drivers/gpu/drm/i915/i915_deps.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/i915/i915_deps.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/i915/i915_deps.c
Extension
.c
Size
6640 bytes
Lines
238
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (ctx->no_wait_gpu && !dma_fence_is_signaled(*fences)) {
			ret = -EBUSY;
			break;
		}

		ret = dma_fence_wait(*fences, ctx->interruptible);
		if (!ret)
			ret = (*fences)->error;
		if (ret)
			break;
	}

	return ret;
}

/**
 * i915_deps_add_dependency - Add a fence to the dependency collection
 * @deps: Pointer to the i915_deps structure a fence is to be added to.
 * @fence: The fence to add.
 * @ctx: Pointer to a struct ttm_operation_ctx indicating how waits are to
 * be performed if waiting.
 *
 * Adds a fence to the dependency collection, and takes a reference on it.
 * If the fence context is not zero and there was a later fence from the
 * same fence context already added, then the fence is not added to the
 * dependency collection. If the fence context is not zero and there was
 * an earlier fence already added, then the fence will replace the older
 * fence from the same context and the reference on the earlier fence will
 * be dropped.
 * If there is a failure to allocate memory to accommodate the new fence to
 * be added, the new fence will instead be waited for and an error may
 * be returned; depending on the value of @ctx, or if there was a fence
 * error. If an error was returned, the dependency collection will be
 * finalized and all fence reference dropped.
 *
 * Return: 0 if success. Negative error code on error.
 */
int i915_deps_add_dependency(struct i915_deps *deps,
			     struct dma_fence *fence,
			     const struct ttm_operation_ctx *ctx)
{
	unsigned int i;
	int ret;

	if (!fence)
		return 0;

	if (dma_fence_is_signaled(fence)) {
		ret = fence->error;
		if (ret)
			i915_deps_fini(deps);
		return ret;
	}

	for (i = 0; i < deps->num_deps; ++i) {
		struct dma_fence *entry = deps->fences[i];

		if (!entry->context || entry->context != fence->context)
			continue;

		if (dma_fence_is_later(fence, entry)) {
			dma_fence_put(entry);
			deps->fences[i] = dma_fence_get(fence);
		}

		return 0;
	}

	return i915_deps_grow(deps, fence, ctx);
}

/**
 * i915_deps_add_resv - Add the fences of a reservation object to a dependency
 * collection.
 * @deps: Pointer to the i915_deps structure a fence is to be added to.
 * @resv: The reservation object, then fences of which to add.
 * @ctx: Pointer to a struct ttm_operation_ctx indicating how waits are to
 * be performed if waiting.
 *
 * Calls i915_deps_add_depencency() on the indicated fences of @resv.
 *
 * Return: Zero on success. Negative error code on error.
 */
int i915_deps_add_resv(struct i915_deps *deps, struct dma_resv *resv,
		       const struct ttm_operation_ctx *ctx)
{
	struct dma_resv_iter iter;
	struct dma_fence *fence;

	dma_resv_assert_held(resv);

Annotation

Implementation Notes