From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Fri, 30 Nov 2012 17:46:05 +0000 Subject: [PATCH 07/10] arm: arch_timer: add arch_counter_enable_user_access In-Reply-To: <1354297568-26366-1-git-send-email-mark.rutland@arm.com> References: <1354297568-26366-1-git-send-email-mark.rutland@arm.com> Message-ID: <1354297568-26366-8-git-send-email-mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Several bits in CNTKCTL reset to 0, including PL0VTEN. For platforms using the generic timer which wish to have a fast gettimeofday vDSO implementation, these bits must be set to 1 by the kernel. Add an arch_counter_enable_user_access function for this. As we don't (currently) use the counter from PL0 on arm, the implementation is an empty stub. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Acked-by: Marc Zyngier --- arch/arm/include/asm/arch_timer.h | 7 +++++++ arch/arm/kernel/arch_timer.c | 2 ++ 2 files changed, 9 insertions(+), 0 deletions(-) diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h index 701f2b7..c50e415 100644 --- a/arch/arm/include/asm/arch_timer.h +++ b/arch/arm/include/asm/arch_timer.h @@ -108,6 +108,13 @@ static inline u64 arch_counter_get_cntvct(void) return cval; } +static inline void __cpuinit arch_counter_enable_user_access(void) +{ + /* + * Do nothing - the counter is never mapped to userspace threads, + * so we don't care whether access is enabled or not. + */ +} #else static inline int arch_timer_of_register(void) diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index 10e1657..28b29f0 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -155,6 +155,8 @@ static int __cpuinit arch_timer_setup(struct clock_event_device *clk) enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0); } + arch_counter_enable_user_access(); + return 0; } -- 1.7.0.4