drivers/gpu/drm/i915/gvt/sched_policy.c

   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->dev_priv, i) {
  43                 if (!list_empty(workload_q_head(vgpu, i)))
  44                         return true;
  45         }
  46
  47         return false;
  48 }
  49
  50 static void try_to_schedule_next_vgpu(struct intel_gvt *gvt)
  51 {
  52         struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
  53         enum intel_engine_id i;
  54         struct intel_engine_cs *engine;
  55
  56         /* no target to schedule */
  57         if (!scheduler->next_vgpu)
  58                 return;
  59
  60         gvt_dbg_sched("try to schedule next vgpu %d\n",
  61                         scheduler->next_vgpu->id);
  62
  63         /*
  64          * after the flag is set, workload dispatch thread will
  65          * stop dispatching workload for current vgpu
  66          */
  67         scheduler->need_reschedule = true;
  68
  69         /* still have uncompleted workload? */
  70         for_each_engine(engine, gvt->dev_priv, i) {
  71                 if (scheduler->current_workload[i]) {
  72                         gvt_dbg_sched("still have running workload\n");
  73                         return;
  74                 }
  75         }
  76
  77         gvt_dbg_sched("switch to next vgpu %d\n",
  78                         scheduler->next_vgpu->id);
  79
  80         /* switch current vgpu */
  81         scheduler->current_vgpu = scheduler->next_vgpu;
  82         scheduler->next_vgpu = NULL;
  83
  84         scheduler->need_reschedule = false;
  85
  86         /* wake up workload dispatch thread */
  87         for_each_engine(engine, gvt->dev_priv, i)
  88                 wake_up(&scheduler->waitq[i]);
  89 }
  90
  91 struct tbs_vgpu_data {
  92         struct list_head list;
  93         struct intel_vgpu *vgpu;
  94         /* put some per-vgpu sched stats here */
  95 };
  96
  97 struct tbs_sched_data {
  98         struct intel_gvt *gvt;
  99         struct delayed_work work;
 100         unsigned long period;
 101         struct list_head runq_head;
 102 };
 103
 104 #define GVT_DEFAULT_TIME_SLICE (1 * HZ / 1000)
 105
 106 static void tbs_sched_func(struct work_struct *work)
 107 {
 108         struct tbs_sched_data *sched_data = container_of(work,
 109                         struct tbs_sched_data, work.work);
 110         struct tbs_vgpu_data *vgpu_data;
 111
 112         struct intel_gvt *gvt = sched_data->gvt;
 113         struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
 114
 115         struct intel_vgpu *vgpu = NULL;
 116         struct list_head *pos, *head;
 117
 118         mutex_lock(&gvt->lock);
 119
 120         /* no vgpu or has already had a target */
 121         if (list_empty(&sched_data->runq_head) || scheduler->next_vgpu)
 122                 goto out;
 123
 124         if (scheduler->current_vgpu) {
 125                 vgpu_data = scheduler->current_vgpu->sched_data;
 126                 head = &vgpu_data->list;
 127         } else {
 128                 head = &sched_data->runq_head;
 129         }
 130
 131         /* search a vgpu with pending workload */
 132         list_for_each(pos, head) {
 133                 if (pos == &sched_data->runq_head)
 134                         continue;
 135
 136                 vgpu_data = container_of(pos, struct tbs_vgpu_data, list);
 137                 if (!vgpu_has_pending_workload(vgpu_data->vgpu))
 138                         continue;
 139
 140                 vgpu = vgpu_data->vgpu;
 141                 break;
 142         }
 143
 144         if (vgpu) {
 145                 scheduler->next_vgpu = vgpu;
 146                 gvt_dbg_sched("pick next vgpu %d\n", vgpu->id);
 147         }
 148 out:
 149         if (scheduler->next_vgpu) {
 150                 gvt_dbg_sched("try to schedule next vgpu %d\n",
 151                                 scheduler->next_vgpu->id);
 152                 try_to_schedule_next_vgpu(gvt);
 153         }
 154
 155         /*
 156          * still have vgpu on runq
 157          * or last schedule haven't finished due to running workload
 158          */
 159         if (!list_empty(&sched_data->runq_head) || scheduler->next_vgpu)
 160                 schedule_delayed_work(&sched_data->work, sched_data->period);
 161
 162         mutex_unlock(&gvt->lock);
 163 }
 164
 165 static int tbs_sched_init(struct intel_gvt *gvt)
 166 {
 167         struct intel_gvt_workload_scheduler *scheduler =
 168                 &gvt->scheduler;
 169
 170         struct tbs_sched_data *data;
 171
 172         data = kzalloc(sizeof(*data), GFP_KERNEL);
 173         if (!data)
 174                 return -ENOMEM;
 175
 176         INIT_LIST_HEAD(&data->runq_head);
 177         INIT_DELAYED_WORK(&data->work, tbs_sched_func);
 178         data->period = GVT_DEFAULT_TIME_SLICE;
 179         data->gvt = gvt;
 180
 181         scheduler->sched_data = data;
 182         return 0;
 183 }
 184
 185 static void tbs_sched_clean(struct intel_gvt *gvt)
 186 {
 187         struct intel_gvt_workload_scheduler *scheduler =
 188                 &gvt->scheduler;
 189         struct tbs_sched_data *data = scheduler->sched_data;
 190
 191         cancel_delayed_work(&data->work);
 192         kfree(data);
 193         scheduler->sched_data = NULL;
 194 }
 195
 196 static int tbs_sched_init_vgpu(struct intel_vgpu *vgpu)
 197 {
 198         struct tbs_vgpu_data *data;
 199
 200         data = kzalloc(sizeof(*data), GFP_KERNEL);
 201         if (!data)
 202                 return -ENOMEM;
 203
 204         data->vgpu = vgpu;
 205         INIT_LIST_HEAD(&data->list);
 206
 207         vgpu->sched_data = data;
 208         return 0;
 209 }
 210
 211 static void tbs_sched_clean_vgpu(struct intel_vgpu *vgpu)
 212 {
 213         kfree(vgpu->sched_data);
 214         vgpu->sched_data = NULL;
 215 }
 216
 217 static void tbs_sched_start_schedule(struct intel_vgpu *vgpu)
 218 {
 219         struct tbs_sched_data *sched_data = vgpu->gvt->scheduler.sched_data;
 220         struct tbs_vgpu_data *vgpu_data = vgpu->sched_data;
 221
 222         if (!list_empty(&vgpu_data->list))
 223                 return;
 224
 225         list_add_tail(&vgpu_data->list, &sched_data->runq_head);
 226         schedule_delayed_work(&sched_data->work, sched_data->period);
 227 }
 228
 229 static void tbs_sched_stop_schedule(struct intel_vgpu *vgpu)
 230 {
 231         struct tbs_vgpu_data *vgpu_data = vgpu->sched_data;
 232
 233         list_del_init(&vgpu_data->list);
 234 }
 235
 236 static struct intel_gvt_sched_policy_ops tbs_schedule_ops = {
 237         .init = tbs_sched_init,
 238         .clean = tbs_sched_clean,
 239         .init_vgpu = tbs_sched_init_vgpu,
 240         .clean_vgpu = tbs_sched_clean_vgpu,
 241         .start_schedule = tbs_sched_start_schedule,
 242         .stop_schedule = tbs_sched_stop_schedule,
 243 };
 244
 245 int intel_gvt_init_sched_policy(struct intel_gvt *gvt)
 246 {
 247         gvt->scheduler.sched_ops = &tbs_schedule_ops;
 248
 249         return gvt->scheduler.sched_ops->init(gvt);
 250 }
 251
 252 void intel_gvt_clean_sched_policy(struct intel_gvt *gvt)
 253 {
 254         gvt->scheduler.sched_ops->clean(gvt);
 255 }
 256
 257 int intel_vgpu_init_sched_policy(struct intel_vgpu *vgpu)
 258 {
 259         return vgpu->gvt->scheduler.sched_ops->init_vgpu(vgpu);
 260 }
 261
 262 void intel_vgpu_clean_sched_policy(struct intel_vgpu *vgpu)
 263 {
 264         vgpu->gvt->scheduler.sched_ops->clean_vgpu(vgpu);
 265 }
 266
 267 void intel_vgpu_start_schedule(struct intel_vgpu *vgpu)
 268 {
 269         gvt_dbg_core("vgpu%d: start schedule\n", vgpu->id);
 270
 271         vgpu->gvt->scheduler.sched_ops->start_schedule(vgpu);
 272 }
 273
 274 void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu)
 275 {
 276         struct intel_gvt_workload_scheduler *scheduler =
 277                 &vgpu->gvt->scheduler;
 278
 279         gvt_dbg_core("vgpu%d: stop schedule\n", vgpu->id);
 280
 281         scheduler->sched_ops->stop_schedule(vgpu);
 282
 283         if (scheduler->next_vgpu == vgpu)
 284                 scheduler->next_vgpu = NULL;
 285
 286         if (scheduler->current_vgpu == vgpu) {
 287                 /* stop workload dispatching */
 288                 scheduler->need_reschedule = true;
 289                 scheduler->current_vgpu = NULL;
 290         }
 291 }