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This is the assembler code for SHA1 implementation with
the SIMD SPE instruction set. With the enhanced instruction
set we can operate on 2 32 bit words in parallel. That helps
reducing the time to calculate W16-W79. For increasing
performance even more the assembler function can compute
hashes for more than one 64 byte input block.
The state of the used SPE registers is preserved via the
stack so we can run from interrupt context. There might
be the case that we interrupt ourselves and push sensitive
data from another context onto our stack. Clear this area
in the stack afterwards to avoid information leakage.
The code is endian independant.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Integrate the module into the kernel configuration
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Integrate the assembler modules into the kernel crypto
framework. Take care to avoid long intervals of disabled
preemption.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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The assembler block cipher module that controls the core
AES functions.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Key generation for big endian core routines.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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The assembler AES encryption and decryption core routines.
Implemented & optimized for big endian. Nevertheless they
work on little endian too.
For most efficient reuse in (higher level) block cipher
routines they are implemented as "fast" call modules without
any stack handling or register saving. The caller must
take care of that part.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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4K AES tables for big endian. To reduce the possiblity of
timing attacks, the size has been cut to 8KB + 256 bytes
in contrast to 16KB in the generic implementation. That
is not perfect but at least a good tradeoff for CPU limited
router devices.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Define some register aliases for better readability.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Integrate the module into the kernel config tree.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Glue code for crypto infrastructure. Call the assembler
code where required. Disable preemption during calculation
and enable SPE instructions in the kernel prior to the
call. Avoid to disable preemption for too long.
Take a little care about small input data. Kick out early
for input chunks < 64 bytes and replace memset for context
cleanup with simple loop.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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This is the assembler code for SHA256 implementation with
the SIMD SPE instruction set. Although being only a 32 bit
architecture GPRs are extended to 64 bit presenting two
32 bit values. With the enhanced instruction set we can
operate on them in parallel. That helps reducing the time
to calculate W16-W64. For increasing performance even more
the assembler function can compute hashes for more than
one 64 byte input block. That saves a lot of register
saving/restoring
The state of the used SPE registers is preserved via the
stack so we can run from interrupt context. There might
be the case that we interrupt ourselves and push sensitive
data from another context onto our stack. Clear this area
in the stack afterwards to avoid information leakage.
The code is endian independant.
Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Implement arch_irq_work_has_interrupt() for powerpc
Commit 9b01f5bf3 introduced a dependency on "IRQ work self-IPIs" for
full dynamic ticks to be enabled, by expecting architectures to
implement a suitable arch_irq_work_has_interrupt() routine.
Several arches have implemented this routine, including x86 (3010279f)
and arm (09f6edd4), but powerpc was omitted.
This patch implements this routine for powerpc.
The symptom, at boot (on powerpc systems) with "nohz_full=<CPU list>"
is displayed:
NO_HZ: Can't run full dynticks because arch doesn't support irq work self-IPIs
after this patch:
NO_HZ: Full dynticks CPUs: <CPU list>.
Tested against 3.19.
powerpc implements "IRQ work self-IPIs" by setting the decrementer to 1 in
arch_irq_work_raise(), which causes a decrementer exception on the next
timebase tick. We then handle the work in __timer_interrupt().
CC: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[mpe: Flesh out change log, fix ws & include guards, remove include of processor.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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git://git.linaro.org/people/mike.turquette/linux
Pull clock framework updates from Mike Turquette:
"The clock framework changes contain the usual driver additions,
enhancements and fixes mostly for ARM32, ARM64, MIPS and Power-based
devices.
Additionally the framework core underwent a bit of surgery with two
major changes:
- The boundary between the clock core and clock providers (e.g clock
drivers) is now more well defined with dedicated provider helper
functions. struct clk no longer maps 1:1 with the hardware clock
but is a true per-user cookie which helps us tracker users of
hardware clocks and debug bad behavior.
- The addition of rate constraints for clocks. Rate ranges are now
supported which are analogous to the voltage ranges in the
regulator framework.
Unfortunately these changes to the core created some breakeage. We
think we fixed it all up but for this reason there are lots of last
minute commits trying to undo the damage"
* tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linux: (113 commits)
clk: Only recalculate the rate if needed
Revert "clk: mxs: Fix invalid 32-bit access to frac registers"
clk: qoriq: Add support for the platform PLL
powerpc/corenet: Enable CLK_QORIQ
clk: Replace explicit clk assignment with __clk_hw_set_clk
clk: Add __clk_hw_set_clk helper function
clk: Don't dereference parent clock if is NULL
MIPS: Alchemy: Remove bogus args from alchemy_clk_fgcs_detr
clkdev: Always allocate a struct clk and call __clk_get() w/ CCF
clk: shmobile: div6: Avoid division by zero in .round_rate()
clk: mxs: Fix invalid 32-bit access to frac registers
clk: omap: compile legacy omap3 clocks conditionally
clkdev: Export clk_register_clkdev
clk: Add rate constraints to clocks
clk: remove clk-private.h
pci: xgene: do not use clk-private.h
arm: omap2+ remove dead clock code
clk: Make clk API return per-user struct clk instances
clk: tegra: Define PLLD_DSI and remove dsia(b)_mux
clk: tegra: Add support for the Tegra132 CAR IP block
...
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Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Use helpers from the asm-compat.h to wrap up assembly mnemonics
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek:
- several cleanups in kbuild
- serialize multiple *config targets so that 'make defconfig kvmconfig'
works
- The cc-ifversion macro got support for an else-branch
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild,gcov: simplify kernel/gcov/Makefile more
kbuild: allow cc-ifversion to have the argument for false condition
kbuild,gcov: simplify kernel/gcov/Makefile
kbuild,gcov: remove unnecessary workaround
kbuild: do not add $(call ...) to invoke cc-version or cc-fullversion
kbuild: fix cc-ifversion macro
kbuild: drop $(version_h) from MRPROPER_FILES
kbuild: use mixed-targets when two or more config targets are given
kbuild: remove redundant line from bounds.h/asm-offsets.h
kbuild: merge bounds.h and asm-offsets.h rules
kbuild: Drop support for clean-rule
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Change-Id: I1a80ad7b9f6854791bd270b746f93a91439155a6
Signed-off-by: Emil Medve <Emilian.Medve@Freescale.com>
Acked-by: Tang Yuantian <Yuantian.Tang@freescale.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
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The recent LBR rework for x86 left a stray flush_branch_stack() user in
the PowerPC code, fix that up.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Add a new kexec preprocessor macro IND_FLAGS, which is the bitwise OR of
all the possible kexec IND_ kimage_entry indirection flags. Having this
macro allows for simplified code in the prosessing of the kexec
kimage_entry items. Also, remove the local powerpc definition and use the
generic one.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Maximilian Attems <max@stro.at>
Cc: Michal Marek <mmarek@suse.cz>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We've replaced remap_file_pages(2) implementation with emulation. Nobody
creates non-linear mapping anymore.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc patches from Greg KH:
"Here's the big char/misc driver update for 3.20-rc1.
Lots of little things in here, all described in the changelog.
Nothing major or unusual, except maybe the binder selinux stuff, which
was all acked by the proper selinux people and they thought it best to
come through this tree.
All of this has been in linux-next with no reported issues for a while"
* tag 'char-misc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (90 commits)
coresight: fix function etm_writel_cp14() parameter order
coresight-etm: remove check for unknown Kconfig macro
coresight: fixing CPU hwid lookup in device tree
coresight: remove the unnecessary function coresight_is_bit_set()
coresight: fix the debug AMBA bus name
coresight: remove the extra spaces
coresight: fix the link between orphan connection and newly added device
coresight: remove the unnecessary replicator property
coresight: fix the replicator subtype value
pdfdocs: Fix 'make pdfdocs' failure for 'uio-howto.tmpl'
mcb: Fix error path of mcb_pci_probe
virtio/console: verify device has config space
ti-st: clean up data types (fix harmless memory corruption)
mei: me: release hw from reset only during the reset flow
mei: mask interrupt set bit on clean reset bit
extcon: max77693: Constify struct regmap_config
extcon: adc-jack: Release IIO channel on driver remove
extcon: Remove duplicated include from extcon-class.c
Drivers: hv: vmbus: hv_process_timer_expiration() can be static
Drivers: hv: vmbus: serialize Offer and Rescind offer
...
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git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux
Pull ACCESS_ONCE() rule tightening from Christian Borntraeger:
"Tighten rules for ACCESS_ONCE
This series tightens the rules for ACCESS_ONCE to only work on scalar
types. It also contains the necessary fixups as indicated by build
bots of linux-next. Now everything is in place to prevent new
non-scalar users of ACCESS_ONCE and we can continue to convert code to
READ_ONCE/WRITE_ONCE"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux:
kernel: Fix sparse warning for ACCESS_ONCE
next: sh: Fix compile error
kernel: tighten rules for ACCESS ONCE
mm/gup: Replace ACCESS_ONCE with READ_ONCE
x86/spinlock: Leftover conversion ACCESS_ONCE->READ_ONCE
x86/xen/p2m: Replace ACCESS_ONCE with READ_ONCE
ppc/hugetlbfs: Replace ACCESS_ONCE with READ_ONCE
ppc/kvm: Replace ACCESS_ONCE with READ_ONCE
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printk and friends can now format bitmaps using '%*pb[l]'. cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.
* Spurious if (len > 1) test dropped from shared_cpu_map_show().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull KVM update from Paolo Bonzini:
"Fairly small update, but there are some interesting new features.
Common:
Optional support for adding a small amount of polling on each HLT
instruction executed in the guest (or equivalent for other
architectures). This can improve latency up to 50% on some
scenarios (e.g. O_DSYNC writes or TCP_RR netperf tests). This
also has to be enabled manually for now, but the plan is to
auto-tune this in the future.
ARM/ARM64:
The highlights are support for GICv3 emulation and dirty page
tracking
s390:
Several optimizations and bugfixes. Also a first: a feature
exposed by KVM (UUID and long guest name in /proc/sysinfo) before
it is available in IBM's hypervisor! :)
MIPS:
Bugfixes.
x86:
Support for PML (page modification logging, a new feature in
Broadwell Xeons that speeds up dirty page tracking), nested
virtualization improvements (nested APICv---a nice optimization),
usual round of emulation fixes.
There is also a new option to reduce latency of the TSC deadline
timer in the guest; this needs to be tuned manually.
Some commits are common between this pull and Catalin's; I see you
have already included his tree.
Powerpc:
Nothing yet.
The KVM/PPC changes will come in through the PPC maintainers,
because I haven't received them yet and I might end up being
offline for some part of next week"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (130 commits)
KVM: ia64: drop kvm.h from installed user headers
KVM: x86: fix build with !CONFIG_SMP
KVM: x86: emulate: correct page fault error code for NoWrite instructions
KVM: Disable compat ioctl for s390
KVM: s390: add cpu model support
KVM: s390: use facilities and cpu_id per KVM
KVM: s390/CPACF: Choose crypto control block format
s390/kernel: Update /proc/sysinfo file with Extended Name and UUID
KVM: s390: reenable LPP facility
KVM: s390: floating irqs: fix user triggerable endless loop
kvm: add halt_poll_ns module parameter
kvm: remove KVM_MMIO_SIZE
KVM: MIPS: Don't leak FPU/DSP to guest
KVM: MIPS: Disable HTW while in guest
KVM: nVMX: Enable nested posted interrupt processing
KVM: nVMX: Enable nested virtual interrupt delivery
KVM: nVMX: Enable nested apic register virtualization
KVM: nVMX: Make nested control MSRs per-cpu
KVM: nVMX: Enable nested virtualize x2apic mode
KVM: nVMX: Prepare for using hardware MSR bitmap
...
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Merge third set of updates from Andrew Morton:
- the rest of MM
[ This includes getting rid of the numa hinting bits, in favor of
just generic protnone logic. Yay. - Linus ]
- core kernel
- procfs
- some of lib/ (lots of lib/ material this time)
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (104 commits)
lib/lcm.c: replace include
lib/percpu_ida.c: remove redundant includes
lib/strncpy_from_user.c: replace module.h include
lib/stmp_device.c: replace module.h include
lib/sort.c: move include inside #if 0
lib/show_mem.c: remove redundant include
lib/radix-tree.c: change to simpler include
lib/plist.c: remove redundant include
lib/nlattr.c: remove redundant include
lib/kobject_uevent.c: remove redundant include
lib/llist.c: remove redundant include
lib/md5.c: simplify include
lib/list_sort.c: rearrange includes
lib/genalloc.c: remove redundant include
lib/idr.c: remove redundant include
lib/halfmd4.c: simplify includes
lib/dynamic_queue_limits.c: simplify includes
lib/sort.c: use simpler includes
lib/interval_tree.c: simplify includes
hexdump: make it return number of bytes placed in buffer
...
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On POWER8 virtualised kernels the VTB register can be read to have a view
of time that only increases while the guest is running. This will prevent
guests from seeing time jump if a guest is paused for significant amounts
of time.
On POWER7 and below virtualised kernels stolen time is subtracted from
local_clock as a best effort approximation. This will not eliminate
spurious warnings in the case of a suspended guest but may reduce the
occurance in the case of softlockups due to host over commit.
Bare metal kernels should avoid reading the VTB as KVM does not restore
sane values when not executing, the approxmation is fine as host kernels
won't observe any stolen time.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrew Jones <drjones@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: chai wen <chaiw.fnst@cn.fujitsu.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Ben Zhang <benzh@chromium.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target. This is because the
restart_block is held in the same memory allocation as the kernel stack.
Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.
Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.
It's also a decent simplification, since the restart code is more or less
identical on all architectures.
[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch removes the NUMA PTE bits and associated helpers. As a
side-effect it increases the maximum possible swap space on x86-64.
One potential source of problems is races between the marking of PTEs
PROT_NONE, NUMA hinting faults and migration. It must be guaranteed that
a PTE being protected is not faulted in parallel, seen as a pte_none and
corrupting memory. The base case is safe but transhuge has problems in
the past due to an different migration mechanism and a dependance on page
lock to serialise migrations and warrants a closer look.
task_work hinting update parallel fault
------------------------ --------------
change_pmd_range
change_huge_pmd
__pmd_trans_huge_lock
pmdp_get_and_clear
__handle_mm_fault
pmd_none
do_huge_pmd_anonymous_page
read? pmd_lock blocks until hinting complete, fail !pmd_none test
write? __do_huge_pmd_anonymous_page acquires pmd_lock, checks pmd_none
pmd_modify
set_pmd_at
task_work hinting update parallel migration
------------------------ ------------------
change_pmd_range
change_huge_pmd
__pmd_trans_huge_lock
pmdp_get_and_clear
__handle_mm_fault
do_huge_pmd_numa_page
migrate_misplaced_transhuge_page
pmd_lock waits for updates to complete, recheck pmd_same
pmd_modify
set_pmd_at
Both of those are safe and the case where a transhuge page is inserted
during a protection update is unchanged. The case where two processes try
migrating at the same time is unchanged by this series so should still be
ok. I could not find a case where we are accidentally depending on the
PTE not being cleared and flushed. If one is missed, it'll manifest as
corruption problems that start triggering shortly after this series is
merged and only happen when NUMA balancing is enabled.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
ppc64 should not be depending on DSISR_PROTFAULT and it's unexpected if
they are triggered. This patch adds warnings just in case they are being
accidentally depended upon.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Convert existing users of pte_numa and friends to the new helper. Note
that the kernel is broken after this patch is applied until the other page
table modifiers are also altered. This patch layout is to make review
easier.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This is a preparatory patch that introduces protnone helpers for automatic
NUMA balancing.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Pull block driver changes from Jens Axboe:
"This contains:
- The 4k/partition fixes for brd from Boaz/Matthew.
- A few xen front/back block fixes from David Vrabel and Roger Pau
Monne.
- Floppy changes from Takashi, cleaning the device file creation.
- Switching libata to use the new blk-mq tagging policy, removing
code (and a suboptimal implementation) from libata. This will
throw you a merge conflict, since a bug in the original libata
tagging code was fixed since this code was branched. Trivial.
From Shaohua.
- Conversion of loop to blk-mq, from Ming Lei.
- Cleanup of the io_schedule() handling in bsg from Peter Zijlstra.
He claims it improves on unreadable code, which will cost him a
beer.
- Maintainer update or NDB, now handled by Markus Pargmann.
- NVMe:
- Optimization from me that avoids a kmalloc/kfree per IO for
smaller (<= 8KB) IO. This cuts about 1% of high IOPS CPU
overhead.
- Removal of (now) dead RCU code, a relic from before NVMe was
converted to blk-mq"
* 'for-3.20/drivers' of git://git.kernel.dk/linux-block:
xen-blkback: default to X86_32 ABI on x86
xen-blkfront: fix accounting of reqs when migrating
xen-blkback,xen-blkfront: add myself as maintainer
block: Simplify bsg complete all
floppy: Avoid manual call of device_create_file()
NVMe: avoid kmalloc/kfree for smaller IO
MAINTAINERS: Update NBD maintainer
libata: make sata_sil24 use fifo tag allocator
libata: move sas ata tag allocation to libata-scsi.c
libata: use blk taging
NVMe: within nvme_free_queues(), delete RCU sychro/deferred free
null_blk: suppress invalid partition info
brd: Request from fdisk 4k alignment
brd: Fix all partitions BUGs
axonram: Fix bug in direct_access
loop: add blk-mq.h include
block: loop: don't handle REQ_FUA explicitly
block: loop: introduce lo_discard() and lo_req_flush()
block: loop: say goodby to bio
block: loop: improve performance via blk-mq
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Pull core block IO changes from Jens Axboe:
"This contains:
- A series from Christoph that cleans up and refactors various parts
of the REQ_BLOCK_PC handling. Contributions in that series from
Dongsu Park and Kent Overstreet as well.
- CFQ:
- A bug fix for cfq for realtime IO scheduling from Jeff Moyer.
- A stable patch fixing a potential crash in CFQ in OOM
situations. From Konstantin Khlebnikov.
- blk-mq:
- Add support for tag allocation policies, from Shaohua. This is
a prep patch enabling libata (and other SCSI parts) to use the
blk-mq tagging, instead of rolling their own.
- Various little tweaks from Keith and Mike, in preparation for
DM blk-mq support.
- Minor little fixes or tweaks from me.
- A double free error fix from Tony Battersby.
- The partition 4k issue fixes from Matthew and Boaz.
- Add support for zero+unprovision for blkdev_issue_zeroout() from
Martin"
* 'for-3.20/core' of git://git.kernel.dk/linux-block: (27 commits)
block: remove unused function blk_bio_map_sg
block: handle the null_mapped flag correctly in blk_rq_map_user_iov
blk-mq: fix double-free in error path
block: prevent request-to-request merging with gaps if not allowed
blk-mq: make blk_mq_run_queues() static
dm: fix multipath regression due to initializing wrong request
cfq-iosched: handle failure of cfq group allocation
block: Quiesce zeroout wrapper
block: rewrite and split __bio_copy_iov()
block: merge __bio_map_user_iov into bio_map_user_iov
block: merge __bio_map_kern into bio_map_kern
block: pass iov_iter to the BLOCK_PC mapping functions
block: add a helper to free bio bounce buffer pages
block: use blk_rq_map_user_iov to implement blk_rq_map_user
block: simplify bio_map_kern
block: mark blk-mq devices as stackable
block: keep established cmd_flags when cloning into a blk-mq request
block: add blk-mq support to blk_insert_cloned_request()
block: require blk_rq_prep_clone() be given an initialized clone request
blk-mq: add tag allocation policy
...
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git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU updates from Joerg Roedel:
"This time with:
- Generic page-table framework for ARM IOMMUs using the LPAE
page-table format, ARM-SMMU and Renesas IPMMU make use of it
already.
- Break out the IO virtual address allocator from the Intel IOMMU so
that it can be used by other DMA-API implementations too. The
first user will be the ARM64 common DMA-API implementation for
IOMMUs
- Device tree support for Renesas IPMMU
- Various fixes and cleanups all over the place"
* tag 'iommu-updates-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (36 commits)
iommu/amd: Convert non-returned local variable to boolean when relevant
iommu: Update my email address
iommu/amd: Use wait_event in put_pasid_state_wait
iommu/amd: Fix amd_iommu_free_device()
iommu/arm-smmu: Avoid build warning
iommu/fsl: Various cleanups
iommu/fsl: Use %pa to print phys_addr_t
iommu/omap: Print phys_addr_t using %pa
iommu: Make more drivers depend on COMPILE_TEST
iommu/ipmmu-vmsa: Fix IOMMU lookup when multiple IOMMUs are registered
iommu: Disable on !MMU builds
iommu/fsl: Remove unused fsl_of_pamu_ids[]
iommu/fsl: Fix section mismatch
iommu/ipmmu-vmsa: Use the ARM LPAE page table allocator
iommu: Fix trace_map() to report original iova and original size
iommu/arm-smmu: add support for iova_to_phys through ATS1PR
iopoll: Introduce memory-mapped IO polling macros
iommu/arm-smmu: don't touch the secure STLBIALL register
iommu/arm-smmu: make use of generic LPAE allocator
iommu: io-pgtable-arm: add non-secure quirk
...
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Merge second set of updates from Andrew Morton:
"More of MM"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (83 commits)
mm/nommu.c: fix arithmetic overflow in __vm_enough_memory()
mm/mmap.c: fix arithmetic overflow in __vm_enough_memory()
vmstat: Reduce time interval to stat update on idle cpu
mm/page_owner.c: remove unnecessary stack_trace field
Documentation/filesystems/proc.txt: describe /proc/<pid>/map_files
mm: incorporate read-only pages into transparent huge pages
vmstat: do not use deferrable delayed work for vmstat_update
mm: more aggressive page stealing for UNMOVABLE allocations
mm: always steal split buddies in fallback allocations
mm: when stealing freepages, also take pages created by splitting buddy page
mincore: apply page table walker on do_mincore()
mm: /proc/pid/clear_refs: avoid split_huge_page()
mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)
mempolicy: apply page table walker on queue_pages_range()
arch/powerpc/mm/subpage-prot.c: use walk->vma and walk_page_vma()
memcg: cleanup preparation for page table walk
numa_maps: remove numa_maps->vma
numa_maps: fix typo in gather_hugetbl_stats
pagemap: use walk->vma instead of calling find_vma()
clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux
Pull powerpc updates from Michael Ellerman:
- Update of all defconfigs
- Addition of a bunch of config options to modernise our defconfigs
- Some PS3 updates from Geoff
- Optimised memcmp for 64 bit from Anton
- Fix for kprobes that allows 'perf probe' to work from Naveen
- Several cxl updates from Ian & Ryan
- Expanded support for the '24x7' PMU from Cody & Sukadev
- Freescale updates from Scott:
"Highlights include 8xx optimizations, some more work on datapath
device tree content, e300 machine check support, t1040 corenet
error reporting, and various cleanups and fixes"
* tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (102 commits)
cxl: Add missing return statement after handling AFU errror
cxl: Fail AFU initialisation if an invalid configuration record is found
cxl: Export optional AFU configuration record in sysfs
powerpc/mm: Warn on flushing tlb page in kernel context
powerpc/powernv: Add OPAL soft-poweroff routine
powerpc/perf/hv-24x7: Document sysfs event description entries
powerpc/perf/hv-gpci: add the remaining gpci requests
powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated
powerpc/perf/hv-24x7: parse catalog and populate sysfs with events
perf: define EVENT_DEFINE_RANGE_FORMAT_LITE helper
perf: add PMU_EVENT_ATTR_STRING() helper
perf: provide sysfs_show for struct perf_pmu_events_attr
powerpc/kernel: Avoid initializing device-tree pointer twice
powerpc: Remove old compile time disabled syscall tracing code
powerpc/kernel: Make syscall_exit a local label
cxl: Fix device_node reference counting
powerpc/mm: bail out early when flushing TLB page
powerpc: defconfigs: add MTD_SPI_NOR (new dependency for M25P80)
perf/powerpc: reset event hw state when adding it to the PMU
powerpc/qe: Use strlcpy()
...
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We don't have to use mm_walk->private to pass vma to the callback function
because of mm_walk->vma. And walk_page_vma() is useful if we walk over a
single vma.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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LKP has triggered a compiler warning after my recent patch "mm: account
pmd page tables to the process":
mm/mmap.c: In function 'exit_mmap':
>> mm/mmap.c:2857:2: warning: right shift count >= width of type [enabled by default]
The code:
> 2857 WARN_ON(mm_nr_pmds(mm) >
2858 round_up(FIRST_USER_ADDRESS, PUD_SIZE) >> PUD_SHIFT);
In this, on tile, we have FIRST_USER_ADDRESS defined as 0. round_up() has
the same type -- int. PUD_SHIFT.
I think the best way to fix it is to define FIRST_USER_ADDRESS as unsigned
long. On every arch for consistency.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently we have many duplicates in definitions around
follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this
patch tries to remove the m. The basic idea is to put the default
implementation for these functions in mm/hugetlb.c as weak symbols
(regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement
arch-specific code only when the arch needs it.
For follow_huge_addr(), only powerpc and ia64 have their own
implementation, and in all other architectures this function just returns
ERR_PTR(-EINVAL). So this patch sets returning ERR_PTR(-EINVAL) as
default.
As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to
always return 0 in your architecture (like in ia64 or sparc,) it's never
called (the callsite is optimized away) no matter how implemented it is.
So in such architectures, we don't need arch-specific implementation.
In some architecture (like mips, s390 and tile,) their current
arch-specific follow_huge_(pmd|pud)() are effectively identical with the
common code, so this patch lets these architecture use the common code.
One exception is metag, where pmd_huge() could return non-zero but it
expects follow_huge_pmd() to always return NULL. This means that we need
arch-specific implementation which returns NULL. This behavior looks
strange to me (because non-zero pmd_huge() implies that the architecture
supports PMD-based hugepage, so follow_huge_pmd() can/should return some
relevant value,) but that's beyond this cleanup patch, so let's keep it.
Justification of non-trivial changes:
- in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this
patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE
is true when follow_huge_pmd() can be called (note that pmd_huge() has
the same check and always returns 0 for !MACHINE_HAS_HPAGE.)
- in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common
code. This patch forces these archs use PMD_MASK, but it's OK because
they are identical in both archs.
In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20.
In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and
PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but
PTE_ORDER is always 0, so these are identical.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI changes from Bjorn Helgaas:
"Enumeration
- Move domain assignment from arm64 to generic code (Lorenzo Pieralisi)
- ARM: Remove artificial dependency on pci_sys_data domain (Lorenzo Pieralisi)
- ARM: Move to generic PCI domains (Lorenzo Pieralisi)
- Generate uppercase hex for modalias var in uevent (Ricardo Ribalda Delgado)
- Add and use generic config accessors on ARM, PowerPC (Rob Herring)
Resource management
- Free resources on failure in of_pci_get_host_bridge_resources() (Lorenzo Pieralisi)
- Fix infinite loop with ROM image of size 0 (Michel Dänzer)
PCI device hotplug
- Handle surprise add even if surprise removal isn't supported (Bjorn Helgaas)
Virtualization
- Mark AMD/ATI VGA devices that don't reset on D3hot->D0 transition (Alex Williamson)
- Add DMA alias quirk for Adaptec 3405 (Alex Williamson)
- Add Wellsburg (X99) to Intel PCH root port ACS quirk (Alex Williamson)
- Add ACS quirk for Emulex NICs (Vasundhara Volam)
MSI
- Fail MSI-X mappings if there's no space assigned to MSI-X BAR (Yijing Wang)
Freescale Layerscape host bridge driver
- Fix platform_no_drv_owner.cocci warnings (Julia Lawall)
NVIDIA Tegra host bridge driver
- Remove unnecessary tegra_pcie_fixup_bridge() (Lucas Stach)
Renesas R-Car host bridge driver
- Fix error handling of irq_of_parse_and_map() (Dmitry Torokhov)
TI Keystone host bridge driver
- Fix error handling of irq_of_parse_and_map() (Dmitry Torokhov)
- Fix misspelling of current function in debug output (Julia Lawall)
Xilinx AXI host bridge driver
- Fix harmless format string warning (Arnd Bergmann)
Miscellaneous
- Use standard parsing functions for ASPM sysfs setters (Chris J Arges)
- Add pci_device_to_OF_node() stub for !CONFIG_OF (Kevin Hao)
- Delete unnecessary NULL pointer checks (Markus Elfring)
- Add and use defines for PCIe Max_Read_Request_Size (Rafał Miłecki)
- Include clk.h instead of clk-private.h (Stephen Boyd)"
* tag 'pci-v3.20-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (48 commits)
PCI: Add pci_device_to_OF_node() stub for !CONFIG_OF
PCI: xilinx: Convert to use generic config accessors
PCI: xgene: Convert to use generic config accessors
PCI: tegra: Convert to use generic config accessors
PCI: rcar: Convert to use generic config accessors
PCI: generic: Convert to use generic config accessors
powerpc/powermac: Convert PCI to use generic config accessors
powerpc/fsl_pci: Convert PCI to use generic config accessors
ARM: ks8695: Convert PCI to use generic config accessors
ARM: sa1100: Convert PCI to use generic config accessors
ARM: integrator: Convert PCI to use generic config accessors
PCI: versatile: Add DT-based ARM Versatile PB PCIe host driver
ARM: dts: versatile: add PCI controller binding
of/pci: Free resources on failure in of_pci_get_host_bridge_resources()
PCI: versatile: Add DT docs for ARM Versatile PB PCIe driver
PCI: Fail MSI-X mappings if there's no space assigned to MSI-X BAR
r8169: use PCI define for Max_Read_Request_Size
[SCSI] esas2r: use PCI define for Max_Read_Request_Size
tile: use PCI define for Max_Read_Request_Size
rapidio/tsi721: use PCI define for Max_Read_Request_Size
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
"The main RCU changes in this cycle are:
- Documentation updates.
- Miscellaneous fixes.
- Preemptible-RCU fixes, including fixing an old bug in the
interaction of RCU priority boosting and CPU hotplug.
- SRCU updates.
- RCU CPU stall-warning updates.
- RCU torture-test updates"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
rcu: Initialize tiny RCU stall-warning timeouts at boot
rcu: Fix RCU CPU stall detection in tiny implementation
rcu: Add GP-kthread-starvation checks to CPU stall warnings
rcu: Make cond_resched_rcu_qs() apply to normal RCU flavors
rcu: Optionally run grace-period kthreads at real-time priority
ksoftirqd: Use new cond_resched_rcu_qs() function
ksoftirqd: Enable IRQs and call cond_resched() before poking RCU
rcutorture: Add more diagnostics in rcu_barrier() test failure case
torture: Flag console.log file to prevent holdovers from earlier runs
torture: Add "-enable-kvm -soundhw pcspk" to qemu command line
rcutorture: Handle different mpstat versions
rcutorture: Check from beginning to end of grace period
rcu: Remove redundant rcu_batches_completed() declaration
rcutorture: Drop rcu_torture_completed() and friends
rcu: Provide rcu_batches_completed_sched() for TINY_RCU
rcutorture: Use unsigned for Reader Batch computations
rcutorture: Make build-output parsing correctly flag RCU's warnings
rcu: Make _batches_completed() functions return unsigned long
rcutorture: Issue warnings on close calls due to Reader Batch blows
documentation: Fix smp typo in memory-barriers.txt
...
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This patch introduces a new module parameter for the KVM module; when it
is present, KVM attempts a bit of polling on every HLT before scheduling
itself out via kvm_vcpu_block.
This parameter helps a lot for latency-bound workloads---in particular
I tested it with O_DSYNC writes with a battery-backed disk in the host.
In this case, writes are fast (because the data doesn't have to go all
the way to the platters) but they cannot be merged by either the host or
the guest. KVM's performance here is usually around 30% of bare metal,
or 50% if you use cache=directsync or cache=writethrough (these
parameters avoid that the guest sends pointless flush requests, and
at the same time they are not slow because of the battery-backed cache).
The bad performance happens because on every halt the host CPU decides
to halt itself too. When the interrupt comes, the vCPU thread is then
migrated to a new physical CPU, and in general the latency is horrible
because the vCPU thread has to be scheduled back in.
With this patch performance reaches 60-65% of bare metal and, more
important, 99% of what you get if you use idle=poll in the guest. This
means that the tunable gets rid of this particular bottleneck, and more
work can be done to improve performance in the kernel or QEMU.
Of course there is some price to pay; every time an otherwise idle vCPUs
is interrupted by an interrupt, it will poll unnecessarily and thus
impose a little load on the host. The above results were obtained with
a mostly random value of the parameter (500000), and the load was around
1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU.
The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll,
that can be used to tune the parameter. It counts how many HLT
instructions received an interrupt during the polling period; each
successful poll avoids that Linux schedules the VCPU thread out and back
in, and may also avoid a likely trip to C1 and back for the physical CPU.
While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second.
Of these halts, almost all are failed polls. During the benchmark,
instead, basically all halts end within the polling period, except a more
or less constant stream of 50 per second coming from vCPUs that are not
running the benchmark. The wasted time is thus very low. Things may
be slightly different for Windows VMs, which have a ~10 ms timer tick.
The effect is also visible on Marcelo's recently-introduced latency
test for the TSC deadline timer. Though of course a non-RT kernel has
awful latency bounds, the latency of the timer is around 8000-10000 clock
cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC
deadline timer, thus, the effect is both a smaller average latency and
a smaller variance.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Kim Phillips reported following build failure.
LD init/built-in.o
mm/built-in.o: In function `free_pages_prepare':
mm/page_alloc.c:770: undefined reference to `.kernel_map_pages'
mm/built-in.o: In function `prep_new_page':
mm/page_alloc.c:933: undefined reference to `.kernel_map_pages'
mm/built-in.o: In function `map_pages':
mm/compaction.c:61: undefined reference to `.kernel_map_pages'
make: *** [vmlinux] Error 1
Reason for this problem is that commit 031bc5743f15
("mm/debug-pagealloc: make debug-pagealloc boottime configurable")
forgot to remove the old declaration of kernel_map_pages() for some
architectures. This patch removes them to fix build failure.
Reported-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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and 'core' into next
Conflicts:
drivers/iommu/Kconfig
drivers/iommu/Makefile
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Function __flush_tlb_page() must only be called for user contexts, so
put in extra hardening to warn on calling it for kernel context.
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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