[PATCH 2/2] drm/i915/pmu: Make PMU sample array two-dimensional

[Ashutosh Dixit]

No functional changes but we can remove some unsightly index computation
and read/write functions if we convert the PMU sample array from a
one-dimensional to a two-dimensional array.

Suggested-by: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
---
 drivers/gpu/drm/i915/i915_pmu.c | 60 ++++++++++-----------------------
 drivers/gpu/drm/i915/i915_pmu.h |  2 +-
 2 files changed, 19 insertions(+), 43 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index b47d890d4ada1..137e0df9573ee 100644
--- a/drivers/gpu/drm/i915/i915_pmu.c
+++ b/drivers/gpu/drm/i915/i915_pmu.c
@@ -195,33 +195,6 @@ static inline s64 ktime_since_raw(const ktime_t kt)
 	return ktime_to_ns(ktime_sub(ktime_get_raw(), kt));
 }
 
-static unsigned int
-__sample_idx(struct i915_pmu *pmu, unsigned int gt_id, int sample)
-{
-	unsigned int idx = gt_id * __I915_NUM_PMU_SAMPLERS + sample;
-
-	GEM_BUG_ON(idx >= ARRAY_SIZE(pmu->sample));
-
-	return idx;
-}
-
-static u64 read_sample(struct i915_pmu *pmu, unsigned int gt_id, int sample)
-{
-	return pmu->sample[__sample_idx(pmu, gt_id, sample)].cur;
-}
-
-static void
-store_sample(struct i915_pmu *pmu, unsigned int gt_id, int sample, u64 val)
-{
-	pmu->sample[__sample_idx(pmu, gt_id, sample)].cur = val;
-}
-
-static void
-add_sample_mult(struct i915_pmu *pmu, unsigned int gt_id, int sample, u32 val, u32 mul)
-{
-	pmu->sample[__sample_idx(pmu, gt_id, sample)].cur += mul_u32_u32(val, mul);
-}
-
 static u64 get_rc6(struct intel_gt *gt)
 {
 	struct drm_i915_private *i915 = gt->i915;
@@ -240,7 +213,7 @@ static u64 get_rc6(struct intel_gt *gt)
 	spin_lock_irqsave(&pmu->lock, flags);
 
 	if (awake) {
-		store_sample(pmu, gt_id, __I915_SAMPLE_RC6, val);
+		pmu->sample[gt_id][__I915_SAMPLE_RC6].cur = val;
 	} else {
 		/*
 		 * We think we are runtime suspended.
@@ -250,13 +223,13 @@ static u64 get_rc6(struct intel_gt *gt)
 		 * counter value.
 		 */
 		val = ktime_since_raw(pmu->sleep_last[gt_id]);
-		val += read_sample(pmu, gt_id, __I915_SAMPLE_RC6);
+		val += pmu->sample[gt_id][__I915_SAMPLE_RC6].cur;
 	}
 
-	if (val < read_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED))
-		val = read_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED);
+	if (val < pmu->sample[gt_id][__I915_SAMPLE_RC6_LAST_REPORTED].cur)
+		val = pmu->sample[gt_id][__I915_SAMPLE_RC6_LAST_REPORTED].cur;
 	else
-		store_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED, val);
+		pmu->sample[gt_id][__I915_SAMPLE_RC6_LAST_REPORTED].cur = val;
 
 	spin_unlock_irqrestore(&pmu->lock, flags);
 
@@ -275,9 +248,8 @@ static void init_rc6(struct i915_pmu *pmu)
 		with_intel_runtime_pm(gt->uncore->rpm, wakeref) {
 			u64 val = __get_rc6(gt);
 
-			store_sample(pmu, i, __I915_SAMPLE_RC6, val);
-			store_sample(pmu, i, __I915_SAMPLE_RC6_LAST_REPORTED,
-				     val);
+			pmu->sample[i][__I915_SAMPLE_RC6].cur = val;
+			pmu->sample[i][__I915_SAMPLE_RC6_LAST_REPORTED].cur = val;
 			pmu->sleep_last[i] = ktime_get_raw();
 		}
 	}
@@ -287,7 +259,7 @@ static void park_rc6(struct intel_gt *gt)
 {
 	struct i915_pmu *pmu = &gt->i915->pmu;
 
-	store_sample(pmu, gt->info.id, __I915_SAMPLE_RC6, __get_rc6(gt));
+	pmu->sample[gt->info.id][__I915_SAMPLE_RC6].cur = __get_rc6(gt);
 	pmu->sleep_last[gt->info.id] = ktime_get_raw();
 }
 
@@ -428,6 +400,12 @@ engines_sample(struct intel_gt *gt, unsigned int period_ns)
 	}
 }
 
+static void
+add_sample_mult(struct i915_pmu_sample *sample, u32 val, u32 mul)
+{
+	sample->cur += mul_u32_u32(val, mul);
+}
+
 static bool
 frequency_sampling_enabled(struct i915_pmu *pmu, unsigned int gt)
 {
@@ -467,12 +445,12 @@ frequency_sample(struct intel_gt *gt, unsigned int period_ns)
 		if (!val)
 			val = intel_gpu_freq(rps, rps->cur_freq);
 
-		add_sample_mult(pmu, gt_id, __I915_SAMPLE_FREQ_ACT,
+		add_sample_mult(&pmu->sample[gt_id][__I915_SAMPLE_FREQ_ACT],
 				val, period_ns / 1000);
 	}
 
 	if (pmu->enable & config_mask(__I915_PMU_REQUESTED_FREQUENCY(gt_id))) {
-		add_sample_mult(pmu, gt_id, __I915_SAMPLE_FREQ_REQ,
+		add_sample_mult(&pmu->sample[gt_id][__I915_SAMPLE_FREQ_REQ],
 				intel_rps_get_requested_frequency(rps),
 				period_ns / 1000);
 	}
@@ -673,14 +651,12 @@ static u64 __i915_pmu_event_read(struct perf_event *event)
 		switch (config) {
 		case I915_PMU_ACTUAL_FREQUENCY:
 			val =
-			   div_u64(read_sample(pmu, gt_id,
-					       __I915_SAMPLE_FREQ_ACT),
+			   div_u64(pmu->sample[gt_id][__I915_SAMPLE_FREQ_ACT].cur,
 				   USEC_PER_SEC /* to MHz */);
 			break;
 		case I915_PMU_REQUESTED_FREQUENCY:
 			val =
-			   div_u64(read_sample(pmu, gt_id,
-					       __I915_SAMPLE_FREQ_REQ),
+			   div_u64(pmu->sample[gt_id][__I915_SAMPLE_FREQ_REQ].cur,
 				   USEC_PER_SEC /* to MHz */);
 			break;
 		case I915_PMU_INTERRUPTS:
diff --git a/drivers/gpu/drm/i915/i915_pmu.h b/drivers/gpu/drm/i915/i915_pmu.h
index 33d80fbaab8bc..d20592e7db999 100644
--- a/drivers/gpu/drm/i915/i915_pmu.h
+++ b/drivers/gpu/drm/i915/i915_pmu.h
@@ -127,7 +127,7 @@ struct i915_pmu {
 	 * Only global counters are held here, while the per-engine ones are in
 	 * struct intel_engine_cs.
 	 */
-	struct i915_pmu_sample sample[I915_PMU_MAX_GTS * __I915_NUM_PMU_SAMPLERS];
+	struct i915_pmu_sample sample[I915_PMU_MAX_GTS][__I915_NUM_PMU_SAMPLERS];
 	/**
 	 * @sleep_last: Last time GT parked for RC6 estimation.
 	 */
-- 
2.38.0