Re: [PATCH v5 2/5] ARM: arch_timer: add support to configure and enable event stream
On Wed, Aug 28, 2013 at 11:44:46AM +0100, Sudeep KarkadaNagesha wrote:
> From: Sudeep KarkadaNagesha
>
> This patch adds support for configuring the event stream frequency
> and enabling it.
>
> It also adds the hwcaps definitions to the user to detect this event
> stream feature.
>
> Cc: Russell King
> Cc: Lorenzo Pieralisi
> Cc: Will Deacon
> Cc: Catalin Marinas
> Signed-off-by: Sudeep KarkadaNagesha
> ---
> arch/arm/include/asm/arch_timer.h | 33 -
> arch/arm/include/uapi/asm/hwcap.h | 1 +
> arch/arm/kernel/setup.c | 1 +
> 3 files changed, 30 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/include/asm/arch_timer.h
> b/arch/arm/include/asm/arch_timer.h
> index 1a3e967..4e38609 100644
> --- a/arch/arm/include/asm/arch_timer.h
> +++ b/arch/arm/include/asm/arch_timer.h
> @@ -89,22 +89,45 @@ static inline u64 arch_counter_get_cntvct(void)
> return cval;
> }
>
> -static inline void arch_counter_set_user_access(void)
> +static inline u32 arch_timer_get_cntkctl(void)
> {
> u32 cntkctl;
> -
> asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl));
> + return cntkctl;
> +}
> +
> +static inline void arch_timer_set_cntkctl(u32 cntkctl)
> +{
> + asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
> +}
> +
> +static inline void arch_counter_set_user_access(void)
> +{
> + u32 cntkctl = arch_timer_get_cntkctl();
>
> /* Disable user access to both physical/virtual counters/timers */
> - /* 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);
> + arch_timer_set_cntkctl(cntkctl);
> +}
You can keep the ARCH_TIMER_VIRT_EVT_EN clearing here, especially if we
drop the bool enable argument to arch_timer_evtstrm_config(). You can
add the same clearing to arm64 in one of the latter patches.
--
Catalin
--
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Re: [PATCH v5 2/5] ARM: arch_timer: add support to configure and enable event stream
On Wed, Aug 28, 2013 at 11:44:46AM +0100, Sudeep KarkadaNagesha wrote:
From: Sudeep KarkadaNagesha sudeep.karkadanage...@arm.com
This patch adds support for configuring the event stream frequency
and enabling it.
It also adds the hwcaps definitions to the user to detect this event
stream feature.
Cc: Russell King li...@arm.linux.org.uk
Cc: Lorenzo Pieralisi lorenzo.pieral...@arm.com
Cc: Will Deacon will.dea...@arm.com
Cc: Catalin Marinas catalin.mari...@arm.com
Signed-off-by: Sudeep KarkadaNagesha sudeep.karkadanage...@arm.com
---
arch/arm/include/asm/arch_timer.h | 33 -
arch/arm/include/uapi/asm/hwcap.h | 1 +
arch/arm/kernel/setup.c | 1 +
3 files changed, 30 insertions(+), 5 deletions(-)
diff --git a/arch/arm/include/asm/arch_timer.h
b/arch/arm/include/asm/arch_timer.h
index 1a3e967..4e38609 100644
--- a/arch/arm/include/asm/arch_timer.h
+++ b/arch/arm/include/asm/arch_timer.h
@@ -89,22 +89,45 @@ static inline u64 arch_counter_get_cntvct(void)
return cval;
}
-static inline void arch_counter_set_user_access(void)
+static inline u32 arch_timer_get_cntkctl(void)
{
u32 cntkctl;
-
asm volatile(mrc p15, 0, %0, c14, c1, 0 : =r (cntkctl));
+ return cntkctl;
+}
+
+static inline void arch_timer_set_cntkctl(u32 cntkctl)
+{
+ asm volatile(mcr p15, 0, %0, c14, c1, 0 : : r (cntkctl));
+}
+
+static inline void arch_counter_set_user_access(void)
+{
+ u32 cntkctl = arch_timer_get_cntkctl();
/* Disable user access to both physical/virtual counters/timers */
- /* 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);
+ arch_timer_set_cntkctl(cntkctl);
+}
You can keep the ARCH_TIMER_VIRT_EVT_EN clearing here, especially if we
drop the bool enable argument to arch_timer_evtstrm_config(). You can
add the same clearing to arm64 in one of the latter patches.
--
Catalin
--
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the body of a message to majord...@vger.kernel.org
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