lib/librte_eal/linuxapp/eal/eal_alarm.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33 #include <stdio.h>
  34 #include <stdint.h>
  35 #include <signal.h>
  36 #include <errno.h>
  37 #include <string.h>
  38 #include <sys/queue.h>
  39 #include <sys/time.h>
  40 #include <sys/timerfd.h>
  41
  42 #include <rte_memory.h>
  43 #include <rte_memzone.h>
  44 #include <rte_interrupts.h>
  45 #include <rte_alarm.h>
  46 #include <rte_common.h>
  47 #include <rte_per_lcore.h>
  48 #include <rte_tailq.h>
  49 #include <rte_eal.h>
  50 #include <rte_launch.h>
  51 #include <rte_lcore.h>
  52 #include <rte_errno.h>
  53 #include <rte_malloc.h>
  54 #include <rte_spinlock.h>
  55 #include <eal_private.h>
  56
  57 #ifndef TFD_NONBLOCK
  58 #include <fcntl.h>
  59 #define TFD_NONBLOCK    O_NONBLOCK
  60 #endif
  61
  62 #define NS_PER_US 1000
  63 #define US_PER_MS 1000
  64 #define MS_PER_S 1000
  65 #define US_PER_S (US_PER_MS * MS_PER_S)
  66
  67 struct alarm_entry {
  68         LIST_ENTRY(alarm_entry) next;
  69         struct timeval time;
  70         rte_eal_alarm_callback cb_fn;
  71         void *cb_arg;
  72         volatile uint8_t executing;
  73         volatile pthread_t executing_id;
  74 };
  75
  76 static LIST_HEAD(alarm_list, alarm_entry) alarm_list = LIST_HEAD_INITIALIZER();
  77 static rte_spinlock_t alarm_list_lk = RTE_SPINLOCK_INITIALIZER;
  78
  79 static struct rte_intr_handle intr_handle = {.fd = -1 };
  80 static int handler_registered = 0;
  81 static void eal_alarm_callback(struct rte_intr_handle *hdl, void *arg);
  82
  83 int
  84 rte_eal_alarm_init(void)
  85 {
  86         intr_handle.type = RTE_INTR_HANDLE_ALARM;
  87         /* create a timerfd file descriptor */
  88         intr_handle.fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
  89         if (intr_handle.fd == -1)
  90                 goto error;
  91
  92         return 0;
  93
  94 error:
  95         rte_errno = errno;
  96         return -1;
  97 }
  98
  99 static void
 100 eal_alarm_callback(struct rte_intr_handle *hdl __rte_unused,
 101                 void *arg __rte_unused)
 102 {
 103         struct timeval now;
 104         struct alarm_entry *ap;
 105
 106         rte_spinlock_lock(&alarm_list_lk);
 107         while ((ap = LIST_FIRST(&alarm_list)) !=NULL &&
 108                         gettimeofday(&now, NULL) == 0 &&
 109                         (ap->time.tv_sec < now.tv_sec || (ap->time.tv_sec == now.tv_sec &&
 110                                                 ap->time.tv_usec <= now.tv_usec))){
 111                 ap->executing = 1;
 112                 ap->executing_id = pthread_self();
 113                 rte_spinlock_unlock(&alarm_list_lk);
 114
 115                 ap->cb_fn(ap->cb_arg);
 116
 117                 rte_spinlock_lock(&alarm_list_lk);
 118
 119                 LIST_REMOVE(ap, next);
 120                 rte_free(ap);
 121         }
 122
 123         if (!LIST_EMPTY(&alarm_list)) {
 124                 struct itimerspec atime = { .it_interval = { 0, 0 } };
 125
 126                 ap = LIST_FIRST(&alarm_list);
 127                 atime.it_value.tv_sec = ap->time.tv_sec;
 128                 atime.it_value.tv_nsec = ap->time.tv_usec * NS_PER_US;
 129                 /* perform borrow for subtraction if necessary */
 130                 if (now.tv_usec > ap->time.tv_usec)
 131                         atime.it_value.tv_sec--, atime.it_value.tv_nsec += US_PER_S * NS_PER_US;
 132
 133                 atime.it_value.tv_sec -= now.tv_sec;
 134                 atime.it_value.tv_nsec -= now.tv_usec * NS_PER_US;
 135                 timerfd_settime(intr_handle.fd, 0, &atime, NULL);
 136         }
 137         rte_spinlock_unlock(&alarm_list_lk);
 138 }
 139
 140 int
 141 rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb_fn, void *cb_arg)
 142 {
 143         struct timeval now;
 144         int ret = 0;
 145         struct alarm_entry *ap, *new_alarm;
 146
 147         /* Check parameters, including that us won't cause a uint64_t overflow */
 148         if (us < 1 || us > (UINT64_MAX - US_PER_S) || cb_fn == NULL)
 149                 return -EINVAL;
 150
 151         new_alarm = rte_zmalloc(NULL, sizeof(*new_alarm), 0);
 152         if (new_alarm == NULL)
 153                 return -ENOMEM;
 154
 155         /* use current time to calculate absolute time of alarm */
 156         gettimeofday(&now, NULL);
 157
 158         new_alarm->cb_fn = cb_fn;
 159         new_alarm->cb_arg = cb_arg;
 160         new_alarm->time.tv_usec = (now.tv_usec + us) % US_PER_S;
 161         new_alarm->time.tv_sec = now.tv_sec + ((now.tv_usec + us) / US_PER_S);
 162
 163         rte_spinlock_lock(&alarm_list_lk);
 164         if (!handler_registered) {
 165                 ret |= rte_intr_callback_register(&intr_handle,
 166                                 eal_alarm_callback, NULL);
 167                 handler_registered = (ret == 0) ? 1 : 0;
 168         }
 169
 170         if (LIST_EMPTY(&alarm_list))
 171                 LIST_INSERT_HEAD(&alarm_list, new_alarm, next);
 172         else {
 173                 LIST_FOREACH(ap, &alarm_list, next) {
 174                         if (ap->time.tv_sec > new_alarm->time.tv_sec ||
 175                                         (ap->time.tv_sec == new_alarm->time.tv_sec &&
 176                                                         ap->time.tv_usec > new_alarm->time.tv_usec)){
 177                                 LIST_INSERT_BEFORE(ap, new_alarm, next);
 178                                 break;
 179                         }
 180                         if (LIST_NEXT(ap, next) == NULL) {
 181                                 LIST_INSERT_AFTER(ap, new_alarm, next);
 182                                 break;
 183                         }
 184                 }
 185         }
 186
 187         if (LIST_FIRST(&alarm_list) == new_alarm) {
 188                 struct itimerspec alarm_time = {
 189                         .it_interval = {0, 0},
 190                         .it_value = {
 191                                 .tv_sec = us / US_PER_S,
 192                                 .tv_nsec = (us % US_PER_S) * NS_PER_US,
 193                         },
 194                 };
 195                 ret |= timerfd_settime(intr_handle.fd, 0, &alarm_time, NULL);
 196         }
 197         rte_spinlock_unlock(&alarm_list_lk);
 198
 199         return ret;
 200 }
 201
 202 int
 203 rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg)
 204 {
 205         struct alarm_entry *ap, *ap_prev;
 206         int count = 0;
 207         int err = 0;
 208         int executing;
 209
 210         if (!cb_fn) {
 211                 rte_errno = EINVAL;
 212                 return -1;
 213         }
 214
 215         do {
 216                 executing = 0;
 217                 rte_spinlock_lock(&alarm_list_lk);
 218                 /* remove any matches at the start of the list */
 219                 while ((ap = LIST_FIRST(&alarm_list)) != NULL &&
 220                                 cb_fn == ap->cb_fn &&
 221                                 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
 222
 223                         if (ap->executing == 0) {
 224                                 LIST_REMOVE(ap, next);
 225                                 rte_free(ap);
 226                                 count++;
 227                         } else {
 228                                 /* If calling from other context, mark that alarm is executing
 229                                  * so loop can spin till it finish. Otherwise we are trying to
 230                                  * cancel our self - mark it by EINPROGRESS */
 231                                 if (pthread_equal(ap->executing_id, pthread_self()) == 0)
 232                                         executing++;
 233                                 else
 234                                         err = EINPROGRESS;
 235
 236                                 break;
 237                         }
 238                 }
 239                 ap_prev = ap;
 240
 241                 /* now go through list, removing entries not at start */
 242                 LIST_FOREACH(ap, &alarm_list, next) {
 243                         /* this won't be true first time through */
 244                         if (cb_fn == ap->cb_fn &&
 245                                         (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
 246
 247                                 if (ap->executing == 0) {
 248                                         LIST_REMOVE(ap, next);
 249                                         rte_free(ap);
 250                                         count++;
 251                                         ap = ap_prev;
 252                                 } else if (pthread_equal(ap->executing_id, pthread_self()) == 0)
 253                                         executing++;
 254                                 else
 255                                         err = EINPROGRESS;
 256                         }
 257                         ap_prev = ap;
 258                 }
 259                 rte_spinlock_unlock(&alarm_list_lk);
 260         } while (executing != 0);
 261
 262         if (count == 0 && err == 0)
 263                 rte_errno = ENOENT;
 264         else if (err)
 265                 rte_errno = err;
 266
 267         return count;
 268 }