-/**
- * Request queue structure.
- *
- * The request queue allows us to note sequence numbers that have been emitted
- * and may be associated with active buffers to be retired.
- *
- * By keeping this list, we can avoid having to do questionable sequence
- * number comparisons on buffer last_read|write_seqno. It also allows an
- * emission time to be associated with the request for tracking how far ahead
- * of the GPU the submission is.
- *
- * The requests are reference counted, so upon creation they should have an
- * initial reference taken using kref_init
- */
-struct drm_i915_gem_request {
- struct kref ref;
-
- /** On Which ring this request was generated */
- struct drm_i915_private *i915;
- struct intel_engine_cs *engine;
- struct intel_signal_node signaling;
-
- /** GEM sequence number associated with the previous request,
- * when the HWS breadcrumb is equal to this the GPU is processing
- * this request.
- */
- u32 previous_seqno;
-
- /** GEM sequence number associated with this request,
- * when the HWS breadcrumb is equal or greater than this the GPU
- * has finished processing this request.
- */
- u32 seqno;
-
- /** Position in the ringbuffer of the start of the request */
- u32 head;
-
- /**
- * Position in the ringbuffer of the start of the postfix.
- * This is required to calculate the maximum available ringbuffer
- * space without overwriting the postfix.
- */
- u32 postfix;
-
- /** Position in the ringbuffer of the end of the whole request */
- u32 tail;
-
- /** Preallocate space in the ringbuffer for the emitting the request */
- u32 reserved_space;
-
- /**
- * Context and ring buffer related to this request
- * Contexts are refcounted, so when this request is associated with a
- * context, we must increment the context's refcount, to guarantee that
- * it persists while any request is linked to it. Requests themselves
- * are also refcounted, so the request will only be freed when the last
- * reference to it is dismissed, and the code in
- * i915_gem_request_free() will then decrement the refcount on the
- * context.
- */
- struct i915_gem_context *ctx;
- struct intel_ringbuffer *ringbuf;
-
- /**
- * Context related to the previous request.
- * As the contexts are accessed by the hardware until the switch is
- * completed to a new context, the hardware may still be writing
- * to the context object after the breadcrumb is visible. We must
- * not unpin/unbind/prune that object whilst still active and so
- * we keep the previous context pinned until the following (this)
- * request is retired.
- */
- struct i915_gem_context *previous_context;
-
- /** Batch buffer related to this request if any (used for
- error state dump only) */
- struct drm_i915_gem_object *batch_obj;
-
- /** Time at which this request was emitted, in jiffies. */
- unsigned long emitted_jiffies;
-
- /** global list entry for this request */
- struct list_head list;
-
- struct drm_i915_file_private *file_priv;
- /** file_priv list entry for this request */
- struct list_head client_list;
-
- /** process identifier submitting this request */
- struct pid *pid;
-
- /**
- * The ELSP only accepts two elements at a time, so we queue
- * context/tail pairs on a given queue (ring->execlist_queue) until the
- * hardware is available. The queue serves a double purpose: we also use
- * it to keep track of the up to 2 contexts currently in the hardware
- * (usually one in execution and the other queued up by the GPU): We
- * only remove elements from the head of the queue when the hardware
- * informs us that an element has been completed.
- *
- * All accesses to the queue are mediated by a spinlock
- * (ring->execlist_lock).
- */
-
- /** Execlist link in the submission queue.*/
- struct list_head execlist_link;
-
- /** Execlists no. of times this request has been sent to the ELSP */
- int elsp_submitted;
-
- /** Execlists context hardware id. */
- unsigned ctx_hw_id;
-};
-
-struct drm_i915_gem_request * __must_check
-i915_gem_request_alloc(struct intel_engine_cs *engine,
- struct i915_gem_context *ctx);
-void i915_gem_request_free(struct kref *req_ref);
-int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
- struct drm_file *file);
-
-static inline uint32_t
-i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
-{
- return req ? req->seqno : 0;
-}
-
-static inline struct intel_engine_cs *
-i915_gem_request_get_engine(struct drm_i915_gem_request *req)
-{
- return req ? req->engine : NULL;
-}
-
-static inline struct drm_i915_gem_request *
-i915_gem_request_reference(struct drm_i915_gem_request *req)
-{
- if (req)
- kref_get(&req->ref);
- return req;
-}
-
-static inline void
-i915_gem_request_unreference(struct drm_i915_gem_request *req)
-{
- kref_put(&req->ref, i915_gem_request_free);
-}
-
-static inline void i915_gem_request_assign(struct drm_i915_gem_request **pdst,
- struct drm_i915_gem_request *src)
-{
- if (src)
- i915_gem_request_reference(src);
-
- if (*pdst)
- i915_gem_request_unreference(*pdst);
-
- *pdst = src;
-}
-
-/*
- * XXX: i915_gem_request_completed should be here but currently needs the
- * definition of i915_seqno_passed() which is below. It will be moved in
- * a later patch when the call to i915_seqno_passed() is obsoleted...
- */
-