From: Stephen Warren:
ARM: tegra: core SoC enhancements for 3.12
This branch includes a number of enhancements to core SoC support for
Tegra devices. The major new features are:
* Adds a new CPU-power-gated cpuidle state for Tegra114.
* Adds initial system suspend support for Tegra114, initially supporting
just CPU-power-gating during suspend.
* Adds "LP1" suspend mode support for all of Tegra20/30/114. This mode
both gates CPU power, and places the DRAM into self-refresh mode.
* A new DT-driven PCIe driver to Tegra20/30. The driver is also moved
from arch/arm/mach-tegra/ to drivers/pci/host/.
The PCIe driver work depends on the following tag from Thomas Petazzoni:
git://git.infradead.org/linux-mvebu.git mis-3.12.2
... which is merged into the middle of this pull request.
* tag 'tegra-for-3.12-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra: (33 commits)
ARM: tegra: disable LP2 cpuidle state if PCIe is enabled
MAINTAINERS: Add myself as Tegra PCIe maintainer
PCI: tegra: set up PADS_REFCLK_CFG1
PCI: tegra: Add Tegra 30 PCIe support
PCI: tegra: Move PCIe driver to drivers/pci/host
PCI: msi: add default MSI operations for !HAVE_GENERIC_HARDIRQS platforms
ARM: tegra: add LP1 suspend support for Tegra114
ARM: tegra: add LP1 suspend support for Tegra20
ARM: tegra: add LP1 suspend support for Tegra30
ARM: tegra: add common LP1 suspend support
clk: tegra114: add LP1 suspend/resume support
ARM: tegra: config the polarity of the request of sys clock
ARM: tegra: add common resume handling code for LP1 resuming
ARM: pci: add ->add_bus() and ->remove_bus() hooks to hw_pci
of: pci: add registry of MSI chips
PCI: Introduce new MSI chip infrastructure
PCI: remove ARCH_SUPPORTS_MSI kconfig option
PCI: use weak functions for MSI arch-specific functions
ARM: tegra: unify Tegra's Kconfig a bit more
ARM: tegra: remove the limitation that Tegra114 can't support suspend
...
Signed-off-by: Kevin Hilman <khilman@linaro.org>
This affects xen pv guests with sufficiently old versions of xen and
sufficiently new hardware. On such a system, a guest with a btrfs
root won't even boot.
Signed-off-by: John Haxby <john.haxby@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Prevent crash_kexec() from deadlocking on ioapic_lock. When
crash_kexec() is executed on a CPU, the CPU will take ioapic_lock
in disable_IO_APIC(). So if the cpu gets an NMI while locking
ioapic_lock, a deadlock will happen.
In this patch, ioapic_lock is zapped/initialized before disable_IO_APIC().
You can reproduce this deadlock the following way:
1. Add mdelay(1000) after raw_spin_lock_irqsave() in
native_ioapic_set_affinity()@arch/x86/kernel/apic/io_apic.c
Although the deadlock can occur without this modification, it will increase
the potential of the deadlock problem.
2. Build and install the kernel
3. Set up the OS which will run panic() and kexec when NMI is injected
# echo "kernel.unknown_nmi_panic=1" >> /etc/sysctl.conf
# vim /etc/default/grub
add "nmi_watchdog=0 crashkernel=256M" in GRUB_CMDLINE_LINUX line
# grub2-mkconfig
4. Reboot the OS
5. Run following command for each vcpu on the guest
# while true; do echo <CPU num> > /proc/irq/<IO-APIC-edge or IO-APIC-fasteoi>/smp_affinitity; done;
By running this command, cpus will get ioapic_lock for setting affinity.
6. Inject NMI (push a dump button or execute 'virsh inject-nmi <domain>' if you
use VM). After injecting NMI, panic() is called in an nmi-handler context.
Then, kexec will normally run in panic(), but the operation will be stopped
by deadlock on ioapic_lock in crash_kexec()->machine_crash_shutdown()->
native_machine_crash_shutdown()->disable_IO_APIC()->clear_IO_APIC()->
clear_IO_APIC_pin()->ioapic_read_entry().
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/20130820070107.28245.83806.stgit@yunodevel
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Ingo Molnar:
"Two AMD microcode loader fixes and an OLPC firmware support fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, microcode, AMD: Fix early microcode loading
x86, microcode, AMD: Make cpu_has_amd_erratum() use the correct struct cpuinfo_x86
x86: Don't clear olpc_ofw_header when sentinel is detected
Merge a bunch of fixes from Andrew Morton.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
fs/proc/task_mmu.c: fix buffer overflow in add_page_map()
arch: *: Kconfig: add "kernel/Kconfig.freezer" to "arch/*/Kconfig"
ocfs2: fix null pointer dereference in ocfs2_dir_foreach_blk_id()
x86 get_unmapped_area(): use proper mmap base for bottom-up direction
ocfs2: fix NULL pointer dereference in ocfs2_duplicate_clusters_by_page
ocfs2: Revert 40bd62e to avoid regression in extended allocation
drivers/rtc/rtc-stmp3xxx.c: provide timeout for potentially endless loop polling a HW bit
hugetlb: fix lockdep splat caused by pmd sharing
aoe: adjust ref of head for compound page tails
microblaze: fix clone syscall
mm: save soft-dirty bits on file pages
mm: save soft-dirty bits on swapped pages
memcg: don't initialize kmem-cache destroying work for root caches
During smp_boot_cpus paravirtualied KVM guest detects if the hypervisor has
required feature (KVM_FEATURE_PV_UNHALT) to support pv-ticketlocks. If so,
support for pv-ticketlocks is registered via pv_lock_ops.
Use KVM_HC_KICK_CPU hypercall to wakeup waiting/halted vcpu.
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20130810193849.GA25260@linux.vnet.ibm.com
Signed-off-by: Suzuki Poulose <suzuki@in.ibm.com>
[Raghu: check_zero race fix, enum for kvm_contention_stat, jumplabel related changes,
addition of safe_halt for irq enabled case, bailout spinning in nmi case(Gleb)]
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull AMD microcode fixes from Borislav Petkov:
" Those are basically two fixes which correct the AMD early ucode loader
from accessing cpu_data too early, i.e. before smp_store_cpu_info()
has copied the boot_cpu_data ontop and overwritten an already empty
structure (which we shouldn't access that early in the first place
anyway).
The second patch is kinda largish for that late in the game but it
shouldn't be problematic because we're simply switching from using
cpu_data to use the CPU family number directly and thus again, not use
uninitialized cpu_data structure. "
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Type SETUP_PCI, added by setup_efi_pci(), may advertise a ROM size
larger than early_memremap() is able to handle, which is currently
limited to 256kB. If this occurs it leads to a NULL dereference in
parse_setup_data().
To avoid this, remap the setup_data header and allow parsing functions
for individual types to handle their own data remapping.
Signed-off-by: Linn Crosetto <linn@hp.com>
Link: http://lkml.kernel.org/r/1376430401-67445-1-git-send-email-linn@hp.com
Acked-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Andy Lutomirski reported that if a page with _PAGE_SOFT_DIRTY bit set
get swapped out, the bit is getting lost and no longer available when
pte read back.
To resolve this we introduce _PTE_SWP_SOFT_DIRTY bit which is saved in
pte entry for the page being swapped out. When such page is to be read
back from a swap cache we check for bit presence and if it's there we
clear it and restore the former _PAGE_SOFT_DIRTY bit back.
One of the problem was to find a place in pte entry where we can save
the _PTE_SWP_SOFT_DIRTY bit while page is in swap. The _PAGE_PSE was
chosen for that, it doesn't intersect with swap entry format stored in
pte.
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is only theoretical, but after try_to_wake_up(p) was changed
to check p->state under p->pi_lock the code like
__set_current_state(TASK_INTERRUPTIBLE);
schedule();
can miss a signal. This is the special case of wait-for-condition,
it relies on try_to_wake_up/schedule interaction and thus it does
not need mb() between __set_current_state() and if(signal_pending).
However, this __set_current_state() can move into the critical
section protected by rq->lock, now that try_to_wake_up() takes
another lock we need to ensure that it can't be reordered with
"if (signal_pending(current))" check inside that section.
The patch is actually one-liner, it simply adds smp_wmb() before
spin_lock_irq(rq->lock). This is what try_to_wake_up() already
does by the same reason.
We turn this wmb() into the new helper, smp_mb__before_spinlock(),
for better documentation and to allow the architectures to change
the default implementation.
While at it, kill smp_mb__after_lock(), it has no callers.
Perhaps we can also add smp_mb__before/after_spinunlock() for
prepare_to_wait().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add decoding for INVEPT and reorder the list according to the reason
numbers.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull MCE-uncorrected-error fix from Tony Luck:
"Bit 12 may or may not be set in MCi_STATUS.MCACOD when
an uncorrected error is reported. Ignore it when checking
error signatures."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
load_microcode_amd() (and the helper it is using) should not have an
cpu parameter. The microcode loading does not depend on the CPU wrt the
patches loaded since they will end up in a global list for all CPUs
anyway.
The change from cpu to x86family in load_microcode_amd()
now allows to drop the code messing with cpu_data(cpu) from
collect_cpu_info_amd_early(), which is wrong anyway because at that
point the per-cpu cpu_info is not yet setup (These values would later be
overwritten by smp_store_boot_cpu_info() / smp_store_cpu_info()).
Fold the rest of collect_cpu_info_amd_early() into load_ucode_amd_ap(),
because its only used at one place and without the cpuinfo_x86 accesses
it was not much left.
Signed-off-by: Torsten Kaiser <just.for.lkml@googlemail.com>
[ Fengguang: build fix ]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
[ Boris: adapt it to current tree. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
OpenFirmware wasn't quite following the protocol described in boot.txt
and the kernel has detected this through use of the sentinel value
in boot_params. OFW does zero out almost all of the stuff that it should
do, but not the sentinel.
This causes the kernel to clear olpc_ofw_header, which breaks x86 OLPC
support.
OpenFirmware has now been fixed. However, it would be nice if we could
maintain Linux compatibility with old firmware versions. To do that, we just
have to avoid zeroing out olpc_ofw_header.
OFW does not write to any other parts of the header that are being zapped
by the sentinel-detection code, and all users of olpc_ofw_header are
somewhat protected through checking for the OLPC_OFW_SIG magic value
before using it. So this should not cause any problems for anyone.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/20130809221420.618E6FAB03@dev.laptop.org
Acked-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.9+
This is based on a patch that Zhenzhong Duan had sent - which
was missing some of the remaining pieces. The kernel has the
logic to handle Xen-type-exceptions using the paravirt interface
in the assembler code (see PARAVIRT_ADJUST_EXCEPTION_FRAME -
pv_irq_ops.adjust_exception_frame and and INTERRUPT_RETURN -
pv_cpu_ops.iret).
That means the nmi handler (and other exception handlers) use
the hypervisor iret.
The other changes that would be neccessary for this would
be to translate the NMI_VECTOR to one of the entries on the
ipi_vector and make xen_send_IPI_mask_allbutself use different
events.
Fortunately for us commit 1db01b4903
(xen: Clean up apic ipi interface) implemented this and we piggyback
on the cleanup such that the apic IPI interface will pass the right
vector value for NMI.
With this patch we can trigger NMIs within a PV guest (only tested
x86_64).
For this to work with normal PV guests (not initial domain)
we need the domain to be able to use the APIC ops - they are
already implemented to use the Xen event channels. For that
to be turned on in a PV domU we need to remove the masking
of X86_FEATURE_APIC.
Incidentally that means kgdb will also now work within
a PV guest without using the 'nokgdbroundup' workaround.
Note that the 32-bit version is different and this patch
does not enable that.
CC: Lisa Nguyen <lisa@xenapiadmin.com>
CC: Ben Guthro <benjamin.guthro@citrix.com>
CC: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v1: Fixed up per David Vrabel comments]
Reviewed-by: Ben Guthro <benjamin.guthro@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Maintain a flag in the LSB of the ticket lock tail which indicates
whether anyone is in the lock slowpath and may need kicking when
the current holder unlocks. The flags are set when the first locker
enters the slowpath, and cleared when unlocking to an empty queue (ie,
no contention).
In the specific implementation of lock_spinning(), make sure to set
the slowpath flags on the lock just before blocking. We must do
this before the last-chance pickup test to prevent a deadlock
with the unlocker:
Unlocker Locker
test for lock pickup
-> fail
unlock
test slowpath
-> false
set slowpath flags
block
Whereas this works in any ordering:
Unlocker Locker
set slowpath flags
test for lock pickup
-> fail
block
unlock
test slowpath
-> true, kick
If the unlocker finds that the lock has the slowpath flag set but it is
actually uncontended (ie, head == tail, so nobody is waiting), then it
clears the slowpath flag.
The unlock code uses a locked add to update the head counter. This also
acts as a full memory barrier so that its safe to subsequently
read back the slowflag state, knowing that the updated lock is visible
to the other CPUs. If it were an unlocked add, then the flag read may
just be forwarded from the store buffer before it was visible to the other
CPUs, which could result in a deadlock.
Unfortunately this means we need to do a locked instruction when
unlocking with PV ticketlocks. However, if PV ticketlocks are not
enabled, then the old non-locked "add" is the only unlocking code.
Note: this code relies on gcc making sure that unlikely() code is out of
line of the fastpath, which only happens when OPTIMIZE_SIZE=n. If it
doesn't the generated code isn't too bad, but its definitely suboptimal.
Thanks to Srivatsa Vaddagiri for providing a bugfix to the original
version of this change, which has been folded in.
Thanks to Stephan Diestelhorst for commenting on some code which relied
on an inaccurate reading of the x86 memory ordering rules.
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Link: http://lkml.kernel.org/r/1376058122-8248-11-git-send-email-raghavendra.kt@linux.vnet.ibm.com
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stephan Diestelhorst <stephan.diestelhorst@amd.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Rather than outright replacing the entire spinlock implementation in
order to paravirtualize it, keep the ticket lock implementation but add
a couple of pvops hooks on the slow patch (long spin on lock, unlocking
a contended lock).
Ticket locks have a number of nice properties, but they also have some
surprising behaviours in virtual environments. They enforce a strict
FIFO ordering on cpus trying to take a lock; however, if the hypervisor
scheduler does not schedule the cpus in the correct order, the system can
waste a huge amount of time spinning until the next cpu can take the lock.
(See Thomas Friebel's talk "Prevent Guests from Spinning Around"
http://www.xen.org/files/xensummitboston08/LHP.pdf for more details.)
To address this, we add two hooks:
- __ticket_spin_lock which is called after the cpu has been
spinning on the lock for a significant number of iterations but has
failed to take the lock (presumably because the cpu holding the lock
has been descheduled). The lock_spinning pvop is expected to block
the cpu until it has been kicked by the current lock holder.
- __ticket_spin_unlock, which on releasing a contended lock
(there are more cpus with tail tickets), it looks to see if the next
cpu is blocked and wakes it if so.
When compiled with CONFIG_PARAVIRT_SPINLOCKS disabled, a set of stub
functions causes all the extra code to go away.
Results:
=======
setup: 32 core machine with 32 vcpu KVM guest (HT off) with 8GB RAM
base = 3.11-rc
patched = base + pvspinlock V12
+-----------------+----------------+--------+
dbench (Throughput in MB/sec. Higher is better)
+-----------------+----------------+--------+
| base (stdev %)|patched(stdev%) | %gain |
+-----------------+----------------+--------+
| 15035.3 (0.3) |15150.0 (0.6) | 0.8 |
| 1470.0 (2.2) | 1713.7 (1.9) | 16.6 |
| 848.6 (4.3) | 967.8 (4.3) | 14.0 |
| 652.9 (3.5) | 685.3 (3.7) | 5.0 |
+-----------------+----------------+--------+
pvspinlock shows benefits for overcommit ratio > 1 for PLE enabled cases,
and undercommits results are flat
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Link: http://lkml.kernel.org/r/1376058122-8248-2-git-send-email-raghavendra.kt@linux.vnet.ibm.com
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Attilio Rao <attilio.rao@citrix.com>
[ Raghavendra: Changed SPIN_THRESHOLD, fixed redefinition of arch_spinlock_t]
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Moves the relocation handling into C, after decompression. This requires
that the decompressed size is passed to the decompression routine as
well so that relocations can be found. Only kernels that need relocation
support will use the code (currently just x86_32), but this is laying
the ground work for 64-bit using it in support of KASLR.
Based on work by Neill Clift and Michael Davidson.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20130708161517.GA4832@www.outflux.net
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
If we let L1 use EPT, we should probably also support the INVEPT instruction.
In our current nested EPT implementation, when L1 changes its EPT table
for L2 (i.e., EPT12), L0 modifies the shadow EPT table (EPT02), and in
the course of this modification already calls INVEPT. But if last level
of shadow page is unsync not all L1's changes to EPT12 are intercepted,
which means roots need to be synced when L1 calls INVEPT. Global INVEPT
should not be different since roots are synced by kvm_mmu_load() each
time EPTP02 changes.
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
Signed-off-by: Xinhao Xu <xinhao.xu@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As specified by H. Peter Anvin, the best nops for x86 without knowing
the running computer is:
32bit:
0x3e, 0x8d, 0x74, 0x26, 0x00 also known as GENERIC_NOP5_ATOMIC
64bit:
0x0f, 0x1f, 0x44, 0x00, 0x00 also known as P6_NOP5_ATOMIC
Currently the default nop that is used by jump label is:
0xe9 0x00 0x00 0x00 0x00
Which is really a 5byte jump to the next position.
It's better to use a real nop than a jmp.
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The 0x1000 bit of the MCACOD field of machine check MCi_STATUS
registers is only defined for corrected errors (where it means
that hardware may be filtering errors see SDM section 15.9.2.1).
For uncorrected errors it may, or may not be set - so we should mask
it out when checking for the architecturaly defined recoverable
error signatures (see SDM 15.9.3.1 and 15.9.3.2)
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The current situation regarding boot-framebuffers (VGA, VESA/VBE, EFI) on
x86 causes troubles when loading multiple fbdev drivers. The global
"struct screen_info" does not provide any state-tracking about which
drivers use the FBs. request_mem_region() theoretically works, but
unfortunately vesafb/efifb ignore it due to quirks for broken boards.
Avoid this by creating a platform framebuffer devices with a pointer
to the "struct screen_info" as platform-data. Drivers can now create
platform-drivers and the driver-core will refuse multiple drivers being
active simultaneously.
We keep the screen_info available for backwards-compatibility. Drivers
can be converted in follow-up patches.
Different devices are created for VGA/VESA/EFI FBs to allow multiple
drivers to be loaded on distro kernels. We create:
- "vesa-framebuffer" for VBE/VESA graphics FBs
- "efi-framebuffer" for EFI FBs
- "platform-framebuffer" for everything else
This allows to load vesafb, efifb and others simultaneously and each
picks up only the supported FB types.
Apart from platform-framebuffer devices, this also introduces a
compatibility option for "simple-framebuffer" drivers which recently got
introduced for OF based systems. If CONFIG_X86_SYSFB is selected, we
try to match the screen_info against a simple-framebuffer supported
format. If we succeed, we create a "simple-framebuffer" device instead
of a platform-framebuffer.
This allows to reuse the simplefb.c driver across architectures and also
to introduce a SimpleDRM driver. There is no need to have vesafb.c,
efifb.c, simplefb.c and more just to have architecture specific quirks
in their setup-routines.
Instead, we now move the architecture specific quirks into x86-setup and
provide a generic simple-framebuffer. For backwards-compatibility (if
strange formats are used), we still allow vesafb/efifb to be loaded
simultaneously and pick up all remaining devices.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Link: http://lkml.kernel.org/r/1375445127-15480-4-git-send-email-dh.herrmann@gmail.com
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Dick Fowles, Don Zickus and Joe Mario have been working on
improvements to perf, and noticed heavy cache line contention
on the mm_cpumask, running linpack on a 60 core / 120 thread
system.
The cause turned out to be unnecessary atomic accesses to the
mm_cpumask. When in lazy TLB mode, the CPU is only removed from
the mm_cpumask if there is a TLB flush event.
Most of the time, no such TLB flush happens, and the kernel
skips the TLB reload. It can also skip the atomic memory
set & test.
Here is a summary of Joe's test results:
* The __schedule function dropped from 24% of all program cycles down
to 5.5%.
* The cacheline contention/hotness for accesses to that bitmask went
from being the 1st/2nd hottest - down to the 84th hottest (0.3% of
all shared misses which is now quite cold)
* The average load latency for the bit-test-n-set instruction in
__schedule dropped from 10k-15k cycles down to an average of 600 cycles.
* The linpack program results improved from 133 GFlops to 144 GFlops.
Peak GFlops rose from 133 to 153.
Reported-by: Don Zickus <dzickus@redhat.com>
Reported-by: Joe Mario <jmario@redhat.com>
Tested-by: Joe Mario <jmario@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Paul Turner <pjt@google.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20130731221421.616d3d20@annuminas.surriel.com
[ Made the comments consistent around the modified code. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
