1 /* 2 * Copyright © 2008-2018 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 */ 24 25 #ifndef I915_REQUEST_H 26 #define I915_REQUEST_H 27 28 #include <linux/dma-fence.h> 29 #include <linux/lockdep.h> 30 31 #include "i915_gem.h" 32 #include "i915_scheduler.h" 33 #include "i915_selftest.h" 34 #include "i915_sw_fence.h" 35 36 #include <uapi/drm/i915_drm.h> 37 38 struct drm_file; 39 struct drm_i915_gem_object; 40 struct i915_request; 41 struct i915_timeline; 42 struct i915_timeline_cacheline; 43 44 struct i915_capture_list { 45 struct i915_capture_list *next; 46 struct i915_vma *vma; 47 }; 48 49 enum { 50 /* 51 * I915_FENCE_FLAG_ACTIVE - this request is currently submitted to HW. 52 * 53 * Set by __i915_request_submit() on handing over to HW, and cleared 54 * by __i915_request_unsubmit() if we preempt this request. 55 * 56 * Finally cleared for consistency on retiring the request, when 57 * we know the HW is no longer running this request. 58 * 59 * See i915_request_is_active() 60 */ 61 I915_FENCE_FLAG_ACTIVE = DMA_FENCE_FLAG_USER_BITS, 62 63 /* 64 * I915_FENCE_FLAG_SIGNAL - this request is currently on signal_list 65 * 66 * Internal bookkeeping used by the breadcrumb code to track when 67 * a request is on the various signal_list. 68 */ 69 I915_FENCE_FLAG_SIGNAL, 70 }; 71 72 /** 73 * Request queue structure. 74 * 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. 77 * 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. 82 * 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. 89 * 90 * The requests are reference counted. 91 */ 92 struct i915_request { 93 struct dma_fence fence; 94 spinlock_t lock; 95 96 /** On Which ring this request was generated */ 97 struct drm_i915_private *i915; 98 99 /** 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 107 * context. 108 */ 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; 115 116 /* 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. 121 */ 122 unsigned long rcustate; 123 124 /* 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 129 * construction. 130 */ 131 struct pin_cookie cookie; 132 133 /* 134 * Fences for the various phases in the request's lifetime. 135 * 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. 139 */ 140 struct i915_sw_fence submit; 141 union { 142 wait_queue_entry_t submitq; 143 struct i915_sw_dma_fence_cb dmaq; 144 }; 145 struct list_head execute_cb; 146 struct i915_sw_fence semaphore; 147 148 /* 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. 156 */ 157 struct i915_sched_node sched; 158 struct i915_dependency dep; 159 160 /* 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. 164 */ 165 const u32 *hwsp_seqno; 166 167 /* 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. 174 */ 175 struct i915_timeline_cacheline *hwsp_cacheline; 176 177 /** Position in the ring of the start of the request */ 178 u32 head; 179 180 /** Position in the ring of the start of the user packets */ 181 u32 infix; 182 183 /** 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. 187 */ 188 u32 postfix; 189 190 /** Position in the ring of the end of the whole request */ 191 u32 tail; 192 193 /** Position in the ring of the end of any workarounds after the tail */ 194 u32 wa_tail; 195 196 /** Preallocate space in the ring for the emitting the request */ 197 u32 reserved_space; 198 199 /** Batch buffer related to this request if any (used for 200 * error state dump only). 201 */ 202 struct i915_vma *batch; 203 /** 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). 208 */ 209 struct i915_capture_list *capture_list; 210 struct list_head active_list; 211 212 /** Time at which this request was emitted, in jiffies. */ 213 unsigned long emitted_jiffies; 214 215 bool waitboost; 216 217 /** engine->request_list entry for this request */ 218 struct list_head link; 219 220 /** ring->request_list entry for this request */ 221 struct list_head ring_link; 222 223 struct drm_i915_file_private *file_priv; 224 /** file_priv list entry for this request */ 225 struct list_head client_link; 226 227 I915_SELFTEST_DECLARE(struct { 228 struct list_head link; 229 unsigned long delay; 230 } mock;) 231 }; 232 233 #define I915_FENCE_GFP (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN) 234 235 extern const struct dma_fence_ops i915_fence_ops; 236 237 static inline bool dma_fence_is_i915(const struct dma_fence *fence) 238 { 239 return fence->ops == &i915_fence_ops; 240 } 241 242 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); 246 247 static inline struct i915_request * 248 to_request(struct dma_fence *fence) 249 { 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); 254 } 255 256 static inline struct i915_request * 257 i915_request_get(struct i915_request *rq) 258 { 259 return to_request(dma_fence_get(&rq->fence)); 260 } 261 262 static inline struct i915_request * 263 i915_request_get_rcu(struct i915_request *rq) 264 { 265 return to_request(dma_fence_get_rcu(&rq->fence)); 266 } 267 268 static inline void 269 i915_request_put(struct i915_request *rq) 270 { 271 dma_fence_put(&rq->fence); 272 } 273 274 int i915_request_await_object(struct i915_request *to, 275 struct drm_i915_gem_object *obj, 276 bool write); 277 int i915_request_await_dma_fence(struct i915_request *rq, 278 struct dma_fence *fence); 279 280 void i915_request_add(struct i915_request *rq); 281 282 void __i915_request_submit(struct i915_request *request); 283 void i915_request_submit(struct i915_request *request); 284 285 void i915_request_skip(struct i915_request *request, int error); 286 287 void __i915_request_unsubmit(struct i915_request *request); 288 void i915_request_unsubmit(struct i915_request *request); 289 290 /* 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); 293 294 long i915_request_wait(struct i915_request *rq, 295 unsigned int flags, 296 long timeout) 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) 303 304 static inline bool i915_request_signaled(const struct i915_request *rq) 305 { 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); 308 } 309 310 static inline bool i915_request_is_active(const struct i915_request *rq) 311 { 312 return test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags); 313 } 314 315 /** 316 * Returns true if seq1 is later than seq2. 317 */ 318 static inline bool i915_seqno_passed(u32 seq1, u32 seq2) 319 { 320 return (s32)(seq1 - seq2) >= 0; 321 } 322 323 static inline u32 __hwsp_seqno(const struct i915_request *rq) 324 { 325 return READ_ONCE(*rq->hwsp_seqno); 326 } 327 328 /** 329 * hwsp_seqno - the current breadcrumb value in the HW status page 330 * @rq: the request, to chase the relevant HW status page 331 * 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. 335 * 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. 340 */ 341 static inline u32 hwsp_seqno(const struct i915_request *rq) 342 { 343 u32 seqno; 344 345 rcu_read_lock(); /* the HWSP may be freed at runtime */ 346 seqno = __hwsp_seqno(rq); 347 rcu_read_unlock(); 348 349 return seqno; 350 } 351 352 static inline bool __i915_request_has_started(const struct i915_request *rq) 353 { 354 return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno - 1); 355 } 356 357 /** 358 * i915_request_started - check if the request has begun being executed 359 * @rq: the request 360 * 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. 364 * 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). 370 * 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 373 * the user payload. 374 * 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. 377 * 378 * See also i915_request_is_active(). 379 * 380 * Returns true if the request has begun executing the user payload, or 381 * has completed: 382 */ 383 static inline bool i915_request_started(const struct i915_request *rq) 384 { 385 if (i915_request_signaled(rq)) 386 return true; 387 388 /* Remember: started but may have since been preempted! */ 389 return __i915_request_has_started(rq); 390 } 391 392 /** 393 * i915_request_is_running - check if the request may actually be executing 394 * @rq: the request 395 * 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! 399 */ 400 static inline bool i915_request_is_running(const struct i915_request *rq) 401 { 402 if (!i915_request_is_active(rq)) 403 return false; 404 405 return __i915_request_has_started(rq); 406 } 407 408 static inline bool i915_request_completed(const struct i915_request *rq) 409 { 410 if (i915_request_signaled(rq)) 411 return true; 412 413 return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno); 414 } 415 416 static inline void i915_request_mark_complete(struct i915_request *rq) 417 { 418 rq->hwsp_seqno = (u32 *)&rq->fence.seqno; /* decouple from HWSP */ 419 } 420 421 void i915_retire_requests(struct drm_i915_private *i915); 422 423 #endif /* I915_REQUEST_H */ 424