drm/msm/gpu: Respect PM QoS constraints

Re-work the boost and idle clamping to use PM QoS requests instead, so
they get aggreggated with other requests (such as cooling device).

This does have the minor side-effect that devfreq sysfs min_freq/
max_freq files now reflect the boost and idle clamping, as they show
(despite what they are documented to show) the aggregated min/max freq.
Fixing that in devfreq does not look straightforward after considering
that OPPs can be dynamically added/removed.  However writes to the
sysfs files still behave as expected.

v2: Use 64b math to avoid potential 32b overflow

Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20211120200103.1051459-3-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>

1 files changed, 23 insertions, 10 deletions

diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 37b3ecb33cbd..445c6bfd4b6b 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -88,6 +88,21 @@ struct msm_gpu_devfreq {
 	struct devfreq *devfreq;
 
 	/**
+	 * idle_constraint:
+	 *
+	 * A PM QoS constraint to limit max freq while the GPU is idle.
+	 */
+	struct dev_pm_qos_request idle_freq;
+
+	/**
+	 * boost_constraint:
+	 *
+	 * A PM QoS constraint to boost min freq for a period of time
+	 * until the boost expires.
+	 */
+	struct dev_pm_qos_request boost_freq;
+
+	/**
 	 * busy_cycles:
 	 *
 	 * Used by implementation of gpu->gpu_busy() to track the last
@@ -103,22 +118,19 @@ struct msm_gpu_devfreq {
 	ktime_t idle_time;
 
 	/**
-	 * idle_freq:
+	 * idle_work:
 	 *
-	 * Shadow frequency used while the GPU is idle.  From the PoV of
-	 * the devfreq governor, we are continuing to sample busyness and
-	 * adjust frequency while the GPU is idle, but we use this shadow
-	 * value as the GPU is actually clamped to minimum frequency while
-	 * it is inactive.
+	 * Used to delay clamping to idle freq on active->idle transition.
 	 */
-	unsigned long idle_freq;
+	struct msm_hrtimer_work idle_work;
 
 	/**
-	 * idle_work:
+	 * boost_work:
 	 *
-	 * Used to delay clamping to idle freq on active->idle transition.
+	 * Used to reset the boost_constraint after the boost period has
+	 * elapsed
 	 */
-	struct msm_hrtimer_work idle_work;
+	struct msm_hrtimer_work boost_work;
 };
 
 struct msm_gpu {
@@ -522,6 +534,7 @@ void msm_devfreq_init(struct msm_gpu *gpu);
 void msm_devfreq_cleanup(struct msm_gpu *gpu);
 void msm_devfreq_resume(struct msm_gpu *gpu);
 void msm_devfreq_suspend(struct msm_gpu *gpu);
+void msm_devfreq_boost(struct msm_gpu *gpu, unsigned factor);
 void msm_devfreq_active(struct msm_gpu *gpu);
 void msm_devfreq_idle(struct msm_gpu *gpu);