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25 #ifndef I915_REQUEST_H
26 #define I915_REQUEST_H
28 #include <linux/dma-fence.h>
29 #include <linux/lockdep.h>
32 #include "i915_scheduler.h"
33 #include "i915_selftest.h"
34 #include "i915_sw_fence.h"
36 #include <uapi/drm/i915_drm.h>
39 struct drm_i915_gem_object;
42 struct i915_timeline_cacheline;
44 struct i915_capture_list {
45 struct i915_capture_list *next;
51 * I915_FENCE_FLAG_ACTIVE - this request is currently submitted to HW.
53 * Set by __i915_request_submit() on handing over to HW, and cleared
54 * by __i915_request_unsubmit() if we preempt this request.
56 * Finally cleared for consistency on retiring the request, when
57 * we know the HW is no longer running this request.
59 * See i915_request_is_active()
61 I915_FENCE_FLAG_ACTIVE = DMA_FENCE_FLAG_USER_BITS,
64 * I915_FENCE_FLAG_SIGNAL - this request is currently on signal_list
66 * Internal bookkeeping used by the breadcrumb code to track when
67 * a request is on the various signal_list.
69 I915_FENCE_FLAG_SIGNAL,
73 * Request queue structure.
75 * The request queue allows us to note sequence numbers that have been emitted
76 * and may be associated with active buffers to be retired.
78 * By keeping this list, we can avoid having to do questionable sequence
79 * number comparisons on buffer last_read|write_seqno. It also allows an
80 * emission time to be associated with the request for tracking how far ahead
81 * of the GPU the submission is.
83 * When modifying this structure be very aware that we perform a lockless
84 * RCU lookup of it that may race against reallocation of the struct
85 * from the slab freelist. We intentionally do not zero the structure on
86 * allocation so that the lookup can use the dangling pointers (and is
87 * cogniscent that those pointers may be wrong). Instead, everything that
88 * needs to be initialised must be done so explicitly.
90 * The requests are reference counted.
93 struct dma_fence fence;
96 /** On Which ring this request was generated */
97 struct drm_i915_private *i915;
100 * Context and ring buffer related to this request
101 * Contexts are refcounted, so when this request is associated with a
102 * context, we must increment the context's refcount, to guarantee that
103 * it persists while any request is linked to it. Requests themselves
104 * are also refcounted, so the request will only be freed when the last
105 * reference to it is dismissed, and the code in
106 * i915_request_free() will then decrement the refcount on the
109 struct i915_gem_context *gem_context;
110 struct intel_engine_cs *engine;
111 struct intel_context *hw_context;
112 struct intel_ring *ring;
113 struct i915_timeline *timeline;
114 struct list_head signal_link;
117 * The rcu epoch of when this request was allocated. Used to judiciously
118 * apply backpressure on future allocations to ensure that under
119 * mempressure there is sufficient RCU ticks for us to reclaim our
120 * RCU protected slabs.
122 unsigned long rcustate;
125 * We pin the timeline->mutex while constructing the request to
126 * ensure that no caller accidentally drops it during construction.
127 * The timeline->mutex must be held to ensure that only this caller
128 * can use the ring and manipulate the associated timeline during
131 struct pin_cookie cookie;
134 * Fences for the various phases in the request's lifetime.
136 * The submit fence is used to await upon all of the request's
137 * dependencies. When it is signaled, the request is ready to run.
138 * It is used by the driver to then queue the request for execution.
140 struct i915_sw_fence submit;
142 wait_queue_entry_t submitq;
143 struct i915_sw_dma_fence_cb dmaq;
145 struct list_head execute_cb;
146 struct i915_sw_fence semaphore;
149 * A list of everyone we wait upon, and everyone who waits upon us.
150 * Even though we will not be submitted to the hardware before the
151 * submit fence is signaled (it waits for all external events as well
152 * as our own requests), the scheduler still needs to know the
153 * dependency tree for the lifetime of the request (from execbuf
154 * to retirement), i.e. bidirectional dependency information for the
155 * request not tied to individual fences.
157 struct i915_sched_node sched;
158 struct i915_dependency dep;
161 * A convenience pointer to the current breadcrumb value stored in
162 * the HW status page (or our timeline's local equivalent). The full
163 * path would be rq->hw_context->ring->timeline->hwsp_seqno.
165 const u32 *hwsp_seqno;
168 * If we need to access the timeline's seqno for this request in
169 * another request, we need to keep a read reference to this associated
170 * cacheline, so that we do not free and recycle it before the foreign
171 * observers have completed. Hence, we keep a pointer to the cacheline
172 * inside the timeline's HWSP vma, but it is only valid while this
173 * request has not completed and guarded by the timeline mutex.
175 struct i915_timeline_cacheline *hwsp_cacheline;
177 /** Position in the ring of the start of the request */
180 /** Position in the ring of the start of the user packets */
184 * Position in the ring of the start of the postfix.
185 * This is required to calculate the maximum available ring space
186 * without overwriting the postfix.
190 /** Position in the ring of the end of the whole request */
193 /** Position in the ring of the end of any workarounds after the tail */
196 /** Preallocate space in the ring for the emitting the request */
199 /** Batch buffer related to this request if any (used for
200 * error state dump only).
202 struct i915_vma *batch;
204 * Additional buffers requested by userspace to be captured upon
205 * a GPU hang. The vma/obj on this list are protected by their
206 * active reference - all objects on this list must also be
207 * on the active_list (of their final request).
209 struct i915_capture_list *capture_list;
210 struct list_head active_list;
212 /** Time at which this request was emitted, in jiffies. */
213 unsigned long emitted_jiffies;
217 /** engine->request_list entry for this request */
218 struct list_head link;
220 /** ring->request_list entry for this request */
221 struct list_head ring_link;
223 struct drm_i915_file_private *file_priv;
224 /** file_priv list entry for this request */
225 struct list_head client_link;
227 I915_SELFTEST_DECLARE(struct {
228 struct list_head link;
233 #define I915_FENCE_GFP (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN)
235 extern const struct dma_fence_ops i915_fence_ops;
237 static inline bool dma_fence_is_i915(const struct dma_fence *fence)
239 return fence->ops == &i915_fence_ops;
242 struct i915_request * __must_check
243 i915_request_alloc(struct intel_engine_cs *engine,
244 struct i915_gem_context *ctx);
245 void i915_request_retire_upto(struct i915_request *rq);
247 static inline struct i915_request *
248 to_request(struct dma_fence *fence)
250 /* We assume that NULL fence/request are interoperable */
251 BUILD_BUG_ON(offsetof(struct i915_request, fence) != 0);
252 GEM_BUG_ON(fence && !dma_fence_is_i915(fence));
253 return container_of(fence, struct i915_request, fence);
256 static inline struct i915_request *
257 i915_request_get(struct i915_request *rq)
259 return to_request(dma_fence_get(&rq->fence));
262 static inline struct i915_request *
263 i915_request_get_rcu(struct i915_request *rq)
265 return to_request(dma_fence_get_rcu(&rq->fence));
269 i915_request_put(struct i915_request *rq)
271 dma_fence_put(&rq->fence);
274 int i915_request_await_object(struct i915_request *to,
275 struct drm_i915_gem_object *obj,
277 int i915_request_await_dma_fence(struct i915_request *rq,
278 struct dma_fence *fence);
280 void i915_request_add(struct i915_request *rq);
282 void __i915_request_submit(struct i915_request *request);
283 void i915_request_submit(struct i915_request *request);
285 void i915_request_skip(struct i915_request *request, int error);
287 void __i915_request_unsubmit(struct i915_request *request);
288 void i915_request_unsubmit(struct i915_request *request);
290 /* Note: part of the intel_breadcrumbs family */
291 bool i915_request_enable_breadcrumb(struct i915_request *request);
292 void i915_request_cancel_breadcrumb(struct i915_request *request);
294 long i915_request_wait(struct i915_request *rq,
297 __attribute__((nonnull(1)));
298 #define I915_WAIT_INTERRUPTIBLE BIT(0)
299 #define I915_WAIT_LOCKED BIT(1) /* struct_mutex held, handle GPU reset */
300 #define I915_WAIT_PRIORITY BIT(2) /* small priority bump for the request */
301 #define I915_WAIT_ALL BIT(3) /* used by i915_gem_object_wait() */
302 #define I915_WAIT_FOR_IDLE_BOOST BIT(4)
304 static inline bool i915_request_signaled(const struct i915_request *rq)
306 /* The request may live longer than its HWSP, so check flags first! */
307 return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags);
310 static inline bool i915_request_is_active(const struct i915_request *rq)
312 return test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags);
316 * Returns true if seq1 is later than seq2.
318 static inline bool i915_seqno_passed(u32 seq1, u32 seq2)
320 return (s32)(seq1 - seq2) >= 0;
323 static inline u32 __hwsp_seqno(const struct i915_request *rq)
325 return READ_ONCE(*rq->hwsp_seqno);
329 * hwsp_seqno - the current breadcrumb value in the HW status page
330 * @rq: the request, to chase the relevant HW status page
332 * The emphasis in naming here is that hwsp_seqno() is not a property of the
333 * request, but an indication of the current HW state (associated with this
334 * request). Its value will change as the GPU executes more requests.
336 * Returns the current breadcrumb value in the associated HW status page (or
337 * the local timeline's equivalent) for this request. The request itself
338 * has the associated breadcrumb value of rq->fence.seqno, when the HW
339 * status page has that breadcrumb or later, this request is complete.
341 static inline u32 hwsp_seqno(const struct i915_request *rq)
345 rcu_read_lock(); /* the HWSP may be freed at runtime */
346 seqno = __hwsp_seqno(rq);
352 static inline bool __i915_request_has_started(const struct i915_request *rq)
354 return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno - 1);
358 * i915_request_started - check if the request has begun being executed
361 * If the timeline is not using initial breadcrumbs, a request is
362 * considered started if the previous request on its timeline (i.e.
363 * context) has been signaled.
365 * If the timeline is using semaphores, it will also be emitting an
366 * "initial breadcrumb" after the semaphores are complete and just before
367 * it began executing the user payload. A request can therefore be active
368 * on the HW and not yet started as it is still busywaiting on its
369 * dependencies (via HW semaphores).
371 * If the request has started, its dependencies will have been signaled
372 * (either by fences or by semaphores) and it will have begun processing
375 * However, even if a request has started, it may have been preempted and
376 * so no longer active, or it may have already completed.
378 * See also i915_request_is_active().
380 * Returns true if the request has begun executing the user payload, or
383 static inline bool i915_request_started(const struct i915_request *rq)
385 if (i915_request_signaled(rq))
388 /* Remember: started but may have since been preempted! */
389 return __i915_request_has_started(rq);
393 * i915_request_is_running - check if the request may actually be executing
396 * Returns true if the request is currently submitted to hardware, has passed
397 * its start point (i.e. the context is setup and not busywaiting). Note that
398 * it may no longer be running by the time the function returns!
400 static inline bool i915_request_is_running(const struct i915_request *rq)
402 if (!i915_request_is_active(rq))
405 return __i915_request_has_started(rq);
408 static inline bool i915_request_completed(const struct i915_request *rq)
410 if (i915_request_signaled(rq))
413 return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno);
416 static inline void i915_request_mark_complete(struct i915_request *rq)
418 rq->hwsp_seqno = (u32 *)&rq->fence.seqno; /* decouple from HWSP */
421 void i915_retire_requests(struct drm_i915_private *i915);
423 #endif /* I915_REQUEST_H */