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Commit 176e1ab1 authored by Chunming Zhou's avatar Chunming Zhou Committed by Alex Deucher
Browse files

drm/amdgpu: protect fence_process from multiple context 



fence_process may be called from kthread, user thread and interrupt context.
it is possible to called concurrently, then will wake up fence queue multiple times.

Signed-off-by: default avatarChunming Zhou <david1.zhou@amd.com>
Reviewed-by: default avatarJammy Zhou <Jammy.Zhou@amd.com>
parent e0d8f3c3

drivers/gpu/drm/amd/amdgpu/amdgpu.h

+1 −0
Original line number Diff line number Diff line
@@ -869,6 +869,7 @@ struct amdgpu_ring { 
	struct amdgpu_fence_driver	fence_drv;

	struct amd_gpu_scheduler 	*scheduler;



	spinlock_t              fence_lock;

	struct mutex		*ring_lock;

	struct amdgpu_bo	*ring_obj;

	volatile uint32_t	*ring;

drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c

+5 −1
Original line number Diff line number Diff line
@@ -295,6 +295,7 @@ void amdgpu_fence_process(struct amdgpu_ring *ring) 
	uint64_t seq, last_seq, last_emitted;

	unsigned count_loop = 0;

	bool wake = false;

	unsigned long irqflags;



	/* Note there is a scenario here for an infinite loop but it's

	 * very unlikely to happen. For it to happen, the current polling
@@ -317,6 +318,7 @@ void amdgpu_fence_process(struct amdgpu_ring *ring) 
	 * have temporarly set the last_seq not to the true real last

	 * seq but to an older one.

	 */

	spin_lock_irqsave(&ring->fence_lock, irqflags);

	last_seq = atomic64_read(&ring->fence_drv.last_seq);

	do {

		last_emitted = ring->fence_drv.sync_seq[ring->idx];
@@ -355,7 +357,7 @@ void amdgpu_fence_process(struct amdgpu_ring *ring) 
			if (handled_seq == latest_seq) {

				DRM_ERROR("ring %d, EOP without seq update (lastest_seq=%llu)\n",

					  ring->idx, latest_seq);

				return;

				goto exit;

			}

			do {

				amd_sched_isr(ring->scheduler);
@@ -364,6 +366,8 @@ void amdgpu_fence_process(struct amdgpu_ring *ring) 


		wake_up_all(&ring->adev->fence_queue);

	}

exit:

	spin_unlock_irqrestore(&ring->fence_lock, irqflags);

}



/**

drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c

+1 −1
Original line number Diff line number Diff line
@@ -367,7 +367,7 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring, 
	}

	ring->next_rptr_gpu_addr = adev->wb.gpu_addr + (ring->next_rptr_offs * 4);

	ring->next_rptr_cpu_addr = &adev->wb.wb[ring->next_rptr_offs];



	spin_lock_init(&ring->fence_lock);

	r = amdgpu_fence_driver_start_ring(ring, irq_src, irq_type);

	if (r) {

		dev_err(adev->dev, "failed initializing fences (%d).\n", r);