linux-brain/arch/arm64/include/asm/vdso
Will Deacon 07fd256d53 arm64: vdso: Avoid ISB after reading from cntvct_el0
commit 77ec462536a13d4b428a1eead725c4818a49f0b1 upstream.

We can avoid the expensive ISB instruction after reading the counter in
the vDSO gettime functions by creating a fake address hazard against a
dummy stack read, just like we do inside the kernel.

Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/20210318170738.7756-5-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
2021-08-12 13:21:04 +02:00
..
clocksource.h arm64: Introduce a way to disable the 32bit vdso 2020-07-22 09:32:50 +02:00
compat_barrier.h arm64: vdso32: Detect binutils support for dmb ishld 2019-10-07 11:07:16 +01:00
compat_gettimeofday.h arm64: Introduce a way to disable the 32bit vdso 2020-07-22 09:32:50 +02:00
gettimeofday.h arm64: vdso: Avoid ISB after reading from cntvct_el0 2021-08-12 13:21:04 +02:00
vsyscall.h arm64: Introduce a way to disable the 32bit vdso 2020-07-22 09:32:50 +02:00