[RFC 3/3] drm/msm: Wire up gpu boost

[Rob Clark]

From: Rob Clark <robdclark@xxxxxxxxxxxx>

Note, at this point I haven't given a lot of consideration into how much
we should boost, and for how long.  And perhaps we should only boost at
less than 50% utilization?  At this point, this is only an example of
dma_fence_boost() implementation.

Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
 drivers/gpu/drm/msm/msm_fence.c | 10 ++++++++++
 drivers/gpu/drm/msm/msm_gpu.c   | 13 +++++++++++++
 drivers/gpu/drm/msm/msm_gpu.h   |  2 ++
 3 files changed, 25 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_fence.c b/drivers/gpu/drm/msm/msm_fence.c
index cd59a5918038..e58895603726 100644
--- a/drivers/gpu/drm/msm/msm_fence.c
+++ b/drivers/gpu/drm/msm/msm_fence.c
@@ -8,6 +8,7 @@
 
 #include "msm_drv.h"
 #include "msm_fence.h"
+#include "msm_gpu.h"
 
 
 struct msm_fence_context *
@@ -114,10 +115,19 @@ static bool msm_fence_signaled(struct dma_fence *fence)
 	return fence_completed(f->fctx, f->base.seqno);
 }
 
+static void msm_fence_boost(struct dma_fence *fence)
+{
+	struct msm_fence *f = to_msm_fence(fence);
+	struct msm_drm_private *priv = f->fctx->dev->dev_private;
+
+	msm_gpu_boost(priv->gpu);
+}
+
 static const struct dma_fence_ops msm_fence_ops = {
 	.get_driver_name = msm_fence_get_driver_name,
 	.get_timeline_name = msm_fence_get_timeline_name,
 	.signaled = msm_fence_signaled,
+	.boost = msm_fence_boost,
 };
 
 struct dma_fence *
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 9dd1c58430ab..c90b79116500 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -62,6 +62,10 @@ static int msm_devfreq_get_dev_status(struct device *dev,
 	status->total_time = ktime_us_delta(time, gpu->devfreq.time);
 	gpu->devfreq.time = time;
 
+	if (atomic_dec_if_positive(&gpu->devfreq.boost) >= 0) {
+		status->busy_time = status->total_time;
+	}
+
 	return 0;
 }
 
@@ -84,6 +88,15 @@ static struct devfreq_dev_profile msm_devfreq_profile = {
 	.get_cur_freq = msm_devfreq_get_cur_freq,
 };
 
+void msm_gpu_boost(struct msm_gpu *gpu)
+{
+	if (!gpu->funcs->gpu_busy)
+		return;
+
+	/* Add three devfreq polling intervals worth of boost: */
+	atomic_add(3, &gpu->devfreq.boost);
+}
+
 static void msm_devfreq_init(struct msm_gpu *gpu)
 {
 	/* We need target support to do devfreq */
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 18baf935e143..7a082a12d98f 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -150,6 +150,7 @@ struct msm_gpu {
 		struct devfreq *devfreq;
 		u64 busy_cycles;
 		ktime_t time;
+		atomic_t boost;
 	} devfreq;
 
 	uint32_t suspend_count;
@@ -295,6 +296,7 @@ static inline void gpu_write64(struct msm_gpu *gpu, u32 lo, u32 hi, u64 val)
 int msm_gpu_pm_suspend(struct msm_gpu *gpu);
 int msm_gpu_pm_resume(struct msm_gpu *gpu);
 void msm_gpu_resume_devfreq(struct msm_gpu *gpu);
+void msm_gpu_boost(struct msm_gpu *gpu);
 
 int msm_gpu_hw_init(struct msm_gpu *gpu);
 
-- 
2.30.2