lib/librte_eal/freebsd/eal_alarm.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2018 Intel Corporation
   3  */
   4
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <fcntl.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <time.h>
  12 #include <errno.h>
  13
  14 #include <rte_alarm.h>
  15 #include <rte_cycles.h>
  16 #include <rte_common.h>
  17 #include <rte_errno.h>
  18 #include <rte_interrupts.h>
  19 #include <rte_spinlock.h>
  20 #include <rte_eal_trace.h>
  21
  22 #include "eal_private.h"
  23 #include "eal_alarm_private.h"
  24
  25 #define NS_PER_US 1000
  26
  27 #ifdef CLOCK_MONOTONIC_RAW /* Defined in glibc bits/time.h */
  28 #define CLOCK_TYPE_ID CLOCK_MONOTONIC_RAW
  29 #else
  30 #define CLOCK_TYPE_ID CLOCK_MONOTONIC
  31 #endif
  32
  33 struct alarm_entry {
  34         LIST_ENTRY(alarm_entry) next;
  35         struct rte_intr_handle handle;
  36         struct timespec time;
  37         rte_eal_alarm_callback cb_fn;
  38         void *cb_arg;
  39         volatile uint8_t executing;
  40         volatile pthread_t executing_id;
  41 };
  42
  43 static LIST_HEAD(alarm_list, alarm_entry) alarm_list = LIST_HEAD_INITIALIZER();
  44 static rte_spinlock_t alarm_list_lk = RTE_SPINLOCK_INITIALIZER;
  45
  46 static struct rte_intr_handle intr_handle = {.fd = -1 };
  47 static void eal_alarm_callback(void *arg);
  48
  49 int
  50 rte_eal_alarm_init(void)
  51 {
  52         intr_handle.type = RTE_INTR_HANDLE_ALARM;
  53
  54         /* on FreeBSD, timers don't use fd's, and their identifiers are stored
  55          * in separate namespace from fd's, so using any value is OK. however,
  56          * EAL interrupts handler expects fd's to be unique, so use an actual fd
  57          * to guarantee unique timer identifier.
  58          */
  59         intr_handle.fd = open("/dev/zero", O_RDONLY);
  60
  61         return 0;
  62 }
  63
  64 static inline int
  65 timespec_cmp(const struct timespec *now, const struct timespec *at)
  66 {
  67         if (now->tv_sec < at->tv_sec)
  68                 return -1;
  69         if (now->tv_sec > at->tv_sec)
  70                 return 1;
  71         if (now->tv_nsec < at->tv_nsec)
  72                 return -1;
  73         if (now->tv_nsec > at->tv_nsec)
  74                 return 1;
  75         return 0;
  76 }
  77
  78 static inline uint64_t
  79 diff_ns(struct timespec *now, struct timespec *at)
  80 {
  81         uint64_t now_ns, at_ns;
  82
  83         if (timespec_cmp(now, at) >= 0)
  84                 return 0;
  85
  86         now_ns = now->tv_sec * NS_PER_S + now->tv_nsec;
  87         at_ns = at->tv_sec * NS_PER_S + at->tv_nsec;
  88
  89         return at_ns - now_ns;
  90 }
  91
  92 int
  93 eal_alarm_get_timeout_ns(uint64_t *val)
  94 {
  95         struct alarm_entry *ap;
  96         struct timespec now;
  97
  98         if (clock_gettime(CLOCK_TYPE_ID, &now) < 0)
  99                 return -1;
 100
 101         if (LIST_EMPTY(&alarm_list))
 102                 return -1;
 103
 104         ap = LIST_FIRST(&alarm_list);
 105
 106         *val = diff_ns(&now, &ap->time);
 107
 108         return 0;
 109 }
 110
 111 static int
 112 unregister_current_callback(void)
 113 {
 114         struct alarm_entry *ap;
 115         int ret = 0;
 116
 117         if (!LIST_EMPTY(&alarm_list)) {
 118                 ap = LIST_FIRST(&alarm_list);
 119
 120                 do {
 121                         ret = rte_intr_callback_unregister(&intr_handle,
 122                                 eal_alarm_callback, &ap->time);
 123                 } while (ret == -EAGAIN);
 124         }
 125
 126         return ret;
 127 }
 128
 129 static int
 130 register_first_callback(void)
 131 {
 132         struct alarm_entry *ap;
 133         int ret = 0;
 134
 135         if (!LIST_EMPTY(&alarm_list)) {
 136                 ap = LIST_FIRST(&alarm_list);
 137
 138                 /* register a new callback */
 139                 ret = rte_intr_callback_register(&intr_handle,
 140                                 eal_alarm_callback, &ap->time);
 141         }
 142         return ret;
 143 }
 144
 145 static void
 146 eal_alarm_callback(void *arg __rte_unused)
 147 {
 148         struct timespec now;
 149         struct alarm_entry *ap;
 150
 151         rte_spinlock_lock(&alarm_list_lk);
 152         ap = LIST_FIRST(&alarm_list);
 153
 154         if (clock_gettime(CLOCK_TYPE_ID, &now) < 0)
 155                 return;
 156
 157         while (ap != NULL && timespec_cmp(&now, &ap->time) >= 0) {
 158                 ap->executing = 1;
 159                 ap->executing_id = pthread_self();
 160                 rte_spinlock_unlock(&alarm_list_lk);
 161
 162                 ap->cb_fn(ap->cb_arg);
 163
 164                 rte_spinlock_lock(&alarm_list_lk);
 165
 166                 LIST_REMOVE(ap, next);
 167                 free(ap);
 168
 169                 ap = LIST_FIRST(&alarm_list);
 170         }
 171
 172         /* timer has been deleted from the kqueue, so recreate it if needed */
 173         register_first_callback();
 174
 175         rte_spinlock_unlock(&alarm_list_lk);
 176 }
 177
 178
 179 int
 180 rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb_fn, void *cb_arg)
 181 {
 182         struct alarm_entry *ap, *new_alarm;
 183         struct timespec now;
 184         uint64_t ns;
 185         int ret = 0;
 186
 187         /* check parameters, also ensure us won't cause a uint64_t overflow */
 188         if (us < 1 || us > (UINT64_MAX - US_PER_S) || cb_fn == NULL)
 189                 return -EINVAL;
 190
 191         new_alarm = calloc(1, sizeof(*new_alarm));
 192         if (new_alarm == NULL)
 193                 return -ENOMEM;
 194
 195         /* use current time to calculate absolute time of alarm */
 196         clock_gettime(CLOCK_TYPE_ID, &now);
 197
 198         ns = us * NS_PER_US;
 199
 200         new_alarm->cb_fn = cb_fn;
 201         new_alarm->cb_arg = cb_arg;
 202         new_alarm->time.tv_nsec = (now.tv_nsec + ns) % NS_PER_S;
 203         new_alarm->time.tv_sec = now.tv_sec + ((now.tv_nsec + ns) / NS_PER_S);
 204
 205         rte_spinlock_lock(&alarm_list_lk);
 206
 207         if (LIST_EMPTY(&alarm_list))
 208                 LIST_INSERT_HEAD(&alarm_list, new_alarm, next);
 209         else {
 210                 LIST_FOREACH(ap, &alarm_list, next) {
 211                         if (timespec_cmp(&new_alarm->time, &ap->time) < 0) {
 212                                 LIST_INSERT_BEFORE(ap, new_alarm, next);
 213                                 break;
 214                         }
 215                         if (LIST_NEXT(ap, next) == NULL) {
 216                                 LIST_INSERT_AFTER(ap, new_alarm, next);
 217                                 break;
 218                         }
 219                 }
 220         }
 221
 222         /* re-register first callback just in case */
 223         register_first_callback();
 224
 225         rte_spinlock_unlock(&alarm_list_lk);
 226
 227         rte_eal_trace_alarm_set(us, cb_fn, cb_arg, ret);
 228         return ret;
 229 }
 230
 231 int
 232 rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg)
 233 {
 234         struct alarm_entry *ap, *ap_prev;
 235         int count = 0;
 236         int err = 0;
 237         int executing;
 238
 239         if (!cb_fn) {
 240                 rte_errno = EINVAL;
 241                 return -1;
 242         }
 243
 244         do {
 245                 executing = 0;
 246                 rte_spinlock_lock(&alarm_list_lk);
 247                 /* remove any matches at the start of the list */
 248                 while (1) {
 249                         ap = LIST_FIRST(&alarm_list);
 250                         if (ap == NULL)
 251                                 break;
 252                         if (cb_fn != ap->cb_fn)
 253                                 break;
 254                         if (cb_arg != ap->cb_arg && cb_arg != (void *) -1)
 255                                 break;
 256                         if (ap->executing == 0) {
 257                                 LIST_REMOVE(ap, next);
 258                                 free(ap);
 259                                 count++;
 260                         } else {
 261                                 /* If calling from other context, mark that
 262                                  * alarm is executing so loop can spin till it
 263                                  * finish. Otherwise we are trying to cancel
 264                                  * ourselves - mark it by EINPROGRESS.
 265                                  */
 266                                 if (pthread_equal(ap->executing_id,
 267                                                 pthread_self()) == 0)
 268                                         executing++;
 269                                 else
 270                                         err = EINPROGRESS;
 271
 272                                 break;
 273                         }
 274                 }
 275                 ap_prev = ap;
 276
 277                 /* now go through list, removing entries not at start */
 278                 LIST_FOREACH(ap, &alarm_list, next) {
 279                         /* this won't be true first time through */
 280                         if (cb_fn == ap->cb_fn &&
 281                                         (cb_arg == (void *)-1 ||
 282                                          cb_arg == ap->cb_arg)) {
 283                                 if (ap->executing == 0) {
 284                                         LIST_REMOVE(ap, next);
 285                                         free(ap);
 286                                         count++;
 287                                         ap = ap_prev;
 288                                 } else if (pthread_equal(ap->executing_id,
 289                                                          pthread_self()) == 0) {
 290                                         executing++;
 291                                 } else {
 292                                         err = EINPROGRESS;
 293                                 }
 294                         }
 295                         ap_prev = ap;
 296                 }
 297                 rte_spinlock_unlock(&alarm_list_lk);
 298         } while (executing != 0);
 299
 300         if (count == 0 && err == 0)
 301                 rte_errno = ENOENT;
 302         else if (err)
 303                 rte_errno = err;
 304
 305         rte_spinlock_lock(&alarm_list_lk);
 306
 307         /* unregister if no alarms left, otherwise re-register first */
 308         if (LIST_EMPTY(&alarm_list))
 309                 unregister_current_callback();
 310         else
 311                 register_first_callback();
 312
 313         rte_spinlock_unlock(&alarm_list_lk);
 314
 315         rte_eal_trace_alarm_cancel(cb_fn, cb_arg, count);
 316         return count;
 317 }