[Intel-xe] [PATCH] drm/xe/pmu: Drop interrupt pmu event

[Jani Nikula]

On Tue, 17 Oct 2023, Aravind Iddamsetty <aravind.iddamsetty at linux.intel.com> wrote:
> Drop interrupt event from PMU as that is not useful and not being used
> by any UMD.

Is the i915 interrupt event used by anyone? Could it be dropped too?

BR,
Jani.

>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
> Cc: Francois Dugast <francois.dugast at intel.com>
> Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty at linux.intel.com>
> ---
>  drivers/gpu/drm/xe/xe_irq.c       | 18 ------------------
>  drivers/gpu/drm/xe/xe_pmu.c       |  9 ---------
>  drivers/gpu/drm/xe/xe_pmu_types.h |  8 --------
>  include/uapi/drm/xe_drm.h         | 13 ++++++-------
>  4 files changed, 6 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_irq.c b/drivers/gpu/drm/xe/xe_irq.c
> index 61350ed32c61..29f539f1b94b 100644
> --- a/drivers/gpu/drm/xe/xe_irq.c
> +++ b/drivers/gpu/drm/xe/xe_irq.c
> @@ -27,20 +27,6 @@
>  #define IIR(offset)				XE_REG(offset + 0x8)
>  #define IER(offset)				XE_REG(offset + 0xc)
>  
> -/*
> - * Interrupt statistic for PMU. Increments the counter only if the
> - * interrupt originated from the GPU so interrupts from a device which
> - * shares the interrupt line are not accounted.
> - */
> -static __always_inline void xe_pmu_irq_stats(struct xe_device *xe)
> -{
> -	/*
> -	 * A clever compiler translates that into INC. A not so clever one
> -	 * should at least prevent store tearing.
> -	 */
> -	WRITE_ONCE(xe->pmu.irq_count, xe->pmu.irq_count + 1);
> -}
> -
>  static void assert_iir_is_zero(struct xe_gt *mmio, struct xe_reg reg)
>  {
>  	u32 val = xe_mmio_read32(mmio, reg);
> @@ -361,8 +347,6 @@ static irqreturn_t xelp_irq_handler(int irq, void *arg)
>  
>  	xe_display_irq_enable(xe, gu_misc_iir);
>  
> -	xe_pmu_irq_stats(xe);
> -
>  	return IRQ_HANDLED;
>  }
>  
> @@ -459,8 +443,6 @@ static irqreturn_t dg1_irq_handler(int irq, void *arg)
>  	dg1_intr_enable(xe, false);
>  	xe_display_irq_enable(xe, gu_misc_iir);
>  
> -	xe_pmu_irq_stats(xe);
> -
>  	return IRQ_HANDLED;
>  }
>  
> diff --git a/drivers/gpu/drm/xe/xe_pmu.c b/drivers/gpu/drm/xe/xe_pmu.c
> index abfc0b3aeac4..318bbc9c1c9b 100644
> --- a/drivers/gpu/drm/xe/xe_pmu.c
> +++ b/drivers/gpu/drm/xe/xe_pmu.c
> @@ -114,10 +114,6 @@ config_status(struct xe_device *xe, u64 config)
>  		return -ENOENT;
>  
>  	switch (config_counter(config)) {
> -	case XE_PMU_INTERRUPTS(0):
> -		if (gt_id)
> -			return -ENOENT;
> -		break;
>  	case XE_PMU_RENDER_GROUP_BUSY(0):
>  	case XE_PMU_COPY_GROUP_BUSY(0):
>  	case XE_PMU_ANY_ENGINE_GROUP_BUSY(0):
> @@ -181,13 +177,9 @@ static u64 __xe_pmu_event_read(struct perf_event *event)
>  	const unsigned int gt_id = config_gt_id(event->attr.config);
>  	const u64 config = event->attr.config;
>  	struct xe_gt *gt = xe_device_get_gt(xe, gt_id);
> -	struct xe_pmu *pmu = &xe->pmu;
>  	u64 val;
>  
>  	switch (config_counter(config)) {
> -	case XE_PMU_INTERRUPTS(0):
> -		val = READ_ONCE(pmu->irq_count);
> -		break;
>  	case XE_PMU_RENDER_GROUP_BUSY(0):
>  	case XE_PMU_COPY_GROUP_BUSY(0):
>  	case XE_PMU_ANY_ENGINE_GROUP_BUSY(0):
> @@ -361,7 +353,6 @@ create_event_attributes(struct xe_pmu *pmu)
>  		const char *unit;
>  		bool global;
>  	} events[] = {
> -		__global_event(0, "interrupts", NULL),
>  		__event(1, "render-group-busy", "ns"),
>  		__event(2, "copy-group-busy", "ns"),
>  		__event(3, "media-group-busy", "ns"),
> diff --git a/drivers/gpu/drm/xe/xe_pmu_types.h b/drivers/gpu/drm/xe/xe_pmu_types.h
> index 4ccc7e9042f6..9cadbd243f57 100644
> --- a/drivers/gpu/drm/xe/xe_pmu_types.h
> +++ b/drivers/gpu/drm/xe/xe_pmu_types.h
> @@ -51,14 +51,6 @@ struct xe_pmu {
>  	 *
>  	 */
>  	u64 sample[XE_PMU_MAX_GT][__XE_NUM_PMU_SAMPLERS];
> -	/**
> -	 * @irq_count: Number of interrupts
> -	 *
> -	 * Intentionally unsigned long to avoid atomics or heuristics on 32bit.
> -	 * 4e9 interrupts are a lot and postprocessing can really deal with an
> -	 * occasional wraparound easily. It's 32bit after all.
> -	 */
> -	unsigned long irq_count;
>  	/**
>  	 * @events_attr_group: Device events attribute group.
>  	 */
> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> index 24bf8f0f52e8..be43ef0b92e6 100644
> --- a/include/uapi/drm/xe_drm.h
> +++ b/include/uapi/drm/xe_drm.h
> @@ -1041,7 +1041,7 @@ struct drm_xe_vm_madvise {
>   * in 'struct perf_event_attr' as part of perf_event_open syscall to read a
>   * particular event.
>   *
> - * For example to open the XE_PMU_INTERRUPTS(0):
> + * For example to open the XE_PMU_RENDER_GROUP_BUSY(0):
>   *
>   * .. code-block:: C
>   *
> @@ -1055,7 +1055,7 @@ struct drm_xe_vm_madvise {
>   *	attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED;
>   *	attr.use_clockid = 1;
>   *	attr.clockid = CLOCK_MONOTONIC;
> - *	attr.config = XE_PMU_INTERRUPTS(0);
> + *	attr.config = XE_PMU_RENDER_GROUP_BUSY(0);
>   *
>   *	fd = syscall(__NR_perf_event_open, &attr, -1, cpu, -1, 0);
>   */
> @@ -1068,11 +1068,10 @@ struct drm_xe_vm_madvise {
>  #define ___XE_PMU_OTHER(gt, x) \
>  	(((__u64)(x)) | ((__u64)(gt) << __XE_PMU_GT_SHIFT))
>  
> -#define XE_PMU_INTERRUPTS(gt)			___XE_PMU_OTHER(gt, 0)
> -#define XE_PMU_RENDER_GROUP_BUSY(gt)		___XE_PMU_OTHER(gt, 1)
> -#define XE_PMU_COPY_GROUP_BUSY(gt)		___XE_PMU_OTHER(gt, 2)
> -#define XE_PMU_MEDIA_GROUP_BUSY(gt)		___XE_PMU_OTHER(gt, 3)
> -#define XE_PMU_ANY_ENGINE_GROUP_BUSY(gt)	___XE_PMU_OTHER(gt, 4)
> +#define XE_PMU_RENDER_GROUP_BUSY(gt)		___XE_PMU_OTHER(gt, 0)
> +#define XE_PMU_COPY_GROUP_BUSY(gt)		___XE_PMU_OTHER(gt, 1)
> +#define XE_PMU_MEDIA_GROUP_BUSY(gt)		___XE_PMU_OTHER(gt, 2)
> +#define XE_PMU_ANY_ENGINE_GROUP_BUSY(gt)	___XE_PMU_OTHER(gt, 3)
>  
>  #if defined(__cplusplus)
>  }

-- 
Jani Nikula, Intel