1 /* 2 * Copyright © 2015 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 #include <linux/kthread.h> 26 #include <trace/events/dma_fence.h> 27 #include <uapi/linux/sched/types.h> 28 29 #include "i915_drv.h" 30 #include "i915_trace.h" 31 #include "intel_gt_pm.h" 32 #include "intel_gt_requests.h" 33 34 static void irq_enable(struct intel_engine_cs *engine) 35 { 36 if (!engine->irq_enable) 37 return; 38 39 /* Caller disables interrupts */ 40 spin_lock(&engine->gt->irq_lock); 41 engine->irq_enable(engine); 42 spin_unlock(&engine->gt->irq_lock); 43 } 44 45 static void irq_disable(struct intel_engine_cs *engine) 46 { 47 if (!engine->irq_disable) 48 return; 49 50 /* Caller disables interrupts */ 51 spin_lock(&engine->gt->irq_lock); 52 engine->irq_disable(engine); 53 spin_unlock(&engine->gt->irq_lock); 54 } 55 56 static void __intel_breadcrumbs_disarm_irq(struct intel_breadcrumbs *b) 57 { 58 struct intel_engine_cs *engine = 59 container_of(b, struct intel_engine_cs, breadcrumbs); 60 61 lockdep_assert_held(&b->irq_lock); 62 63 GEM_BUG_ON(!b->irq_enabled); 64 if (!--b->irq_enabled) 65 irq_disable(engine); 66 67 b->irq_armed = false; 68 intel_gt_pm_put_async(engine->gt); 69 } 70 71 void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine) 72 { 73 struct intel_breadcrumbs *b = &engine->breadcrumbs; 74 unsigned long flags; 75 76 if (!b->irq_armed) 77 return; 78 79 spin_lock_irqsave(&b->irq_lock, flags); 80 if (b->irq_armed) 81 __intel_breadcrumbs_disarm_irq(b); 82 spin_unlock_irqrestore(&b->irq_lock, flags); 83 } 84 85 static inline bool __request_completed(const struct i915_request *rq) 86 { 87 return i915_seqno_passed(__hwsp_seqno(rq), rq->fence.seqno); 88 } 89 90 __maybe_unused static bool 91 check_signal_order(struct intel_context *ce, struct i915_request *rq) 92 { 93 if (!list_is_last(&rq->signal_link, &ce->signals) && 94 i915_seqno_passed(rq->fence.seqno, 95 list_next_entry(rq, signal_link)->fence.seqno)) 96 return false; 97 98 if (!list_is_first(&rq->signal_link, &ce->signals) && 99 i915_seqno_passed(list_prev_entry(rq, signal_link)->fence.seqno, 100 rq->fence.seqno)) 101 return false; 102 103 return true; 104 } 105 106 static bool 107 __dma_fence_signal(struct dma_fence *fence) 108 { 109 return !test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags); 110 } 111 112 static void 113 __dma_fence_signal__timestamp(struct dma_fence *fence, ktime_t timestamp) 114 { 115 fence->timestamp = timestamp; 116 set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags); 117 trace_dma_fence_signaled(fence); 118 } 119 120 static void 121 __dma_fence_signal__notify(struct dma_fence *fence, 122 const struct list_head *list) 123 { 124 struct dma_fence_cb *cur, *tmp; 125 126 lockdep_assert_held(fence->lock); 127 128 list_for_each_entry_safe(cur, tmp, list, node) { 129 INIT_LIST_HEAD(&cur->node); 130 cur->func(fence, cur); 131 } 132 } 133 134 static void add_retire(struct intel_breadcrumbs *b, struct intel_timeline *tl) 135 { 136 struct intel_engine_cs *engine = 137 container_of(b, struct intel_engine_cs, breadcrumbs); 138 139 intel_engine_add_retire(engine, tl); 140 } 141 142 static void signal_irq_work(struct irq_work *work) 143 { 144 struct intel_breadcrumbs *b = container_of(work, typeof(*b), irq_work); 145 const ktime_t timestamp = ktime_get(); 146 struct intel_context *ce, *cn; 147 struct list_head *pos, *next; 148 LIST_HEAD(signal); 149 150 spin_lock(&b->irq_lock); 151 152 if (b->irq_armed && list_empty(&b->signalers)) 153 __intel_breadcrumbs_disarm_irq(b); 154 155 list_for_each_entry_safe(ce, cn, &b->signalers, signal_link) { 156 GEM_BUG_ON(list_empty(&ce->signals)); 157 158 list_for_each_safe(pos, next, &ce->signals) { 159 struct i915_request *rq = 160 list_entry(pos, typeof(*rq), signal_link); 161 162 GEM_BUG_ON(!check_signal_order(ce, rq)); 163 164 if (!__request_completed(rq)) 165 break; 166 167 GEM_BUG_ON(!test_bit(I915_FENCE_FLAG_SIGNAL, 168 &rq->fence.flags)); 169 clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); 170 171 if (!__dma_fence_signal(&rq->fence)) 172 continue; 173 174 /* 175 * Queue for execution after dropping the signaling 176 * spinlock as the callback chain may end up adding 177 * more signalers to the same context or engine. 178 */ 179 i915_request_get(rq); 180 list_add_tail(&rq->signal_link, &signal); 181 } 182 183 /* 184 * We process the list deletion in bulk, only using a list_add 185 * (not list_move) above but keeping the status of 186 * rq->signal_link known with the I915_FENCE_FLAG_SIGNAL bit. 187 */ 188 if (!list_is_first(pos, &ce->signals)) { 189 /* Advance the list to the first incomplete request */ 190 __list_del_many(&ce->signals, pos); 191 if (&ce->signals == pos) { /* now empty */ 192 list_del_init(&ce->signal_link); 193 add_retire(b, ce->timeline); 194 } 195 } 196 } 197 198 spin_unlock(&b->irq_lock); 199 200 list_for_each_safe(pos, next, &signal) { 201 struct i915_request *rq = 202 list_entry(pos, typeof(*rq), signal_link); 203 struct list_head cb_list; 204 205 spin_lock(&rq->lock); 206 list_replace(&rq->fence.cb_list, &cb_list); 207 __dma_fence_signal__timestamp(&rq->fence, timestamp); 208 __dma_fence_signal__notify(&rq->fence, &cb_list); 209 spin_unlock(&rq->lock); 210 211 i915_request_put(rq); 212 } 213 } 214 215 static bool __intel_breadcrumbs_arm_irq(struct intel_breadcrumbs *b) 216 { 217 struct intel_engine_cs *engine = 218 container_of(b, struct intel_engine_cs, breadcrumbs); 219 220 lockdep_assert_held(&b->irq_lock); 221 if (b->irq_armed) 222 return true; 223 224 if (!intel_gt_pm_get_if_awake(engine->gt)) 225 return false; 226 227 /* 228 * The breadcrumb irq will be disarmed on the interrupt after the 229 * waiters are signaled. This gives us a single interrupt window in 230 * which we can add a new waiter and avoid the cost of re-enabling 231 * the irq. 232 */ 233 b->irq_armed = true; 234 235 /* 236 * Since we are waiting on a request, the GPU should be busy 237 * and should have its own rpm reference. This is tracked 238 * by i915->gt.awake, we can forgo holding our own wakref 239 * for the interrupt as before i915->gt.awake is released (when 240 * the driver is idle) we disarm the breadcrumbs. 241 */ 242 243 if (!b->irq_enabled++) 244 irq_enable(engine); 245 246 return true; 247 } 248 249 void intel_engine_init_breadcrumbs(struct intel_engine_cs *engine) 250 { 251 struct intel_breadcrumbs *b = &engine->breadcrumbs; 252 253 spin_lock_init(&b->irq_lock); 254 INIT_LIST_HEAD(&b->signalers); 255 256 init_irq_work(&b->irq_work, signal_irq_work); 257 } 258 259 void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine) 260 { 261 struct intel_breadcrumbs *b = &engine->breadcrumbs; 262 unsigned long flags; 263 264 spin_lock_irqsave(&b->irq_lock, flags); 265 266 if (b->irq_enabled) 267 irq_enable(engine); 268 else 269 irq_disable(engine); 270 271 spin_unlock_irqrestore(&b->irq_lock, flags); 272 } 273 274 void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine) 275 { 276 } 277 278 bool i915_request_enable_breadcrumb(struct i915_request *rq) 279 { 280 lockdep_assert_held(&rq->lock); 281 282 if (test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags)) { 283 struct intel_breadcrumbs *b = &rq->engine->breadcrumbs; 284 struct intel_context *ce = rq->context; 285 struct list_head *pos; 286 287 spin_lock(&b->irq_lock); 288 GEM_BUG_ON(test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)); 289 290 if (!__intel_breadcrumbs_arm_irq(b)) 291 goto unlock; 292 293 /* 294 * We keep the seqno in retirement order, so we can break 295 * inside intel_engine_signal_breadcrumbs as soon as we've 296 * passed the last completed request (or seen a request that 297 * hasn't event started). We could walk the timeline->requests, 298 * but keeping a separate signalers_list has the advantage of 299 * hopefully being much smaller than the full list and so 300 * provides faster iteration and detection when there are no 301 * more interrupts required for this context. 302 * 303 * We typically expect to add new signalers in order, so we 304 * start looking for our insertion point from the tail of 305 * the list. 306 */ 307 list_for_each_prev(pos, &ce->signals) { 308 struct i915_request *it = 309 list_entry(pos, typeof(*it), signal_link); 310 311 if (i915_seqno_passed(rq->fence.seqno, it->fence.seqno)) 312 break; 313 } 314 list_add(&rq->signal_link, pos); 315 if (pos == &ce->signals) /* catch transitions from empty list */ 316 list_move_tail(&ce->signal_link, &b->signalers); 317 GEM_BUG_ON(!check_signal_order(ce, rq)); 318 319 set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); 320 unlock: 321 spin_unlock(&b->irq_lock); 322 } 323 324 return !__request_completed(rq); 325 } 326 327 void i915_request_cancel_breadcrumb(struct i915_request *rq) 328 { 329 struct intel_breadcrumbs *b = &rq->engine->breadcrumbs; 330 331 lockdep_assert_held(&rq->lock); 332 333 /* 334 * We must wait for b->irq_lock so that we know the interrupt handler 335 * has released its reference to the intel_context and has completed 336 * the DMA_FENCE_FLAG_SIGNALED_BIT/I915_FENCE_FLAG_SIGNAL dance (if 337 * required). 338 */ 339 spin_lock(&b->irq_lock); 340 if (test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)) { 341 struct intel_context *ce = rq->context; 342 343 list_del(&rq->signal_link); 344 if (list_empty(&ce->signals)) 345 list_del_init(&ce->signal_link); 346 347 clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags); 348 } 349 spin_unlock(&b->irq_lock); 350 } 351 352 void intel_engine_print_breadcrumbs(struct intel_engine_cs *engine, 353 struct drm_printer *p) 354 { 355 struct intel_breadcrumbs *b = &engine->breadcrumbs; 356 struct intel_context *ce; 357 struct i915_request *rq; 358 359 if (list_empty(&b->signalers)) 360 return; 361 362 drm_printf(p, "Signals:\n"); 363 364 spin_lock_irq(&b->irq_lock); 365 list_for_each_entry(ce, &b->signalers, signal_link) { 366 list_for_each_entry(rq, &ce->signals, signal_link) { 367 drm_printf(p, "\t[%llx:%llx%s] @ %dms\n", 368 rq->fence.context, rq->fence.seqno, 369 i915_request_completed(rq) ? "!" : 370 i915_request_started(rq) ? "*" : 371 "", 372 jiffies_to_msecs(jiffies - rq->emitted_jiffies)); 373 } 374 } 375 spin_unlock_irq(&b->irq_lock); 376 } 377