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test_kretprobe() uses jprobe_func_called at the
last test, but it must check kretprobe_handler_called.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jon Medhurst <tixy@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/150976985182.2012.15495311380682779381.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Some of the files generated by the build process were not listed.
Signed-off-by: Changbin Du <changbin.du@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: yamada.masahiro@socionext.com
Link: http://lkml.kernel.org/r/1509939179-7556-5-git-send-email-changbin.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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It avoids the following warning triggered by newer versions of mkisofs:
-input-charset not specified, using utf-8 (detected in locale settings)
Signed-off-by: Changbin Du <changbin.du@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: yamada.masahiro@socionext.com
Link: http://lkml.kernel.org/r/1509939179-7556-4-git-send-email-changbin.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Recently I failed to build isoimage target, because the path of isolinux.bin
changed to /usr/xxx/ISOLINUX/isolinux.bin, as well as ldlinux.c32 which
changed to /usr/xxx/syslinux/modules/bios/ldlinux.c32.
This patch improves the file search logic:
- Show a error message instead of silent fail.
- Add above new paths.
Signed-off-by: Changbin Du <changbin.du@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: yamada.masahiro@socionext.com
Link: http://lkml.kernel.org/r/1509939179-7556-3-git-send-email-changbin.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The build messages for fdimage/isoimage generation are pretty unstructured,
just the raw shell command blocks are printed.
Emit shortened messages similar to existing kbuild messages, and move
the Makefile commands into a separate shell script - which is much
easier to handle.
This patch factors out the commands used for fdimage/isoimage generation
from arch/x86/boot/Makefile to a new script arch/x86/boot/genimage.sh.
Then it adds the new kbuild command 'genimage' which invokes the new script.
All fdimages/isoimage files are now generated by a call to 'genimage' with
different parameters.
Now 'make isoimage' becomes:
...
Kernel: arch/x86/boot/bzImage is ready (#30)
GENIMAGE arch/x86/boot/image.iso
Size of boot image is 4 sectors -> No emulation
15.37% done, estimate finish Sun Nov 5 23:36:57 2017
30.68% done, estimate finish Sun Nov 5 23:36:57 2017
46.04% done, estimate finish Sun Nov 5 23:36:57 2017
61.35% done, estimate finish Sun Nov 5 23:36:57 2017
76.69% done, estimate finish Sun Nov 5 23:36:57 2017
92.00% done, estimate finish Sun Nov 5 23:36:57 2017
Total translation table size: 2048
Total rockridge attributes bytes: 659
Total directory bytes: 0
Path table size(bytes): 10
Max brk space used 0
32608 extents written (63 MB)
Kernel: arch/x86/boot/image.iso is ready
Before:
Kernel: arch/x86/boot/bzImage is ready (#63)
rm -rf arch/x86/boot/isoimage
mkdir arch/x86/boot/isoimage
for i in lib lib64 share end ; do \
if [ -f /usr/$i/syslinux/isolinux.bin ] ; then \
cp /usr/$i/syslinux/isolinux.bin arch/x86/boot/isoimage ; \
if [ -f /usr/$i/syslinux/ldlinux.c32 ]; then \
cp /usr/$i/syslinux/ldlinux.c32 arch/x86/boot/isoimage ; \
fi ; \
break ; \
fi ; \
if [ $i = end ] ; then exit 1 ; fi ; \
done
...
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Changbin Du <changbin.du@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1509939179-7556-2-git-send-email-changbin.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Change the err_ctx type to "enum context" to match the type passed in.
No functionality change.
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20171106174633.13576-2-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The AMD severity grading function was introduced in kernel 4.1. The
current logic can possibly give MCE_AR_SEVERITY for uncorrectable
errors in kernel context. The system may then get stuck in a loop as
memory_failure() will try to handle the bad kernel memory and find it
busy.
Return MCE_PANIC_SEVERITY for all UC errors IN_KERNEL context on AMD
systems.
After:
b2f9d678e28c ("x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries")
was accepted in v4.6, this issue was masked because of the tail-end attempt
at kernel mode recovery in the #MC handler.
However, uncorrectable errors IN_KERNEL context should always be considered
unrecoverable and cause a panic.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.9.x
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Fixes: bf80bbd7dcf5 (x86/mce: Add an AMD severities-grading function)
Link: http://lkml.kernel.org/r/20171106174633.13576-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Kept this commit separate from the re-tabulation changes, to make
the changes easier to review:
- add better explanation for entries with no explanation
- fix/enhance the text of some of the entries
- fix the vertical alignment of some of the feature number definitions
- fix inconsistent capitalization
- ... and lots of other small details
i.e. make it all more of a coherent unit, instead of a patchwork of years of additions.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171031121723.28524-4-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Over the years asm/cpufeatures.h has become somewhat of a mess: the original
tabulation style was too narrow, while x86 feature names also kept growing
in length, creating frequent field width overflows.
Re-tabulate it to make it wider and easier to read/modify. Also harmonize
the tabulation of the other defines in this file to match it.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171031121723.28524-3-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Conflicts:
arch/x86/entry/syscalls/Makefile
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Conflicts:
arch/x86/kernel/cpu/Makefile
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Conflicts:
arch/x86/include/asm/x2apic.h
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Conflicts:
include/linux/compiler-clang.h
include/linux/compiler-gcc.h
include/linux/compiler-intel.h
include/uapi/linux/stddef.h
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Conflicts:
tools/perf/arch/arm/annotate/instructions.c
tools/perf/arch/arm64/annotate/instructions.c
tools/perf/arch/powerpc/annotate/instructions.c
tools/perf/arch/s390/annotate/instructions.c
tools/perf/arch/x86/tests/intel-cqm.c
tools/perf/ui/tui/progress.c
tools/perf/util/zlib.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The call to /proc/cpuinfo in turn calls cpufreq_quick_get() which
returns the last frequency requested by the kernel, but may not
reflect the actual frequency the processor is running at. This patch
makes a call to cpufreq_get() instead which returns the current
frequency reported by the hardware.
Fixes: fb5153d05a7d ("powerpc: powernv: Implement ppc_md.get_proc_freq()")
Signed-off-by: Shriya <shriyak@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Add support for Sysam stmark2 board, an open hardware embedded
Linux board, see http://sysam.it/cff_stmark2.html for any info.
Signed-off-by: Angelo Dureghello <angelo@sysam.it>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
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This patch adds initial module base address and irq for dspi0.
It also defines the dspi0 clock to be used by the Freescale driver.
Signed-off-by: Angelo Dureghello <angelo@sysam.it>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
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Update arch/x86/include/asm/xen/cpuid.h from the Xen tree to get newest
definitions.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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The grant v2 support was removed from the kernel with
commit 438b33c7145ca8a5131a30c36d8f59bce119a19a ("xen/grant-table:
remove support for V2 tables") as the higher memory footprint of v2
grants resulted in less grants being possible for a kernel compared
to the v1 grant interface.
As machines with more than 16TB of memory are expected to be more
common in the near future support of grant v2 is mandatory in order
to be able to run a Xen pv domain at any memory location.
So re-add grant v2 support basically by reverting above commit.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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This fixes a missing semi-colon. It went unnoticed initially since it is
only built under certain defconfigs.
Reported-by: kbuild test robot
Signed-off-by: Kees Cook <keescook@chromium.org>
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HS48 cpus will have a new MMUv5, although Linux is currently not
explicitly supporting the newer features (so remains at V4).
The existing software/hardware version check is very tight and causes
boot abort. Given that the MMUv5 hardware is backwards compatible,
relax the boot check to allow current kernel support level to work
with new hardware.
Also while at it, move the ancient MMU related code to under ARCompact
builds as baseline MMU for HS cpus is v4.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
"This fixes an unaligned panic in x86/sha-mb and a bug in ccm that
triggers with certain underlying implementations"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: ccm - preserve the IV buffer
crypto: x86/sha1-mb - fix panic due to unaligned access
crypto: x86/sha256-mb - fix panic due to unaligned access
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The GICv4 support introduces a hard dependency between the KVM
core and the ITS infrastructure. arm64 already selects it at
the architecture level, but 32bit doesn't. In order to avoid
littering the kernel with #ifdefs, let's just select the whole
of the GICv3 suport code.
You know you want it.
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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This patch selects IRQ_BYPASS_MANAGER and HAVE_KVM_IRQ_BYPASS
configs for ARM/ARM64.
kvm_arch_has_irq_bypass() now is implemented and returns true.
As a consequence the irq bypass consumer will be registered for
ARM/ARM64 with the forwarding callbacks:
- stop/start: halt/resume guest execution
- add/del_producer: set/unset forwarding at vgic/irqchip level
We don't have any actual support yet, so nothing gets actually
forwarded.
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
[maz: dropped the DEOI stuff for the time being in order to
reduce the dependency chain, amended commit message]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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kvm_vcpu_dabt_isextabt() tries to match a full fault syndrome, but
calls kvm_vcpu_trap_get_fault_type() that only returns the fault class,
thus reducing the scope of the check. This doesn't cause any observable
bug yet as we end-up matching a closely related syndrome for which we
return the same value.
Using kvm_vcpu_trap_get_fault() instead fixes it for good.
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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Both arm and arm64 implementations are capable of injecting
faults, and yet have completely divergent implementations,
leading to different bugs and reduced maintainability.
Let's elect the arm64 version as the canonical one
and move it into aarch32.c, which is common to both
architectures.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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On reset we clear the valid bits of GITS_CBASER and GITS_BASER<n>.
We also clear command queue registers and free the cache (device,
collection, and lpi lists).
As we need to take the same locks as save/restore functions, we
create a vgic_its_ctrl() wrapper that handles KVM_DEV_ARM_VGIC_GRP_CTRL
group functions.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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When trapping on a guest access to one of the timer registers, we were
messing with the internals of the timer state from the sysregs handling
code, and that logic was about to receive more added complexity when
optimizing the timer handling code.
Therefore, since we already have timer register access functions (to
access registers from userspace), reuse those for the timer register
traps from a VM and let the timer code maintain its own consistency.
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
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Add suport for the physical timer registers in kvm_arm_timer_set_reg and
kvm_arm_timer_get_reg so that these functions can be reused to interact
with the rest of the system.
Note that this paves part of the way for the physical timer state
save/restore, but we still need to add those registers to
KVM_GET_REG_LIST before we support migrating the physical timer state.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
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As we are about to be lazy with saving and restoring the timer
registers, we prepare by moving all possible timer configuration logic
out of the hyp code. All virtual timer registers can be programmed from
EL1 and since the arch timer is always a level triggered interrupt we
can safely do this with interrupts disabled in the host kernel on the
way to the guest without taking vtimer interrupts in the host kernel
(yet).
The downside is that the cntvoff register can only be programmed from
hyp mode, so we jump into hyp mode and back to program it. This is also
safe, because the host kernel doesn't use the virtual timer in the KVM
code. It may add a little performance performance penalty, but only
until following commits where we move this operation to vcpu load/put.
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
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Using the physical counter allows KVM to retain the offset between the
virtual and physical counter as long as it is actively running a VCPU.
As soon as a VCPU is released, another thread is scheduled or we start
running userspace applications, we reset the offset to 0, so that
userspace accessing the virtual timer can still read the virtual counter
and get the same view of time as the kernel.
This opens up potential improvements for KVM performance, but we have to
make a few adjustments to preserve system consistency.
Currently get_cycles() is hardwired to arch_counter_get_cntvct() on
arm64, but as we move to using the physical timer for the in-kernel
time-keeping on systems that boot in EL2, we should use the same counter
for get_cycles() as for other in-kernel timekeeping operations.
Similarly, implementations of arch_timer_set_next_event_phys() is
modified to use the counter specific to the timer being programmed.
VHE kernels or kernels continuing to use the virtual timer are
unaffected.
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
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As we are about to use the physical counter on arm64 systems that have
KVM support, implement arch_counter_get_cntpct() and the associated
errata workaround functionality for stable timer reads.
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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When CONFIG_DEBUG_USER is enabled, it's possible for a user to
deliberately trigger dump_instr() with a chosen kernel address.
Let's avoid problems resulting from this by using get_user() rather than
__get_user(), ensuring that we don't erroneously access kernel memory.
So that we can use the same code to dump user instructions and kernel
instructions, the common dumping code is factored out to __dump_instr(),
with the fs manipulated appropriately in dump_instr() around calls to
this.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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The reworked MPU code produces a new warning in some configurations,
presumably starting with the code move after the compiler now makes
different inlining decisions:
arch/arm/mm/pmsa-v7.c: In function 'adjust_lowmem_bounds_mpu':
arch/arm/mm/pmsa-v7.c:310:5: error: 'specified_mem_size' may be used uninitialized in this function [-Werror=maybe-uninitialized]
This appears to be harmless, as we know that there is always at
least one memblock, and the only way this could get triggered is
if the for_each_memblock() loop was never entered.
I could not come up with a better workaround than initializing
the specified_mem_size to zero, but at least that is the value
that the variable would have in the hypothetical case of no
memblocks.
Fixes: 877ec119dbbf ("ARM: 8706/1: NOMMU: Move out MPU setup in separate module")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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Some terminals apparently have issues with "\n\r" and mess up the
display. Let's use the traditional "\r\n" ordering.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reported-by: Chris Brandt <Chris.Brandt@renesas.com>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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DD2.1 does not have to save MMCR0 for all state-loss idle states,
only after deep idle states (like other PMU registers).
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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DD2.1 does not have to flush the ERAT after a state-loss idle.
Performance testing was done on a DD2.1 using only the stop0 idle state
(the shallowest state which supports state loss), using context_switch
selftest configured to ping-poing between two threads on the same core
and two different cores.
Performance improvement for same core is 7.0%, different cores is 14.8%.
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Cc: Michael Neuling <mikey@neuling.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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After handling a transactional FP, Altivec or VSX unavailable exception.
The return to userspace code will detect that the TIF_RESTORE_TM bit is
set and call restore_tm_state(). restore_tm_state() will call
restore_math() to ensure that the correct facilities are loaded.
This means that all the loadup code in {fp,altivec,vsx}_unavailable_tm()
is doing pointless work and can simply be removed.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Lazy save and restore of FP/Altivec means that a userspace process can
be sent to userspace with FP or Altivec disabled and loaded only as
required (by way of an FP/Altivec unavailable exception). Transactional
Memory complicates this situation as a transaction could be started
without FP/Altivec being loaded up. This causes the hardware to
checkpoint incorrect registers. Handling FP/Altivec unavailable
exceptions while a thread is transactional requires a reclaim and
recheckpoint to ensure the CPU has correct state for both sets of
registers.
tm_reclaim() has optimisations to not always save the FP/Altivec
registers to the checkpointed save area. This was originally done
because the caller might have information that the checkpointed
registers aren't valid due to lazy save and restore. We've also been a
little vague as to how tm_reclaim() leaves the FP/Altivec state since it
doesn't necessarily always save it to the thread struct. This has lead
to an (incorrect) assumption that it leaves the checkpointed state on
the CPU.
tm_recheckpoint() has similar optimisations in reverse. It may not
always reload the checkpointed FP/Altivec registers from the thread
struct before the trecheckpoint. It is therefore quite unclear where it
expects to get the state from. This didn't help with the assumption
made about tm_reclaim().
These optimisations sit in what is by definition a slow path. If a
process has to go through a reclaim/recheckpoint then its transaction
will be doomed on returning to userspace. This mean that the process
will be unable to complete its transaction and be forced to its failure
handler. This is already an out if line case for userspace. Furthermore,
the cost of copying 64 times 128 bits from registers isn't very long[0]
(at all) on modern processors. As such it appears these optimisations
have only served to increase code complexity and are unlikely to have
had a measurable performance impact.
Our transactional memory handling has been riddled with bugs. A cause
of this has been difficulty in following the code flow, code complexity
has not been our friend here. It makes sense to remove these
optimisations in favour of a (hopefully) more stable implementation.
This patch does mean that some times the assembly will needlessly save
'junk' registers which will subsequently get overwritten with the
correct value by the C code which calls the assembly function. This
small inefficiency is far outweighed by the reduction in complexity for
general TM code, context switching paths, and transactional facility
unavailable exception handler.
0: I tried to measure it once for other work and found that it was
hiding in the noise of everything else I was working with. I find it
exceedingly likely this will be the case here.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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exception
Lazy save and restore of FP/Altivec means that a userspace process can
be sent to userspace with FP or Altivec disabled and loaded only as
required (by way of an FP/Altivec unavailable exception). Transactional
Memory complicates this situation as a transaction could be started
without FP/Altivec being loaded up. This causes the hardware to
checkpoint incorrect registers. Handling FP/Altivec unavailable
exceptions while a thread is transactional requires a reclaim and
recheckpoint to ensure the CPU has correct state for both sets of
registers.
tm_reclaim() has optimisations to not always save the FP/Altivec
registers to the checkpointed save area. This was originally done
because the caller might have information that the checkpointed
registers aren't valid due to lazy save and restore. We've also been a
little vague as to how tm_reclaim() leaves the FP/Altivec state since it
doesn't necessarily always save it to the thread struct. This has lead
to an (incorrect) assumption that it leaves the checkpointed state on
the CPU.
tm_recheckpoint() has similar optimisations in reverse. It may not
always reload the checkpointed FP/Altivec registers from the thread
struct before the trecheckpoint. It is therefore quite unclear where it
expects to get the state from. This didn't help with the assumption
made about tm_reclaim().
This patch is a minimal fix for ease of backporting. A more correct fix
which removes the msr parameter to tm_reclaim() and tm_recheckpoint()
altogether has been upstreamed to apply on top of this patch.
Fixes: dc3106690b20 ("powerpc: tm: Always use fp_state and vr_state to
store live registers")
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Lazy save and restore of FP/Altivec means that a userspace process can
be sent to userspace with FP or Altivec disabled and loaded only as
required (by way of an FP/Altivec unavailable exception). Transactional
Memory complicates this situation as a transaction could be started
without FP/Altivec being loaded up. This causes the hardware to
checkpoint incorrect registers. Handling FP/Altivec unavailable
exceptions while a thread is transactional requires a reclaim and
recheckpoint to ensure the CPU has correct state for both sets of
registers.
Lazy save and restore of FP/Altivec cannot be done if a process is
transactional. If a facility was enabled it must remain enabled whenever
a thread is transactional.
Commit dc16b553c949 ("powerpc: Always restore FPU/VEC/VSX if hardware
transactional memory in use") ensures that the facilities are always
enabled if a thread is transactional. A bug in the introduced code may
cause it to inadvertently enable a facility that was (and should remain)
disabled. The problem with this extraneous enablement is that the
registers for the erroneously enabled facility have not been correctly
recheckpointed - the recheckpointing code assumed the facility would
remain disabled.
Further compounding the issue, the transactional {fp,altivec,vsx}
unavailable code has been incorrectly using the MSR to enable
facilities. The presence of the {FP,VEC,VSX} bit in the regs->msr simply
means if the registers are live on the CPU, not if the kernel should
load them before returning to userspace. This has worked due to the bug
mentioned above.
This causes transactional threads which return to their failure handler
to observe incorrect checkpointed registers. Perhaps an example will
help illustrate the problem:
A userspace process is running and uses both FP and Altivec registers.
This process then continues to run for some time without touching
either sets of registers. The kernel subsequently disables the
facilities as part of lazy save and restore. The userspace process then
performs a tbegin and the CPU checkpoints 'junk' FP and Altivec
registers. The process then performs a floating point instruction
triggering a fp unavailable exception in the kernel.
The kernel then loads the FP registers - and only the FP registers.
Since the thread is transactional it must perform a reclaim and
recheckpoint to ensure both the checkpointed registers and the
transactional registers are correct. It then (correctly) enables
MSR[FP] for the process. Later (on exception exist) the kernel also
(inadvertently) enables MSR[VEC]. The process is then returned to
userspace.
Since the act of loading the FP registers doomed the transaction we know
CPU will fail the transaction, restore its checkpointed registers, and
return the process to its failure handler. The problem is that we're
now running with Altivec enabled and the 'junk' checkpointed registers
are restored. The kernel had only recheckpointed FP.
This patch solves this by only activating FP/Altivec if userspace was
using them when it entered the kernel and not simply if the process is
transactional.
Fixes: dc16b553c949 ("powerpc: Always restore FPU/VEC/VSX if hardware
transactional memory in use")
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Also export opal_error_code() so that it can be used in modules
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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This patch adds an _interruptible version of opal_async_wait_response().
This is useful when a long running OPAL call is performed on behalf of
a userspace thread, for example, the opal_flash_{read,write,erase}
functions performed by the powernv-flash MTD driver.
It is foreseeable that these functions would take upwards of two
minutes causing the wait_event() to block long enough to cause hung
task warnings. Furthermore, wait_event_interruptible() is preferable
as otherwise there is no way for signals to stop the process which is
going to be confusing in userspace.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Parallel sensor reads could run out of async tokens due to
opal_get_sensor_data grabbing tokens but then doing the sensor
read behind a mutex, essentially serializing the (possibly
asynchronous and relatively slow) sensor read.
It turns out that the mutex isn't needed at all, not only
should the OPAL interface allow concurrent reads, the implementation
is certainly safe for that, and if any sensor we were reading
from somewhere isn't, doing the mutual exclusion in the kernel
is the wrong place to do it, OPAL should be doing it for the kernel.
So, remove the mutex.
Additionally, we shouldn't be printing out an error when we don't
get a token as the only way this should happen is if we've been
interrupted in down_interruptible() on the semaphore.
Reported-by: Robert Lippert <rlippert@google.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Future work will add an opal_async_wait_response_interruptible()
which will call wait_event_interruptible(). This work requires extra
token state to be tracked as wait_event_interruptible() can return and
the caller could release the token before OPAL responds.
Currently token state is tracked with two bitfields which are 64 bits
big but may not need to be as OPAL informs Linux how many async tokens
there are. It also uses an array indexed by token to store response
messages for each token.
The bitfields make it difficult to add more state and also provide a
hard maximum as to how many tokens there can be - it is possible that
OPAL will inform Linux that there are more than 64 tokens.
Rather than add a bitfield to track the extra state, rework the
internals slightly.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Fix __opal_async_get_token() when no tokens are free]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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There are no callers of both __opal_async_get_token() and
__opal_async_release_token().
This patch also removes the possibility of "emergency through
synchronous call to __opal_async_get_token()" as such it makes more
sense to initialise opal_sync_sem for the maximum number of async
tokens.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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The current code checks the completion map to look for the first token
that is complete. In some cases, a completion can come in but the
token can still be on lease to the caller processing the completion.
If this completed but unreleased token is the first token found in the
bitmap by another tasks trying to acquire a token, then the
__test_and_set_bit call will fail since the token will still be on
lease. The acquisition will then fail with an EBUSY.
This patch reorganizes the acquisition code to look at the
opal_async_token_map for an unleased token. If the token has no lease
it must have no outstanding completions so we should never see an
EBUSY, unless we have leased out too many tokens. Since
opal_async_get_token_inrerruptible is protected by a semaphore, we
will practically never see EBUSY anymore.
Fixes: 8d7248232208 ("powerpc/powernv: Infrastructure to support OPAL async completion")
Signed-off-by: William A. Kennington III <wak@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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... so that the difference is obvious.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171103102028.20284-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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