Impact: more robust DS feature enumeration
Detect the size of the pointer-type fields in the DS area
configuration via the DTES64 features rather than based on
the cpuid.
Rename a variable to denote that size to reflect that it only
covers the pointer-type fields.
Add more boot-time diagnostics giving the detected size and
the sizes of BTS and PEBS records.
Use the size of the BTS/PEBS record to indicate that the
respective feature is not available (if the record size is zero).
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090313104218.A30096@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: bug fix + BIOS workaround
BIOS is expected to clear the SYSCFG[MtrrFixDramModEn] on AMD CPUs
after fixed MTRRs are configured.
Some BIOSes do not clear SYSCFG[MtrrFixDramModEn] on BP (and on APs).
This can lead to obfuscation in Linux when this bit is not cleared on
BP but cleared on APs. A consequence of this is that the saved
fixed-MTRR state (from BP) differs from the fixed-MTRRs of APs --
because RdDram/WrDram bits are read as zero when
SYSCFG[MtrrFixDramModEn] is cleared -- and Linux tries to sync
fixed-MTRR state from BP to AP. This implies that Linux sets
SYSCFG[MtrrFixDramEn] and activates those bits.
More important is that (some) systems change these bits in SMM when
ACPI is enabled. Hence it is racy if Linux modifies RdMem/WrMem bits,
too.
(1) The patch modifies an old fix from Bernhard Kaindl to get
suspend/resume working on some Acer Laptops. Bernhard's patch
tried to sync RdMem/WrMem bits of fixed MTRR registers and that
helped on those old Laptops. (Don't ask me why -- can't test it
myself). But this old problem was not the motivation for the
patch. (See http://lkml.org/lkml/2007/4/3/110)
(2) The more important effect is to fix issues on some more current systems.
On those systems Linux panics or just freezes, see
http://bugzilla.kernel.org/show_bug.cgi?id=11541
(and also duplicates of this bug:
http://bugzilla.kernel.org/show_bug.cgi?id=11737http://bugzilla.kernel.org/show_bug.cgi?id=11714)
The affected systems boot only using acpi=ht, acpi=off or
when the kernel is built with CONFIG_MTRR=n.
The acpi options prevent full enablement of ACPI. Obviously when
ACPI is enabled the BIOS/SMM modfies RdMem/WrMem bits. When
CONFIG_MTRR=y Linux also accesses and modifies those bits when it
needs to sync fixed-MTRRs across cores (Bernhard's fix, see (1)).
How do you synchronize that? You can't. As a consequence Linux
shouldn't touch those bits at all (Rationale are AMD's BKDGs which
recommend to clear the bit that makes RdMem/WrMem accessible).
This is the purpose of this patch. And (so far) this suffices to
fix (1) and (2).
I suggest not to touch RdDram/WrDram bits of fixed-MTRRs and
SYSCFG[MtrrFixDramEn] and to clear SYSCFG[MtrrFixDramModEn] as
suggested by AMD K8, and AMD family 10h/11h BKDGs.
BIOS is expected to do this anyway. This should avoid that
Linux and SMM tread on each other's toes ...
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: trenn@suse.de
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090312163937.GH20716@alberich.amd.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix left range size on head
| commit 5c0e6f035d
| x86: fix code paths used by update_mptable
| Impact: fix crashes under Xen due to unrobust e820 code
fixes one e820 bug, but introduces another bug.
Need to update size for left range at first in case it is header.
also add __e820_add_region take more parameter.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: jbeulich@novell.com
LKML-Reference: <49B9E286.502@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
We are removing cpumask_t in favour of struct cpumask: mainly as a
marker of what code is now CONFIG_CPUMASK_OFFSTACK-safe.
The only non-trivial change here is vector_allocation_domain():
explicitly clear the mask and set the first word, rather than using
assignment.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: cleanup
It's not legal to do assignments into cpumask_var_t; they will soon be of
variable length.
So explicitly clear the mask and set the first word, rather than using
assignment.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: cleanup, remove cpumask from stack
summit_send_IPI_allbutself might as well call
default_send_IPI_mask_allbutself_logical(). Also change cpumask_t to
struct cpumask and &cpu_online_map to cpu_online_mask while here.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: reduce kernel memory usage when CONFIG_CPUMASK_OFFSTACK=y
Straightforward conversion: done for 32 and 64 bit kernels.
node_to_cpumask_map is now a cpumask_var_t array.
64-bit used to be a dynamic cpumask_t array, and 32-bit used to be a
static cpumask_t array.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: cleanup
We take the 64-bit code and use it on 32-bit as well. The new file
is called mm/numa.c.
In a minor cleanup, we use cpu_none_mask instead of declaring a local
cpu_mask_none.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: reduce kernel memory usage when CONFIG_CPUMASK_OFFSTACK=y
Simple conversion of mce_device_initialized to cpumask_var_t. We don't
check the alloc_cpumask_var() return since it's boot-time only, and
the misc_register() in that same function isn't checked.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: reduce per-cpu size for CONFIG_CPUMASK_OFFSTACK=y
In most places it's cleaner to use the accessors cpu_sibling_mask()
and cpu_core_mask() wrappers which already exist.
I couldn't avoid cleaning up the access in oprofile, either.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: cleanup, reduce memory usage for CONFIG_CPUMASK_OFFSTACK=y
I *think* every path calls check_nmi_watchdog before using the
watchdog, so that's the right place for the initialization.
If that's wrong, we'll get a nice NULL-deref with
CONFIG_CPUMASK_OFFSTACK=y, and have uncovered another bug.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: cleanup
(Thanks to Al Viro for reminding me of this, via Ingo)
CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:
#define CPU_MASK_ALL (cpumask_t) { { ... } }
Taking the address of such a temporary is questionable at best,
unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added
CPU_MASK_ALL_PTR:
#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)
Which formalizes this practice. One day gcc could bite us over this
usage (though we seem to have gotten away with it so far).
So replace everywhere which used &CPU_MASK_ALL or CPU_MASK_ALL_PTR
with the modern "cpu_all_mask" (a real const struct cpumask *), and remove
CPU_MASK_ALL_PTR altogether.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mike Travis <travis@sgi.com>
Impact: cleanup
mtrr main.c is too big, seperate mtrr cleanup and mtrr e820 trim
code to another file.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B87C7B.80809@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: improve MTRR debugging messages
There's still inefficiencies suspected with the MTRR sanitizing
code, so make sure we get all the info we need from a dmesg.
- Remove unneeded mtrr_show
(It will only printout one time by first cpu, so it is no big deal.)
- Also print out directly from get_mtrr, because it doesn't update mtrr_state.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B9BA5A.40108@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix crashes under Xen due to unrobust e820 code
find_e820_area_size() must return a properly distinguishable and
out-of-bounds value when it fails, and -1UL does not meet that
criteria on i386/PAE. Additionally, callers of the function must
check against that value.
early_reserve_e820() should be prepared for the region found to be
outside of the addressable range on 32-bits.
e820_update_range_map() should not blindly update e820, but should do
all it work on the map it got a pointer passed for (which in 50% of the
cases is &e820_saved). It must also not call e820_add_region(), as that
again acts on e820 unconditionally.
The issues were found when trying to make this option work in our Xen
kernel (i.e. where some of the silent assumptions made in the code
would not hold).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B9171B.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Without apic=verbose, using the update_mptable option would result in
garbled and confusing output due to the inconsistent use of printk() vs
apic_printk().
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B914B6.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: 32/64-bit consolidation
In a first step, this allows fixing phys_addr_valid() for PAE (which
until now reported all addresses to be valid). Subsequently, this will
also allow simplifying some MTRR handling code.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B9101E.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: change /proc/interrupts output ABI
With the number of interrupts on large systems growing, assumptions on
the width an interrupt number requires when converted to a decimal
string turn invalid. Therefore, calculate the maximum number of digits
dynamically.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B911EB.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: debuggability and micro-optimization
Putting whatever is possible into the (final) .rodata section increases
the likelihood of catching memory corruption bugs early, and reduces
false cache line sharing.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B90961.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: mark save_paranoid as non-kprobe-able code
This appears to be necessary as the function gets called from
kprobes-unsafe exception handling stubs (i.e. which themselves
live in .kprobes.text).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B8F44F.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
move store_ldt outside the CONFIG_PARAVIRT section and
also clean up the code a bit.
Signed-off-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: saving power _very_ little
round_jiffies() round up absolute jiffies to full second.
round_jiffies_relative() round up relative jiffies to full second.
The "t->expires" is absolute jiffies. Then, round_jiffies() should be
used instead round_jiffies_relative().
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: New major feature
This patch add kexec jump support for x86_64. More information about
kexec jump can be found in corresponding x86_32 support patch.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: Fix corner case that cannot yet occur
image->start may be outside of 0 ~ max_pfn, for example when jumping
back to original kernel from kexeced kenrel. This patch add identity
map for pages at image->start.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: Cleanup
Fix some coding style issue for kexec x86.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: micro-optimization
There's a number of variables in the sched_clock() path that are
in .data/.bss - but not marked __read_mostly. This creates the
danger of accidental false cacheline sharing with some other,
write-often variable.
So mark them __read_mostly.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Introduce:
cat /sys/kernel/debug/x86/cpu/*
for Intel and AMD processors to view / debug the state of each CPU.
By using this we can debug whole range of registers and other
cpu information for debugging purpose and monitor how things
are changing.
This can be useful for developers as well as for users.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
LKML-Reference: <1236701373.3387.4.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
