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 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 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 63 nvkm_timer_read(struct nvkm_timer *tmr) 64 { 65 return tmr->func->read(tmr); 66 } 67 68 void 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 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 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 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 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 * 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 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