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| author | Will Deacon <will.deacon@arm.com> | 2018-09-20 10:26:40 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-12-07 12:35:53 +0000 |
| commit | 396244692232fcf0881cb6ba2404be2906f47681 (patch) | |
| tree | 154bdebdb94f8ec79c1b19a8273ca9e0809036f5 /arch/arm64/include/asm/Kbuild | |
| parent | 08861d33d680838753f1f9d3ba9480d3651b764d (diff) | |
| download | linux-stable-396244692232fcf0881cb6ba2404be2906f47681.tar.gz linux-stable-396244692232fcf0881cb6ba2404be2906f47681.tar.bz2 linux-stable-396244692232fcf0881cb6ba2404be2906f47681.zip | |
arm64: preempt: Provide our own implementation of asm/preempt.h
The asm-generic/preempt.h implementation doesn't make use of the
PREEMPT_NEED_RESCHED flag, since this can interact badly with load/store
architectures which rely on the preempt_count word being unchanged across
an interrupt.
However, since we're a 64-bit architecture and the preempt count is
only 32 bits wide, we can simply pack it next to the resched flag and
load the whole thing in one go, so that a dec-and-test operation doesn't
need to load twice.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/Kbuild')
| -rw-r--r-- | arch/arm64/include/asm/Kbuild | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index 1877f29f6d97..1e17ea5c372b 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -14,7 +14,6 @@ generic-y += local64.h generic-y += mcs_spinlock.h generic-y += mm-arch-hooks.h generic-y += msi.h -generic-y += preempt.h generic-y += qrwlock.h generic-y += qspinlock.h generic-y += rwsem.h |