-based execution/verification.
This provides a more stable measurement and a higher assurance of
system configuration and initial state than would be otherwise
possible. Since the tboot project is open source, source code for
almost all parts of the trust chain is available (excepting SMM and
Intel-provided firmware).
How Does it Work?
=================
o Tboot is an executable that is launched by the bootloader as
the "kernel" (the binary the bootloader executes).
o It performs all of the work necessary to determine if the
platform supports Intel TXT and, if so, executes the GETSEC[SENTER]
processor instruction that initiates the dynamic root of trust.
- If tboot determines that the system does not support Intel TXT
or is not configured correctly (e.g. the SINIT AC Module was
incorrect), it will directly launch the kernel with no changes
to any state.
- Tboot will output various information about its progress to the
terminal, serial port, and/or an in-memory log; the output
locations can be configured with a command line switch.
o The GETSEC[SENTER] instruction will return control to tboot and
tboot then verifies certain aspects of the environment (e.g. TPM NV
lock, e820 table does not have invalid entries, etc.).
o It will wake the APs from the special sleep state the GETSEC[SENTER]
instruction had put them in and place them into a wait-for-SIPI
state.
- Because the processors will not respond to an INIT or SIPI when
in the TXT environment, it is necessary to create a small VT-x
guest for the APs. When they run in this guest, they will
simply wait for the INIT-SIPI-SIPI sequence, which will cause
VMEXITs, and then disable VT and jump to the SIPI vector. This
approach seemed like a better choice than having to insert
special code into the kernel's MP wakeup sequence.
o Tboot then applies an (optional) user-defined launch policy to
verify the kernel and initrd.
- This policy is rooted in TPM NV and is described in the tboot
project. The tboot project also contains code for tools to
create and provision the policy.
- Policies are completely under user control and if not present
then any kernel will be launched.
- Policy action is flexible and can include halting on failures
or simply logging them and continuing.
o Tboot adjusts the e820 table provided by the bootloader to reserve
its own location in memory as well as to reserve certain other
TXT-related regions.
o As part of it's launch, tboot DMA protects all of RAM (using the
VT-d PMRs). Thus, the kernel must be booted with 'intel_iommu=on'
in order to remove this blanket protection and use VT-d's
page-level protection.
o Tboot will populate a shared page with some data about itself and
pass this to the Linux kernel as it transfers control.
- The location of the shared page is passed via the boot_params
struct as a physical address.
o The kernel will look for the tboot shared page address and, if it
exists, map it.
o As one of the checks/protections provided by TXT, it makes a copy
of the VT-d DMARs in a DMA-protected region of memory and verifies
them for correctness. The VT-d code will detect if the kernel was
launched with tboot and use this copy instead of the one in the
ACPI table.
o At this point, tboot and TXT are out of the picture until a
shutdown (S<n>)
o In order to put a system into any of the sleep states after a TXT
launch, TXT must first be exited. This is to prevent attacks that
attempt to crash the system to gain control on reboot and steal
data left in memory.
- The kernel will perform all of its sleep preparation and
populate the shared page with the ACPI data needed to put the
platform in the desired sleep state.
- Then the kernel jumps into tboot via the vector specified in the
shared page.
- Tboot will clean up the environment and disable TXT, then use the
kernel-provided ACPI information to actually place the platform
into the desired sleep state.
- In the case of S3, tboot will also register itself as the resume
vector. This is necessary because it must re-establish the
measured environment upon resume. Once the TXT environment
has been restored, it will restore the TPM PCRs and then
transfer control back to the kernel's S3 resume vector.
In order to preserve system integrity across S3, the kernel
provides tboot with a set of memory ranges (kernel
code/data/bss, S3 resume code, and AP trampoline) that tboot
will calculate a MAC (message authentication code) over and then
seal with the TPM. On resume and once the measured environment
has been re-established, tboot will re-calculate the MAC and
verify it against the sealed value. Tboot's policy determines
what happens if the verification fails.
That's pretty much it for TXT support.
Configuring the System:
======================
This code works with 32bit, 32bit PAE, and 64bit (x86_64) kernels.
In BIOS, the user must enable: TPM, TXT, VT-x, VT-d. Not all BIOSes
allow these to be individually enabled/disabled and the screens in
which to find them are BIOS-specific.
grub.conf needs to be modified as follows:
title Linux 2.6.29-tip w/ tboot
root (hd0,0)
kernel /tboot.gz logging=serial,vga,memory
module /vmlinuz-2.6.29-tip intel_iommu=on ro
root=LABEL=/ rhgb console=ttyS0,115200 3
module /initrd-2.6.29-tip.img
module /Q35_SINIT_17.BIN
The kernel option for enabling Intel TXT support is found under the
Security top-level menu and is called "Enable Intel(R) Trusted
Execution Technology (TXT)". It is marked as EXPERIMENTAL and
depends on the generic x86 support (to allow maximum flexibility in
kernel build options), since the tboot code will detect whether the
platform actually supports Intel TXT and thus whether any of the
kernel code is executed.
The Q35_SINIT_17.BIN file is what Intel TXT refers to as an
Authenticated Code Module. It is specific to the chipset in the
system and can also be found on the Trusted Boot site. It is an
(unencrypted) module signed by Intel that is used as part of the
DRTM process to verify and configure the system. It is signed
because it operates at a higher privilege level in the system than
any other macrocode and its correct operation is critical to the
establishment of the DRTM. The process for determining the correct
SINIT ACM for a system is documented in the SINIT-guide.txt file
that is on the tboot SourceForge site under the SINIT ACM downloads.

3
Documentation/ioctl/ioctl-number.txt
View File

@@ -121,6 +121,7 @@ Code Seq# Include File Comments
'c' 00-7F linux/comstats.h conflict!
'c' 00-7F linux/coda.h conflict!
'c' 80-9F arch/s390/include/asm/chsc.h
'c' A0-AF arch/x86/include/asm/msr.h
'd' 00-FF linux/char/drm/drm/h conflict!
'd' F0-FF linux/digi1.h
'e' all linux/digi1.h conflict!
@@ -192,7 +193,7 @@ Code Seq# Include File Comments
0xAD 00 Netfilter device in development:
<mailto:rusty@rustcorp.com.au>
0xAE all linux/kvm.h Kernel-based Virtual Machine
<mailto:kvm-devel@lists.sourceforge.net>
<mailto:kvm@vger.kernel.org>
0xB0 all RATIO devices in development:
<mailto:vgo@ratio.de>
0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca>

89
Documentation/kernel-parameters.txt
View File

@@ -57,6 +57,7 @@ parameter is applicable:
ISAPNP ISA PnP code is enabled.
ISDN Appropriate ISDN support is enabled.
JOY Appropriate joystick support is enabled.
KVM Kernel Virtual Machine support is enabled.
LIBATA Libata driver is enabled
LP Printer support is enabled.
LOOP Loopback device support is enabled.
@@ -1098,6 +1099,44 @@ and is between 256 and 4096 characters. It is defined in the file
kstack=N [X86] Print N words from the kernel stack
in oops dumps.
kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
Default is 0 (don't ignore, but inject #GP)
kvm.oos_shadow= [KVM] Disable out-of-sync shadow paging.
Default is 1 (enabled)
kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
Default is 0 (off)
kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
for all guests.
Default is 1 (enabled) if in 64bit or 32bit-PAE mode
kvm-intel.bypass_guest_pf=
[KVM,Intel] Disables bypassing of guest page faults
on Intel chips. Default is 1 (enabled)
kvm-intel.ept= [KVM,Intel] Disable extended page tables
(virtualized MMU) support on capable Intel chips.
Default is 1 (enabled)
kvm-intel.emulate_invalid_guest_state=
[KVM,Intel] Enable emulation of invalid guest states
Default is 0 (disabled)
kvm-intel.flexpriority=
[KVM,Intel] Disable FlexPriority feature (TPR shadow).
Default is 1 (enabled)
kvm-intel.unrestricted_guest=
[KVM,Intel] Disable unrestricted guest feature
(virtualized real and unpaged mode) on capable
Intel chips. Default is 1 (enabled)
kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
feature (tagged TLBs) on capable Intel chips.
Default is 1 (enabled)
l2cr= [PPC]
l3cr= [PPC]
@@ -1503,6 +1542,14 @@ and is between 256 and 4096 characters. It is defined in the file
[NFS] set the TCP port on which the NFSv4 callback
channel should listen.
nfs.cache_getent=
[NFS] sets the pathname to the program which is used
to update the NFS client cache entries.
nfs.cache_getent_timeout=
[NFS] sets the timeout after which an attempt to
update a cache entry is deemed to have failed.
nfs.idmap_cache_timeout=
[NFS] set the maximum lifetime for idmapper cache
entries.
@@ -1535,6 +1582,11 @@ and is between 256 and 4096 characters. It is defined in the file
symbolic names: lapic and ioapic
Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
netpoll.carrier_timeout=
[NET] Specifies amount of time (in seconds) that
netpoll should wait for a carrier. By default netpoll
waits 4 seconds.
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
emulation library even if a 387 maths coprocessor
is present.
@@ -1919,11 +1971,12 @@ and is between 256 and 4096 characters. It is defined in the file
Format: { 0 | 1 }
See arch/parisc/kernel/pdc_chassis.c
percpu_alloc= [X86] Select which percpu first chunk allocator to use.
Allowed values are one of "lpage", "embed" and "4k".
See comments in arch/x86/kernel/setup_percpu.c for
details on each allocator. This parameter is primarily
for debugging and performance comparison.
percpu_alloc= Select which percpu first chunk allocator to use.
Currently supported values are "embed" and "page".
Archs may support subset or none of the selections.
See comments in mm/percpu.c for details on each
allocator. This parameter is primarily for debugging
and performance comparison.
pf. [PARIDE]
See Documentation/blockdev/paride.txt.
@@ -2395,6 +2448,18 @@ and is between 256 and 4096 characters. It is defined in the file
stifb= [HW]
Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
sunrpc.min_resvport=
sunrpc.max_resvport=
[NFS,SUNRPC]
SunRPC servers often require that client requests
originate from a privileged port (i.e. a port in the
range 0 < portnr < 1024).
An administrator who wishes to reserve some of these
ports for other uses may adjust the range that the
kernel's sunrpc client considers to be privileged
using these two parameters to set the minimum and
maximum port values.
sunrpc.pool_mode=
[NFS]
Control how the NFS server code allocates CPUs to
@@ -2411,6 +2476,15 @@ and is between 256 and 4096 characters. It is defined in the file
pernode one pool for each NUMA node (equivalent
to global on non-NUMA machines)
sunrpc.tcp_slot_table_entries=
sunrpc.udp_slot_table_entries=
[NFS,SUNRPC]
Sets the upper limit on the number of simultaneous
RPC calls that can be sent from the client to a
server. Increasing these values may allow you to
improve throughput, but will also increase the
amount of memory reserved for use by the client.
swiotlb= [IA-64] Number of I/O TLB slabs
switches= [HW,M68k]
@@ -2480,6 +2554,11 @@ and is between 256 and 4096 characters. It is defined in the file
trace_buf_size=nn[KMG]
[FTRACE] will set tracing buffer size.
trace_event=[event-list]
[FTRACE] Set and start specified trace events in order
to facilitate early boot debugging.
See also Documentation/trace/events.txt
trix= [HW,OSS] MediaTrix AudioTrix Pro
Format:
<io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>

39
Documentation/keys.txt
View File

@@ -26,7 +26,7 @@ This document has the following sections:
- Notes on accessing payload contents
- Defining a key type
- Request-key callback service
- Key access filesystem
- Garbage collection
============
@@ -113,6 +113,9 @@ Each key has a number of attributes:
(*) Dead. The key's type was unregistered, and so the key is now useless.
Keys in the last three states are subject to garbage collection. See the
section on "Garbage collection".
====================
KEY SERVICE OVERVIEW
@@ -754,6 +757,26 @@ The keyctl syscall functions are:
successful.
(*) Install the calling process's session keyring on its parent.
long keyctl(KEYCTL_SESSION_TO_PARENT);
This functions attempts to install the calling process's session keyring
on to the calling process's parent, replacing the parent's current session
keyring.
The calling process must have the same ownership as its parent, the
keyring must have the same ownership as the calling process, the calling
process must have LINK permission on the keyring and the active LSM module
mustn't deny permission, otherwise error EPERM will be returned.
Error ENOMEM will be returned if there was insufficient memory to complete
the operation, otherwise 0 will be returned to indicate success.
The keyring will be replaced next time the parent process leaves the
kernel and resumes executing userspace.
===============
KERNEL SERVICES
===============
@@ -1231,3 +1254,17 @@ by executing:
In this case, the program isn't required to actually attach the key to a ring;
the rings are provided for reference.
==================
GARBAGE COLLECTION
==================
Dead keys (for which the type has been removed) will be automatically unlinked
from those keyrings that point to them and deleted as soon as possible by a
background garbage collector.
Similarly, revoked and expired keys will be garbage collected, but only after a
certain amount of time has passed. This time is set as a number of seconds in:
/proc/sys/kernel/keys/gc_delay

31
Documentation/kmemleak.txt
View File

@@ -27,6 +27,13 @@ To trigger an intermediate memory scan:
# echo scan > /sys/kernel/debug/kmemleak
To clear the list of all current possible memory leaks:
# echo clear > /sys/kernel/debug/kmemleak
New leaks will then come up upon reading /sys/kernel/debug/kmemleak
again.
Note that the orphan objects are listed in the order they were allocated
and one object at the beginning of the list may cause other subsequent
objects to be reported as orphan.
@@ -42,6 +49,9 @@ Memory scanning parameters can be modified at run-time by writing to the
scan=<secs> - set the automatic memory scanning period in seconds
(default 600, 0 to stop the automatic scanning)
scan - trigger a memory scan
clear - clear list of current memory leak suspects, done by
marking all current reported unreferenced objects grey
dump=<addr> - dump information about the object found at <addr>
Kmemleak can also be disabled at boot-time by passing "kmemleak=off" on
the kernel command line.
@@ -86,6 +96,27 @@ avoid this, kmemleak can also store the number of values pointing to an
address inside the block address range that need to be found so that the
block is not considered a leak. One example is __vmalloc().
Testing specific sections with kmemleak
---------------------------------------
Upon initial bootup your /sys/kernel/debug/kmemleak output page may be
quite extensive. This can also be the case if you have very buggy code
when doing development. To work around these situations you can use the
'clear' command to clear all reported unreferenced objects from the
/sys/kernel/debug/kmemleak output. By issuing a 'scan' after a 'clear'
you can find new unreferenced objects; this should help with testing
specific sections of code.
To test a critical section on demand with a clean kmemleak do:
# echo clear > /sys/kernel/debug/kmemleak
... test your kernel or modules ...
# echo scan > /sys/kernel/debug/kmemleak
Then as usual to get your report with:
# cat /sys/kernel/debug/kmemleak
Kmemleak API
------------

759
Documentation/kvm/api.txt Normal file
View File

@@ -0,0 +1,759 @@
The Definitive KVM (Kernel-based Virtual Machine) API Documentation
===================================================================
1. General description
The kvm API is a set of ioctls that are issued to control various aspects
of a virtual machine. The ioctls belong to three classes
- System ioctls: These query and set global attributes which affect the
whole kvm subsystem. In addition a system ioctl is used to create
virtual machines
- VM ioctls: These query and set attributes that affect an entire virtual
machine, for example memory layout. In addition a VM ioctl is used to
create virtual cpus (vcpus).
Only run VM ioctls from the same process (address space) that was used
to create the VM.
- vcpu ioctls: These query and set attributes that control the operation
of a single virtual cpu.
Only run vcpu ioctls from the same thread that was used to create the
vcpu.
2. File descritpors
The kvm API is centered around file descriptors. An initial
open("/dev/kvm") obtains a handle to the kvm subsystem; this handle
can be used to issue system ioctls. A KVM_CREATE_VM ioctl on this
handle will create a VM file descripror which can be used to issue VM
ioctls. A KVM_CREATE_VCPU ioctl on a VM fd will create a virtual cpu
and return a file descriptor pointing to it. Finally, ioctls on a vcpu
fd can be used to control the vcpu, including the important task of
actually running guest code.
In general file descriptors can be migrated among processes by means
of fork() and the SCM_RIGHTS facility of unix domain socket. These
kinds of tricks are explicitly not supported by kvm. While they will
not cause harm to the host, their actual behavior is not guaranteed by
the API. The only supported use is one virtual machine per process,
and one vcpu per thread.
3. Extensions
As of Linux 2.6.22, the KVM ABI has been stabilized: no backward
incompatible change are allowed. However, there is an extension
facility that allows backward-compatible extensions to the API to be
queried and used.
The extension mechanism is not based on on the Linux version number.
Instead, kvm defines extension identifiers and a facility to query
whether a particular extension identifier is available. If it is, a
set of ioctls is available for application use.
4. API description
This section describes ioctls that can be used to control kvm guests.
For each ioctl, the following information is provided along with a
description:
Capability: which KVM extension provides this ioctl. Can be 'basic',
which means that is will be provided by any kernel that supports
API version 12 (see section 4.1), or a KVM_CAP_xyz constant, which
means availability needs to be checked with KVM_CHECK_EXTENSION
(see section 4.4).
Architectures: which instruction set architectures provide this ioctl.
x86 includes both i386 and x86_64.
Type: system, vm, or vcpu.
Parameters: what parameters are accepted by the ioctl.
Returns: the return value. General error numbers (EBADF, ENOMEM, EINVAL)
are not detailed, but errors with specific meanings are.
4.1 KVM_GET_API_VERSION
Capability: basic
Architectures: all
Type: system ioctl
Parameters: none
Returns: the constant KVM_API_VERSION (=12)
This identifies the API version as the stable kvm API. It is not
expected that this number will change. However, Linux 2.6.20 and
2.6.21 report earlier versions; these are not documented and not
supported. Applications should refuse to run if KVM_GET_API_VERSION
returns a value other than 12. If this check passes, all ioctls
described as 'basic' will be available.
4.2 KVM_CREATE_VM
Capability: basic
Architectures: all
Type: system ioctl
Parameters: none
Returns: a VM fd that can be used to control the new virtual machine.
The new VM has no virtual cpus and no memory. An mmap() of a VM fd
will access the virtual machine's physical address space; offset zero
corresponds to guest physical address zero. Use of mmap() on a VM fd
is discouraged if userspace memory allocation (KVM_CAP_USER_MEMORY) is
available.
4.3 KVM_GET_MSR_INDEX_LIST
Capability: basic
Architectures: x86
Type: system
Parameters: struct kvm_msr_list (in/out)
Returns: 0 on success; -1 on error
Errors:
E2BIG: the msr index list is to be to fit in the array specified by
the user.
struct kvm_msr_list {
__u32 nmsrs; /* number of msrs in entries */
__u32 indices[0];
};
This ioctl returns the guest msrs that are supported. The list varies
by kvm version and host processor, but does not change otherwise. The
user fills in the size of the indices array in nmsrs, and in return
kvm adjusts nmsrs to reflect the actual number of msrs and fills in
the indices array with their numbers.
4.4 KVM_CHECK_EXTENSION
Capability: basic
Architectures: all
Type: system ioctl
Parameters: extension identifier (KVM_CAP_*)
Returns: 0 if unsupported; 1 (or some other positive integer) if supported
The API allows the application to query about extensions to the core
kvm API. Userspace passes an extension identifier (an integer) and
receives an integer that describes the extension availability.
Generally 0 means no and 1 means yes, but some extensions may report
additional information in the integer return value.
4.5 KVM_GET_VCPU_MMAP_SIZE
Capability: basic
Architectures: all
Type: system ioctl
Parameters: none
Returns: size of vcpu mmap area, in bytes
The KVM_RUN ioctl (cf.) communicates with userspace via a shared
memory region. This ioctl returns the size of that region. See the
KVM_RUN documentation for details.
4.6 KVM_SET_MEMORY_REGION
Capability: basic
Architectures: all
Type: vm ioctl
Parameters: struct kvm_memory_region (in)
Returns: 0 on success, -1 on error
struct kvm_memory_region {
__u32 slot;
__u32 flags;
__u64 guest_phys_addr;
__u64 memory_size; /* bytes */
};
/* for kvm_memory_region::flags */
#define KVM_MEM_LOG_DIRTY_PAGES 1UL
This ioctl allows the user to create or modify a guest physical memory
slot. When changing an existing slot, it may be moved in the guest
physical memory space, or its flags may be modified. It may not be
resized. Slots may not overlap.
The flags field supports just one flag, KVM_MEM_LOG_DIRTY_PAGES, which
instructs kvm to keep track of writes to memory within the slot. See
the KVM_GET_DIRTY_LOG ioctl.
It is recommended to use the KVM_SET_USER_MEMORY_REGION ioctl instead
of this API, if available. This newer API allows placing guest memory
at specified locations in the host address space, yielding better
control and easy access.
4.6 KVM_CREATE_VCPU
Capability: basic
Architectures: all
Type: vm ioctl
Parameters: vcpu id (apic id on x86)
Returns: vcpu fd on success, -1 on error
This API adds a vcpu to a virtual machine. The vcpu id is a small integer
in the range [0, max_vcpus).
4.7 KVM_GET_DIRTY_LOG (vm ioctl)
Capability: basic
Architectures: x86
Type: vm ioctl
Parameters: struct kvm_dirty_log (in/out)
Returns: 0 on success, -1 on error
/* for KVM_GET_DIRTY_LOG */
struct kvm_dirty_log {
__u32 slot;
__u32 padding;
union {
void __user *dirty_bitmap; /* one bit per page */
__u64 padding;
};
};
Given a memory slot, return a bitmap containing any pages dirtied
since the last call to this ioctl. Bit 0 is the first page in the
memory slot. Ensure the entire structure is cleared to avoid padding
issues.
4.8 KVM_SET_MEMORY_ALIAS
Capability: basic
Architectures: x86
Type: vm ioctl
Parameters: struct kvm_memory_alias (in)
Returns: 0 (success), -1 (error)
struct kvm_memory_alias {
__u32 slot; /* this has a different namespace than memory slots */
__u32 flags;
__u64 guest_phys_addr;
__u64 memory_size;
__u64 target_phys_addr;
};
Defines a guest physical address space region as an alias to another
region. Useful for aliased address, for example the VGA low memory
window. Should not be used with userspace memory.
4.9 KVM_RUN
Capability: basic
Architectures: all
Type: vcpu ioctl
Parameters: none
Returns: 0 on success, -1 on error
Errors:
EINTR: an unmasked signal is pending
This ioctl is used to run a guest virtual cpu. While there are no
explicit parameters, there is an implicit parameter block that can be
obtained by mmap()ing the vcpu fd at offset 0, with the size given by
KVM_GET_VCPU_MMAP_SIZE. The parameter block is formatted as a 'struct
kvm_run' (see below).
4.10 KVM_GET_REGS
Capability: basic
Architectures: all
Type: vcpu ioctl
Parameters: struct kvm_regs (out)
Returns: 0 on success, -1 on error
Reads the general purpose registers from the vcpu.
/* x86 */
struct kvm_regs {
/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
__u64 rax, rbx, rcx, rdx;
__u64 rsi, rdi, rsp, rbp;
__u64 r8, r9, r10, r11;
__u64 r12, r13, r14, r15;
__u64 rip, rflags;
};
4.11 KVM_SET_REGS
Capability: basic
Architectures: all
Type: vcpu ioctl
Parameters: struct kvm_regs (in)
Returns: 0 on success, -1 on error
Writes the general purpose registers into the vcpu.
See KVM_GET_REGS for the data structure.
4.12 KVM_GET_SREGS
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_sregs (out)
Returns: 0 on success, -1 on error
Reads special registers from the vcpu.
/* x86 */
struct kvm_sregs {
struct kvm_segment cs, ds, es, fs, gs, ss;
struct kvm_segment tr, ldt;
struct kvm_dtable gdt, idt;
__u64 cr0, cr2, cr3, cr4, cr8;
__u64 efer;
__u64 apic_base;
__u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64];
};
interrupt_bitmap is a bitmap of pending external interrupts. At most
one bit may be set. This interrupt has been acknowledged by the APIC
but not yet injected into the cpu core.
4.13 KVM_SET_SREGS
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_sregs (in)
Returns: 0 on success, -1 on error
Writes special registers into the vcpu. See KVM_GET_SREGS for the
data structures.
4.14 KVM_TRANSLATE
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_translation (in/out)
Returns: 0 on success, -1 on error
Translates a virtual address according to the vcpu's current address
translation mode.
struct kvm_translation {
/* in */
__u64 linear_address;
/* out */
__u64 physical_address;
__u8 valid;
__u8 writeable;
__u8 usermode;
__u8 pad[5];
};
4.15 KVM_INTERRUPT
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_interrupt (in)
Returns: 0 on success, -1 on error
Queues a hardware interrupt vector to be injected. This is only
useful if in-kernel local APIC is not used.
/* for KVM_INTERRUPT */
struct kvm_interrupt {
/* in */
__u32 irq;
};
Note 'irq' is an interrupt vector, not an interrupt pin or line.
4.16 KVM_DEBUG_GUEST
Capability: basic
Architectures: none
Type: vcpu ioctl
Parameters: none)
Returns: -1 on error
Support for this has been removed. Use KVM_SET_GUEST_DEBUG instead.
4.17 KVM_GET_MSRS
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_msrs (in/out)
Returns: 0 on success, -1 on error
Reads model-specific registers from the vcpu. Supported msr indices can
be obtained using KVM_GET_MSR_INDEX_LIST.
struct kvm_msrs {
__u32 nmsrs; /* number of msrs in entries */
__u32 pad;
struct kvm_msr_entry entries[0];
};
struct kvm_msr_entry {
__u32 index;
__u32 reserved;
__u64 data;
};
Application code should set the 'nmsrs' member (which indicates the
size of the entries array) and the 'index' member of each array entry.
kvm will fill in the 'data' member.
4.18 KVM_SET_MSRS
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_msrs (in)
Returns: 0 on success, -1 on error
Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the
data structures.
Application code should set the 'nmsrs' member (which indicates the
size of the entries array), and the 'index' and 'data' members of each
array entry.
4.19 KVM_SET_CPUID
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_cpuid (in)
Returns: 0 on success, -1 on error
Defines the vcpu responses to the cpuid instruction. Applications
should use the KVM_SET_CPUID2 ioctl if available.
struct kvm_cpuid_entry {
__u32 function;
__u32 eax;
__u32 ebx;
__u32 ecx;
__u32 edx;
__u32 padding;
};
/* for KVM_SET_CPUID */
struct kvm_cpuid {
__u32 nent;
__u32 padding;
struct kvm_cpuid_entry entries[0];
};
4.20 KVM_SET_SIGNAL_MASK
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_signal_mask (in)
Returns: 0 on success, -1 on error
Defines which signals are blocked during execution of KVM_RUN. This
signal mask temporarily overrides the threads signal mask. Any
unblocked signal received (except SIGKILL and SIGSTOP, which retain
their traditional behaviour) will cause KVM_RUN to return with -EINTR.
Note the signal will only be delivered if not blocked by the original
signal mask.
/* for KVM_SET_SIGNAL_MASK */
struct kvm_signal_mask {
__u32 len;
__u8 sigset[0];
};
4.21 KVM_GET_FPU
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_fpu (out)
Returns: 0 on success, -1 on error
Reads the floating point state from the vcpu.
/* for KVM_GET_FPU and KVM_SET_FPU */
struct kvm_fpu {
__u8 fpr[8][16];
__u16 fcw;
__u16 fsw;
__u8 ftwx; /* in fxsave format */
__u8 pad1;
__u16 last_opcode;
__u64 last_ip;
__u64 last_dp;
__u8 xmm[16][16];
__u32 mxcsr;
__u32 pad2;
};
4.22 KVM_SET_FPU
Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_fpu (in)
Returns: 0 on success, -1 on error
Writes the floating point state to the vcpu.
/* for KVM_GET_FPU and KVM_SET_FPU */
struct kvm_fpu {
__u8 fpr[8][16];
__u16 fcw;
__u16 fsw;
__u8 ftwx; /* in fxsave format */
__u8 pad1;
__u16 last_opcode;
__u64 last_ip;
__u64 last_dp;
__u8 xmm[16][16];
__u32 mxcsr;
__u32 pad2;
};
4.23 KVM_CREATE_IRQCHIP
Capability: KVM_CAP_IRQCHIP
Architectures: x86, ia64
Type: vm ioctl
Parameters: none
Returns: 0 on success, -1 on error
Creates an interrupt controller model in the kernel. On x86, creates a virtual
ioapic, a virtual PIC (two PICs, nested), and sets up future vcpus to have a
local APIC. IRQ routing for GSIs 0-15 is set to both PIC and IOAPIC; GSI 16-23
only go to the IOAPIC. On ia64, a IOSAPIC is created.
4.24 KVM_IRQ_LINE
Capability: KVM_CAP_IRQCHIP
Architectures: x86, ia64
Type: vm ioctl
Parameters: struct kvm_irq_level
Returns: 0 on success, -1 on error
Sets the level of a GSI input to the interrupt controller model in the kernel.
Requires that an interrupt controller model has been previously created with
KVM_CREATE_IRQCHIP. Note that edge-triggered interrupts require the level
to be set to 1 and then back to 0.
struct kvm_irq_level {
union {
__u32 irq; /* GSI */
__s32 status; /* not used for KVM_IRQ_LEVEL */
};
__u32 level; /* 0 or 1 */
};
4.25 KVM_GET_IRQCHIP
Capability: KVM_CAP_IRQCHIP
Architectures: x86, ia64
Type: vm ioctl
Parameters: struct kvm_irqchip (in/out)
Returns: 0 on success, -1 on error
Reads the state of a kernel interrupt controller created with
KVM_CREATE_IRQCHIP into a buffer provided by the caller.
struct kvm_irqchip {
__u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
__u32 pad;
union {
char dummy[512]; /* reserving space */
struct kvm_pic_state pic;
struct kvm_ioapic_state ioapic;
} chip;
};
4.26 KVM_SET_IRQCHIP
Capability: KVM_CAP_IRQCHIP
Architectures: x86, ia64
Type: vm ioctl
Parameters: struct kvm_irqchip (in)
Returns: 0 on success, -1 on error
Sets the state of a kernel interrupt controller created with
KVM_CREATE_IRQCHIP from a buffer provided by the caller.
struct kvm_irqchip {
__u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
__u32 pad;
union {
char dummy[512]; /* reserving space */
struct kvm_pic_state pic;
struct kvm_ioapic_state ioapic;
} chip;
};
5. The kvm_run structure
Application code obtains a pointer to the kvm_run structure by
mmap()ing a vcpu fd. From that point, application code can control
execution by changing fields in kvm_run prior to calling the KVM_RUN
ioctl, and obtain information about the reason KVM_RUN returned by
looking up structure members.
struct kvm_run {
/* in */
__u8 request_interrupt_window;
Request that KVM_RUN return when it becomes possible to inject external
interrupts into the guest. Useful in conjunction with KVM_INTERRUPT.
__u8 padding1[7];
/* out */
__u32 exit_reason;
When KVM_RUN has returned successfully (return value 0), this informs
application code why KVM_RUN has returned. Allowable values for this
field are detailed below.
__u8 ready_for_interrupt_injection;
If request_interrupt_window has been specified, this field indicates
an interrupt can be injected now with KVM_INTERRUPT.
__u8 if_flag;
The value of the current interrupt flag. Only valid if in-kernel
local APIC is not used.
__u8 padding2[2];
/* in (pre_kvm_run), out (post_kvm_run) */
__u64 cr8;
The value of the cr8 register. Only valid if in-kernel local APIC is
not used. Both input and output.
__u64 apic_base;
The value of the APIC BASE msr. Only valid if in-kernel local
APIC is not used. Both input and output.
union {
/* KVM_EXIT_UNKNOWN */
struct {
__u64 hardware_exit_reason;
} hw;
If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown
reasons. Further architecture-specific information is available in
hardware_exit_reason.
/* KVM_EXIT_FAIL_ENTRY */
struct {
__u64 hardware_entry_failure_reason;
} fail_entry;
If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due
to unknown reasons. Further architecture-specific information is
available in hardware_entry_failure_reason.
/* KVM_EXIT_EXCEPTION */
struct {
__u32 exception;
__u32 error_code;
} ex;
Unused.
/* KVM_EXIT_IO */
struct {
#define KVM_EXIT_IO_IN 0
#define KVM_EXIT_IO_OUT 1
__u8 direction;
__u8 size; /* bytes */
__u16 port;
__u32 count;
__u64 data_offset; /* relative to kvm_run start */
} io;
If exit_reason is KVM_EXIT_IO_IN or KVM_EXIT_IO_OUT, then the vcpu has
executed a port I/O instruction which could not be satisfied by kvm.
data_offset describes where the data is located (KVM_EXIT_IO_OUT) or
where kvm expects application code to place the data for the next
KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a patcked array.
struct {
struct kvm_debug_exit_arch arch;
} debug;
Unused.
/* KVM_EXIT_MMIO */
struct {
__u64 phys_addr;
__u8 data[8];
__u32 len;
__u8 is_write;
} mmio;
If exit_reason is KVM_EXIT_MMIO or KVM_EXIT_IO_OUT, then the vcpu has
executed a memory-mapped I/O instruction which could not be satisfied
by kvm. The 'data' member contains the written data if 'is_write' is
true, and should be filled by application code otherwise.
/* KVM_EXIT_HYPERCALL */
struct {
__u64 nr;
__u64 args[6];
__u64 ret;
__u32 longmode;
__u32 pad;
} hypercall;
Unused.
/* KVM_EXIT_TPR_ACCESS */
struct {
__u64 rip;
__u32 is_write;
__u32 pad;
} tpr_access;
To be documented (KVM_TPR_ACCESS_REPORTING).
/* KVM_EXIT_S390_SIEIC */
struct {
__u8 icptcode;
__u64 mask; /* psw upper half */
__u64 addr; /* psw lower half */
__u16 ipa;
__u32 ipb;
} s390_sieic;
s390 specific.
/* KVM_EXIT_S390_RESET */
#define KVM_S390_RESET_POR 1
#define KVM_S390_RESET_CLEAR 2
#define KVM_S390_RESET_SUBSYSTEM 4
#define KVM_S390_RESET_CPU_INIT 8
#define KVM_S390_RESET_IPL 16
__u64 s390_reset_flags;
s390 specific.
/* KVM_EXIT_DCR */
struct {
__u32 dcrn;
__u32 data;
__u8 is_write;
} dcr;
powerpc specific.
/* Fix the size of the union. */
char padding[256];
};
};

2
Documentation/networking/00-INDEX
View File

@@ -60,6 +60,8 @@ framerelay.txt
- info on using Frame Relay/Data Link Connection Identifier (DLCI).
generic_netlink.txt
- info on Generic Netlink
ieee802154.txt
- Linux IEEE 802.15.4 implementation, API and drivers
ip-sysctl.txt
- /proc/sys/net/ipv4/* variables
ip_dynaddr.txt

20
Documentation/networking/ieee802154.txt
View File

@@ -22,7 +22,7 @@ int sd = socket(PF_IEEE802154, SOCK_DGRAM, 0);
.....
The address family, socket addresses etc. are defined in the
include/net/ieee802154/af_ieee802154.h header or in the special header
include/net/af_ieee802154.h header or in the special header
in our userspace package (see either linux-zigbee sourceforge download page
or git tree at git://linux-zigbee.git.sourceforge.net/gitroot/linux-zigbee).
@@ -33,7 +33,7 @@ MLME - MAC Level Management
============================
Most of IEEE 802.15.4 MLME interfaces are directly mapped on netlink commands.
See the include/net/ieee802154/nl802154.h header. Our userspace tools package
See the include/net/nl802154.h header. Our userspace tools package
(see above) provides CLI configuration utility for radio interfaces and simple
coordinator for IEEE 802.15.4 networks as an example users of MLME protocol.
@@ -54,10 +54,14 @@ Those types of devices require different approach to be hooked into Linux kernel
HardMAC
=======
See the header include/net/ieee802154/netdevice.h. You have to implement Linux
See the header include/net/ieee802154_netdev.h. You have to implement Linux
net_device, with .type = ARPHRD_IEEE802154. Data is exchanged with socket family
code via plain sk_buffs. The control block of sk_buffs will contain additional
info as described in the struct ieee802154_mac_cb.
code via plain sk_buffs. On skb reception skb->cb must contain additional
info as described in the struct ieee802154_mac_cb. During packet transmission
the skb->cb is used to provide additional data to device's header_ops->create
function. Be aware, that this data can be overriden later (when socket code
submits skb to qdisc), so if you need something from that cb later, you should
store info in the skb->data on your own.
To hook the MLME interface you have to populate the ml_priv field of your
net_device with a pointer to struct ieee802154_mlme_ops instance. All fields are
@@ -69,8 +73,8 @@ We provide an example of simple HardMAC driver at drivers/ieee802154/fakehard.c
SoftMAC
=======
We are going to provide intermediate layer impelementing IEEE 802.15.4 MAC
We are going to provide intermediate layer implementing IEEE 802.15.4 MAC
in software. This is currently WIP.
See header include/net/ieee802154/mac802154.h and several drivers in
drivers/ieee802154/
See header include/net/mac802154.h and several drivers in drivers/ieee802154/.

47
Documentation/networking/ip-sysctl.txt
View File

@@ -311,9 +311,12 @@ tcp_no_metrics_save - BOOLEAN
connections.
tcp_orphan_retries - INTEGER
How may times to retry before killing TCP connection, closed
by our side. Default value 7 corresponds to ~50sec-16min
depending on RTO. If you machine is loaded WEB server,
This value influences the timeout of a locally closed TCP connection,
when RTO retransmissions remain unacknowledged.
See tcp_retries2 for more details.
The default value is 7.
If your machine is a loaded WEB server,
you should think about lowering this value, such sockets
may consume significant resources. Cf. tcp_max_orphans.
@@ -327,16 +330,28 @@ tcp_retrans_collapse - BOOLEAN
certain TCP stacks.
tcp_retries1 - INTEGER
How many times to retry before deciding that something is wrong
and it is necessary to report this suspicion to network layer.
Minimal RFC value is 3, it is default, which corresponds
to ~3sec-8min depending on RTO.
This value influences the time, after which TCP decides, that
something is wrong due to unacknowledged RTO retransmissions,
and reports this suspicion to the network layer.
See tcp_retries2 for more details.
RFC 1122 recommends at least 3 retransmissions, which is the
default.
tcp_retries2 - INTEGER
How may times to retry before killing alive TCP connection.
RFC1122 says that the limit should be longer than 100 sec.
It is too small number. Default value 15 corresponds to ~13-30min
depending on RTO.
This value influences the timeout of an alive TCP connection,
when RTO retransmissions remain unacknowledged.
Given a value of N, a hypothetical TCP connection following
exponential backoff with an initial RTO of TCP_RTO_MIN would
retransmit N times before killing the connection at the (N+1)th RTO.
The default value of 15 yields a hypothetical timeout of 924.6
seconds and is a lower bound for the effective timeout.
TCP will effectively time out at the first RTO which exceeds the
hypothetical timeout.
RFC 1122 recommends at least 100 seconds for the timeout,
which corresponds to a value of at least 8.
tcp_rfc1337 - BOOLEAN
If set, the TCP stack behaves conforming to RFC1337. If unset,
@@ -1282,6 +1297,16 @@ sctp_rmem - vector of 3 INTEGERs: min, default, max
sctp_wmem - vector of 3 INTEGERs: min, default, max
See tcp_wmem for a description.
addr_scope_policy - INTEGER
Control IPv4 address scoping - draft-stewart-tsvwg-sctp-ipv4-00
0 - Disable IPv4 address scoping
1 - Enable IPv4 address scoping
2 - Follow draft but allow IPv4 private addresses
3 - Follow draft but allow IPv4 link local addresses
Default: 1
/proc/sys/net/core/*
dev_weight - INTEGER

7
Documentation/s390/s390dbf.txt
View File

@@ -495,6 +495,13 @@ and for each vararg a long value. So e.g. for a debug entry with a format
string plus two varargs one would need to allocate a (3 * sizeof(long))
byte data area in the debug_register() function.
IMPORTANT: Using "%s" in sprintf event functions is dangerous. You can only
use "%s" in the sprintf event functions, if the memory for the passed string is
available as long as the debug feature exists. The reason behind this is that
due to performance considerations only a pointer to the string is stored in
the debug feature. If you log a string that is freed afterwards, you will get
an OOPS when inspecting the debug feature, because then the debug feature will
access the already freed memory.
NOTE: If using the sprintf view do NOT use other event/exception functions
than the sprintf-event and -exception functions.

30
Documentation/sound/alsa/ALSA-Configuration.txt
View File

@@ -60,6 +60,12 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
slots - Reserve the slot index for the given driver.
This option takes multiple strings.
See "Module Autoloading Support" section for details.
debug - Specifies the debug message level
(0 = disable debug prints, 1 = normal debug messages,
2 = verbose debug messages)
This option appears only when CONFIG_SND_DEBUG=y.
This option can be dynamically changed via sysfs
/sys/modules/snd/parameters/debug file.
Module snd-pcm-oss
------------------
@@ -513,6 +519,26 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
or input, but you may use this module for any application which
requires a sound card (like RealPlayer).
pcm_devs - Number of PCM devices assigned to each card
(default = 1, up to 4)
pcm_substreams - Number of PCM substreams assigned to each PCM
(default = 8, up to 16)
hrtimer - Use hrtimer (=1, default) or system timer (=0)
fake_buffer - Fake buffer allocations (default = 1)
When multiple PCM devices are created, snd-dummy gives different
behavior to each PCM device:
0 = interleaved with mmap support
1 = non-interleaved with mmap support
2 = interleaved without mmap
3 = non-interleaved without mmap
As default, snd-dummy drivers doesn't allocate the real buffers
but either ignores read/write or mmap a single dummy page to all
buffer pages, in order to save the resouces. If your apps need
the read/ written buffer data to be consistent, pass fake_buffer=0
option.
The power-management is supported.
Module snd-echo3g
@@ -768,6 +794,10 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
bdl_pos_adj - Specifies the DMA IRQ timing delay in samples.
Passing -1 will make the driver to choose the appropriate
value based on the controller chip.
patch - Specifies the early "patch" files to modify the HD-audio
setup before initializing the codecs. This option is
available only when CONFIG_SND_HDA_PATCH_LOADER=y is set.
See HD-Audio.txt for details.
[Single (global) options]
single_cmd - Use single immediate commands to communicate with

33
Documentation/sound/alsa/HD-Audio-Models.txt
View File

@@ -114,8 +114,8 @@ ALC662/663/272
samsung-nc10 Samsung NC10 mini notebook
auto auto-config reading BIOS (default)
ALC882/885
==========
ALC882/883/885/888/889
======================
3stack-dig 3-jack with SPDIF I/O
6stack-dig 6-jack digital with SPDIF I/O
arima Arima W820Di1
@@ -127,12 +127,8 @@ ALC882/885
mbp3 Macbook Pro rev3
imac24 iMac 24'' with jack detection
w2jc ASUS W2JC
auto auto-config reading BIOS (default)
ALC883/888
==========
3stack-dig 3-jack with SPDIF I/O
6stack-dig 6-jack digital with SPDIF I/O
3stack-2ch-dig 3-jack with SPDIF I/O (ALC883)
alc883-6stack-dig 6-jack digital with SPDIF I/O (ALC883)
3stack-6ch 3-jack 6-channel
3stack-6ch-dig 3-jack 6-channel with SPDIF I/O
6stack-dig-demo 6-jack digital for Intel demo board
@@ -140,6 +136,7 @@ ALC883/888
acer-aspire Acer Aspire 9810
acer-aspire-4930g Acer Aspire 4930G
acer-aspire-6530g Acer Aspire 6530G
acer-aspire-7730g Acer Aspire 7730G
acer-aspire-8930g Acer Aspire 8930G
medion Medion Laptops
medion-md2 Medion MD2
@@ -155,10 +152,13 @@ ALC883/888
3stack-hp HP machines with 3stack (Lucknow, Samba boards)
6stack-dell Dell machines with 6stack (Inspiron 530)
mitac Mitac 8252D
clevo-m540r Clevo M540R (6ch + digital)
clevo-m720 Clevo M720 laptop series
fujitsu-pi2515 Fujitsu AMILO Pi2515
fujitsu-xa3530 Fujitsu AMILO XA3530
3stack-6ch-intel Intel DG33* boards
intel-alc889a Intel IbexPeak with ALC889A
intel-x58 Intel DX58 with ALC889
asus-p5q ASUS P5Q-EM boards
mb31 MacBook 3,1
sony-vaio-tt Sony VAIO TT
@@ -229,7 +229,7 @@ AD1984
======
basic default configuration
thinkpad Lenovo Thinkpad T61/X61
dell Dell T3400
dell_desktop Dell T3400
AD1986A
=======
@@ -258,6 +258,7 @@ Conexant 5045
laptop-micsense Laptop with Mic sense (old model fujitsu)
laptop-hpmicsense Laptop with HP and Mic senses
benq Benq R55E
laptop-hp530 HP 530 laptop
test for testing/debugging purpose, almost all controls
can be adjusted. Appearing only when compiled with
$CONFIG_SND_DEBUG=y
@@ -278,9 +279,16 @@ Conexant 5051
hp-dv6736 HP dv6736
lenovo-x200 Lenovo X200 laptop
Conexant 5066
=============
laptop Basic Laptop config (default)
dell-laptop Dell laptops
olpc-xo-1_5 OLPC XO 1.5
STAC9200
========
ref Reference board
oqo OQO Model 2
dell-d21 Dell (unknown)
dell-d22 Dell (unknown)
dell-d23 Dell (unknown)
@@ -368,10 +376,12 @@ STAC92HD73*
===========
ref Reference board
no-jd BIOS setup but without jack-detection
intel Intel DG45* mobos
dell-m6-amic Dell desktops/laptops with analog mics
dell-m6-dmic Dell desktops/laptops with digital mics
dell-m6 Dell desktops/laptops with both type of mics
dell-eq Dell desktops/laptops
alienware Alienware M17x
auto BIOS setup (default)
STAC92HD83*
@@ -385,3 +395,8 @@ STAC9872
========
vaio VAIO laptop without SPDIF
auto BIOS setup (default)
Cirrus Logic CS4206/4207
========================
mbp55 MacBook Pro 5,5
auto BIOS setup (default)

64
Documentation/sound/alsa/HD-Audio.txt
View File

@@ -138,6 +138,10 @@ override the BIOS setup or to provide more comprehensive features.
The driver checks PCI SSID and looks through the static configuration
table until any matching entry is found. If you have a new machine,
you may see a message like below:
------------------------------------------------------------------------
hda_codec: ALC880: BIOS auto-probing.
------------------------------------------------------------------------
Meanwhile, in the earlier versions, you would see a message like:
------------------------------------------------------------------------
hda_codec: Unknown model for ALC880, trying auto-probe from BIOS...
------------------------------------------------------------------------
@@ -403,6 +407,66 @@ re-configure based on that state, run like below:
------------------------------------------------------------------------
Early Patching
~~~~~~~~~~~~~~
When CONFIG_SND_HDA_PATCH_LOADER=y is set, you can pass a "patch" as a
firmware file for modifying the HD-audio setup before initializing the
codec. This can work basically like the reconfiguration via sysfs in
the above, but it does it before the first codec configuration.
A patch file is a plain text file which looks like below:
------------------------------------------------------------------------
[codec]
0x12345678 0xabcd1234 2
[model]
auto
[pincfg]
0x12 0x411111f0
[verb]
0x20 0x500 0x03
0x20 0x400 0xff
[hint]
hp_detect = yes
------------------------------------------------------------------------
The file needs to have a line `[codec]`. The next line should contain
three numbers indicating the codec vendor-id (0x12345678 in the
example), the codec subsystem-id (0xabcd1234) and the address (2) of
the codec. The rest patch entries are applied to this specified codec
until another codec entry is given.
The `[model]` line allows to change the model name of the each codec.
In the example above, it will be changed to model=auto.
Note that this overrides the module option.
After the `[pincfg]` line, the contents are parsed as the initial
default pin-configurations just like `user_pin_configs` sysfs above.
The values can be shown in user_pin_configs sysfs file, too.
Similarly, the lines after `[verb]` are parsed as `init_verbs`
sysfs entries, and the lines after `[hint]` are parsed as `hints`
sysfs entries, respectively.
The hd-audio driver reads the file via request_firmware(). Thus,
a patch file has to be located on the appropriate firmware path,
typically, /lib/firmware. For example, when you pass the option
`patch=hda-init.fw`, the file /lib/firmware/hda-init-fw must be
present.
The patch module option is specific to each card instance, and you
need to give one file name for each instance, separated by commas.
For example, if you have two cards, one for an on-board analog and one
for an HDMI video board, you may pass patch option like below:
------------------------------------------------------------------------
options snd-hda-intel patch=on-board-patch,hdmi-patch
------------------------------------------------------------------------
Power-Saving
~~~~~~~~~~~~
The power-saving is a kind of auto-suspend of the device. When the

16
Documentation/sysctl/kernel.txt
View File

@@ -19,6 +19,7 @@ Currently, these files might (depending on your configuration)
show up in /proc/sys/kernel:
- acpi_video_flags
- acct
- callhome [ S390 only ]
- auto_msgmni
- core_pattern
- core_uses_pid
@@ -91,6 +92,21 @@ valid for 30 seconds.
==============================================================
callhome:
Controls the kernel's callhome behavior in case of a kernel panic.
The s390 hardware allows an operating system to send a notification
to a service organization (callhome) in case of an operating system panic.
When the value in this file is 0 (which is the default behavior)
nothing happens in case of a kernel panic. If this value is set to "1"
the complete kernel oops message is send to the IBM customer service
organization in case the mainframe the Linux operating system is running
on has a service contract with IBM.
==============================================================
core_pattern:
core_pattern is used to specify a core dumpfile pattern name.

9
Documentation/trace/events.txt
View File

@@ -83,6 +83,15 @@ When reading one of these enable files, there are four results:
X - there is a mixture of events enabled and disabled
? - this file does not affect any event
2.3 Boot option
---------------
In order to facilitate early boot debugging, use boot option:
trace_event=[event-list]
The format of this boot option is the same as described in section 2.1.
3. Defining an event-enabled tracepoint
=======================================

68
Documentation/trace/ftrace.txt
View File

@@ -85,26 +85,19 @@ of ftrace. Here is a list of some of the key files:
This file holds the output of the trace in a human
readable format (described below).
latency_trace:
This file shows the same trace but the information
is organized more to display possible latencies
in the system (described below).
trace_pipe:
The output is the same as the "trace" file but this
file is meant to be streamed with live tracing.
Reads from this file will block until new data
is retrieved. Unlike the "trace" and "latency_trace"
files, this file is a consumer. This means reading
from this file causes sequential reads to display
more current data. Once data is read from this
file, it is consumed, and will not be read
again with a sequential read. The "trace" and
"latency_trace" files are static, and if the
tracer is not adding more data, they will display
the same information every time they are read.
Reads from this file will block until new data is
retrieved. Unlike the "trace" file, this file is a
consumer. This means reading from this file causes
sequential reads to display more current data. Once
data is read from this file, it is consumed, and
will not be read again with a sequential read. The
"trace" file is static, and if the tracer is not
adding more data,they will display the same
information every time they are read.
trace_options:
@@ -117,10 +110,10 @@ of ftrace. Here is a list of some of the key files:
Some of the tracers record the max latency.
For example, the time interrupts are disabled.
This time is saved in this file. The max trace
will also be stored, and displayed by either
"trace" or "latency_trace". A new max trace will
only be recorded if the latency is greater than
the value in this file. (in microseconds)
will also be stored, and displayed by "trace".
A new max trace will only be recorded if the
latency is greater than the value in this
file. (in microseconds)
buffer_size_kb:
@@ -210,7 +203,7 @@ Here is the list of current tracers that may be configured.
the trace with the longest max latency.
See tracing_max_latency. When a new max is recorded,
it replaces the old trace. It is best to view this
trace via the latency_trace file.
trace with the latency-format option enabled.
"preemptoff"
@@ -307,8 +300,8 @@ the lowest priority thread (pid 0).
Latency trace format
--------------------
For traces that display latency times, the latency_trace file
gives somewhat more information to see why a latency happened.
When the latency-format option is enabled, the trace file gives
somewhat more information to see why a latency happened.
Here is a typical trace.
# tracer: irqsoff
@@ -380,9 +373,10 @@ explains which is which.
The above is mostly meaningful for kernel developers.
time: This differs from the trace file output. The trace file output
includes an absolute timestamp. The timestamp used by the
latency_trace file is relative to the start of the trace.
time: When the latency-format option is enabled, the trace file
output includes a timestamp relative to the start of the
trace. This differs from the output when latency-format
is disabled, which includes an absolute timestamp.
delay: This is just to help catch your eye a bit better. And
needs to be fixed to be only relative to the same CPU.
@@ -440,7 +434,8 @@ Here are the available options:
sym-addr:
bash-4000 [01] 1477.606694: simple_strtoul <c0339346>
verbose - This deals with the latency_trace file.
verbose - This deals with the trace file when the
latency-format option is enabled.
bash 4000 1 0 00000000 00010a95 [58127d26] 1720.415ms \
(+0.000ms): simple_strtoul (strict_strtoul)
@@ -472,7 +467,7 @@ Here are the available options:
the app is no longer running
The lookup is performed when you read
trace,trace_pipe,latency_trace. Example:
trace,trace_pipe. Example:
a.out-1623 [000] 40874.465068: /root/a.out[+0x480] <-/root/a.out[+0
x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6]
@@ -481,6 +476,11 @@ x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6]
every scheduling event. Will add overhead if
there's a lot of tasks running at once.
latency-format - This option changes the trace. When
it is enabled, the trace displays
additional information about the
latencies, as described in "Latency
trace format".
sched_switch
------------
@@ -596,12 +596,13 @@ To reset the maximum, echo 0 into tracing_max_latency. Here is
an example:
# echo irqsoff > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# ls -ltr
[...]
# echo 0 > tracing_enabled
# cat latency_trace
# cat trace
# tracer: irqsoff
#
irqsoff latency trace v1.1.5 on 2.6.26
@@ -703,12 +704,13 @@ which preemption was disabled. The control of preemptoff tracer
is much like the irqsoff tracer.
# echo preemptoff > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# ls -ltr
[...]
# echo 0 > tracing_enabled
# cat latency_trace
# cat trace
# tracer: preemptoff
#
preemptoff latency trace v1.1.5 on 2.6.26-rc8
@@ -850,12 +852,13 @@ Again, using this trace is much like the irqsoff and preemptoff
tracers.
# echo preemptirqsoff > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# ls -ltr
[...]
# echo 0 > tracing_enabled
# cat latency_trace
# cat trace
# tracer: preemptirqsoff
#
preemptirqsoff latency trace v1.1.5 on 2.6.26-rc8
@@ -1012,11 +1015,12 @@ Instead of performing an 'ls', we will run 'sleep 1' under
'chrt' which changes the priority of the task.
# echo wakeup > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# chrt -f 5 sleep 1
# echo 0 > tracing_enabled
# cat latency_trace
# cat trace
# tracer: wakeup
#
wakeup latency trace v1.1.5 on 2.6.26-rc8

42
Documentation/trace/function-graph-fold.vim Normal file
View File

@@ -0,0 +1,42 @@
" Enable folding for ftrace function_graph traces.
"
" To use, :source this file while viewing a function_graph trace, or use vim's
" -S option to load from the command-line together with a trace. You can then
" use the usual vim fold commands, such as "za", to open and close nested
" functions. While closed, a fold will show the total time taken for a call,
" as would normally appear on the line with the closing brace. Folded
" functions will not include finish_task_switch(), so folding should remain
" relatively sane even through a context switch.
"
" Note that this will almost certainly only work well with a
" single-CPU trace (e.g. trace-cmd report --cpu 1).
function! FunctionGraphFoldExpr(lnum)
let line = getline(a:lnum)
if line[-1:] == '{'
if line =~ 'finish_task_switch() {$'
return '>1'
endif
return 'a1'
elseif line[-1:] == '}'
return 's1'
else
return '='
endif
endfunction
function! FunctionGraphFoldText()
let s = split(getline(v:foldstart), '|', 1)
if getline(v:foldend+1) =~ 'finish_task_switch() {$'
let s[2] = ' task switch '
else
let e = split(getline(v:foldend), '|', 1)
let s[2] = e[2]
endif
return join(s, '|')
endfunction
setlocal foldexpr=FunctionGraphFoldExpr(v:lnum)
setlocal foldtext=FunctionGraphFoldText()
setlocal foldcolumn=12
setlocal foldmethod=expr

955
Documentation/trace/ring-buffer-design.txt Normal file
View File

@@ -0,0 +1,955 @@
Lockless Ring Buffer Design
===========================
Copyright 2009 Red Hat Inc.
Author: Steven Rostedt <srostedt@redhat.com>
License: The GNU Free Documentation License, Version 1.2
(dual licensed under the GPL v2)
Reviewers: Mathieu Desnoyers, Huang Ying, Hidetoshi Seto,
and Frederic Weisbecker.
Written for: 2.6.31
Terminology used in this Document
---------------------------------
tail - where new writes happen in the ring buffer.
head - where new reads happen in the ring buffer.
producer - the task that writes into the ring buffer (same as writer)
writer - same as producer
consumer - the task that reads from the buffer (same as reader)
reader - same as consumer.
reader_page - A page outside the ring buffer used solely (for the most part)
by the reader.
head_page - a pointer to the page that the reader will use next
tail_page - a pointer to the page that will be written to next
commit_page - a pointer to the page with the last finished non nested write.
cmpxchg - hardware assisted atomic transaction that performs the following:
A = B iff previous A == C
R = cmpxchg(A, C, B) is saying that we replace A with B if and only if
current A is equal to C, and we put the old (current) A into R
R gets the previous A regardless if A is updated with B or not.
To see if the update was successful a compare of R == C may be used.
The Generic Ring Buffer
-----------------------
The ring buffer can be used in either an overwrite mode or in
producer/consumer mode.
Producer/consumer mode is where the producer were to fill up the
buffer before the consumer could free up anything, the producer
will stop writing to the buffer. This will lose most recent events.
Overwrite mode is where the produce were to fill up the buffer
before the consumer could free up anything, the producer will
overwrite the older data. This will lose the oldest events.
No two writers can write at the same time (on the same per cpu buffer),
but a writer may interrupt another writer, but it must finish writing
before the previous writer may continue. This is very important to the
algorithm. The writers act like a "stack". The way interrupts works
enforces this behavior.
writer1 start
<preempted> writer2 start
<preempted> writer3 start
writer3 finishes
writer2 finishes
writer1 finishes
This is very much like a writer being preempted by an interrupt and
the interrupt doing a write as well.
Readers can happen at any time. But no two readers may run at the
same time, nor can a reader preempt/interrupt another reader. A reader
can not preempt/interrupt a writer, but it may read/consume from the
buffer at the same time as a writer is writing, but the reader must be
on another processor to do so. A reader may read on its own processor
and can be preempted by a writer.
A writer can preempt a reader, but a reader can not preempt a writer.
But a reader can read the buffer at the same time (on another processor)
as a writer.
The ring buffer is made up of a list of pages held together by a link list.
At initialization a reader page is allocated for the reader that is not
part of the ring buffer.
The head_page, tail_page and commit_page are all initialized to point
to the same page.
The reader page is initialized to have its next pointer pointing to
the head page, and its previous pointer pointing to a page before
the head page.
The reader has its own page to use. At start up time, this page is
allocated but is not attached to the list. When the reader wants
to read from the buffer, if its page is empty (like it is on start up)
it will swap its page with the head_page. The old reader page will
become part of the ring buffer and the head_page will be removed.
The page after the inserted page (old reader_page) will become the
new head page.
Once the new page is given to the reader, the reader could do what
it wants with it, as long as a writer has left that page.
A sample of how the reader page is swapped: Note this does not
show the head page in the buffer, it is for demonstrating a swap
only.
+------+
|reader| RING BUFFER
|page |
+------+
+---+ +---+ +---+
| |-->| |-->| |
| |<--| |<--| |
+---+ +---+ +---+
^ | ^ |
| +-------------+ |
+-----------------+
+------+
|reader| RING BUFFER
|page |-------------------+
+------+ v
| +---+ +---+ +---+
| | |-->| |-->| |
| | |<--| |<--| |<-+
| +---+ +---+ +---+ |
| ^ | ^ | |
| | +-------------+ | |
| +-----------------+ |
+------------------------------------+
+------+
|reader| RING BUFFER
|page |-------------------+
+------+ <---------------+ v
| ^ +---+ +---+ +---+
| | | |-->| |-->| |
| | | | | |<--| |<-+
| | +---+ +---+ +---+ |
| | | ^ | |
| | +-------------+ | |
| +-----------------------------+ |
+------------------------------------+
+------+
|buffer| RING BUFFER
|page |-------------------+
+------+ <---------------+ v
| ^ +---+ +---+ +---+
| | | | | |-->| |
| | New | | | |<--| |<-+
| | Reader +---+ +---+ +---+ |
| | page ----^ | |
| | | |
| +-----------------------------+ |
+------------------------------------+
It is possible that the page swapped is the commit page and the tail page,
if what is in the ring buffer is less than what is held in a buffer page.
reader page commit page tail page
| | |
v | |
+---+ | |
| |<----------+ |
| |<------------------------+
| |------+
+---+ |
|
v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
This case is still valid for this algorithm.
When the writer leaves the page, it simply goes into the ring buffer
since the reader page still points to the next location in the ring
buffer.
The main pointers:
reader page - The page used solely by the reader and is not part
of the ring buffer (may be swapped in)
head page - the next page in the ring buffer that will be swapped
with the reader page.
tail page - the page where the next write will take place.
commit page - the page that last finished a write.
The commit page only is updated by the outer most writer in the
writer stack. A writer that preempts another writer will not move the
commit page.
When data is written into the ring buffer, a position is reserved
in the ring buffer and passed back to the writer. When the writer
is finished writing data into that position, it commits the write.
Another write (or a read) may take place at anytime during this
transaction. If another write happens it must finish before continuing
with the previous write.
Write reserve:
Buffer page
+---------+
|written |
+---------+ <--- given back to writer (current commit)
|reserved |
+---------+ <--- tail pointer
| empty |
+---------+
Write commit:
Buffer page
+---------+
|written |
+---------+
|written |
+---------+ <--- next positon for write (current commit)
| empty |
+---------+
If a write happens after the first reserve:
Buffer page
+---------+
|written |
+---------+ <-- current commit
|reserved |
+---------+ <--- given back to second writer
|reserved |
+---------+ <--- tail pointer
After second writer commits:
Buffer page
+---------+
|written |
+---------+ <--(last full commit)
|reserved |
+---------+
|pending |
|commit |
+---------+ <--- tail pointer
When the first writer commits:
Buffer page
+---------+
|written |
+---------+
|written |
+---------+
|written |
+---------+ <--(last full commit and tail pointer)
The commit pointer points to the last write location that was
committed without preempting another write. When a write that
preempted another write is committed, it only becomes a pending commit
and will not be a full commit till all writes have been committed.
The commit page points to the page that has the last full commit.
The tail page points to the page with the last write (before
committing).
The tail page is always equal to or after the commit page. It may
be several pages ahead. If the tail page catches up to the commit
page then no more writes may take place (regardless of the mode
of the ring buffer: overwrite and produce/consumer).
The order of pages are:
head page
commit page
tail page
Possible scenario:
tail page
head page commit page |
| | |
v v v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
There is a special case that the head page is after either the commit page
and possibly the tail page. That is when the commit (and tail) page has been
swapped with the reader page. This is because the head page is always
part of the ring buffer, but the reader page is not. When ever there
has been less than a full page that has been committed inside the ring buffer,
and a reader swaps out a page, it will be swapping out the commit page.
reader page commit page tail page
| | |
v | |
+---+ | |
| |<----------+ |
| |<------------------------+
| |------+
+---+ |
|
v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
^
|
head page
In this case, the head page will not move when the tail and commit
move back into the ring buffer.
The reader can not swap a page into the ring buffer if the commit page
is still on that page. If the read meets the last commit (real commit
not pending or reserved), then there is nothing more to read.
The buffer is considered empty until another full commit finishes.
When the tail meets the head page, if the buffer is in overwrite mode,
the head page will be pushed ahead one. If the buffer is in producer/consumer
mode, the write will fail.
Overwrite mode:
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
^
|
head page
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
^
|
head page
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
^
|
head page
Note, the reader page will still point to the previous head page.
But when a swap takes place, it will use the most recent head page.
Making the Ring Buffer Lockless:
--------------------------------
The main idea behind the lockless algorithm is to combine the moving
of the head_page pointer with the swapping of pages with the reader.
State flags are placed inside the pointer to the page. To do this,
each page must be aligned in memory by 4 bytes. This will allow the 2
least significant bits of the address to be used as flags. Since
they will always be zero for the address. To get the address,
simply mask out the flags.
MASK = ~3
address & MASK
Two flags will be kept by these two bits:
HEADER - the page being pointed to is a head page
UPDATE - the page being pointed to is being updated by a writer
and was or is about to be a head page.
reader page
|
v
+---+
| |------+
+---+ |
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-H->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The above pointer "-H->" would have the HEADER flag set. That is
the next page is the next page to be swapped out by the reader.
This pointer means the next page is the head page.
When the tail page meets the head pointer, it will use cmpxchg to
change the pointer to the UPDATE state:
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-H->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
"-U->" represents a pointer in the UPDATE state.
Any access to the reader will need to take some sort of lock to serialize
the readers. But the writers will never take a lock to write to the
ring buffer. This means we only need to worry about a single reader,
and writes only preempt in "stack" formation.
When the reader tries to swap the page with the ring buffer, it
will also use cmpxchg. If the flag bit in the pointer to the
head page does not have the HEADER flag set, the compare will fail
and the reader will need to look for the new head page and try again.
Note, the flag UPDATE and HEADER are never set at the same time.
The reader swaps the reader page as follows:
+------+
|reader| RING BUFFER
|page |
+------+
+---+ +---+ +---+
| |--->| |--->| |
| |<---| |<---| |
+---+ +---+ +---+
^ | ^ |
| +---------------+ |
+-----H-------------+
The reader sets the reader page next pointer as HEADER to the page after
the head page.
+------+
|reader| RING BUFFER
|page |-------H-----------+
+------+ v
| +---+ +---+ +---+
| | |--->| |--->| |
| | |<---| |<---| |<-+
| +---+ +---+ +---+ |
| ^ | ^ | |
| | +---------------+ | |
| +-----H-------------+ |
+--------------------------------------+
It does a cmpxchg with the pointer to the previous head page to make it
point to the reader page. Note that the new pointer does not have the HEADER
flag set. This action atomically moves the head page forward.
+------+
|reader| RING BUFFER
|page |-------H-----------+
+------+ v
| ^ +---+ +---+ +---+
| | | |-->| |-->| |
| | | |<--| |<--| |<-+
| | +---+ +---+ +---+ |
| | | ^ | |
| | +-------------+ | |
| +-----------------------------+ |
+------------------------------------+
After the new head page is set, the previous pointer of the head page is
updated to the reader page.
+------+
|reader| RING BUFFER
|page |-------H-----------+
+------+ <---------------+ v
| ^ +---+ +---+ +---+
| | | |-->| |-->| |
| | | | | |<--| |<-+
| | +---+ +---+ +---+ |
| | | ^ | |
| | +-------------+ | |
| +-----------------------------+ |
+------------------------------------+
+------+
|buffer| RING BUFFER
|page |-------H-----------+ <--- New head page
+------+ <---------------+ v
| ^ +---+ +---+ +---+
| | | | | |-->| |
| | New | | | |<--| |<-+
| | Reader +---+ +---+ +---+ |
| | page ----^ | |
| | | |
| +-----------------------------+ |
+------------------------------------+
Another important point. The page that the reader page points back to
by its previous pointer (the one that now points to the new head page)
never points back to the reader page. That is because the reader page is
not part of the ring buffer. Traversing the ring buffer via the next pointers
will always stay in the ring buffer. Traversing the ring buffer via the
prev pointers may not.
Note, the way to determine a reader page is simply by examining the previous
pointer of the page. If the next pointer of the previous page does not
point back to the original page, then the original page is a reader page:
+--------+
| reader | next +----+
| page |-------->| |<====== (buffer page)
+--------+ +----+
| | ^
| v | next
prev | +----+
+------------->| |
+----+
The way the head page moves forward:
When the tail page meets the head page and the buffer is in overwrite mode
and more writes take place, the head page must be moved forward before the
writer may move the tail page. The way this is done is that the writer
performs a cmpxchg to convert the pointer to the head page from the HEADER
flag to have the UPDATE flag set. Once this is done, the reader will
not be able to swap the head page from the buffer, nor will it be able to
move the head page, until the writer is finished with the move.
This eliminates any races that the reader can have on the writer. The reader
must spin, and this is why the reader can not preempt the writer.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-H->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The following page will be made into the new head page.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |-H->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
After the new head page has been set, we can set the old head page
pointer back to NORMAL.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |-H->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
After the head page has been moved, the tail page may now move forward.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |-H->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The above are the trivial updates. Now for the more complex scenarios.
As stated before, if enough writes preempt the first write, the
tail page may make it all the way around the buffer and meet the commit
page. At this time, we must start dropping writes (usually with some kind
of warning to the user). But what happens if the commit was still on the
reader page? The commit page is not part of the ring buffer. The tail page
must account for this.
reader page commit page
| |
v |
+---+ |
| |<----------+
| |
| |------+
+---+ |
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-H->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
^
|
tail page
If the tail page were to simply push the head page forward, the commit when
leaving the reader page would not be pointing to the correct page.
The solution to this is to test if the commit page is on the reader page
before pushing the head page. If it is, then it can be assumed that the
tail page wrapped the buffer, and we must drop new writes.
This is not a race condition, because the commit page can only be moved
by the outter most writer (the writer that was preempted).
This means that the commit will not move while a writer is moving the
tail page. The reader can not swap the reader page if it is also being
used as the commit page. The reader can simply check that the commit
is off the reader page. Once the commit page leaves the reader page
it will never go back on it unless a reader does another swap with the
buffer page that is also the commit page.
Nested writes
-------------
In the pushing forward of the tail page we must first push forward
the head page if the head page is the next page. If the head page
is not the next page, the tail page is simply updated with a cmpxchg.
Only writers move the tail page. This must be done atomically to protect
against nested writers.
temp_page = tail_page
next_page = temp_page->next
cmpxchg(tail_page, temp_page, next_page)
The above will update the tail page if it is still pointing to the expected
page. If this fails, a nested write pushed it forward, the the current write
does not need to push it.
temp page
|
v
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
Nested write comes in and moves the tail page forward:
tail page (moved by nested writer)
temp page |
| |
v v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The above would fail the cmpxchg, but since the tail page has already
been moved forward, the writer will just try again to reserve storage
on the new tail page.
But the moving of the head page is a bit more complex.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-H->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The write converts the head page pointer to UPDATE.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
But if a nested writer preempts here. It will see that the next
page is a head page, but it is also nested. It will detect that
it is nested and will save that information. The detection is the
fact that it sees the UPDATE flag instead of a HEADER or NORMAL
pointer.
The nested writer will set the new head page pointer.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |-H->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
But it will not reset the update back to normal. Only the writer
that converted a pointer from HEAD to UPDATE will convert it back
to NORMAL.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |-H->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
After the nested writer finishes, the outer most writer will convert
the UPDATE pointer to NORMAL.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |-H->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
It can be even more complex if several nested writes came in and moved
the tail page ahead several pages:
(first writer)
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-H->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The write converts the head page pointer to UPDATE.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |--->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
Next writer comes in, and sees the update and sets up the new
head page.
(second writer)
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |-H->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The nested writer moves the tail page forward. But does not set the old
update page to NORMAL because it is not the outer most writer.
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |-H->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
Another writer preempts and sees the page after the tail page is a head page.
It changes it from HEAD to UPDATE.
(third writer)
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |-U->| |--->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The writer will move the head page forward:
(third writer)
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |-U->| |-H->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
But now that the third writer did change the HEAD flag to UPDATE it
will convert it to normal:
(third writer)
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |--->| |-H->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
Then it will move the tail page, and return back to the second writer.
(second writer)
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |--->| |-H->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The second writer will fail to move the tail page because it was already
moved, so it will try again and add its data to the new tail page.
It will return to the first writer.
(first writer)
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |--->| |-H->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
The first writer can not know atomically test if the tail page moved
while it updates the HEAD page. It will then update the head page to
what it thinks is the new head page.
(first writer)
tail page
|
v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |-H->| |-H->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
Since the cmpxchg returns the old value of the pointer the first writer
will see it succeeded in updating the pointer from NORMAL to HEAD.
But as we can see, this is not good enough. It must also check to see
if the tail page is either where it use to be or on the next page:
(first writer)
A B tail page
| | |
v v v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |-H->| |-H->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
If tail page != A and tail page does not equal B, then it must reset the
pointer back to NORMAL. The fact that it only needs to worry about
nested writers, it only needs to check this after setting the HEAD page.
(first writer)
A B tail page
| | |
v v v
+---+ +---+ +---+ +---+
<---| |--->| |-U->| |--->| |-H->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+
Now the writer can update the head page. This is also why the head page must
remain in UPDATE and only reset by the outer most writer. This prevents
the reader from seeing the incorrect head page.
(first writer)
A B tail page
| | |
v v v
+---+ +---+ +---+ +---+
<---| |--->| |--->| |--->| |-H->
--->| |<---| |<---| |<---| |<---
+---+ +---+ +---+ +---+

2
Documentation/video4linux/CARDLIST.cx23885
View File

@@ -21,3 +21,5 @@
20 -> Hauppauge WinTV-HVR1255 [0070:2251]
21 -> Hauppauge WinTV-HVR1210 [0070:2291,0070:2295]
22 -> Mygica X8506 DMB-TH [14f1:8651]
23 -> Magic-Pro ProHDTV Extreme 2 [14f1:8657]
24 -> Hauppauge WinTV-HVR1850 [0070:8541]

1
Documentation/video4linux/CARDLIST.cx88
View File

@@ -80,3 +80,4 @@
79 -> Terratec Cinergy HT PCI MKII [153b:1177]
80 -> Hauppauge WinTV-IR Only [0070:9290]
81 -> Leadtek WinFast DTV1800 Hybrid [107d:6654]
82 -> WinFast DTV2000 H rev. J [107d:6f2b]

5
Documentation/video4linux/CARDLIST.em28xx
View File

@@ -7,7 +7,7 @@
6 -> Terratec Cinergy 200 USB (em2800)
7 -> Leadtek Winfast USB II (em2800) [0413:6023]
8 -> Kworld USB2800 (em2800)
9 -> Pinnacle Dazzle DVC 90/100/101/107 / Kaiser Baas Video to DVD maker (em2820/em2840) [1b80:e302,2304:0207,2304:021a]
9 -> Pinnacle Dazzle DVC 90/100/101/107 / Kaiser Baas Video to DVD maker (em2820/em2840) [1b80:e302,1b80:e304,2304:0207,2304:021a]
10 -> Hauppauge WinTV HVR 900 (em2880) [2040:6500]
11 -> Terratec Hybrid XS (em2880) [0ccd:0042]
12 -> Kworld PVR TV 2800 RF (em2820/em2840)
@@ -33,7 +33,7 @@
34 -> Terratec Cinergy A Hybrid XS (em2860) [0ccd:004f]
35 -> Typhoon DVD Maker (em2860)
36 -> NetGMBH Cam (em2860)
37 -> Gadmei UTV330 (em2860)
37 -> Gadmei UTV330 (em2860) [eb1a:50a6]
38 -> Yakumo MovieMixer (em2861)
39 -> KWorld PVRTV 300U (em2861) [eb1a:e300]
40 -> Plextor ConvertX PX-TV100U (em2861) [093b:a005]
@@ -67,3 +67,4 @@
69 -> KWorld ATSC 315U HDTV TV Box (em2882) [eb1a:a313]
70 -> Evga inDtube (em2882)
71 -> Silvercrest Webcam 1.3mpix (em2820/em2840)
72 -> Gadmei UTV330+ (em2861)

4
Documentation/video4linux/CARDLIST.saa7134
View File

@@ -167,3 +167,7 @@
166 -> Beholder BeholdTV 607 RDS [5ace:6073]
167 -> Beholder BeholdTV 609 RDS [5ace:6092]
168 -> Beholder BeholdTV 609 RDS [5ace:6093]
169 -> Compro VideoMate S350/S300 [185b:c900]
170 -> AverMedia AverTV Studio 505 [1461:a115]
171 -> Beholder BeholdTV X7 [5ace:7595]
172 -> RoverMedia TV Link Pro FM [19d1:0138]

1
Documentation/video4linux/CARDLIST.tuner
View File

@@ -78,3 +78,4 @@ tuner=77 - TCL tuner MF02GIP-5N-E
tuner=78 - Philips FMD1216MEX MK3 Hybrid Tuner
tuner=79 - Philips PAL/SECAM multi (FM1216 MK5)
tuner=80 - Philips FQ1216LME MK3 PAL/SECAM w/active loopthrough
tuner=81 - Partsnic (Daewoo) PTI-5NF05

4
Documentation/video4linux/CQcam.txt
View File

@@ -18,8 +18,8 @@ Table of Contents
1.0 Introduction
The file ../drivers/char/c-qcam.c is a device driver for the
Logitech (nee Connectix) parallel port interface color CCD camera.
The file ../../drivers/media/video/c-qcam.c is a device driver for
the Logitech (nee Connectix) parallel port interface color CCD camera.
This is a fairly inexpensive device for capturing images. Logitech
does not currently provide information for developers, but many people
have engineered several solutions for non-Microsoft use of the Color

6
Documentation/video4linux/gspca.txt
View File

@@ -140,6 +140,7 @@ spca500 04fc:7333 PalmPixDC85
sunplus 04fc:ffff Pure DigitalDakota
spca501 0506:00df 3Com HomeConnect Lite
sunplus 052b:1513 Megapix V4
sunplus 052b:1803 MegaImage VI
tv8532 0545:808b Veo Stingray
tv8532 0545:8333 Veo Stingray
sunplus 0546:3155 Polaroid PDC3070
@@ -182,6 +183,7 @@ ov534 06f8:3002 Hercules Blog Webcam
ov534 06f8:3003 Hercules Dualpix HD Weblog
sonixj 06f8:3004 Hercules Classic Silver
sonixj 06f8:3008 Hercules Deluxe Optical Glass
pac7311 06f8:3009 Hercules Classic Link
spca508 0733:0110 ViewQuest VQ110
spca508 0130:0130 Clone Digital Webcam 11043
spca501 0733:0401 Intel Create and Share
@@ -235,8 +237,10 @@ pac7311 093a:2621 PAC731x
pac7311 093a:2622 Genius Eye 312
pac7311 093a:2624 PAC7302
pac7311 093a:2626 Labtec 2200
pac7311 093a:2629 Genious iSlim 300
pac7311 093a:262a Webcam 300k
pac7311 093a:262c Philips SPC 230 NC
jeilinj 0979:0280 Sakar 57379
zc3xx 0ac8:0302 Z-star Vimicro zc0302
vc032x 0ac8:0321 Vimicro generic vc0321
vc032x 0ac8:0323 Vimicro Vc0323
@@ -247,6 +251,7 @@ zc3xx 0ac8:305b Z-star Vimicro zc0305b
zc3xx 0ac8:307b Ldlc VC302+Ov7620
vc032x 0ac8:c001 Sony embedded vimicro
vc032x 0ac8:c002 Sony embedded vimicro
vc032x 0ac8:c301 Samsung Q1 Ultra Premium
spca508 0af9:0010 Hama USB Sightcam 100
spca508 0af9:0011 Hama USB Sightcam 100
sonixb 0c45:6001 Genius VideoCAM NB
@@ -284,6 +289,7 @@ sonixj 0c45:613a Microdia Sonix PC Camera
sonixj 0c45:613b Surfer SN-206
sonixj 0c45:613c Sonix Pccam168
sonixj 0c45:6143 Sonix Pccam168
sonixj 0c45:6148 Digitus DA-70811/ZSMC USB PC Camera ZS211/Microdia
sn9c20x 0c45:6240 PC Camera (SN9C201 + MT9M001)
sn9c20x 0c45:6242 PC Camera (SN9C201 + MT9M111)
sn9c20x 0c45:6248 PC Camera (SN9C201 + OV9655)

176
Documentation/video4linux/si4713.txt Normal file
View File

@@ -0,0 +1,176 @@
Driver for I2C radios for the Silicon Labs Si4713 FM Radio Transmitters
Copyright (c) 2009 Nokia Corporation
Contact: Eduardo Valentin <eduardo.valentin@nokia.com>
Information about the Device
============================
This chip is a Silicon Labs product. It is a I2C device, currently on 0x63 address.
Basically, it has transmission and signal noise level measurement features.
The Si4713 integrates transmit functions for FM broadcast stereo transmission.
The chip also allows integrated receive power scanning to identify low signal
power FM channels.
The chip is programmed using commands and responses. There are also several
properties which can change the behavior of this chip.
Users must comply with local regulations on radio frequency (RF) transmission.
Device driver description
=========================
There are two modules to handle this device. One is a I2C device driver
and the other is a platform driver.
The I2C device driver exports a v4l2-subdev interface to the kernel.
All properties can also be accessed by v4l2 extended controls interface, by
using the v4l2-subdev calls (g_ext_ctrls, s_ext_ctrls).
The platform device driver exports a v4l2 radio device interface to user land.
So, it uses the I2C device driver as a sub device in order to send the user
commands to the actual device. Basically it is a wrapper to the I2C device driver.
Applications can use v4l2 radio API to specify frequency of operation, mute state,
etc. But mostly of its properties will be present in the extended controls.
When the v4l2 mute property is set to 1 (true), the driver will turn the chip off.
Properties description
======================
The properties can be accessed using v4l2 extended controls.
Here is an output from v4l2-ctl util:
/ # v4l2-ctl -d /dev/radio0 --all -L
Driver Info:
Driver name : radio-si4713
Card type : Silicon Labs Si4713 Modulator
Bus info :
Driver version: 0
Capabilities : 0x00080800
RDS Output
Modulator
Audio output: 0 (FM Modulator Audio Out)
Frequency: 1408000 (88.000000 MHz)
Video Standard = 0x00000000
Modulator:
Name : FM Modulator
Capabilities : 62.5 Hz stereo rds
Frequency range : 76.0 MHz - 108.0 MHz
Subchannel modulation: stereo+rds
User Controls
mute (bool) : default=1 value=0
FM Radio Modulator Controls
rds_signal_deviation (int) : min=0 max=90000 step=10 default=200 value=200 flags=slider
rds_program_id (int) : min=0 max=65535 step=1 default=0 value=0
rds_program_type (int) : min=0 max=31 step=1 default=0 value=0
rds_ps_name (str) : min=0 max=96 step=8 value='si4713 '
rds_radio_text (str) : min=0 max=384 step=32 value=''
audio_limiter_feature_enabled (bool) : default=1 value=1
audio_limiter_release_time (int) : min=250 max=102390 step=50 default=5010 value=5010 flags=slider
audio_limiter_deviation (int) : min=0 max=90000 step=10 default=66250 value=66250 flags=slider
audio_compression_feature_enabl (bool) : default=1 value=1
audio_compression_gain (int) : min=0 max=20 step=1 default=15 value=15 flags=slider
audio_compression_threshold (int) : min=-40 max=0 step=1 default=-40 value=-40 flags=slider
audio_compression_attack_time (int) : min=0 max=5000 step=500 default=0 value=0 flags=slider
audio_compression_release_time (int) : min=100000 max=1000000 step=100000 default=1000000 value=1000000 flags=slider
pilot_tone_feature_enabled (bool) : default=1 value=1
pilot_tone_deviation (int) : min=0 max=90000 step=10 default=6750 value=6750 flags=slider
pilot_tone_frequency (int) : min=0 max=19000 step=1 default=19000 value=19000 flags=slider
pre_emphasis_settings (menu) : min=0 max=2 default=1 value=1
tune_power_level (int) : min=0 max=120 step=1 default=88 value=88 flags=slider
tune_antenna_capacitor (int) : min=0 max=191 step=1 default=0 value=110 flags=slider
/ #
Here is a summary of them:
* Pilot is an audible tone sent by the device.
pilot_frequency - Configures the frequency of the stereo pilot tone.
pilot_deviation - Configures pilot tone frequency deviation level.
pilot_enabled - Enables or disables the pilot tone feature.
* The si4713 device is capable of applying audio compression to the transmitted signal.
acomp_enabled - Enables or disables the audio dynamic range control feature.
acomp_gain - Sets the gain for audio dynamic range control.
acomp_threshold - Sets the threshold level for audio dynamic range control.
acomp_attack_time - Sets the attack time for audio dynamic range control.
acomp_release_time - Sets the release time for audio dynamic range control.
* Limiter setups audio deviation limiter feature. Once a over deviation occurs,
it is possible to adjust the front-end gain of the audio input and always
prevent over deviation.
limiter_enabled - Enables or disables the limiter feature.
limiter_deviation - Configures audio frequency deviation level.
limiter_release_time - Sets the limiter release time.
* Tuning power
power_level - Sets the output power level for signal transmission.
antenna_capacitor - This selects the value of antenna tuning capacitor manually
or automatically if set to zero.
* RDS related
rds_ps_name - Sets the RDS ps name field for transmission.
rds_radio_text - Sets the RDS radio text for transmission.
rds_pi - Sets the RDS PI field for transmission.
rds_pty - Sets the RDS PTY field for transmission.
* Region related
preemphasis - sets the preemphasis to be applied for transmission.
RNL
===
This device also has an interface to measure received noise level. To do that, you should
ioctl the device node. Here is an code of example:
int main (int argc, char *argv[])
{
struct si4713_rnl rnl;
int fd = open("/dev/radio0", O_RDWR);
int rval;
if (argc < 2)
return -EINVAL;
if (fd < 0)
return fd;
sscanf(argv[1], "%d", &rnl.frequency);
rval = ioctl(fd, SI4713_IOC_MEASURE_RNL, &rnl);
if (rval < 0)
return rval;
printf("received noise level: %d\n", rnl.rnl);
close(fd);
}
The struct si4713_rnl and SI4713_IOC_MEASURE_RNL are defined under
include/media/si4713.h.
Stereo/Mono and RDS subchannels
===============================
The device can also be configured using the available sub channels for
transmission. To do that use S/G_MODULATOR ioctl and configure txsubchans properly.
Refer to v4l2-spec for proper use of this ioctl.
Testing
=======
Testing is usually done with v4l2-ctl utility for managing FM tuner cards.
The tool can be found in v4l-dvb repository under v4l2-apps/util directory.
Example for setting rds ps name:
# v4l2-ctl -d /dev/radio0 --set-ctrl=rds_ps_name="Dummy"

10
Documentation/vm/slub.txt
View File

@@ -41,6 +41,8 @@ Possible debug options are
P Poisoning (object and padding)
U User tracking (free and alloc)
T Trace (please only use on single slabs)
O Switch debugging off for caches that would have
caused higher minimum slab orders
- Switch all debugging off (useful if the kernel is
configured with CONFIG_SLUB_DEBUG_ON)
@@ -59,6 +61,14 @@ to the dentry cache with
slub_debug=F,dentry
Debugging options may require the minimum possible slab order to increase as
a result of storing the metadata (for example, caches with PAGE_SIZE object
sizes). This has a higher liklihood of resulting in slab allocation errors
in low memory situations or if there's high fragmentation of memory. To
switch off debugging for such caches by default, use
slub_debug=O
In case you forgot to enable debugging on the kernel command line: It is
possible to enable debugging manually when the kernel is up. Look at the
contents of:

1
Documentation/x86/zero-page.txt
View File

@@ -12,6 +12,7 @@ Offset Proto Name Meaning
000/040 ALL screen_info Text mode or frame buffer information
(struct screen_info)
040/014 ALL apm_bios_info APM BIOS information (struct apm_bios_info)
058/008 ALL tboot_addr Physical address of tboot shared page
060/010 ALL ist_info Intel SpeedStep (IST) BIOS support information
(struct ist_info)
080/010 ALL hd0_info hd0 disk parameter, OBSOLETE!!