Commit f8b8487c authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm: Add deadline based boost support 



Track the nearest deadline on a fence timeline and set a timer to expire
shortly before to trigger boost if the fence has not yet been signaled.

v2: rebase

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/525816/
Link: https://lore.kernel.org/r/20230308155322.344664-13-robdclark@gmail.com
parent 1ad0510c

drivers/gpu/drm/msm/msm_fence.c

+74 −0
Original line number Diff line number Diff line
@@ -8,6 +8,35 @@ 


#include "msm_drv.h"

#include "msm_fence.h"

#include "msm_gpu.h"



static struct msm_gpu *fctx2gpu(struct msm_fence_context *fctx)

{

	struct msm_drm_private *priv = fctx->dev->dev_private;

	return priv->gpu;

}



static enum hrtimer_restart deadline_timer(struct hrtimer *t)

{

	struct msm_fence_context *fctx = container_of(t,

			struct msm_fence_context, deadline_timer);



	kthread_queue_work(fctx2gpu(fctx)->worker, &fctx->deadline_work);



	return HRTIMER_NORESTART;

}



static void deadline_work(struct kthread_work *work)

{

	struct msm_fence_context *fctx = container_of(work,

			struct msm_fence_context, deadline_work);



	/* If deadline fence has already passed, nothing to do: */

	if (msm_fence_completed(fctx, fctx->next_deadline_fence))

		return;



	msm_devfreq_boost(fctx2gpu(fctx), 2);

}





struct msm_fence_context *
@@ -36,6 +65,13 @@ msm_fence_context_alloc(struct drm_device *dev, volatile uint32_t *fenceptr, 
	fctx->completed_fence = fctx->last_fence;

	*fctx->fenceptr = fctx->last_fence;



	hrtimer_init(&fctx->deadline_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);

	fctx->deadline_timer.function = deadline_timer;



	kthread_init_work(&fctx->deadline_work, deadline_work);



	fctx->next_deadline = ktime_get();



	return fctx;

}
@@ -62,6 +98,8 @@ void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence) 
	spin_lock_irqsave(&fctx->spinlock, flags);

	if (fence_after(fence, fctx->completed_fence))

		fctx->completed_fence = fence;

	if (msm_fence_completed(fctx, fctx->next_deadline_fence))

		hrtimer_cancel(&fctx->deadline_timer);

	spin_unlock_irqrestore(&fctx->spinlock, flags);

}
@@ -92,10 +130,46 @@ static bool msm_fence_signaled(struct dma_fence *fence) 
	return msm_fence_completed(f->fctx, f->base.seqno);

}



static void msm_fence_set_deadline(struct dma_fence *fence, ktime_t deadline)

{

	struct msm_fence *f = to_msm_fence(fence);

	struct msm_fence_context *fctx = f->fctx;

	unsigned long flags;

	ktime_t now;



	spin_lock_irqsave(&fctx->spinlock, flags);

	now = ktime_get();



	if (ktime_after(now, fctx->next_deadline) ||

			ktime_before(deadline, fctx->next_deadline)) {

		fctx->next_deadline = deadline;

		fctx->next_deadline_fence =

			max(fctx->next_deadline_fence, (uint32_t)fence->seqno);



		/*

		 * Set timer to trigger boost 3ms before deadline, or

		 * if we are already less than 3ms before the deadline

		 * schedule boost work immediately.

		 */

		deadline = ktime_sub(deadline, ms_to_ktime(3));



		if (ktime_after(now, deadline)) {

			kthread_queue_work(fctx2gpu(fctx)->worker,

					&fctx->deadline_work);

		} else {

			hrtimer_start(&fctx->deadline_timer, deadline,

					HRTIMER_MODE_ABS);

		}

	}



	spin_unlock_irqrestore(&fctx->spinlock, flags);

}



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,

	.set_deadline = msm_fence_set_deadline,

};



struct dma_fence *

drivers/gpu/drm/msm/msm_fence.h

+20 −0
Original line number Diff line number Diff line
@@ -52,6 +52,26 @@ struct msm_fence_context { 
	volatile uint32_t *fenceptr;



	spinlock_t spinlock;



	/*

	 * TODO this doesn't really deal with multiple deadlines, like

	 * if userspace got multiple frames ahead.. OTOH atomic updates

	 * don't queue, so maybe that is ok

	 */



	/** next_deadline: Time of next deadline */

	ktime_t next_deadline;



	/**

	 * next_deadline_fence:

	 *

	 * Fence value for next pending deadline.  The deadline timer is

	 * canceled when this fence is signaled.

	 */

	uint32_t next_deadline_fence;



	struct hrtimer deadline_timer;

	struct kthread_work deadline_work;

};



struct msm_fence_context * msm_fence_context_alloc(struct drm_device *dev,