1 /* 2 * Copyright(c) 2011-2016 Intel Corporation. All rights reserved. 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 FROM, 20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 21 * SOFTWARE. 22 * 23 * Authors: 24 * Anhua Xu 25 * Kevin Tian <kevin.tian@intel.com> 26 * 27 * Contributors: 28 * Min He <min.he@intel.com> 29 * Bing Niu <bing.niu@intel.com> 30 * Zhi Wang <zhi.a.wang@intel.com> 31 * 32 */ 33 34 #include "i915_drv.h" 35 #include "gvt.h" 36 37 static bool vgpu_has_pending_workload(struct intel_vgpu *vgpu) 38 { 39 enum intel_engine_id i; 40 struct intel_engine_cs *engine; 41 42 for_each_engine(engine, vgpu->gvt->gt, i) { 43 if (!list_empty(workload_q_head(vgpu, engine))) 44 return true; 45 } 46 47 return false; 48 } 49 50 /* We give 2 seconds higher prio for vGPU during start */ 51 #define GVT_SCHED_VGPU_PRI_TIME 2 52 53 struct vgpu_sched_data { 54 struct list_head lru_list; 55 struct intel_vgpu *vgpu; 56 bool active; 57 bool pri_sched; 58 ktime_t pri_time; 59 ktime_t sched_in_time; 60 ktime_t sched_time; 61 ktime_t left_ts; 62 ktime_t allocated_ts; 63 64 struct vgpu_sched_ctl sched_ctl; 65 }; 66 67 struct gvt_sched_data { 68 struct intel_gvt *gvt; 69 struct hrtimer timer; 70 unsigned long period; 71 struct list_head lru_runq_head; 72 ktime_t expire_time; 73 }; 74 75 static void vgpu_update_timeslice(struct intel_vgpu *vgpu, ktime_t cur_time) 76 { 77 ktime_t delta_ts; 78 struct vgpu_sched_data *vgpu_data; 79 80 if (!vgpu || vgpu == vgpu->gvt->idle_vgpu) 81 return; 82 83 vgpu_data = vgpu->sched_data; 84 delta_ts = ktime_sub(cur_time, vgpu_data->sched_in_time); 85 vgpu_data->sched_time = ktime_add(vgpu_data->sched_time, delta_ts); 86 vgpu_data->left_ts = ktime_sub(vgpu_data->left_ts, delta_ts); 87 vgpu_data->sched_in_time = cur_time; 88 } 89 90 #define GVT_TS_BALANCE_PERIOD_MS 100 91 #define GVT_TS_BALANCE_STAGE_NUM 10 92 93 static void gvt_balance_timeslice(struct gvt_sched_data *sched_data) 94 { 95 struct vgpu_sched_data *vgpu_data; 96 struct list_head *pos; 97 static u64 stage_check; 98 int stage = stage_check++ % GVT_TS_BALANCE_STAGE_NUM; 99 100 /* The timeslice accumulation reset at stage 0, which is 101 * allocated again without adding previous debt. 102 */ 103 if (stage == 0) { 104 int total_weight = 0; 105 ktime_t fair_timeslice; 106 107 list_for_each(pos, &sched_data->lru_runq_head) { 108 vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list); 109 total_weight += vgpu_data->sched_ctl.weight; 110 } 111 112 list_for_each(pos, &sched_data->lru_runq_head) { 113 vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list); 114 fair_timeslice = ktime_divns(ms_to_ktime(GVT_TS_BALANCE_PERIOD_MS), 115 total_weight) * vgpu_data->sched_ctl.weight; 116 117 vgpu_data->allocated_ts = fair_timeslice; 118 vgpu_data->left_ts = vgpu_data->allocated_ts; 119 } 120 } else { 121 list_for_each(pos, &sched_data->lru_runq_head) { 122 vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list); 123 124 /* timeslice for next 100ms should add the left/debt 125 * slice of previous stages. 126 */ 127 vgpu_data->left_ts += vgpu_data->allocated_ts; 128 } 129 } 130 } 131 132 static void try_to_schedule_next_vgpu(struct intel_gvt *gvt) 133 { 134 struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler; 135 enum intel_engine_id i; 136 struct intel_engine_cs *engine; 137 struct vgpu_sched_data *vgpu_data; 138 ktime_t cur_time; 139 140 /* no need to schedule if next_vgpu is the same with current_vgpu, 141 * let scheduler chose next_vgpu again by setting it to NULL. 142 */ 143 if (scheduler->next_vgpu == scheduler->current_vgpu) { 144 scheduler->next_vgpu = NULL; 145 return; 146 } 147 148 /* 149 * after the flag is set, workload dispatch thread will 150 * stop dispatching workload for current vgpu 151 */ 152 scheduler->need_reschedule = true; 153 154 /* still have uncompleted workload? */ 155 for_each_engine(engine, gvt->gt, i) { 156 if (scheduler->current_workload[engine->id]) 157 return; 158 } 159 160 cur_time = ktime_get(); 161 vgpu_update_timeslice(scheduler->current_vgpu, cur_time); 162 vgpu_data = scheduler->next_vgpu->sched_data; 163 vgpu_data->sched_in_time = cur_time; 164 165 /* switch current vgpu */ 166 scheduler->current_vgpu = scheduler->next_vgpu; 167 scheduler->next_vgpu = NULL; 168 169 scheduler->need_reschedule = false; 170 171 /* wake up workload dispatch thread */ 172 for_each_engine(engine, gvt->gt, i) 173 wake_up(&scheduler->waitq[engine->id]); 174 } 175 176 static struct intel_vgpu *find_busy_vgpu(struct gvt_sched_data *sched_data) 177 { 178 struct vgpu_sched_data *vgpu_data; 179 struct intel_vgpu *vgpu = NULL; 180 struct list_head *head = &sched_data->lru_runq_head; 181 struct list_head *pos; 182 183 /* search a vgpu with pending workload */ 184 list_for_each(pos, head) { 185 186 vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list); 187 if (!vgpu_has_pending_workload(vgpu_data->vgpu)) 188 continue; 189 190 if (vgpu_data->pri_sched) { 191 if (ktime_before(ktime_get(), vgpu_data->pri_time)) { 192 vgpu = vgpu_data->vgpu; 193 break; 194 } else 195 vgpu_data->pri_sched = false; 196 } 197 198 /* Return the vGPU only if it has time slice left */ 199 if (vgpu_data->left_ts > 0) { 200 vgpu = vgpu_data->vgpu; 201 break; 202 } 203 } 204 205 return vgpu; 206 } 207 208 /* in nanosecond */ 209 #define GVT_DEFAULT_TIME_SLICE 1000000 210 211 static void tbs_sched_func(struct gvt_sched_data *sched_data) 212 { 213 struct intel_gvt *gvt = sched_data->gvt; 214 struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler; 215 struct vgpu_sched_data *vgpu_data; 216 struct intel_vgpu *vgpu = NULL; 217 218 /* no active vgpu or has already had a target */ 219 if (list_empty(&sched_data->lru_runq_head) || scheduler->next_vgpu) 220 goto out; 221 222 vgpu = find_busy_vgpu(sched_data); 223 if (vgpu) { 224 scheduler->next_vgpu = vgpu; 225 vgpu_data = vgpu->sched_data; 226 if (!vgpu_data->pri_sched) { 227 /* Move the last used vGPU to the tail of lru_list */ 228 list_del_init(&vgpu_data->lru_list); 229 list_add_tail(&vgpu_data->lru_list, 230 &sched_data->lru_runq_head); 231 } 232 } else { 233 scheduler->next_vgpu = gvt->idle_vgpu; 234 } 235 out: 236 if (scheduler->next_vgpu) 237 try_to_schedule_next_vgpu(gvt); 238 } 239 240 void intel_gvt_schedule(struct intel_gvt *gvt) 241 { 242 struct gvt_sched_data *sched_data = gvt->scheduler.sched_data; 243 ktime_t cur_time; 244 245 mutex_lock(&gvt->sched_lock); 246 cur_time = ktime_get(); 247 248 if (test_and_clear_bit(INTEL_GVT_REQUEST_SCHED, 249 (void *)&gvt->service_request)) { 250 if (cur_time >= sched_data->expire_time) { 251 gvt_balance_timeslice(sched_data); 252 sched_data->expire_time = ktime_add_ms( 253 cur_time, GVT_TS_BALANCE_PERIOD_MS); 254 } 255 } 256 clear_bit(INTEL_GVT_REQUEST_EVENT_SCHED, (void *)&gvt->service_request); 257 258 vgpu_update_timeslice(gvt->scheduler.current_vgpu, cur_time); 259 tbs_sched_func(sched_data); 260 261 mutex_unlock(&gvt->sched_lock); 262 } 263 264 static enum hrtimer_restart tbs_timer_fn(struct hrtimer *timer_data) 265 { 266 struct gvt_sched_data *data; 267 268 data = container_of(timer_data, struct gvt_sched_data, timer); 269 270 intel_gvt_request_service(data->gvt, INTEL_GVT_REQUEST_SCHED); 271 272 hrtimer_add_expires_ns(&data->timer, data->period); 273 274 return HRTIMER_RESTART; 275 } 276 277 static int tbs_sched_init(struct intel_gvt *gvt) 278 { 279 struct intel_gvt_workload_scheduler *scheduler = 280 &gvt->scheduler; 281 282 struct gvt_sched_data *data; 283 284 data = kzalloc(sizeof(*data), GFP_KERNEL); 285 if (!data) 286 return -ENOMEM; 287 288 INIT_LIST_HEAD(&data->lru_runq_head); 289 hrtimer_init(&data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); 290 data->timer.function = tbs_timer_fn; 291 data->period = GVT_DEFAULT_TIME_SLICE; 292 data->gvt = gvt; 293 294 scheduler->sched_data = data; 295 296 return 0; 297 } 298 299 static void tbs_sched_clean(struct intel_gvt *gvt) 300 { 301 struct intel_gvt_workload_scheduler *scheduler = 302 &gvt->scheduler; 303 struct gvt_sched_data *data = scheduler->sched_data; 304 305 hrtimer_cancel(&data->timer); 306 307 kfree(data); 308 scheduler->sched_data = NULL; 309 } 310 311 static int tbs_sched_init_vgpu(struct intel_vgpu *vgpu) 312 { 313 struct vgpu_sched_data *data; 314 315 data = kzalloc(sizeof(*data), GFP_KERNEL); 316 if (!data) 317 return -ENOMEM; 318 319 data->sched_ctl.weight = vgpu->sched_ctl.weight; 320 data->vgpu = vgpu; 321 INIT_LIST_HEAD(&data->lru_list); 322 323 vgpu->sched_data = data; 324 325 return 0; 326 } 327 328 static void tbs_sched_clean_vgpu(struct intel_vgpu *vgpu) 329 { 330 struct intel_gvt *gvt = vgpu->gvt; 331 struct gvt_sched_data *sched_data = gvt->scheduler.sched_data; 332 333 kfree(vgpu->sched_data); 334 vgpu->sched_data = NULL; 335 336 /* this vgpu id has been removed */ 337 if (idr_is_empty(&gvt->vgpu_idr)) 338 hrtimer_cancel(&sched_data->timer); 339 } 340 341 static void tbs_sched_start_schedule(struct intel_vgpu *vgpu) 342 { 343 struct gvt_sched_data *sched_data = vgpu->gvt->scheduler.sched_data; 344 struct vgpu_sched_data *vgpu_data = vgpu->sched_data; 345 ktime_t now; 346 347 if (!list_empty(&vgpu_data->lru_list)) 348 return; 349 350 now = ktime_get(); 351 vgpu_data->pri_time = ktime_add(now, 352 ktime_set(GVT_SCHED_VGPU_PRI_TIME, 0)); 353 vgpu_data->pri_sched = true; 354 355 list_add(&vgpu_data->lru_list, &sched_data->lru_runq_head); 356 357 if (!hrtimer_active(&sched_data->timer)) 358 hrtimer_start(&sched_data->timer, ktime_add_ns(ktime_get(), 359 sched_data->period), HRTIMER_MODE_ABS); 360 vgpu_data->active = true; 361 } 362 363 static void tbs_sched_stop_schedule(struct intel_vgpu *vgpu) 364 { 365 struct vgpu_sched_data *vgpu_data = vgpu->sched_data; 366 367 list_del_init(&vgpu_data->lru_list); 368 vgpu_data->active = false; 369 } 370 371 static const struct intel_gvt_sched_policy_ops tbs_schedule_ops = { 372 .init = tbs_sched_init, 373 .clean = tbs_sched_clean, 374 .init_vgpu = tbs_sched_init_vgpu, 375 .clean_vgpu = tbs_sched_clean_vgpu, 376 .start_schedule = tbs_sched_start_schedule, 377 .stop_schedule = tbs_sched_stop_schedule, 378 }; 379 380 int intel_gvt_init_sched_policy(struct intel_gvt *gvt) 381 { 382 int ret; 383 384 mutex_lock(&gvt->sched_lock); 385 gvt->scheduler.sched_ops = &tbs_schedule_ops; 386 ret = gvt->scheduler.sched_ops->init(gvt); 387 mutex_unlock(&gvt->sched_lock); 388 389 return ret; 390 } 391 392 void intel_gvt_clean_sched_policy(struct intel_gvt *gvt) 393 { 394 mutex_lock(&gvt->sched_lock); 395 gvt->scheduler.sched_ops->clean(gvt); 396 mutex_unlock(&gvt->sched_lock); 397 } 398 399 /* for per-vgpu scheduler policy, there are 2 per-vgpu data: 400 * sched_data, and sched_ctl. We see these 2 data as part of 401 * the global scheduler which are proteced by gvt->sched_lock. 402 * Caller should make their decision if the vgpu_lock should 403 * be hold outside. 404 */ 405 406 int intel_vgpu_init_sched_policy(struct intel_vgpu *vgpu) 407 { 408 int ret; 409 410 mutex_lock(&vgpu->gvt->sched_lock); 411 ret = vgpu->gvt->scheduler.sched_ops->init_vgpu(vgpu); 412 mutex_unlock(&vgpu->gvt->sched_lock); 413 414 return ret; 415 } 416 417 void intel_vgpu_clean_sched_policy(struct intel_vgpu *vgpu) 418 { 419 mutex_lock(&vgpu->gvt->sched_lock); 420 vgpu->gvt->scheduler.sched_ops->clean_vgpu(vgpu); 421 mutex_unlock(&vgpu->gvt->sched_lock); 422 } 423 424 void intel_vgpu_start_schedule(struct intel_vgpu *vgpu) 425 { 426 struct vgpu_sched_data *vgpu_data = vgpu->sched_data; 427 428 mutex_lock(&vgpu->gvt->sched_lock); 429 if (!vgpu_data->active) { 430 gvt_dbg_core("vgpu%d: start schedule\n", vgpu->id); 431 vgpu->gvt->scheduler.sched_ops->start_schedule(vgpu); 432 } 433 mutex_unlock(&vgpu->gvt->sched_lock); 434 } 435 436 void intel_gvt_kick_schedule(struct intel_gvt *gvt) 437 { 438 mutex_lock(&gvt->sched_lock); 439 intel_gvt_request_service(gvt, INTEL_GVT_REQUEST_EVENT_SCHED); 440 mutex_unlock(&gvt->sched_lock); 441 } 442 443 void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu) 444 { 445 struct intel_gvt_workload_scheduler *scheduler = 446 &vgpu->gvt->scheduler; 447 struct vgpu_sched_data *vgpu_data = vgpu->sched_data; 448 struct drm_i915_private *dev_priv = vgpu->gvt->gt->i915; 449 struct intel_engine_cs *engine; 450 enum intel_engine_id id; 451 452 if (!vgpu_data->active) 453 return; 454 455 gvt_dbg_core("vgpu%d: stop schedule\n", vgpu->id); 456 457 mutex_lock(&vgpu->gvt->sched_lock); 458 scheduler->sched_ops->stop_schedule(vgpu); 459 460 if (scheduler->next_vgpu == vgpu) 461 scheduler->next_vgpu = NULL; 462 463 if (scheduler->current_vgpu == vgpu) { 464 /* stop workload dispatching */ 465 scheduler->need_reschedule = true; 466 scheduler->current_vgpu = NULL; 467 } 468 469 intel_runtime_pm_get(&dev_priv->runtime_pm); 470 spin_lock_bh(&scheduler->mmio_context_lock); 471 for_each_engine(engine, vgpu->gvt->gt, id) { 472 if (scheduler->engine_owner[engine->id] == vgpu) { 473 intel_gvt_switch_mmio(vgpu, NULL, engine); 474 scheduler->engine_owner[engine->id] = NULL; 475 } 476 } 477 spin_unlock_bh(&scheduler->mmio_context_lock); 478 intel_runtime_pm_put_unchecked(&dev_priv->runtime_pm); 479 mutex_unlock(&vgpu->gvt->sched_lock); 480 } 481