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 	struct intel_vgpu_execlist *execlist;
40 	enum intel_engine_id i;
41 	struct intel_engine_cs *engine;
42 
43 	for_each_engine(engine, vgpu->gvt->dev_priv, i) {
44 		execlist = &vgpu->execlist[i];
45 		if (!list_empty(workload_q_head(vgpu, i)))
46 			return true;
47 	}
48 
49 	return false;
50 }
51 
52 static void try_to_schedule_next_vgpu(struct intel_gvt *gvt)
53 {
54 	struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
55 	enum intel_engine_id i;
56 	struct intel_engine_cs *engine;
57 
58 	/* no target to schedule */
59 	if (!scheduler->next_vgpu)
60 		return;
61 
62 	gvt_dbg_sched("try to schedule next vgpu %d\n",
63 			scheduler->next_vgpu->id);
64 
65 	/*
66 	 * after the flag is set, workload dispatch thread will
67 	 * stop dispatching workload for current vgpu
68 	 */
69 	scheduler->need_reschedule = true;
70 
71 	/* still have uncompleted workload? */
72 	for_each_engine(engine, gvt->dev_priv, i) {
73 		if (scheduler->current_workload[i]) {
74 			gvt_dbg_sched("still have running workload\n");
75 			return;
76 		}
77 	}
78 
79 	gvt_dbg_sched("switch to next vgpu %d\n",
80 			scheduler->next_vgpu->id);
81 
82 	/* switch current vgpu */
83 	scheduler->current_vgpu = scheduler->next_vgpu;
84 	scheduler->next_vgpu = NULL;
85 
86 	scheduler->need_reschedule = false;
87 
88 	/* wake up workload dispatch thread */
89 	for_each_engine(engine, gvt->dev_priv, i)
90 		wake_up(&scheduler->waitq[i]);
91 }
92 
93 struct tbs_vgpu_data {
94 	struct list_head list;
95 	struct intel_vgpu *vgpu;
96 	/* put some per-vgpu sched stats here */
97 };
98 
99 struct tbs_sched_data {
100 	struct intel_gvt *gvt;
101 	struct delayed_work work;
102 	unsigned long period;
103 	struct list_head runq_head;
104 };
105 
106 #define GVT_DEFAULT_TIME_SLICE (1 * HZ / 1000)
107 
108 static void tbs_sched_func(struct work_struct *work)
109 {
110 	struct tbs_sched_data *sched_data = container_of(work,
111 			struct tbs_sched_data, work.work);
112 	struct tbs_vgpu_data *vgpu_data;
113 
114 	struct intel_gvt *gvt = sched_data->gvt;
115 	struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
116 
117 	struct intel_vgpu *vgpu = NULL;
118 	struct list_head *pos, *head;
119 
120 	mutex_lock(&gvt->lock);
121 
122 	/* no vgpu or has already had a target */
123 	if (list_empty(&sched_data->runq_head) || scheduler->next_vgpu)
124 		goto out;
125 
126 	if (scheduler->current_vgpu) {
127 		vgpu_data = scheduler->current_vgpu->sched_data;
128 		head = &vgpu_data->list;
129 	} else {
130 		gvt_dbg_sched("no current vgpu search from q head\n");
131 		head = &sched_data->runq_head;
132 	}
133 
134 	/* search a vgpu with pending workload */
135 	list_for_each(pos, head) {
136 		if (pos == &sched_data->runq_head)
137 			continue;
138 
139 		vgpu_data = container_of(pos, struct tbs_vgpu_data, list);
140 		if (!vgpu_has_pending_workload(vgpu_data->vgpu))
141 			continue;
142 
143 		vgpu = vgpu_data->vgpu;
144 		break;
145 	}
146 
147 	if (vgpu) {
148 		scheduler->next_vgpu = vgpu;
149 		gvt_dbg_sched("pick next vgpu %d\n", vgpu->id);
150 	}
151 out:
152 	if (scheduler->next_vgpu) {
153 		gvt_dbg_sched("try to schedule next vgpu %d\n",
154 				scheduler->next_vgpu->id);
155 		try_to_schedule_next_vgpu(gvt);
156 	}
157 
158 	/*
159 	 * still have vgpu on runq
160 	 * or last schedule haven't finished due to running workload
161 	 */
162 	if (!list_empty(&sched_data->runq_head) || scheduler->next_vgpu)
163 		schedule_delayed_work(&sched_data->work, sched_data->period);
164 
165 	mutex_unlock(&gvt->lock);
166 }
167 
168 static int tbs_sched_init(struct intel_gvt *gvt)
169 {
170 	struct intel_gvt_workload_scheduler *scheduler =
171 		&gvt->scheduler;
172 
173 	struct tbs_sched_data *data;
174 
175 	data = kzalloc(sizeof(*data), GFP_KERNEL);
176 	if (!data)
177 		return -ENOMEM;
178 
179 	INIT_LIST_HEAD(&data->runq_head);
180 	INIT_DELAYED_WORK(&data->work, tbs_sched_func);
181 	data->period = GVT_DEFAULT_TIME_SLICE;
182 	data->gvt = gvt;
183 
184 	scheduler->sched_data = data;
185 	return 0;
186 }
187 
188 static void tbs_sched_clean(struct intel_gvt *gvt)
189 {
190 	struct intel_gvt_workload_scheduler *scheduler =
191 		&gvt->scheduler;
192 	struct tbs_sched_data *data = scheduler->sched_data;
193 
194 	cancel_delayed_work(&data->work);
195 	kfree(data);
196 	scheduler->sched_data = NULL;
197 }
198 
199 static int tbs_sched_init_vgpu(struct intel_vgpu *vgpu)
200 {
201 	struct tbs_vgpu_data *data;
202 
203 	data = kzalloc(sizeof(*data), GFP_KERNEL);
204 	if (!data)
205 		return -ENOMEM;
206 
207 	data->vgpu = vgpu;
208 	INIT_LIST_HEAD(&data->list);
209 
210 	vgpu->sched_data = data;
211 	return 0;
212 }
213 
214 static void tbs_sched_clean_vgpu(struct intel_vgpu *vgpu)
215 {
216 	kfree(vgpu->sched_data);
217 	vgpu->sched_data = NULL;
218 }
219 
220 static void tbs_sched_start_schedule(struct intel_vgpu *vgpu)
221 {
222 	struct tbs_sched_data *sched_data = vgpu->gvt->scheduler.sched_data;
223 	struct tbs_vgpu_data *vgpu_data = vgpu->sched_data;
224 
225 	if (!list_empty(&vgpu_data->list))
226 		return;
227 
228 	list_add_tail(&vgpu_data->list, &sched_data->runq_head);
229 	schedule_delayed_work(&sched_data->work, sched_data->period);
230 }
231 
232 static void tbs_sched_stop_schedule(struct intel_vgpu *vgpu)
233 {
234 	struct tbs_vgpu_data *vgpu_data = vgpu->sched_data;
235 
236 	list_del_init(&vgpu_data->list);
237 }
238 
239 static struct intel_gvt_sched_policy_ops tbs_schedule_ops = {
240 	.init = tbs_sched_init,
241 	.clean = tbs_sched_clean,
242 	.init_vgpu = tbs_sched_init_vgpu,
243 	.clean_vgpu = tbs_sched_clean_vgpu,
244 	.start_schedule = tbs_sched_start_schedule,
245 	.stop_schedule = tbs_sched_stop_schedule,
246 };
247 
248 int intel_gvt_init_sched_policy(struct intel_gvt *gvt)
249 {
250 	gvt->scheduler.sched_ops = &tbs_schedule_ops;
251 
252 	return gvt->scheduler.sched_ops->init(gvt);
253 }
254 
255 void intel_gvt_clean_sched_policy(struct intel_gvt *gvt)
256 {
257 	gvt->scheduler.sched_ops->clean(gvt);
258 }
259 
260 int intel_vgpu_init_sched_policy(struct intel_vgpu *vgpu)
261 {
262 	return vgpu->gvt->scheduler.sched_ops->init_vgpu(vgpu);
263 }
264 
265 void intel_vgpu_clean_sched_policy(struct intel_vgpu *vgpu)
266 {
267 	vgpu->gvt->scheduler.sched_ops->clean_vgpu(vgpu);
268 }
269 
270 void intel_vgpu_start_schedule(struct intel_vgpu *vgpu)
271 {
272 	gvt_dbg_core("vgpu%d: start schedule\n", vgpu->id);
273 
274 	vgpu->gvt->scheduler.sched_ops->start_schedule(vgpu);
275 }
276 
277 void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu)
278 {
279 	struct intel_gvt_workload_scheduler *scheduler =
280 		&vgpu->gvt->scheduler;
281 
282 	gvt_dbg_core("vgpu%d: stop schedule\n", vgpu->id);
283 
284 	scheduler->sched_ops->stop_schedule(vgpu);
285 
286 	if (scheduler->next_vgpu == vgpu)
287 		scheduler->next_vgpu = NULL;
288 
289 	if (scheduler->current_vgpu == vgpu) {
290 		/* stop workload dispatching */
291 		scheduler->need_reschedule = true;
292 		scheduler->current_vgpu = NULL;
293 	}
294 }
295