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