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