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