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; 58 static int handler_registered = 0; 59 static void eal_alarm_callback(void *arg); 60 61 void 62 rte_eal_alarm_cleanup(void) 63 { 64 rte_intr_instance_free(intr_handle); 65 } 66 67 int 68 rte_eal_alarm_init(void) 69 { 70 71 intr_handle = rte_intr_instance_alloc(RTE_INTR_INSTANCE_F_PRIVATE); 72 if (intr_handle == NULL) { 73 RTE_LOG(ERR, EAL, "Fail to allocate intr_handle\n"); 74 goto error; 75 } 76 77 if (rte_intr_type_set(intr_handle, RTE_INTR_HANDLE_ALARM)) 78 goto error; 79 80 /* create a timerfd file descriptor */ 81 if (rte_intr_fd_set(intr_handle, 82 timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK))) 83 goto error; 84 85 if (rte_intr_fd_get(intr_handle) == -1) 86 goto error; 87 return 0; 88 89 error: 90 rte_intr_instance_free(intr_handle); 91 rte_errno = errno; 92 return -1; 93 } 94 95 static void 96 eal_alarm_callback(void *arg __rte_unused) 97 { 98 struct timespec now; 99 struct alarm_entry *ap; 100 101 rte_spinlock_lock(&alarm_list_lk); 102 while ((ap = LIST_FIRST(&alarm_list)) !=NULL && 103 clock_gettime(CLOCK_TYPE_ID, &now) == 0 && 104 (ap->time.tv_sec < now.tv_sec || (ap->time.tv_sec == now.tv_sec && 105 (ap->time.tv_usec * NS_PER_US) <= now.tv_nsec))) { 106 ap->executing = 1; 107 ap->executing_id = pthread_self(); 108 rte_spinlock_unlock(&alarm_list_lk); 109 110 ap->cb_fn(ap->cb_arg); 111 112 rte_spinlock_lock(&alarm_list_lk); 113 114 LIST_REMOVE(ap, next); 115 free(ap); 116 } 117 118 if (!LIST_EMPTY(&alarm_list)) { 119 struct itimerspec atime = { .it_interval = { 0, 0 } }; 120 121 ap = LIST_FIRST(&alarm_list); 122 atime.it_value.tv_sec = ap->time.tv_sec; 123 atime.it_value.tv_nsec = ap->time.tv_usec * NS_PER_US; 124 /* perform borrow for subtraction if necessary */ 125 if (now.tv_nsec > (ap->time.tv_usec * NS_PER_US)) 126 atime.it_value.tv_sec--, atime.it_value.tv_nsec += US_PER_S * NS_PER_US; 127 128 atime.it_value.tv_sec -= now.tv_sec; 129 atime.it_value.tv_nsec -= now.tv_nsec; 130 timerfd_settime(rte_intr_fd_get(intr_handle), 0, &atime, NULL); 131 } 132 rte_spinlock_unlock(&alarm_list_lk); 133 } 134 135 int 136 rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb_fn, void *cb_arg) 137 { 138 struct timespec now; 139 int ret = 0; 140 struct alarm_entry *ap, *new_alarm; 141 142 /* Check parameters, including that us won't cause a uint64_t overflow */ 143 if (us < 1 || us > (UINT64_MAX - US_PER_S) || cb_fn == NULL) 144 return -EINVAL; 145 146 new_alarm = calloc(1, sizeof(*new_alarm)); 147 if (new_alarm == NULL) 148 return -ENOMEM; 149 150 /* use current time to calculate absolute time of alarm */ 151 clock_gettime(CLOCK_TYPE_ID, &now); 152 153 new_alarm->cb_fn = cb_fn; 154 new_alarm->cb_arg = cb_arg; 155 new_alarm->time.tv_usec = ((now.tv_nsec / NS_PER_US) + us) % US_PER_S; 156 new_alarm->time.tv_sec = now.tv_sec + (((now.tv_nsec / NS_PER_US) + us) / US_PER_S); 157 158 rte_spinlock_lock(&alarm_list_lk); 159 if (!handler_registered) { 160 /* registration can fail, callback can be registered later */ 161 if (rte_intr_callback_register(intr_handle, 162 eal_alarm_callback, NULL) == 0) 163 handler_registered = 1; 164 } 165 166 if (LIST_EMPTY(&alarm_list)) 167 LIST_INSERT_HEAD(&alarm_list, new_alarm, next); 168 else { 169 LIST_FOREACH(ap, &alarm_list, next) { 170 if (ap->time.tv_sec > new_alarm->time.tv_sec || 171 (ap->time.tv_sec == new_alarm->time.tv_sec && 172 ap->time.tv_usec > new_alarm->time.tv_usec)){ 173 LIST_INSERT_BEFORE(ap, new_alarm, next); 174 break; 175 } 176 if (LIST_NEXT(ap, next) == NULL) { 177 LIST_INSERT_AFTER(ap, new_alarm, next); 178 break; 179 } 180 } 181 } 182 183 if (LIST_FIRST(&alarm_list) == new_alarm) { 184 struct itimerspec alarm_time = { 185 .it_interval = {0, 0}, 186 .it_value = { 187 .tv_sec = us / US_PER_S, 188 .tv_nsec = (us % US_PER_S) * NS_PER_US, 189 }, 190 }; 191 ret |= timerfd_settime(rte_intr_fd_get(intr_handle), 0, &alarm_time, NULL); 192 } 193 rte_spinlock_unlock(&alarm_list_lk); 194 195 rte_eal_trace_alarm_set(us, cb_fn, cb_arg, ret); 196 return ret; 197 } 198 199 int 200 rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg) 201 { 202 struct alarm_entry *ap, *ap_prev; 203 int count = 0; 204 int err = 0; 205 int executing; 206 207 if (!cb_fn) { 208 rte_errno = EINVAL; 209 return -1; 210 } 211 212 do { 213 executing = 0; 214 rte_spinlock_lock(&alarm_list_lk); 215 /* remove any matches at the start of the list */ 216 while ((ap = LIST_FIRST(&alarm_list)) != NULL && 217 cb_fn == ap->cb_fn && 218 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) { 219 220 if (ap->executing == 0) { 221 LIST_REMOVE(ap, next); 222 free(ap); 223 count++; 224 } else { 225 /* If calling from other context, mark that alarm is executing 226 * so loop can spin till it finish. Otherwise we are trying to 227 * cancel our self - mark it by EINPROGRESS */ 228 if (pthread_equal(ap->executing_id, pthread_self()) == 0) 229 executing++; 230 else 231 err = EINPROGRESS; 232 233 break; 234 } 235 } 236 ap_prev = ap; 237 238 /* now go through list, removing entries not at start */ 239 LIST_FOREACH(ap, &alarm_list, next) { 240 /* this won't be true first time through */ 241 if (cb_fn == ap->cb_fn && 242 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) { 243 244 if (ap->executing == 0) { 245 LIST_REMOVE(ap, next); 246 free(ap); 247 count++; 248 ap = ap_prev; 249 } else if (pthread_equal(ap->executing_id, pthread_self()) == 0) 250 executing++; 251 else 252 err = EINPROGRESS; 253 } 254 ap_prev = ap; 255 } 256 rte_spinlock_unlock(&alarm_list_lk); 257 } while (executing != 0); 258 259 if (count == 0 && err == 0) 260 rte_errno = ENOENT; 261 else if (err) 262 rte_errno = err; 263 264 rte_eal_trace_alarm_cancel(cb_fn, cb_arg, count); 265 return count; 266 } 267