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 need to schedule if next_vgpu is the same with current_vgpu,
  57          * let scheduler chose next_vgpu again by setting it to NULL.
  58          */
  59         if (scheduler->next_vgpu == scheduler->current_vgpu) {
  60                 scheduler->next_vgpu = NULL;
  61                 return;
  62         }
  63
  64         gvt_dbg_sched("try to schedule next vgpu %d\n",
  65                         scheduler->next_vgpu->id);
  66
  67         /*
  68          * after the flag is set, workload dispatch thread will
  69          * stop dispatching workload for current vgpu
  70          */
  71         scheduler->need_reschedule = true;
  72
  73         /* still have uncompleted workload? */
  74         for_each_engine(engine, gvt->dev_priv, i) {
  75                 if (scheduler->current_workload[i]) {
  76                         gvt_dbg_sched("still have running workload\n");
  77                         return;
  78                 }
  79         }
  80
  81         gvt_dbg_sched("switch to next vgpu %d\n",
  82                         scheduler->next_vgpu->id);
  83
  84         /* switch current vgpu */
  85         scheduler->current_vgpu = scheduler->next_vgpu;
  86         scheduler->next_vgpu = NULL;
  87
  88         scheduler->need_reschedule = false;
  89
  90         /* wake up workload dispatch thread */
  91         for_each_engine(engine, gvt->dev_priv, i)
  92                 wake_up(&scheduler->waitq[i]);
  93 }
  94
  95 struct tbs_vgpu_data {
  96         struct list_head list;
  97         struct intel_vgpu *vgpu;
  98         /* put some per-vgpu sched stats here */
  99 };
 100
 101 struct tbs_sched_data {
 102         struct intel_gvt *gvt;
 103         struct delayed_work work;
 104         unsigned long period;
 105         struct list_head runq_head;
 106 };
 107
 108 #define GVT_DEFAULT_TIME_SLICE (msecs_to_jiffies(1))
 109
 110 static void tbs_sched_func(struct work_struct *work)
 111 {
 112         struct tbs_sched_data *sched_data = container_of(work,
 113                         struct tbs_sched_data, work.work);
 114         struct tbs_vgpu_data *vgpu_data;
 115
 116         struct intel_gvt *gvt = sched_data->gvt;
 117         struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
 118
 119         struct intel_vgpu *vgpu = NULL;
 120         struct list_head *pos, *head;
 121
 122         mutex_lock(&gvt->lock);
 123
 124         /* no vgpu or has already had a target */
 125         if (list_empty(&sched_data->runq_head) || scheduler->next_vgpu)
 126                 goto out;
 127
 128         if (scheduler->current_vgpu) {
 129                 vgpu_data = scheduler->current_vgpu->sched_data;
 130                 head = &vgpu_data->list;
 131         } else {
 132                 head = &sched_data->runq_head;
 133         }
 134
 135         /* search a vgpu with pending workload */
 136         list_for_each(pos, head) {
 137                 if (pos == &sched_data->runq_head)
 138                         continue;
 139
 140                 vgpu_data = container_of(pos, struct tbs_vgpu_data, list);
 141                 if (!vgpu_has_pending_workload(vgpu_data->vgpu))
 142                         continue;
 143
 144                 vgpu = vgpu_data->vgpu;
 145                 break;
 146         }
 147
 148         if (vgpu) {
 149                 scheduler->next_vgpu = vgpu;
 150                 gvt_dbg_sched("pick next vgpu %d\n", vgpu->id);
 151         }
 152 out:
 153         if (scheduler->next_vgpu) {
 154                 gvt_dbg_sched("try to schedule next vgpu %d\n",
 155                                 scheduler->next_vgpu->id);
 156                 try_to_schedule_next_vgpu(gvt);
 157         }
 158
 159         /*
 160          * still have vgpu on runq
 161          * or last schedule haven't finished due to running workload
 162          */
 163         if (!list_empty(&sched_data->runq_head) || scheduler->next_vgpu)
 164                 schedule_delayed_work(&sched_data->work, sched_data->period);
 165
 166         mutex_unlock(&gvt->lock);
 167 }
 168
 169 static int tbs_sched_init(struct intel_gvt *gvt)
 170 {
 171         struct intel_gvt_workload_scheduler *scheduler =
 172                 &gvt->scheduler;
 173
 174         struct tbs_sched_data *data;
 175
 176         data = kzalloc(sizeof(*data), GFP_KERNEL);
 177         if (!data)
 178                 return -ENOMEM;
 179
 180         INIT_LIST_HEAD(&data->runq_head);
 181         INIT_DELAYED_WORK(&data->work, tbs_sched_func);
 182         data->period = GVT_DEFAULT_TIME_SLICE;
 183         data->gvt = gvt;
 184
 185         scheduler->sched_data = data;
 186         return 0;
 187 }
 188
 189 static void tbs_sched_clean(struct intel_gvt *gvt)
 190 {
 191         struct intel_gvt_workload_scheduler *scheduler =
 192                 &gvt->scheduler;
 193         struct tbs_sched_data *data = scheduler->sched_data;
 194
 195         cancel_delayed_work(&data->work);
 196         kfree(data);
 197         scheduler->sched_data = NULL;
 198 }
 199
 200 static int tbs_sched_init_vgpu(struct intel_vgpu *vgpu)
 201 {
 202         struct tbs_vgpu_data *data;
 203
 204         data = kzalloc(sizeof(*data), GFP_KERNEL);
 205         if (!data)
 206                 return -ENOMEM;
 207
 208         data->vgpu = vgpu;
 209         INIT_LIST_HEAD(&data->list);
 210
 211         vgpu->sched_data = data;
 212         return 0;
 213 }
 214
 215 static void tbs_sched_clean_vgpu(struct intel_vgpu *vgpu)
 216 {
 217         kfree(vgpu->sched_data);
 218         vgpu->sched_data = NULL;
 219 }
 220
 221 static void tbs_sched_start_schedule(struct intel_vgpu *vgpu)
 222 {
 223         struct tbs_sched_data *sched_data = vgpu->gvt->scheduler.sched_data;
 224         struct tbs_vgpu_data *vgpu_data = vgpu->sched_data;
 225
 226         if (!list_empty(&vgpu_data->list))
 227                 return;
 228
 229         list_add_tail(&vgpu_data->list, &sched_data->runq_head);
 230         schedule_delayed_work(&sched_data->work, 0);
 231 }
 232
 233 static void tbs_sched_stop_schedule(struct intel_vgpu *vgpu)
 234 {
 235         struct tbs_vgpu_data *vgpu_data = vgpu->sched_data;
 236
 237         list_del_init(&vgpu_data->list);
 238 }
 239
 240 static struct intel_gvt_sched_policy_ops tbs_schedule_ops = {
 241         .init = tbs_sched_init,
 242         .clean = tbs_sched_clean,
 243         .init_vgpu = tbs_sched_init_vgpu,
 244         .clean_vgpu = tbs_sched_clean_vgpu,
 245         .start_schedule = tbs_sched_start_schedule,
 246         .stop_schedule = tbs_sched_stop_schedule,
 247 };
 248
 249 int intel_gvt_init_sched_policy(struct intel_gvt *gvt)
 250 {
 251         gvt->scheduler.sched_ops = &tbs_schedule_ops;
 252
 253         return gvt->scheduler.sched_ops->init(gvt);
 254 }
 255
 256 void intel_gvt_clean_sched_policy(struct intel_gvt *gvt)
 257 {
 258         gvt->scheduler.sched_ops->clean(gvt);
 259 }
 260
 261 int intel_vgpu_init_sched_policy(struct intel_vgpu *vgpu)
 262 {
 263         return vgpu->gvt->scheduler.sched_ops->init_vgpu(vgpu);
 264 }
 265
 266 void intel_vgpu_clean_sched_policy(struct intel_vgpu *vgpu)
 267 {
 268         vgpu->gvt->scheduler.sched_ops->clean_vgpu(vgpu);
 269 }
 270
 271 void intel_vgpu_start_schedule(struct intel_vgpu *vgpu)
 272 {
 273         gvt_dbg_core("vgpu%d: start schedule\n", vgpu->id);
 274
 275         vgpu->gvt->scheduler.sched_ops->start_schedule(vgpu);
 276 }
 277
 278 void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu)
 279 {
 280         struct intel_gvt_workload_scheduler *scheduler =
 281                 &vgpu->gvt->scheduler;
 282
 283         gvt_dbg_core("vgpu%d: stop schedule\n", vgpu->id);
 284
 285         scheduler->sched_ops->stop_schedule(vgpu);
 286
 287         if (scheduler->next_vgpu == vgpu)
 288                 scheduler->next_vgpu = NULL;
 289
 290         if (scheduler->current_vgpu == vgpu) {
 291                 /* stop workload dispatching */
 292                 scheduler->need_reschedule = true;
 293                 scheduler->current_vgpu = NULL;
 294         }
 295 }