Re: [PATCH v5 5/7] arm64/perf: Access pmu register using <read/write>_sys_reg

[Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>]

On Tue, Apr 19, 2016 at 11:54:20AM -0700, Ashok Kumar wrote:
> changed pmu register access to make use of <read/write>_sys_reg
> from sysreg.h instead of accessing them directly.
> 
> Signed-off-by: Ashok Kumar <ashoks-dY08KVG/lbpWk0Htik3J/w@public.gmane.org>
> ---
>  arch/arm64/kernel/perf_event.c | 33 ++++++++++++++++-----------------
>  1 file changed, 16 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
> index 2ee61e8..86790d2 100644
> --- a/arch/arm64/kernel/perf_event.c
> +++ b/arch/arm64/kernel/perf_event.c
> @@ -22,6 +22,7 @@
>  #include <asm/irq_regs.h>
>  #include <asm/perf_event.h>
>  #include <asm/virt.h>
> +#include <asm/sysreg.h>

Please move this between the includes of <asm/perf_event.h> and
<asm/virt.h>, so as to keep them in alphabetical order.

Otherwise, this looks like a nice cleanup!

With that fixed up:

Reviewed-by: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>

Mark.

>  
>  #include <linux/of.h>
>  #include <linux/perf/arm_pmu.h>
> @@ -476,16 +477,14 @@ static const struct attribute_group *armv8_pmuv3_attr_groups[] = {
>  
>  static inline u32 armv8pmu_pmcr_read(void)
>  {
> -	u32 val;
> -	asm volatile("mrs %0, pmcr_el0" : "=r" (val));
> -	return val;
> +	return read_sysreg(pmcr_el0);
>  }
>  
>  static inline void armv8pmu_pmcr_write(u32 val)
>  {
>  	val &= ARMV8_PMU_PMCR_MASK;
>  	isb();
> -	asm volatile("msr pmcr_el0, %0" :: "r" (val));
> +	write_sysreg(val, pmcr_el0);
>  }
>  
>  static inline int armv8pmu_has_overflowed(u32 pmovsr)
> @@ -507,7 +506,7 @@ static inline int armv8pmu_counter_has_overflowed(u32 pmnc, int idx)
>  static inline int armv8pmu_select_counter(int idx)
>  {
>  	u32 counter = ARMV8_IDX_TO_COUNTER(idx);
> -	asm volatile("msr pmselr_el0, %0" :: "r" (counter));
> +	write_sysreg(counter, pmselr_el0);
>  	isb();
>  
>  	return idx;
> @@ -524,9 +523,9 @@ static inline u32 armv8pmu_read_counter(struct perf_event *event)
>  		pr_err("CPU%u reading wrong counter %d\n",
>  			smp_processor_id(), idx);
>  	else if (idx == ARMV8_IDX_CYCLE_COUNTER)
> -		asm volatile("mrs %0, pmccntr_el0" : "=r" (value));
> +		value = read_sysreg(pmccntr_el0);
>  	else if (armv8pmu_select_counter(idx) == idx)
> -		asm volatile("mrs %0, pmxevcntr_el0" : "=r" (value));
> +		value = read_sysreg(pmxevcntr_el0);
>  
>  	return value;
>  }
> @@ -548,47 +547,47 @@ static inline void armv8pmu_write_counter(struct perf_event *event, u32 value)
>  		 */
>  		u64 value64 = 0xffffffff00000000ULL | value;
>  
> -		asm volatile("msr pmccntr_el0, %0" :: "r" (value64));
> +		write_sysreg(value64, pmccntr_el0);
>  	} else if (armv8pmu_select_counter(idx) == idx)
> -		asm volatile("msr pmxevcntr_el0, %0" :: "r" (value));
> +		write_sysreg(value, pmxevcntr_el0);
>  }
>  
>  static inline void armv8pmu_write_evtype(int idx, u32 val)
>  {
>  	if (armv8pmu_select_counter(idx) == idx) {
>  		val &= ARMV8_PMU_EVTYPE_MASK;
> -		asm volatile("msr pmxevtyper_el0, %0" :: "r" (val));
> +		write_sysreg(val, pmxevtyper_el0);
>  	}
>  }
>  
>  static inline int armv8pmu_enable_counter(int idx)
>  {
>  	u32 counter = ARMV8_IDX_TO_COUNTER(idx);
> -	asm volatile("msr pmcntenset_el0, %0" :: "r" (BIT(counter)));
> +	write_sysreg(BIT(counter), pmcntenset_el0);
>  	return idx;
>  }
>  
>  static inline int armv8pmu_disable_counter(int idx)
>  {
>  	u32 counter = ARMV8_IDX_TO_COUNTER(idx);
> -	asm volatile("msr pmcntenclr_el0, %0" :: "r" (BIT(counter)));
> +	write_sysreg(BIT(counter), pmcntenclr_el0);
>  	return idx;
>  }
>  
>  static inline int armv8pmu_enable_intens(int idx)
>  {
>  	u32 counter = ARMV8_IDX_TO_COUNTER(idx);
> -	asm volatile("msr pmintenset_el1, %0" :: "r" (BIT(counter)));
> +	write_sysreg(BIT(counter), pmintenset_el1);
>  	return idx;
>  }
>  
>  static inline int armv8pmu_disable_intens(int idx)
>  {
>  	u32 counter = ARMV8_IDX_TO_COUNTER(idx);
> -	asm volatile("msr pmintenclr_el1, %0" :: "r" (BIT(counter)));
> +	write_sysreg(BIT(counter), pmintenclr_el1);
>  	isb();
>  	/* Clear the overflow flag in case an interrupt is pending. */
> -	asm volatile("msr pmovsclr_el0, %0" :: "r" (BIT(counter)));
> +	write_sysreg(BIT(counter), pmovsclr_el0);
>  	isb();
>  
>  	return idx;
> @@ -599,11 +598,11 @@ static inline u32 armv8pmu_getreset_flags(void)
>  	u32 value;
>  
>  	/* Read */
> -	asm volatile("mrs %0, pmovsclr_el0" : "=r" (value));
> +	value = read_sysreg(pmovsclr_el0);
>  
>  	/* Write to clear flags */
>  	value &= ARMV8_PMU_OVSR_MASK;
> -	asm volatile("msr pmovsclr_el0, %0" :: "r" (value));
> +	write_sysreg(value, pmovsclr_el0);
>  
>  	return value;
>  }
> -- 
> 2.1.0
> 
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