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| author | Vincenzo Frascino <vincenzo.frascino@arm.com> | 2019-10-16 15:40:24 +0200 |
|---|---|---|
| committer | Paul Burton <paulburton@kernel.org> | 2019-10-18 23:29:16 +0200 |
| commit | 8a1bef4193e81c8afae4d2f107f1c09c8ce89470 (patch) | |
| tree | 1d26ba9a9e6eb48bc256f270f6c0c011d695ba63 /arch | |
| parent | MAINTAINERS: Use @kernel.org address for Paul Burton (diff) | |
| download | linux-8a1bef4193e81c8afae4d2f107f1c09c8ce89470.tar.xz linux-8a1bef4193e81c8afae4d2f107f1c09c8ce89470.zip | |
mips: vdso: Fix __arch_get_hw_counter()
On some MIPS variants (e.g. MIPS r1), vDSO clock_mode is set to
VDSO_CLOCK_NONE.
When VDSO_CLOCK_NONE is set the expected kernel behavior is to fallback
on syscalls. To do that the generic vDSO library expects UULONG_MAX as
return value of __arch_get_hw_counter().
Fix __arch_get_hw_counter() on MIPS defining a __VDSO_USE_SYSCALL case
that addressed the described scenario.
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/include/asm/vdso/gettimeofday.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h index e78462e8ca2e..b08825531e9f 100644 --- a/arch/mips/include/asm/vdso/gettimeofday.h +++ b/arch/mips/include/asm/vdso/gettimeofday.h @@ -24,6 +24,8 @@ #define VDSO_HAS_CLOCK_GETRES 1 +#define __VDSO_USE_SYSCALL ULLONG_MAX + #ifdef CONFIG_MIPS_CLOCK_VSYSCALL static __always_inline long gettimeofday_fallback( @@ -205,7 +207,7 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) break; #endif default: - cycle_now = 0; + cycle_now = __VDSO_USE_SYSCALL; break; } |