1 /* $NetBSD: nouveau_nvkm_subdev_timer_base.c,v 1.6 2021/12/19 11:34:46 riastradh Exp $ */ 2 3 /* 4 * Copyright 2012 Red Hat Inc. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 22 * OTHER DEALINGS IN THE SOFTWARE. 23 * 24 * Authors: Ben Skeggs 25 */ 26 #include <sys/cdefs.h> 27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_timer_base.c,v 1.6 2021/12/19 11:34:46 riastradh Exp $"); 28 29 #include "priv.h" 30 31 #include <linux/nbsd-namespace.h> 32 s64 33 nvkm_timer_wait_test(struct nvkm_timer_wait *wait) 34 { 35 struct nvkm_subdev *subdev = &wait->tmr->subdev; 36 u64 time = nvkm_timer_read(wait->tmr); 37 38 if (wait->reads == 0) { 39 wait->time0 = time; 40 wait->time1 = time; 41 } 42 43 if (wait->time1 == time) { 44 if (wait->reads++ == 16) { 45 nvkm_fatal(subdev, "stalled at %016"PRIx64"\n", time); 46 return -ETIMEDOUT; 47 } 48 } else { 49 wait->time1 = time; 50 wait->reads = 1; 51 } 52 53 if (wait->time1 - wait->time0 > wait->limit) 54 return -ETIMEDOUT; 55 56 return wait->time1 - wait->time0; 57 } 58 59 void 60 nvkm_timer_wait_init(struct nvkm_device *device, u64 nsec, 61 struct nvkm_timer_wait *wait) 62 { 63 wait->tmr = device->timer; 64 wait->limit = nsec; 65 wait->reads = 0; 66 } 67 68 u64 69 nvkm_timer_read(struct nvkm_timer *tmr) 70 { 71 return tmr->func->read(tmr); 72 } 73 74 void 75 nvkm_timer_alarm_trigger(struct nvkm_timer *tmr) 76 { 77 struct nvkm_alarm *alarm, *atemp; 78 unsigned long flags; 79 LIST_HEAD(exec); 80 81 /* Process pending alarms. */ 82 spin_lock_irqsave(&tmr->lock, flags); 83 list_for_each_entry_safe(alarm, atemp, &tmr->alarms, head) { 84 /* Have we hit the earliest alarm that hasn't gone off? */ 85 if (alarm->timestamp > nvkm_timer_read(tmr)) { 86 /* Schedule it. If we didn't race, we're done. */ 87 tmr->func->alarm_init(tmr, alarm->timestamp); 88 if (alarm->timestamp > nvkm_timer_read(tmr)) 89 break; 90 } 91 92 /* Move to completed list. We'll drop the lock before 93 * executing the callback so it can reschedule itself. 94 */ 95 list_del_init(&alarm->head); 96 list_add(&alarm->exec, &exec); 97 } 98 99 /* Shut down interrupt if no more pending alarms. */ 100 if (list_empty(&tmr->alarms)) 101 tmr->func->alarm_fini(tmr); 102 spin_unlock_irqrestore(&tmr->lock, flags); 103 104 /* Execute completed callbacks. */ 105 list_for_each_entry_safe(alarm, atemp, &exec, exec) { 106 list_del(&alarm->exec); 107 alarm->func(alarm); 108 } 109 } 110 111 void 112 nvkm_timer_alarm(struct nvkm_timer *tmr, u32 nsec, struct nvkm_alarm *alarm) 113 { 114 struct nvkm_alarm *list; 115 unsigned long flags; 116 117 /* Remove alarm from pending list. 118 * 119 * This both protects against the corruption of the list, 120 * and implements alarm rescheduling/cancellation. 121 */ 122 spin_lock_irqsave(&tmr->lock, flags); 123 list_del_init(&alarm->head); 124 125 if (nsec) { 126 /* Insert into pending list, ordered earliest to latest. */ 127 alarm->timestamp = nvkm_timer_read(tmr) + nsec; 128 list_for_each_entry(list, &tmr->alarms, head) { 129 if (list->timestamp > alarm->timestamp) 130 break; 131 } 132 133 list_add_tail(&alarm->head, &list->head); 134 135 /* Update HW if this is now the earliest alarm. */ 136 list = list_first_entry(&tmr->alarms, typeof(*list), head); 137 if (list == alarm) { 138 tmr->func->alarm_init(tmr, alarm->timestamp); 139 /* This shouldn't happen if callers aren't stupid. 140 * 141 * Worst case scenario is that it'll take roughly 142 * 4 seconds for the next alarm to trigger. 143 */ 144 WARN_ON(alarm->timestamp <= nvkm_timer_read(tmr)); 145 } 146 } 147 spin_unlock_irqrestore(&tmr->lock, flags); 148 } 149 150 static void 151 nvkm_timer_intr(struct nvkm_subdev *subdev) 152 { 153 struct nvkm_timer *tmr = nvkm_timer(subdev); 154 tmr->func->intr(tmr); 155 } 156 157 static int 158 nvkm_timer_fini(struct nvkm_subdev *subdev, bool suspend) 159 { 160 struct nvkm_timer *tmr = nvkm_timer(subdev); 161 tmr->func->alarm_fini(tmr); 162 return 0; 163 } 164 165 static int 166 nvkm_timer_init(struct nvkm_subdev *subdev) 167 { 168 struct nvkm_timer *tmr = nvkm_timer(subdev); 169 if (tmr->func->init) 170 tmr->func->init(tmr); 171 tmr->func->time(tmr, ktime_to_ns(ktime_get())); 172 nvkm_timer_alarm_trigger(tmr); 173 return 0; 174 } 175 176 static void * 177 nvkm_timer_dtor(struct nvkm_subdev *subdev) 178 { 179 spin_lock_destroy(&nvkm_timer(subdev)->lock); 180 return nvkm_timer(subdev); 181 } 182 183 static const struct nvkm_subdev_func 184 nvkm_timer = { 185 .dtor = nvkm_timer_dtor, 186 .init = nvkm_timer_init, 187 .fini = nvkm_timer_fini, 188 .intr = nvkm_timer_intr, 189 }; 190 191 int 192 nvkm_timer_new_(const struct nvkm_timer_func *func, struct nvkm_device *device, 193 int index, struct nvkm_timer **ptmr) 194 { 195 struct nvkm_timer *tmr; 196 197 if (!(tmr = *ptmr = kzalloc(sizeof(*tmr), GFP_KERNEL))) 198 return -ENOMEM; 199 200 nvkm_subdev_ctor(&nvkm_timer, device, index, &tmr->subdev); 201 tmr->func = func; 202 INIT_LIST_HEAD(&tmr->alarms); 203 spin_lock_init(&tmr->lock); 204 return 0; 205 } 206
Indexes created Sat Sep 20 22:09:52 GMT 2025