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 u64
nvkm_timer_read(struct nvkm_timer * tmr)27 nvkm_timer_read(struct nvkm_timer *tmr)
28 {
29 return tmr->func->read(tmr);
30 }
31
32 void
nvkm_timer_alarm_trigger(struct nvkm_timer * tmr)33 nvkm_timer_alarm_trigger(struct nvkm_timer *tmr)
34 {
35 struct nvkm_alarm *alarm, *atemp;
36 unsigned long flags;
37 LIST_HEAD(exec);
38
39 /* move any due alarms off the pending list */
40 spin_lock_irqsave(&tmr->lock, flags);
41 list_for_each_entry_safe(alarm, atemp, &tmr->alarms, head) {
42 if (alarm->timestamp <= nvkm_timer_read(tmr))
43 list_move_tail(&alarm->head, &exec);
44 }
45
46 /* reschedule interrupt for next alarm time */
47 if (!list_empty(&tmr->alarms)) {
48 alarm = list_first_entry(&tmr->alarms, typeof(*alarm), head);
49 tmr->func->alarm_init(tmr, alarm->timestamp);
50 } else {
51 tmr->func->alarm_fini(tmr);
52 }
53 spin_unlock_irqrestore(&tmr->lock, flags);
54
55 /* execute any pending alarm handlers */
56 list_for_each_entry_safe(alarm, atemp, &exec, head) {
57 list_del_init(&alarm->head);
58 alarm->func(alarm);
59 }
60 }
61
62 void
nvkm_timer_alarm(struct nvkm_timer * tmr,u32 nsec,struct nvkm_alarm * alarm)63 nvkm_timer_alarm(struct nvkm_timer *tmr, u32 nsec, struct nvkm_alarm *alarm)
64 {
65 struct nvkm_alarm *list;
66 unsigned long flags;
67
68 alarm->timestamp = nvkm_timer_read(tmr) + nsec;
69
70 /* append new alarm to list, in soonest-alarm-first order */
71 spin_lock_irqsave(&tmr->lock, flags);
72 if (!nsec) {
73 if (!list_empty(&alarm->head))
74 list_del(&alarm->head);
75 } else {
76 list_for_each_entry(list, &tmr->alarms, head) {
77 if (list->timestamp > alarm->timestamp)
78 break;
79 }
80 list_add_tail(&alarm->head, &list->head);
81 }
82 spin_unlock_irqrestore(&tmr->lock, flags);
83
84 /* process pending alarms */
85 nvkm_timer_alarm_trigger(tmr);
86 }
87
88 void
nvkm_timer_alarm_cancel(struct nvkm_timer * tmr,struct nvkm_alarm * alarm)89 nvkm_timer_alarm_cancel(struct nvkm_timer *tmr, struct nvkm_alarm *alarm)
90 {
91 unsigned long flags;
92 spin_lock_irqsave(&tmr->lock, flags);
93 list_del_init(&alarm->head);
94 spin_unlock_irqrestore(&tmr->lock, flags);
95 }
96
97 static void
nvkm_timer_intr(struct nvkm_subdev * subdev)98 nvkm_timer_intr(struct nvkm_subdev *subdev)
99 {
100 struct nvkm_timer *tmr = nvkm_timer(subdev);
101 tmr->func->intr(tmr);
102 }
103
104 static int
nvkm_timer_fini(struct nvkm_subdev * subdev,bool suspend)105 nvkm_timer_fini(struct nvkm_subdev *subdev, bool suspend)
106 {
107 struct nvkm_timer *tmr = nvkm_timer(subdev);
108 tmr->func->alarm_fini(tmr);
109 return 0;
110 }
111
112 static int
nvkm_timer_init(struct nvkm_subdev * subdev)113 nvkm_timer_init(struct nvkm_subdev *subdev)
114 {
115 struct nvkm_timer *tmr = nvkm_timer(subdev);
116 if (tmr->func->init)
117 tmr->func->init(tmr);
118 tmr->func->time(tmr, ktime_to_ns(ktime_get()));
119 nvkm_timer_alarm_trigger(tmr);
120 return 0;
121 }
122
123 static void *
nvkm_timer_dtor(struct nvkm_subdev * subdev)124 nvkm_timer_dtor(struct nvkm_subdev *subdev)
125 {
126 return nvkm_timer(subdev);
127 }
128
129 static const struct nvkm_subdev_func
130 nvkm_timer = {
131 .dtor = nvkm_timer_dtor,
132 .init = nvkm_timer_init,
133 .fini = nvkm_timer_fini,
134 .intr = nvkm_timer_intr,
135 };
136
137 int
nvkm_timer_new_(const struct nvkm_timer_func * func,struct nvkm_device * device,int index,struct nvkm_timer ** ptmr)138 nvkm_timer_new_(const struct nvkm_timer_func *func, struct nvkm_device *device,
139 int index, struct nvkm_timer **ptmr)
140 {
141 struct nvkm_timer *tmr;
142
143 if (!(tmr = *ptmr = kzalloc(sizeof(*tmr), GFP_KERNEL)))
144 return -ENOMEM;
145
146 nvkm_subdev_ctor(&nvkm_timer, device, index, 0, &tmr->subdev);
147 tmr->func = func;
148 INIT_LIST_HEAD(&tmr->alarms);
149 spin_lock_init(&tmr->lock);
150 return 0;
151 }
152