1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright(c) 2010-2014 Intel Corporation 3 */ 4 #include <stdio.h> 5 #include <stdint.h> 6 #include <stdlib.h> 7 #include <errno.h> 8 #include <pthread.h> 9 #include <sys/queue.h> 10 #include <sys/time.h> 11 #include <sys/timerfd.h> 12 13 #include <eal_trace_internal.h> 14 #include <rte_interrupts.h> 15 #include <rte_alarm.h> 16 #include <rte_common.h> 17 #include <rte_errno.h> 18 #include <rte_spinlock.h> 19 20 #include <eal_private.h> 21 22 #ifndef TFD_NONBLOCK 23 #include <fcntl.h> 24 #define TFD_NONBLOCK O_NONBLOCK 25 #endif 26 27 #define NS_PER_US 1000 28 #define US_PER_MS 1000 29 #define MS_PER_S 1000 30 #ifndef US_PER_S 31 #define US_PER_S (US_PER_MS * MS_PER_S) 32 #endif 33 34 #ifdef CLOCK_MONOTONIC_RAW /* Defined in glibc bits/time.h */ 35 #define CLOCK_TYPE_ID CLOCK_MONOTONIC_RAW 36 #else 37 #define CLOCK_TYPE_ID CLOCK_MONOTONIC 38 #endif 39 40 struct alarm_entry { 41 LIST_ENTRY(alarm_entry) next; 42 struct timeval time; 43 rte_eal_alarm_callback cb_fn; 44 void *cb_arg; 45 volatile uint8_t executing; 46 volatile pthread_t executing_id; 47 }; 48 49 static LIST_HEAD(alarm_list, alarm_entry) alarm_list = LIST_HEAD_INITIALIZER(); 50 static rte_spinlock_t alarm_list_lk = RTE_SPINLOCK_INITIALIZER; 51 52 static struct rte_intr_handle *intr_handle; 53 static int handler_registered = 0; 54 static void eal_alarm_callback(void *arg); 55 56 void 57 rte_eal_alarm_cleanup(void) 58 { 59 rte_intr_instance_free(intr_handle); 60 } 61 62 int 63 rte_eal_alarm_init(void) 64 { 65 66 intr_handle = rte_intr_instance_alloc(RTE_INTR_INSTANCE_F_PRIVATE); 67 if (intr_handle == NULL) { 68 EAL_LOG(ERR, "Fail to allocate intr_handle"); 69 goto error; 70 } 71 72 if (rte_intr_type_set(intr_handle, RTE_INTR_HANDLE_ALARM)) 73 goto error; 74 75 /* create a timerfd file descriptor */ 76 if (rte_intr_fd_set(intr_handle, 77 timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK))) 78 goto error; 79 80 if (rte_intr_fd_get(intr_handle) == -1) 81 goto error; 82 return 0; 83 84 error: 85 rte_intr_instance_free(intr_handle); 86 rte_errno = errno; 87 return -1; 88 } 89 90 static void 91 eal_alarm_callback(void *arg __rte_unused) 92 { 93 struct timespec now; 94 struct alarm_entry *ap; 95 96 rte_spinlock_lock(&alarm_list_lk); 97 while ((ap = LIST_FIRST(&alarm_list)) !=NULL && 98 clock_gettime(CLOCK_TYPE_ID, &now) == 0 && 99 (ap->time.tv_sec < now.tv_sec || (ap->time.tv_sec == now.tv_sec && 100 (ap->time.tv_usec * NS_PER_US) <= now.tv_nsec))) { 101 ap->executing = 1; 102 ap->executing_id = pthread_self(); 103 rte_spinlock_unlock(&alarm_list_lk); 104 105 ap->cb_fn(ap->cb_arg); 106 107 rte_spinlock_lock(&alarm_list_lk); 108 109 LIST_REMOVE(ap, next); 110 free(ap); 111 } 112 113 if (!LIST_EMPTY(&alarm_list)) { 114 struct itimerspec atime = { .it_interval = { 0, 0 } }; 115 116 ap = LIST_FIRST(&alarm_list); 117 atime.it_value.tv_sec = ap->time.tv_sec; 118 atime.it_value.tv_nsec = ap->time.tv_usec * NS_PER_US; 119 /* perform borrow for subtraction if necessary */ 120 if (now.tv_nsec > (ap->time.tv_usec * NS_PER_US)) 121 atime.it_value.tv_sec--, atime.it_value.tv_nsec += US_PER_S * NS_PER_US; 122 123 atime.it_value.tv_sec -= now.tv_sec; 124 atime.it_value.tv_nsec -= now.tv_nsec; 125 timerfd_settime(rte_intr_fd_get(intr_handle), 0, &atime, NULL); 126 } 127 rte_spinlock_unlock(&alarm_list_lk); 128 } 129 130 int 131 rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb_fn, void *cb_arg) 132 { 133 struct timespec now; 134 int ret = 0; 135 struct alarm_entry *ap, *new_alarm; 136 137 /* Check parameters, including that us won't cause a uint64_t overflow */ 138 if (us < 1 || us > (UINT64_MAX - US_PER_S) || cb_fn == NULL) 139 return -EINVAL; 140 141 new_alarm = calloc(1, sizeof(*new_alarm)); 142 if (new_alarm == NULL) 143 return -ENOMEM; 144 145 /* use current time to calculate absolute time of alarm */ 146 clock_gettime(CLOCK_TYPE_ID, &now); 147 148 new_alarm->cb_fn = cb_fn; 149 new_alarm->cb_arg = cb_arg; 150 new_alarm->time.tv_usec = ((now.tv_nsec / NS_PER_US) + us) % US_PER_S; 151 new_alarm->time.tv_sec = now.tv_sec + (((now.tv_nsec / NS_PER_US) + us) / US_PER_S); 152 153 rte_spinlock_lock(&alarm_list_lk); 154 if (!handler_registered) { 155 /* registration can fail, callback can be registered later */ 156 if (rte_intr_callback_register(intr_handle, 157 eal_alarm_callback, NULL) == 0) 158 handler_registered = 1; 159 } 160 161 if (LIST_EMPTY(&alarm_list)) 162 LIST_INSERT_HEAD(&alarm_list, new_alarm, next); 163 else { 164 LIST_FOREACH(ap, &alarm_list, next) { 165 if (ap->time.tv_sec > new_alarm->time.tv_sec || 166 (ap->time.tv_sec == new_alarm->time.tv_sec && 167 ap->time.tv_usec > new_alarm->time.tv_usec)){ 168 LIST_INSERT_BEFORE(ap, new_alarm, next); 169 break; 170 } 171 if (LIST_NEXT(ap, next) == NULL) { 172 LIST_INSERT_AFTER(ap, new_alarm, next); 173 break; 174 } 175 } 176 } 177 178 if (LIST_FIRST(&alarm_list) == new_alarm) { 179 struct itimerspec alarm_time = { 180 .it_interval = {0, 0}, 181 .it_value = { 182 .tv_sec = us / US_PER_S, 183 .tv_nsec = (us % US_PER_S) * NS_PER_US, 184 }, 185 }; 186 ret |= timerfd_settime(rte_intr_fd_get(intr_handle), 0, &alarm_time, NULL); 187 } 188 rte_spinlock_unlock(&alarm_list_lk); 189 190 rte_eal_trace_alarm_set(us, cb_fn, cb_arg, ret); 191 return ret; 192 } 193 194 int 195 rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg) 196 { 197 struct alarm_entry *ap, *ap_prev; 198 int count = 0; 199 int err = 0; 200 int executing; 201 202 if (!cb_fn) { 203 rte_errno = EINVAL; 204 return -1; 205 } 206 207 do { 208 executing = 0; 209 rte_spinlock_lock(&alarm_list_lk); 210 /* remove any matches at the start of the list */ 211 while ((ap = LIST_FIRST(&alarm_list)) != NULL && 212 cb_fn == ap->cb_fn && 213 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) { 214 215 if (ap->executing == 0) { 216 LIST_REMOVE(ap, next); 217 free(ap); 218 count++; 219 } else { 220 /* If calling from other context, mark that alarm is executing 221 * so loop can spin till it finish. Otherwise we are trying to 222 * cancel our self - mark it by EINPROGRESS */ 223 if (pthread_equal(ap->executing_id, pthread_self()) == 0) 224 executing++; 225 else 226 err = EINPROGRESS; 227 228 break; 229 } 230 } 231 ap_prev = ap; 232 233 /* now go through list, removing entries not at start */ 234 LIST_FOREACH(ap, &alarm_list, next) { 235 /* this won't be true first time through */ 236 if (cb_fn == ap->cb_fn && 237 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) { 238 239 if (ap->executing == 0) { 240 LIST_REMOVE(ap, next); 241 free(ap); 242 count++; 243 ap = ap_prev; 244 } else if (pthread_equal(ap->executing_id, pthread_self()) == 0) 245 executing++; 246 else 247 err = EINPROGRESS; 248 } 249 ap_prev = ap; 250 } 251 252 rte_spinlock_unlock(&alarm_list_lk); 253 254 /* Yield control to a second thread executing eal_alarm_callback to avoid 255 * its starvation, as it is waiting for the lock we have just released. 256 */ 257 sched_yield(); 258 } while (executing != 0); 259 260 if (count == 0 && err == 0) 261 rte_errno = ENOENT; 262 else if (err) 263 rte_errno = err; 264 265 rte_eal_trace_alarm_cancel(cb_fn, cb_arg, count); 266 return count; 267 } 268