drm/i915/pmu: Atomically acquire the gt_pm wakeref

Currently, we only sample if the intel_gt is awake, but we acquire our
own runtime_pm wakeref. Since intel_gt has transitioned to tracking its
own wakeref, we can atomically test and acquire that wakeref instead.

v2: Take engine->wakeref for engine sampling

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190801233616.23007-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm.h b/drivers/gpu/drm/i915/gt/intel_gt_pm.h
index 527894fe134588cb179e8a9102b11072784ffba1..e8a18d4b27c9874d30617da2925106de4ab7a41f 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_gt_pm.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.h
@@ -9,7 +9,8 @@
 
 #include <linux/types.h>
 
-struct intel_gt;
+#include "intel_gt_types.h"
+#include "intel_wakeref.h"
 
 enum {
        INTEL_GT_UNPARK,
@@ -19,6 +20,11 @@ enum {
 void intel_gt_pm_get(struct intel_gt *gt);
 void intel_gt_pm_put(struct intel_gt *gt);
 
+static inline bool intel_gt_pm_get_if_awake(struct intel_gt *gt)
+{
+       return intel_wakeref_get_if_active(&gt->wakeref);
+}
+
 void intel_gt_pm_init_early(struct intel_gt *gt);
 
 void intel_gt_sanitize(struct intel_gt *gt, bool force);

diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index e0e0180bca7c244615db9dec6955a806a9c772b7..c2e5f6d5c1e0447034e43b29645a867aaacf612f 100644 (file)
--- a/drivers/gpu/drm/i915/i915_pmu.c
+++ b/drivers/gpu/drm/i915/i915_pmu.c
@@ -8,6 +8,8 @@
 #include <linux/pm_runtime.h>
 
 #include "gt/intel_engine.h"
+#include "gt/intel_engine_pm.h"
+#include "gt/intel_gt_pm.h"
 
 #include "i915_drv.h"
 #include "i915_pmu.h"
@@ -165,30 +167,26 @@ static void
 engines_sample(struct intel_gt *gt, unsigned int period_ns)
 {
        struct drm_i915_private *i915 = gt->i915;
-       struct intel_uncore *uncore = gt->uncore;
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
-       intel_wakeref_t wakeref;
-       unsigned long flags;
 
        if ((i915->pmu.enable & ENGINE_SAMPLE_MASK) == 0)
                return;
 
-       wakeref = 0;
-       if (READ_ONCE(gt->awake))
-               wakeref = intel_runtime_pm_get_if_in_use(&i915->runtime_pm);
-       if (!wakeref)
-               return;
-
-       spin_lock_irqsave(&uncore->lock, flags);
        for_each_engine(engine, i915, id) {
                struct intel_engine_pmu *pmu = &engine->pmu;
+               unsigned long flags;
                bool busy;
                u32 val;
 
+               if (!intel_engine_pm_get_if_awake(engine))
+                       continue;
+
+               spin_lock_irqsave(&engine->uncore->lock, flags);
+
                val = ENGINE_READ_FW(engine, RING_CTL);
                if (val == 0) /* powerwell off => engine idle */
-                       continue;
+                       goto skip;
 
                if (val & RING_WAIT)
                        add_sample(&pmu->sample[I915_SAMPLE_WAIT], period_ns);
@@ -209,10 +207,11 @@ engines_sample(struct intel_gt *gt, unsigned int period_ns)
                }
                if (busy)
                        add_sample(&pmu->sample[I915_SAMPLE_BUSY], period_ns);
-       }
-       spin_unlock_irqrestore(&uncore->lock, flags);
 
-       intel_runtime_pm_put(&i915->runtime_pm, wakeref);
+skip:
+               spin_unlock_irqrestore(&engine->uncore->lock, flags);
+               intel_engine_pm_put(engine);
+       }
 }
 
 static void
@@ -232,15 +231,10 @@ frequency_sample(struct intel_gt *gt, unsigned int period_ns)
                u32 val;
 
                val = i915->gt_pm.rps.cur_freq;
-               if (gt->awake) {
-                       intel_wakeref_t wakeref;
-
-                       with_intel_runtime_pm_if_in_use(&i915->runtime_pm,
-                                                       wakeref) {
-                               val = intel_uncore_read_notrace(uncore,
-                                                               GEN6_RPSTAT1);
-                               val = intel_get_cagf(i915, val);
-                       }
+               if (intel_gt_pm_get_if_awake(gt)) {
+                       val = intel_uncore_read_notrace(uncore, GEN6_RPSTAT1);
+                       val = intel_get_cagf(i915, val);
+                       intel_gt_pm_put(gt);
                }
 
                add_sample_mult(&pmu->sample[__I915_SAMPLE_FREQ_ACT],