1 /*
2 * Copyright 2012 Red Hat Inc.
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 shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * Authors: Ben Skeggs
23 */
24 #include "priv.h"
25
26 s64
nvkm_timer_wait_test(struct nvkm_timer_wait * wait)27 nvkm_timer_wait_test(struct nvkm_timer_wait *wait)
28 {
29 struct nvkm_subdev *subdev = &wait->tmr->subdev;
30 u64 time = nvkm_timer_read(wait->tmr);
31
32 if (wait->reads == 0) {
33 wait->time0 = time;
34 wait->time1 = time;
35 }
36
37 if (wait->time1 == time) {
38 if (wait->reads++ == 16) {
39 nvkm_fatal(subdev, "stalled at %016llx\n", time);
40 return -ETIMEDOUT;
41 }
42 } else {
43 wait->time1 = time;
44 wait->reads = 1;
45 }
46
47 if (wait->time1 - wait->time0 > wait->limit)
48 return -ETIMEDOUT;
49
50 return wait->time1 - wait->time0;
51 }
52
53 void
nvkm_timer_wait_init(struct nvkm_device * device,u64 nsec,struct nvkm_timer_wait * wait)54 nvkm_timer_wait_init(struct nvkm_device *device, u64 nsec,
55 struct nvkm_timer_wait *wait)
56 {
57 wait->tmr = device->timer;
58 wait->limit = nsec;
59 wait->reads = 0;
60 }
61
62 u64
nvkm_timer_read(struct nvkm_timer * tmr)63 nvkm_timer_read(struct nvkm_timer *tmr)
64 {
65 return tmr->func->read(tmr);
66 }
67
68 void
nvkm_timer_alarm_trigger(struct nvkm_timer * tmr)69 nvkm_timer_alarm_trigger(struct nvkm_timer *tmr)
70 {
71 struct nvkm_alarm *alarm, *atemp;
72 unsigned long flags;
73 LIST_HEAD(exec);
74
75 /* Process pending alarms. */
76 spin_lock_irqsave(&tmr->lock, flags);
77 list_for_each_entry_safe(alarm, atemp, &tmr->alarms, head) {
78 /* Have we hit the earliest alarm that hasn't gone off? */
79 if (alarm->timestamp > nvkm_timer_read(tmr)) {
80 /* Schedule it. If we didn't race, we're done. */
81 tmr->func->alarm_init(tmr, alarm->timestamp);
82 if (alarm->timestamp > nvkm_timer_read(tmr))
83 break;
84 }
85
86 /* Move to completed list. We'll drop the lock before
87 * executing the callback so it can reschedule itself.
88 */
89 list_del_init(&alarm->head);
90 list_add(&alarm->exec, &exec);
91 }
92
93 /* Shut down interrupt if no more pending alarms. */
94 if (list_empty(&tmr->alarms))
95 tmr->func->alarm_fini(tmr);
96 spin_unlock_irqrestore(&tmr->lock, flags);
97
98 /* Execute completed callbacks. */
99 list_for_each_entry_safe(alarm, atemp, &exec, exec) {
100 list_del(&alarm->exec);
101 alarm->func(alarm);
102 }
103 }
104
105 void
nvkm_timer_alarm(struct nvkm_timer * tmr,u32 nsec,struct nvkm_alarm * alarm)106 nvkm_timer_alarm(struct nvkm_timer *tmr, u32 nsec, struct nvkm_alarm *alarm)
107 {
108 struct nvkm_alarm *list;
109 unsigned long flags;
110
111 /* Remove alarm from pending list.
112 *
113 * This both protects against the corruption of the list,
114 * and implements alarm rescheduling/cancellation.
115 */
116 spin_lock_irqsave(&tmr->lock, flags);
117 list_del_init(&alarm->head);
118
119 if (nsec) {
120 /* Insert into pending list, ordered earliest to latest. */
121 alarm->timestamp = nvkm_timer_read(tmr) + nsec;
122 list_for_each_entry(list, &tmr->alarms, head) {
123 if (list->timestamp > alarm->timestamp)
124 break;
125 }
126
127 list_add_tail(&alarm->head, &list->head);
128
129 /* Update HW if this is now the earliest alarm. */
130 list = list_first_entry(&tmr->alarms, typeof(*list), head);
131 if (list == alarm) {
132 tmr->func->alarm_init(tmr, alarm->timestamp);
133 /* This shouldn't happen if callers aren't stupid.
134 *
135 * Worst case scenario is that it'll take roughly
136 * 4 seconds for the next alarm to trigger.
137 */
138 WARN_ON(alarm->timestamp <= nvkm_timer_read(tmr));
139 }
140 }
141 spin_unlock_irqrestore(&tmr->lock, flags);
142 }
143
144 static void
nvkm_timer_intr(struct nvkm_subdev * subdev)145 nvkm_timer_intr(struct nvkm_subdev *subdev)
146 {
147 struct nvkm_timer *tmr = nvkm_timer(subdev);
148 tmr->func->intr(tmr);
149 }
150
151 static int
nvkm_timer_fini(struct nvkm_subdev * subdev,bool suspend)152 nvkm_timer_fini(struct nvkm_subdev *subdev, bool suspend)
153 {
154 struct nvkm_timer *tmr = nvkm_timer(subdev);
155 tmr->func->alarm_fini(tmr);
156 return 0;
157 }
158
159 static int
nvkm_timer_init(struct nvkm_subdev * subdev)160 nvkm_timer_init(struct nvkm_subdev *subdev)
161 {
162 struct nvkm_timer *tmr = nvkm_timer(subdev);
163 if (tmr->func->init)
164 tmr->func->init(tmr);
165 tmr->func->time(tmr, ktime_to_ns(ktime_get()));
166 nvkm_timer_alarm_trigger(tmr);
167 return 0;
168 }
169
170 static void *
nvkm_timer_dtor(struct nvkm_subdev * subdev)171 nvkm_timer_dtor(struct nvkm_subdev *subdev)
172 {
173 return nvkm_timer(subdev);
174 }
175
176 static const struct nvkm_subdev_func
177 nvkm_timer = {
178 .dtor = nvkm_timer_dtor,
179 .init = nvkm_timer_init,
180 .fini = nvkm_timer_fini,
181 .intr = nvkm_timer_intr,
182 };
183
184 int
nvkm_timer_new_(const struct nvkm_timer_func * func,struct nvkm_device * device,enum nvkm_subdev_type type,int inst,struct nvkm_timer ** ptmr)185 nvkm_timer_new_(const struct nvkm_timer_func *func, struct nvkm_device *device,
186 enum nvkm_subdev_type type, int inst, struct nvkm_timer **ptmr)
187 {
188 struct nvkm_timer *tmr;
189
190 if (!(tmr = *ptmr = kzalloc(sizeof(*tmr), GFP_KERNEL)))
191 return -ENOMEM;
192
193 nvkm_subdev_ctor(&nvkm_timer, device, type, inst, &tmr->subdev);
194 tmr->func = func;
195 INIT_LIST_HEAD(&tmr->alarms);
196 spin_lock_init(&tmr->lock);
197 return 0;
198 }
199