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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
37static 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
50struct vgpu_sched_data {
51 struct list_head lru_list;
52 struct intel_vgpu *vgpu;
53 bool active;
54
55 ktime_t sched_in_time;
56 ktime_t sched_out_time;
57 ktime_t sched_time;
58 ktime_t left_ts;
59 ktime_t allocated_ts;
60
61 struct vgpu_sched_ctl sched_ctl;
62};
63
64struct gvt_sched_data {
65 struct intel_gvt *gvt;
66 struct hrtimer timer;
67 unsigned long period;
68 struct list_head lru_runq_head;
69};
70
71static void vgpu_update_timeslice(struct intel_vgpu *pre_vgpu)
72{
73 ktime_t delta_ts;
74 struct vgpu_sched_data *vgpu_data = pre_vgpu->sched_data;
75
76 delta_ts = vgpu_data->sched_out_time - vgpu_data->sched_in_time;
77
78 vgpu_data->sched_time += delta_ts;
79 vgpu_data->left_ts -= delta_ts;
80}
81
82#define GVT_TS_BALANCE_PERIOD_MS 100
83#define GVT_TS_BALANCE_STAGE_NUM 10
84
85static void gvt_balance_timeslice(struct gvt_sched_data *sched_data)
86{
87 struct vgpu_sched_data *vgpu_data;
88 struct list_head *pos;
89 static uint64_t stage_check;
90 int stage = stage_check++ % GVT_TS_BALANCE_STAGE_NUM;
91
92 /* The timeslice accumulation reset at stage 0, which is
93 * allocated again without adding previous debt.
94 */
95 if (stage == 0) {
96 int total_weight = 0;
97 ktime_t fair_timeslice;
98
99 list_for_each(pos, &sched_data->lru_runq_head) {
100 vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list);
101 total_weight += vgpu_data->sched_ctl.weight;
102 }
103
104 list_for_each(pos, &sched_data->lru_runq_head) {
105 vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list);
106 fair_timeslice = ktime_divns(ms_to_ktime(GVT_TS_BALANCE_PERIOD_MS),
107 total_weight) * vgpu_data->sched_ctl.weight;
108
109 vgpu_data->allocated_ts = fair_timeslice;
110 vgpu_data->left_ts = vgpu_data->allocated_ts;
111 }
112 } else {
113 list_for_each(pos, &sched_data->lru_runq_head) {
114 vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list);
115
116 /* timeslice for next 100ms should add the left/debt
117 * slice of previous stages.
118 */
119 vgpu_data->left_ts += vgpu_data->allocated_ts;
120 }
121 }
122}
123
124static void try_to_schedule_next_vgpu(struct intel_gvt *gvt)
125{
126 struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
127 enum intel_engine_id i;
128 struct intel_engine_cs *engine;
129 struct vgpu_sched_data *vgpu_data;
130 ktime_t cur_time;
131
132 /* no need to schedule if next_vgpu is the same with current_vgpu,
133 * let scheduler chose next_vgpu again by setting it to NULL.
134 */
135 if (scheduler->next_vgpu == scheduler->current_vgpu) {
136 scheduler->next_vgpu = NULL;
137 return;
138 }
139
140 /*
141 * after the flag is set, workload dispatch thread will
142 * stop dispatching workload for current vgpu
143 */
144 scheduler->need_reschedule = true;
145
146 /* still have uncompleted workload? */
147 for_each_engine(engine, gvt->dev_priv, i) {
148 if (scheduler->current_workload[i])
149 return;
150 }
151
152 cur_time = ktime_get();
153 if (scheduler->current_vgpu) {
154 vgpu_data = scheduler->current_vgpu->sched_data;
155 vgpu_data->sched_out_time = cur_time;
156 vgpu_update_timeslice(scheduler->current_vgpu);
157 }
158 vgpu_data = scheduler->next_vgpu->sched_data;
159 vgpu_data->sched_in_time = cur_time;
160
161 /* switch current vgpu */
162 scheduler->current_vgpu = scheduler->next_vgpu;
163 scheduler->next_vgpu = NULL;
164
165 scheduler->need_reschedule = false;
166
167 /* wake up workload dispatch thread */
168 for_each_engine(engine, gvt->dev_priv, i)
169 wake_up(&scheduler->waitq[i]);
170}
171
172static struct intel_vgpu *find_busy_vgpu(struct gvt_sched_data *sched_data)
173{
174 struct vgpu_sched_data *vgpu_data;
175 struct intel_vgpu *vgpu = NULL;
176 struct list_head *head = &sched_data->lru_runq_head;
177 struct list_head *pos;
178
179 /* search a vgpu with pending workload */
180 list_for_each(pos, head) {
181
182 vgpu_data = container_of(pos, struct vgpu_sched_data, lru_list);
183 if (!vgpu_has_pending_workload(vgpu_data->vgpu))
184 continue;
185
186 /* Return the vGPU only if it has time slice left */
187 if (vgpu_data->left_ts > 0) {
188 vgpu = vgpu_data->vgpu;
189 break;
190 }
191 }
192
193 return vgpu;
194}
195
196/* in nanosecond */
197#define GVT_DEFAULT_TIME_SLICE 1000000
198
199static void tbs_sched_func(struct gvt_sched_data *sched_data)
200{
201 struct intel_gvt *gvt = sched_data->gvt;
202 struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
203 struct vgpu_sched_data *vgpu_data;
204 struct intel_vgpu *vgpu = NULL;
205 /* no active vgpu or has already had a target */
206 if (list_empty(&sched_data->lru_runq_head) || scheduler->next_vgpu)
207 goto out;
208
209 vgpu = find_busy_vgpu(sched_data);
210 if (vgpu) {
211 scheduler->next_vgpu = vgpu;
212
213 /* Move the last used vGPU to the tail of lru_list */
214 vgpu_data = vgpu->sched_data;
215 list_del_init(&vgpu_data->lru_list);
216 list_add_tail(&vgpu_data->lru_list,
217 &sched_data->lru_runq_head);
218 } else {
219 scheduler->next_vgpu = gvt->idle_vgpu;
220 }
221out:
222 if (scheduler->next_vgpu)
223 try_to_schedule_next_vgpu(gvt);
224}
225
226void intel_gvt_schedule(struct intel_gvt *gvt)
227{
228 struct gvt_sched_data *sched_data = gvt->scheduler.sched_data;
229 static uint64_t timer_check;
230
231 mutex_lock(&gvt->lock);
232
233 if (test_and_clear_bit(INTEL_GVT_REQUEST_SCHED,
234 (void *)&gvt->service_request)) {
235 if (!(timer_check++ % GVT_TS_BALANCE_PERIOD_MS))
236 gvt_balance_timeslice(sched_data);
237 }
238 clear_bit(INTEL_GVT_REQUEST_EVENT_SCHED, (void *)&gvt->service_request);
239
240 tbs_sched_func(sched_data);
241
242 mutex_unlock(&gvt->lock);
243}
244
245static enum hrtimer_restart tbs_timer_fn(struct hrtimer *timer_data)
246{
247 struct gvt_sched_data *data;
248
249 data = container_of(timer_data, struct gvt_sched_data, timer);
250
251 intel_gvt_request_service(data->gvt, INTEL_GVT_REQUEST_SCHED);
252
253 hrtimer_add_expires_ns(&data->timer, data->period);
254
255 return HRTIMER_RESTART;
256}
257
258static int tbs_sched_init(struct intel_gvt *gvt)
259{
260 struct intel_gvt_workload_scheduler *scheduler =
261 &gvt->scheduler;
262
263 struct gvt_sched_data *data;
264
265 data = kzalloc(sizeof(*data), GFP_KERNEL);
266 if (!data)
267 return -ENOMEM;
268
269 INIT_LIST_HEAD(&data->lru_runq_head);
270 hrtimer_init(&data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
271 data->timer.function = tbs_timer_fn;
272 data->period = GVT_DEFAULT_TIME_SLICE;
273 data->gvt = gvt;
274
275 scheduler->sched_data = data;
276
277 return 0;
278}
279
280static void tbs_sched_clean(struct intel_gvt *gvt)
281{
282 struct intel_gvt_workload_scheduler *scheduler =
283 &gvt->scheduler;
284 struct gvt_sched_data *data = scheduler->sched_data;
285
286 hrtimer_cancel(&data->timer);
287
288 kfree(data);
289 scheduler->sched_data = NULL;
290}
291
292static int tbs_sched_init_vgpu(struct intel_vgpu *vgpu)
293{
294 struct vgpu_sched_data *data;
295
296 data = kzalloc(sizeof(*data), GFP_KERNEL);
297 if (!data)
298 return -ENOMEM;
299
300 data->sched_ctl.weight = vgpu->sched_ctl.weight;
301 data->vgpu = vgpu;
302 INIT_LIST_HEAD(&data->lru_list);
303
304 vgpu->sched_data = data;
305
306 return 0;
307}
308
309static void tbs_sched_clean_vgpu(struct intel_vgpu *vgpu)
310{
311 struct intel_gvt *gvt = vgpu->gvt;
312 struct gvt_sched_data *sched_data = gvt->scheduler.sched_data;
313
314 kfree(vgpu->sched_data);
315 vgpu->sched_data = NULL;
316
317 /* this vgpu id has been removed */
318 if (idr_is_empty(&gvt->vgpu_idr))
319 hrtimer_cancel(&sched_data->timer);
320}
321
322static void tbs_sched_start_schedule(struct intel_vgpu *vgpu)
323{
324 struct gvt_sched_data *sched_data = vgpu->gvt->scheduler.sched_data;
325 struct vgpu_sched_data *vgpu_data = vgpu->sched_data;
326
327 if (!list_empty(&vgpu_data->lru_list))
328 return;
329
330 list_add_tail(&vgpu_data->lru_list, &sched_data->lru_runq_head);
331
332 if (!hrtimer_active(&sched_data->timer))
333 hrtimer_start(&sched_data->timer, ktime_add_ns(ktime_get(),
334 sched_data->period), HRTIMER_MODE_ABS);
335 vgpu_data->active = true;
336}
337
338static void tbs_sched_stop_schedule(struct intel_vgpu *vgpu)
339{
340 struct vgpu_sched_data *vgpu_data = vgpu->sched_data;
341
342 list_del_init(&vgpu_data->lru_list);
343 vgpu_data->active = false;
344}
345
346static struct intel_gvt_sched_policy_ops tbs_schedule_ops = {
347 .init = tbs_sched_init,
348 .clean = tbs_sched_clean,
349 .init_vgpu = tbs_sched_init_vgpu,
350 .clean_vgpu = tbs_sched_clean_vgpu,
351 .start_schedule = tbs_sched_start_schedule,
352 .stop_schedule = tbs_sched_stop_schedule,
353};
354
355int intel_gvt_init_sched_policy(struct intel_gvt *gvt)
356{
357 gvt->scheduler.sched_ops = &tbs_schedule_ops;
358
359 return gvt->scheduler.sched_ops->init(gvt);
360}
361
362void intel_gvt_clean_sched_policy(struct intel_gvt *gvt)
363{
364 gvt->scheduler.sched_ops->clean(gvt);
365}
366
367int intel_vgpu_init_sched_policy(struct intel_vgpu *vgpu)
368{
369 return vgpu->gvt->scheduler.sched_ops->init_vgpu(vgpu);
370}
371
372void intel_vgpu_clean_sched_policy(struct intel_vgpu *vgpu)
373{
374 vgpu->gvt->scheduler.sched_ops->clean_vgpu(vgpu);
375}
376
377void intel_vgpu_start_schedule(struct intel_vgpu *vgpu)
378{
379 struct vgpu_sched_data *vgpu_data = vgpu->sched_data;
380
381 if (!vgpu_data->active) {
382 gvt_dbg_core("vgpu%d: start schedule\n", vgpu->id);
383 vgpu->gvt->scheduler.sched_ops->start_schedule(vgpu);
384 }
385}
386
387void intel_gvt_kick_schedule(struct intel_gvt *gvt)
388{
389 intel_gvt_request_service(gvt, INTEL_GVT_REQUEST_EVENT_SCHED);
390}
391
392void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu)
393{
394 struct intel_gvt_workload_scheduler *scheduler =
395 &vgpu->gvt->scheduler;
396 int ring_id;
397 struct vgpu_sched_data *vgpu_data = vgpu->sched_data;
398
399 if (!vgpu_data->active)
400 return;
401
402 gvt_dbg_core("vgpu%d: stop schedule\n", vgpu->id);
403
404 scheduler->sched_ops->stop_schedule(vgpu);
405
406 if (scheduler->next_vgpu == vgpu)
407 scheduler->next_vgpu = NULL;
408
409 if (scheduler->current_vgpu == vgpu) {
410 /* stop workload dispatching */
411 scheduler->need_reschedule = true;
412 scheduler->current_vgpu = NULL;
413 }
414
415 spin_lock_bh(&scheduler->mmio_context_lock);
416 for (ring_id = 0; ring_id < I915_NUM_ENGINES; ring_id++) {
417 if (scheduler->engine_owner[ring_id] == vgpu) {
418 intel_gvt_switch_mmio(vgpu, NULL, ring_id);
419 scheduler->engine_owner[ring_id] = NULL;
420 }
421 }
422 spin_unlock_bh(&scheduler->mmio_context_lock);
423}