Re: [PATCH v3 1/6] ARM/ARM64: arch_timer: add macros for bits in control register

Wed, 14 Aug 2013 02:04:30 -0700 

Hi Daniel,

On 2013-08-14 09:50, Daniel Lezcano wrote:

On 08/13/2013 07:29 PM, Sudeep KarkadaNagesha wrote:

From: Sudeep KarkadaNagesha <sudeep.karkadanage...@arm.com>

Add macros to describe the bitfields in the ARM architected timer
control register to make code easy to understand.

Cc: Catalin Marinas <catalin.mari...@arm.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Reviewed-by: Will Deacon <will.dea...@arm.com>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanage...@arm.com>
---
 arch/arm/include/asm/arch_timer.h    |  9 +++++++--
 arch/arm64/include/asm/arch_timer.h  | 12 ++++++++----
 include/clocksource/arm_arch_timer.h |  8 ++++++++
 3 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h 
index e406d57..9ef74da 100644
--- a/arch/arm/include/asm/arch_timer.h
+++ b/arch/arm/include/asm/arch_timer.h
@@ -95,8 +95,13 @@ static inline void arch_counter_set_user_access(void) 

        asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl));

-       /* disable user access to everything */
-       cntkctl &= ~((3 << 8) | (7 << 0));
+ /* 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);

        asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
 }
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h 
index 98abd47..00b09d0 100644
--- a/arch/arm64/include/asm/arch_timer.h
+++ b/arch/arm64/include/asm/arch_timer.h
@@ -101,12 +101,16 @@ static inline void arch_counter_set_user_access(void) 
 {
        u32 cntkctl;

-       /* Disable user access to the timers and the physical counter. */
        asm volatile("mrs  %0, cntkctl_el1" : "=r" (cntkctl));
-       cntkctl &= ~((3 << 8) | (1 << 0));

-       /* Enable user access to the virtual counter and frequency. */
-       cntkctl |= (1 << 1);
+       /* Disable user access to the timers and the physical counter. */
+       cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN
+                       | ARCH_TIMER_USR_VT_ACCESS_EN
+                       | ARCH_TIMER_USR_PCT_ACCESS_EN);
+
+       /* Enable user access to the virtual counter. */
+       cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN;
+
        asm volatile("msr  cntkctl_el1, %0" : : "r" (cntkctl));
 }
Before doing those changes, I suggest you kill include/asm/arch_timer.h header file and move the functions directly in the arm_arch_timer.c as 
they are only used by it.
How do you suggest to proceed? Having #ifdefs in arm_arch_timer.c to cope with the inline assembly functions present in both arm and arm64 include files? Doesn't seem much of a progress to me...
diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h 
index c463ce9..551f7e9 100644
--- a/include/clocksource/arm_arch_timer.h
+++ b/include/clocksource/arm_arch_timer.h
@@ -29,6 +29,14 @@
 #define ARCH_TIMER_PHYS_ACCESS         0
 #define ARCH_TIMER_VIRT_ACCESS         1
+#define ARCH_TIMER_USR_PCT_ACCESS_EN (1 << 0) /* physical counter */ 
+#define ARCH_TIMER_USR_VCT_ACCESS_EN   (1 << 1) /* virtual counter */
+#define ARCH_TIMER_VIRT_EVT_EN         (1 << 2)
+#define ARCH_TIMER_EVT_TRIGGER_SHIFT   (4)
+#define ARCH_TIMER_EVT_TRIGGER_MASK (0xF << ARCH_TIMER_EVT_TRIGGER_SHIFT) +#define ARCH_TIMER_USR_VT_ACCESS_EN (1 << 8) /* virtual timer registers */ +#define ARCH_TIMER_USR_PT_ACCESS_EN (1 << 9) /* physical timer registers */ 
+
 #ifdef CONFIG_ARM_ARCH_TIMER

 extern u32 arch_timer_get_rate(void);



        M.
--
Fast, cheap, reliable. Pick two.
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