| Message ID | 10ed3f4cfce13a80a9a3070934fc0e31619a1242.1398213562.git.nathan_lynch@mentor.com (mailing list archive) |
|---|---|
| State | New, archived |
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On Wed, Apr 23, 2014 at 01:48:53AM +0100, Nathan Lynch wrote: > As ARM64 does. This is a necessary prerequisite for implementing > gettimeofday and clock_gettime in a vdso. Doesn't this change make arch_counter_set_user_access identical for arm and arm64? In which case, we could move it into the driver itself. Will
On 04/23/2014 12:32 PM, Will Deacon wrote: > On Wed, Apr 23, 2014 at 01:48:53AM +0100, Nathan Lynch wrote: >> As ARM64 does. This is a necessary prerequisite for implementing >> gettimeofday and clock_gettime in a vdso. > > Doesn't this change make arch_counter_set_user_access identical for arm and > arm64? In which case, we could move it into the driver itself. True; I had considered this but wasn't sure how it could be staged. Would a single patch updating arch/arm64, arch/arm, and drivers/clocksource/arm_arch_timer.c be okay?
On Wed, Apr 23, 2014 at 06:41:03PM +0100, Nathan Lynch wrote: > On 04/23/2014 12:32 PM, Will Deacon wrote: > > On Wed, Apr 23, 2014 at 01:48:53AM +0100, Nathan Lynch wrote: > >> As ARM64 does. This is a necessary prerequisite for implementing > >> gettimeofday and clock_gettime in a vdso. > > > > Doesn't this change make arch_counter_set_user_access identical for arm and > > arm64? In which case, we could move it into the driver itself. > > True; I had considered this but wasn't sure how it could be staged. > > Would a single patch updating arch/arm64, arch/arm, and > drivers/clocksource/arm_arch_timer.c be okay? I'd probably modify arm_arch_timer.c to have it's own implementation, then have follow-up patches removing the arch-private definitions. You could probably deal with arch_timer_evtstrm_enable at the same time. Will
diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h index 0704e0cf5571..047c800b57f0 100644 --- a/arch/arm/include/asm/arch_timer.h +++ b/arch/arm/include/asm/arch_timer.h @@ -103,13 +103,16 @@ static inline void arch_counter_set_user_access(void) { u32 cntkctl = arch_timer_get_cntkctl(); - /* Disable user access to both physical/virtual counters/timers */ + /* Disable user access to the timers and the physical counter */ /* Also disable virtual event stream */ cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN | ARCH_TIMER_USR_VT_ACCESS_EN | ARCH_TIMER_VIRT_EVT_EN - | ARCH_TIMER_USR_VCT_ACCESS_EN | ARCH_TIMER_USR_PCT_ACCESS_EN); + + /* Enable user access to the virtual counter */ + cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN; + arch_timer_set_cntkctl(cntkctl); }
As ARM64 does. This is a necessary prerequisite for implementing gettimeofday and clock_gettime in a vdso. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> --- arch/arm/include/asm/arch_timer.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)