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 "gt/intel_engine_types.h" 32 33 #include "i915_gem.h" 34 #include "i915_scheduler.h" 35 #include "i915_selftest.h" 36 #include "i915_sw_fence.h" 37 38 #include <uapi/drm/i915_drm.h> 39 40 struct drm_file; 41 struct drm_i915_gem_object; 42 struct i915_request; 43 struct i915_timeline; 44 struct i915_timeline_cacheline; 45 46 struct i915_capture_list { 47 struct i915_capture_list *next; 48 struct i915_vma *vma; 49 }; 50 51 enum { 52 /* 53 * I915_FENCE_FLAG_ACTIVE - this request is currently submitted to HW. 54 * 55 * Set by __i915_request_submit() on handing over to HW, and cleared 56 * by __i915_request_unsubmit() if we preempt this request. 57 * 58 * Finally cleared for consistency on retiring the request, when 59 * we know the HW is no longer running this request. 60 * 61 * See i915_request_is_active() 62 */ 63 I915_FENCE_FLAG_ACTIVE = DMA_FENCE_FLAG_USER_BITS, 64 65 /* 66 * I915_FENCE_FLAG_SIGNAL - this request is currently on signal_list 67 * 68 * Internal bookkeeping used by the breadcrumb code to track when 69 * a request is on the various signal_list. 70 */ 71 I915_FENCE_FLAG_SIGNAL, 72 }; 73 74 /** 75 * Request queue structure. 76 * 77 * The request queue allows us to note sequence numbers that have been emitted 78 * and may be associated with active buffers to be retired. 79 * 80 * By keeping this list, we can avoid having to do questionable sequence 81 * number comparisons on buffer last_read|write_seqno. It also allows an 82 * emission time to be associated with the request for tracking how far ahead 83 * of the GPU the submission is. 84 * 85 * When modifying this structure be very aware that we perform a lockless 86 * RCU lookup of it that may race against reallocation of the struct 87 * from the slab freelist. We intentionally do not zero the structure on 88 * allocation so that the lookup can use the dangling pointers (and is 89 * cogniscent that those pointers may be wrong). Instead, everything that 90 * needs to be initialised must be done so explicitly. 91 * 92 * The requests are reference counted. 93 */ 94 struct i915_request { 95 struct dma_fence fence; 96 spinlock_t lock; 97 98 /** On Which ring this request was generated */ 99 struct drm_i915_private *i915; 100 101 /** 102 * Context and ring buffer related to this request 103 * Contexts are refcounted, so when this request is associated with a 104 * context, we must increment the context's refcount, to guarantee that 105 * it persists while any request is linked to it. Requests themselves 106 * are also refcounted, so the request will only be freed when the last 107 * reference to it is dismissed, and the code in 108 * i915_request_free() will then decrement the refcount on the 109 * context. 110 */ 111 struct i915_gem_context *gem_context; 112 struct intel_engine_cs *engine; 113 struct intel_context *hw_context; 114 struct intel_ring *ring; 115 struct i915_timeline *timeline; 116 struct list_head signal_link; 117 118 /* 119 * The rcu epoch of when this request was allocated. Used to judiciously 120 * apply backpressure on future allocations to ensure that under 121 * mempressure there is sufficient RCU ticks for us to reclaim our 122 * RCU protected slabs. 123 */ 124 unsigned long rcustate; 125 126 /* 127 * We pin the timeline->mutex while constructing the request to 128 * ensure that no caller accidentally drops it during construction. 129 * The timeline->mutex must be held to ensure that only this caller 130 * can use the ring and manipulate the associated timeline during 131 * construction. 132 */ 133 struct pin_cookie cookie; 134 135 /* 136 * Fences for the various phases in the request's lifetime. 137 * 138 * The submit fence is used to await upon all of the request's 139 * dependencies. When it is signaled, the request is ready to run. 140 * It is used by the driver to then queue the request for execution. 141 */ 142 struct i915_sw_fence submit; 143 union { 144 wait_queue_entry_t submitq; 145 struct i915_sw_dma_fence_cb dmaq; 146 }; 147 struct list_head execute_cb; 148 struct i915_sw_fence semaphore; 149 150 /* 151 * A list of everyone we wait upon, and everyone who waits upon us. 152 * Even though we will not be submitted to the hardware before the 153 * submit fence is signaled (it waits for all external events as well 154 * as our own requests), the scheduler still needs to know the 155 * dependency tree for the lifetime of the request (from execbuf 156 * to retirement), i.e. bidirectional dependency information for the 157 * request not tied to individual fences. 158 */ 159 struct i915_sched_node sched; 160 struct i915_dependency dep; 161 intel_engine_mask_t execution_mask; 162 163 /* 164 * A convenience pointer to the current breadcrumb value stored in 165 * the HW status page (or our timeline's local equivalent). The full 166 * path would be rq->hw_context->ring->timeline->hwsp_seqno. 167 */ 168 const u32 *hwsp_seqno; 169 170 /* 171 * If we need to access the timeline's seqno for this request in 172 * another request, we need to keep a read reference to this associated 173 * cacheline, so that we do not free and recycle it before the foreign 174 * observers have completed. Hence, we keep a pointer to the cacheline 175 * inside the timeline's HWSP vma, but it is only valid while this 176 * request has not completed and guarded by the timeline mutex. 177 */ 178 struct i915_timeline_cacheline *hwsp_cacheline; 179 180 /** Position in the ring of the start of the request */ 181 u32 head; 182 183 /** Position in the ring of the start of the user packets */ 184 u32 infix; 185 186 /** 187 * Position in the ring of the start of the postfix. 188 * This is required to calculate the maximum available ring space 189 * without overwriting the postfix. 190 */ 191 u32 postfix; 192 193 /** Position in the ring of the end of the whole request */ 194 u32 tail; 195 196 /** Position in the ring of the end of any workarounds after the tail */ 197 u32 wa_tail; 198 199 /** Preallocate space in the ring for the emitting the request */ 200 u32 reserved_space; 201 202 /** Batch buffer related to this request if any (used for 203 * error state dump only). 204 */ 205 struct i915_vma *batch; 206 /** 207 * Additional buffers requested by userspace to be captured upon 208 * a GPU hang. The vma/obj on this list are protected by their 209 * active reference - all objects on this list must also be 210 * on the active_list (of their final request). 211 */ 212 struct i915_capture_list *capture_list; 213 struct list_head active_list; 214 215 /** Time at which this request was emitted, in jiffies. */ 216 unsigned long emitted_jiffies; 217 218 bool waitboost; 219 220 /** timeline->request entry for this request */ 221 struct list_head link; 222 223 /** ring->request_list entry for this request */ 224 struct list_head ring_link; 225 226 struct drm_i915_file_private *file_priv; 227 /** file_priv list entry for this request */ 228 struct list_head client_link; 229 230 I915_SELFTEST_DECLARE(struct { 231 struct list_head link; 232 unsigned long delay; 233 } mock;) 234 }; 235 236 #define I915_FENCE_GFP (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN) 237 238 extern const struct dma_fence_ops i915_fence_ops; 239 240 static inline bool dma_fence_is_i915(const struct dma_fence *fence) 241 { 242 return fence->ops == &i915_fence_ops; 243 } 244 245 struct i915_request * __must_check 246 __i915_request_create(struct intel_context *ce, gfp_t gfp); 247 struct i915_request * __must_check 248 i915_request_create(struct intel_context *ce); 249 250 struct i915_request *__i915_request_commit(struct i915_request *request); 251 252 void i915_request_retire_upto(struct i915_request *rq); 253 254 static inline struct i915_request * 255 to_request(struct dma_fence *fence) 256 { 257 /* We assume that NULL fence/request are interoperable */ 258 BUILD_BUG_ON(offsetof(struct i915_request, fence) != 0); 259 GEM_BUG_ON(fence && !dma_fence_is_i915(fence)); 260 return container_of(fence, struct i915_request, fence); 261 } 262 263 static inline struct i915_request * 264 i915_request_get(struct i915_request *rq) 265 { 266 return to_request(dma_fence_get(&rq->fence)); 267 } 268 269 static inline struct i915_request * 270 i915_request_get_rcu(struct i915_request *rq) 271 { 272 return to_request(dma_fence_get_rcu(&rq->fence)); 273 } 274 275 static inline void 276 i915_request_put(struct i915_request *rq) 277 { 278 dma_fence_put(&rq->fence); 279 } 280 281 int i915_request_await_object(struct i915_request *to, 282 struct drm_i915_gem_object *obj, 283 bool write); 284 int i915_request_await_dma_fence(struct i915_request *rq, 285 struct dma_fence *fence); 286 int i915_request_await_execution(struct i915_request *rq, 287 struct dma_fence *fence, 288 void (*hook)(struct i915_request *rq, 289 struct dma_fence *signal)); 290 291 void i915_request_add(struct i915_request *rq); 292 293 void __i915_request_submit(struct i915_request *request); 294 void i915_request_submit(struct i915_request *request); 295 296 void i915_request_skip(struct i915_request *request, int error); 297 298 void __i915_request_unsubmit(struct i915_request *request); 299 void i915_request_unsubmit(struct i915_request *request); 300 301 /* Note: part of the intel_breadcrumbs family */ 302 bool i915_request_enable_breadcrumb(struct i915_request *request); 303 void i915_request_cancel_breadcrumb(struct i915_request *request); 304 305 long i915_request_wait(struct i915_request *rq, 306 unsigned int flags, 307 long timeout) 308 __attribute__((nonnull(1))); 309 #define I915_WAIT_INTERRUPTIBLE BIT(0) 310 #define I915_WAIT_LOCKED BIT(1) /* struct_mutex held, handle GPU reset */ 311 #define I915_WAIT_PRIORITY BIT(2) /* small priority bump for the request */ 312 #define I915_WAIT_ALL BIT(3) /* used by i915_gem_object_wait() */ 313 #define I915_WAIT_FOR_IDLE_BOOST BIT(4) 314 315 static inline bool i915_request_signaled(const struct i915_request *rq) 316 { 317 /* The request may live longer than its HWSP, so check flags first! */ 318 return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags); 319 } 320 321 static inline bool i915_request_is_active(const struct i915_request *rq) 322 { 323 return test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags); 324 } 325 326 /** 327 * Returns true if seq1 is later than seq2. 328 */ 329 static inline bool i915_seqno_passed(u32 seq1, u32 seq2) 330 { 331 return (s32)(seq1 - seq2) >= 0; 332 } 333 334 static inline u32 __hwsp_seqno(const struct i915_request *rq) 335 { 336 return READ_ONCE(*rq->hwsp_seqno); 337 } 338 339 /** 340 * hwsp_seqno - the current breadcrumb value in the HW status page 341 * @rq: the request, to chase the relevant HW status page 342 * 343 * The emphasis in naming here is that hwsp_seqno() is not a property of the 344 * request, but an indication of the current HW state (associated with this 345 * request). Its value will change as the GPU executes more requests. 346 * 347 * Returns the current breadcrumb value in the associated HW status page (or 348 * the local timeline's equivalent) for this request. The request itself 349 * has the associated breadcrumb value of rq->fence.seqno, when the HW 350 * status page has that breadcrumb or later, this request is complete. 351 */ 352 static inline u32 hwsp_seqno(const struct i915_request *rq) 353 { 354 u32 seqno; 355 356 rcu_read_lock(); /* the HWSP may be freed at runtime */ 357 seqno = __hwsp_seqno(rq); 358 rcu_read_unlock(); 359 360 return seqno; 361 } 362 363 static inline bool __i915_request_has_started(const struct i915_request *rq) 364 { 365 return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno - 1); 366 } 367 368 /** 369 * i915_request_started - check if the request has begun being executed 370 * @rq: the request 371 * 372 * If the timeline is not using initial breadcrumbs, a request is 373 * considered started if the previous request on its timeline (i.e. 374 * context) has been signaled. 375 * 376 * If the timeline is using semaphores, it will also be emitting an 377 * "initial breadcrumb" after the semaphores are complete and just before 378 * it began executing the user payload. A request can therefore be active 379 * on the HW and not yet started as it is still busywaiting on its 380 * dependencies (via HW semaphores). 381 * 382 * If the request has started, its dependencies will have been signaled 383 * (either by fences or by semaphores) and it will have begun processing 384 * the user payload. 385 * 386 * However, even if a request has started, it may have been preempted and 387 * so no longer active, or it may have already completed. 388 * 389 * See also i915_request_is_active(). 390 * 391 * Returns true if the request has begun executing the user payload, or 392 * has completed: 393 */ 394 static inline bool i915_request_started(const struct i915_request *rq) 395 { 396 if (i915_request_signaled(rq)) 397 return true; 398 399 /* Remember: started but may have since been preempted! */ 400 return __i915_request_has_started(rq); 401 } 402 403 /** 404 * i915_request_is_running - check if the request may actually be executing 405 * @rq: the request 406 * 407 * Returns true if the request is currently submitted to hardware, has passed 408 * its start point (i.e. the context is setup and not busywaiting). Note that 409 * it may no longer be running by the time the function returns! 410 */ 411 static inline bool i915_request_is_running(const struct i915_request *rq) 412 { 413 if (!i915_request_is_active(rq)) 414 return false; 415 416 return __i915_request_has_started(rq); 417 } 418 419 static inline bool i915_request_completed(const struct i915_request *rq) 420 { 421 if (i915_request_signaled(rq)) 422 return true; 423 424 return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno); 425 } 426 427 static inline void i915_request_mark_complete(struct i915_request *rq) 428 { 429 rq->hwsp_seqno = (u32 *)&rq->fence.seqno; /* decouple from HWSP */ 430 } 431 432 bool i915_retire_requests(struct drm_i915_private *i915); 433 434 #endif /* I915_REQUEST_H */ 435