dma-buf: add DMA_RESV_USAGE_BOOKKEEP v3

Add an usage for submissions independent of implicit sync but still
interesting for memory management.

v2: cleanup the kerneldoc a bit
v3: separate amdgpu changes from this

Signed-off-by: Christian König <[e-mail]>
Reviewed-by: Daniel Vetter <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/dma-buf/dma-resv.c

···
 
 	list = NULL;
 
-	dma_resv_iter_begin(&cursor, src, DMA_RESV_USAGE_READ);
+	dma_resv_iter_begin(&cursor, src, DMA_RESV_USAGE_BOOKKEEP);
 	dma_resv_for_each_fence_unlocked(&cursor, f) {
 
 		if (dma_resv_iter_is_restarted(&cursor)) {
···
  */
 void dma_resv_describe(struct dma_resv *obj, struct seq_file *seq)
 {
-	static const char *usage[] = { "kernel", "write", "read" };
+	static const char *usage[] = { "kernel", "write", "read", "bookkeep" };
 	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
 

drivers/dma-buf/st-dma-resv.c

···
 	int r;
 
 	spin_lock_init(&fence_lock);
-	for (usage = DMA_RESV_USAGE_KERNEL; usage <= DMA_RESV_USAGE_READ;
+	for (usage = DMA_RESV_USAGE_KERNEL; usage <= DMA_RESV_USAGE_BOOKKEEP;
 	     ++usage) {
 		r = subtests(tests, (void *)(unsigned long)usage);
 		if (r)

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

···
 	struct dma_fence *fence;
 	int r;
 
-	r = dma_resv_get_singleton(resv, DMA_RESV_USAGE_READ, &fence);
+	r = dma_resv_get_singleton(resv, DMA_RESV_USAGE_BOOKKEEP, &fence);
 	if (r)
 		goto fallback;
 
···
 	/* Not enough memory for the delayed delete, as last resort
 	 * block for all the fences to complete.
 	 */
-	dma_resv_wait_timeout(resv, DMA_RESV_USAGE_READ,
+	dma_resv_wait_timeout(resv, DMA_RESV_USAGE_BOOKKEEP,
 			      false, MAX_SCHEDULE_TIMEOUT);
 	amdgpu_pasid_free(pasid);
 }

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

···
 
 	mmu_interval_set_seq(mni, cur_seq);
 
-	r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_READ,
+	r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_BOOKKEEP,
 				  false, MAX_SCHEDULE_TIMEOUT);
 	mutex_unlock(&adev->notifier_lock);
 	if (r <= 0)

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

···
 		return -EINVAL;
 
 	/* TODO: Use DMA_RESV_USAGE_READ here */
-	dma_resv_for_each_fence(&cursor, resv, DMA_RESV_USAGE_READ, f) {
+	dma_resv_for_each_fence(&cursor, resv, DMA_RESV_USAGE_BOOKKEEP, f) {
 		dma_fence_chain_for_each(f, f) {
 			struct dma_fence *tmp = dma_fence_chain_contained(f);
 

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

···
 	 * be resident to run successfully
 	 */
 	dma_resv_for_each_fence(&resv_cursor, bo->base.resv,
-				DMA_RESV_USAGE_READ, f) {
+				DMA_RESV_USAGE_BOOKKEEP, f) {
 		if (amdkfd_fence_check_mm(f, current->mm))
 			return false;
 	}

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

···
 	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
 
-	dma_resv_for_each_fence(&cursor, resv, DMA_RESV_USAGE_READ, fence) {
+	dma_resv_for_each_fence(&cursor, resv, DMA_RESV_USAGE_BOOKKEEP, fence) {
 		/* Add a callback for each fence in the reservation object */
 		amdgpu_vm_prt_get(adev);
 		amdgpu_vm_add_prt_cb(adev, fence);
···
 		return true;
 
 	/* Don't evict VM page tables while they are busy */
-	if (!dma_resv_test_signaled(bo->tbo.base.resv, DMA_RESV_USAGE_READ))
+	if (!dma_resv_test_signaled(bo->tbo.base.resv, DMA_RESV_USAGE_BOOKKEEP))
 		return false;
 
 	/* Try to block ongoing updates */
···
 long amdgpu_vm_wait_idle(struct amdgpu_vm *vm, long timeout)
 {
 	timeout = dma_resv_wait_timeout(vm->root.bo->tbo.base.resv,
-					DMA_RESV_USAGE_READ,
+					DMA_RESV_USAGE_BOOKKEEP,
 					true, timeout);
 	if (timeout <= 0)
 		return timeout;

drivers/gpu/drm/i915/gem/i915_gem_lmem.c

···
 	struct intel_memory_region *mr = READ_ONCE(obj->mm.region);
 
 #ifdef CONFIG_LOCKDEP
-	GEM_WARN_ON(dma_resv_test_signaled(obj->base.resv, DMA_RESV_USAGE_READ) &&
+	GEM_WARN_ON(dma_resv_test_signaled(obj->base.resv, DMA_RESV_USAGE_BOOKKEEP) &&
 		    i915_gem_object_evictable(obj));
 #endif
 	return mr && (mr->type == INTEL_MEMORY_LOCAL ||

drivers/gpu/drm/i915/gem/i915_gem_userptr.c

···
 		return true;
 
 	/* we will unbind on next submission, still have userptr pins */
-	r = dma_resv_wait_timeout(obj->base.resv, DMA_RESV_USAGE_READ, false,
+	r = dma_resv_wait_timeout(obj->base.resv, DMA_RESV_USAGE_BOOKKEEP, false,
 				  MAX_SCHEDULE_TIMEOUT);
 	if (r <= 0)
 		drm_err(&i915->drm, "(%ld) failed to wait for idle\n", r);

drivers/gpu/drm/qxl/qxl_debugfs.c

···
 		int rel = 0;
 
 		dma_resv_iter_begin(&cursor, bo->tbo.base.resv,
-				    DMA_RESV_USAGE_READ);
+				    DMA_RESV_USAGE_BOOKKEEP);
 		dma_resv_for_each_fence_unlocked(&cursor, fence) {
 			if (dma_resv_iter_is_restarted(&cursor))
 				rel = 0;

drivers/gpu/drm/radeon/radeon_gem.c

···
 	if (domain == RADEON_GEM_DOMAIN_CPU) {
 		/* Asking for cpu access wait for object idle */
 		r = dma_resv_wait_timeout(robj->tbo.base.resv,
-					  DMA_RESV_USAGE_READ,
+					  DMA_RESV_USAGE_BOOKKEEP,
 					  true, 30 * HZ);
 		if (!r)
 			r = -EBUSY;

drivers/gpu/drm/radeon/radeon_mn.c

···
 		return true;
 	}
 
-	r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_READ,
+	r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_BOOKKEEP,
 				  false, MAX_SCHEDULE_TIMEOUT);
 	if (r <= 0)
 		DRM_ERROR("(%ld) failed to wait for user bo\n", r);

drivers/gpu/drm/ttm/ttm_bo.c

···
 	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
 
-	dma_resv_iter_begin(&cursor, resv, DMA_RESV_USAGE_READ);
+	dma_resv_iter_begin(&cursor, resv, DMA_RESV_USAGE_BOOKKEEP);
 	dma_resv_for_each_fence_unlocked(&cursor, fence) {
 		if (!fence->ops->signaled)
 			dma_fence_enable_sw_signaling(fence);
···
 	struct dma_resv *resv = &bo->base._resv;
 	int ret;
 
-	if (dma_resv_test_signaled(resv, DMA_RESV_USAGE_READ))
+	if (dma_resv_test_signaled(resv, DMA_RESV_USAGE_BOOKKEEP))
 		ret = 0;
 	else
 		ret = -EBUSY;
···
 			dma_resv_unlock(bo->base.resv);
 		spin_unlock(&bo->bdev->lru_lock);
 
-		lret = dma_resv_wait_timeout(resv, DMA_RESV_USAGE_READ,
+		lret = dma_resv_wait_timeout(resv, DMA_RESV_USAGE_BOOKKEEP,
 					     interruptible,
 					     30 * HZ);
 
···
 			 * fences block for the BO to become idle
 			 */
 			dma_resv_wait_timeout(bo->base.resv,
-					      DMA_RESV_USAGE_READ, false,
+					      DMA_RESV_USAGE_BOOKKEEP, false,
 					      30 * HZ);
 		}
 
···
 		ttm_mem_io_free(bdev, bo->resource);
 	}
 
-	if (!dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_READ) ||
+	if (!dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP) ||
 	    !dma_resv_trylock(bo->base.resv)) {
 		/* The BO is not idle, resurrect it for delayed destroy */
 		ttm_bo_flush_all_fences(bo);
···
 	long timeout = 15 * HZ;
 
 	if (no_wait) {
-		if (dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_READ))
+		if (dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP))
 			return 0;
 		else
 			return -EBUSY;
 	}
 
-	timeout = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_READ,
+	timeout = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_BOOKKEEP,
 					interruptible, timeout);
 	if (timeout < 0)
 		return timeout;

include/linux/dma-resv.h

···
  * This enum describes the different use cases for a dma_resv object and
  * controls which fences are returned when queried.
  *
- * An important fact is that there is the order KERNEL<WRITE<READ and
+ * An important fact is that there is the order KERNEL<WRITE<READ<BOOKKEEP and
  * when the dma_resv object is asked for fences for one use case the fences
  * for the lower use case are returned as well.
  *
···
 	 * an implicit read dependency.
 	 */
 	DMA_RESV_USAGE_READ,
+
+	/**
+	 * @DMA_RESV_USAGE_BOOKKEEP: No implicit sync.
+	 *
+	 * This should be used by submissions which don't want to participate in
+	 * implicit synchronization.
+	 *
+	 * The most common case are preemption fences as well as page table
+	 * updates and their TLB flushes.
+	 */
+	DMA_RESV_USAGE_BOOKKEEP
 };
 
 /**