include/linux/dma-fence-chain.h

Source file repositories/reference/linux-study-clean/include/linux/dma-fence-chain.h

File Facts

System
Linux kernel
Corpus path
include/linux/dma-fence-chain.h
Extension
.h
Size
3685 bytes
Lines
131
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct dma_fence_chain {
	struct dma_fence base;
	struct dma_fence __rcu *prev;
	u64 prev_seqno;
	struct dma_fence *fence;
	union {
		/**
		 * @cb: callback for signaling
		 *
		 * This is used to add the callback for signaling the
		 * complection of the fence chain. Never used at the same time
		 * as the irq work.
		 */
		struct dma_fence_cb cb;

		/**
		 * @work: irq work item for signaling
		 *
		 * Irq work structure to allow us to add the callback without
		 * running into lock inversion. Never used at the same time as
		 * the callback.
		 */
		struct irq_work work;
	};
};


/**
 * to_dma_fence_chain - cast a fence to a dma_fence_chain
 * @fence: fence to cast to a dma_fence_array
 *
 * Returns NULL if the fence is not a dma_fence_chain,
 * or the dma_fence_chain otherwise.
 */
static inline struct dma_fence_chain *
to_dma_fence_chain(struct dma_fence *fence)
{
	if (!fence || !dma_fence_is_chain(fence))
		return NULL;

	return container_of(fence, struct dma_fence_chain, base);
}

/**
 * dma_fence_chain_contained - return the contained fence
 * @fence: the fence to test
 *
 * If the fence is a dma_fence_chain the function returns the fence contained
 * inside the chain object, otherwise it returns the fence itself.
 */
static inline struct dma_fence *
dma_fence_chain_contained(struct dma_fence *fence)
{
	struct dma_fence_chain *chain = to_dma_fence_chain(fence);

	return chain ? chain->fence : fence;
}

/**
 * dma_fence_chain_alloc
 *
 * Returns a new struct dma_fence_chain object or NULL on failure.
 *
 * This specialized allocator has to be a macro for its allocations to be
 * accounted separately (to have a separate alloc_tag). The typecast is
 * intentional to enforce typesafety.
 */
#define dma_fence_chain_alloc()	\
		kmalloc_obj(struct dma_fence_chain)

/**
 * dma_fence_chain_free
 * @chain: chain node to free
 *
 * Frees up an allocated but not used struct dma_fence_chain object. This
 * doesn't need an RCU grace period since the fence was never initialized nor
 * published. After dma_fence_chain_init() has been called the fence must be
 * released by calling dma_fence_put(), and not through this function.
 */
static inline void dma_fence_chain_free(struct dma_fence_chain *chain)
{
	kfree(chain);
};

/**
 * dma_fence_chain_for_each - iterate over all fences in chain
 * @iter: current fence
 * @head: starting point
 *
 * Iterate over all fences in the chain. We keep a reference to the current

Annotation

Implementation Notes