lib/librte_eal/linuxapp/eal/eal_alarm.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2012 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  */
  34 #include <stdio.h>
  35 #include <stdint.h>
  36 #include <signal.h>
  37 #include <errno.h>
  38 #include <string.h>
  39 #include <sys/queue.h>
  40 #include <sys/time.h>
  41 #include <sys/timerfd.h>
  42
  43 #include <rte_memory.h>
  44 #include <rte_memzone.h>
  45 #include <rte_interrupts.h>
  46 #include <rte_alarm.h>
  47 #include <rte_common.h>
  48 #include <rte_per_lcore.h>
  49 #include <rte_tailq.h>
  50 #include <rte_eal.h>
  51 #include <rte_launch.h>
  52 #include <rte_lcore.h>
  53 #include <rte_errno.h>
  54 #include <rte_malloc.h>
  55 #include <rte_spinlock.h>
  56 #include <eal_private.h>
  57
  58 #define NS_PER_US 1000
  59 #define US_PER_MS 1000
  60 #define MS_PER_S 1000
  61 #define US_PER_S (US_PER_MS * MS_PER_S)
  62
  63 struct alarm_entry {
  64         LIST_ENTRY(alarm_entry) next;
  65         struct timeval time;
  66         rte_eal_alarm_callback cb_fn;
  67         void *cb_arg;
  68         volatile int executing;
  69 };
  70
  71 static LIST_HEAD(alarm_list, alarm_entry) alarm_list = LIST_HEAD_INITIALIZER();
  72 static rte_spinlock_t alarm_list_lk = RTE_SPINLOCK_INITIALIZER;
  73
  74 static struct rte_intr_handle intr_handle = {.fd = -1 };
  75 static int handler_registered = 0;
  76 static void eal_alarm_callback(struct rte_intr_handle *hdl, void *arg);
  77
  78 int
  79 rte_eal_alarm_init(void)
  80 {
  81         intr_handle.type = RTE_INTR_HANDLE_ALARM;
  82         /* create a timerfd file descriptor */
  83         intr_handle.fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
  84         if (intr_handle.fd == -1)
  85                 goto error;
  86
  87         return 0;
  88
  89 error:
  90         rte_errno = errno;
  91         return -1;
  92 }
  93
  94 static void
  95 eal_alarm_callback(struct rte_intr_handle *hdl __rte_unused,
  96                 void *arg __rte_unused)
  97 {
  98         struct timeval now;
  99         struct alarm_entry *ap;
 100
 101         rte_spinlock_lock(&alarm_list_lk);
 102         while ((ap = LIST_FIRST(&alarm_list)) !=NULL &&
 103                         gettimeofday(&now, NULL) == 0 &&
 104                         (ap->time.tv_sec < now.tv_sec || (ap->time.tv_sec == now.tv_sec &&
 105                                                 ap->time.tv_usec <= now.tv_usec))){
 106                 ap->executing = 1;
 107                 rte_spinlock_unlock(&alarm_list_lk);
 108
 109                 ap->cb_fn(ap->cb_arg);
 110
 111                 rte_spinlock_lock(&alarm_list_lk);
 112                 LIST_REMOVE(ap, next);
 113                 rte_free(ap);
 114         }
 115
 116         if (!LIST_EMPTY(&alarm_list)) {
 117                 struct itimerspec atime = { .it_interval = { 0, 0 } };
 118
 119                 ap = LIST_FIRST(&alarm_list);
 120                 atime.it_value.tv_sec = ap->time.tv_sec;
 121                 atime.it_value.tv_nsec = ap->time.tv_usec * NS_PER_US;
 122                 /* perform borrow for subtraction if necessary */
 123                 if (now.tv_usec > ap->time.tv_usec)
 124                         atime.it_value.tv_sec--, atime.it_value.tv_nsec += US_PER_S * NS_PER_US;
 125
 126                 atime.it_value.tv_sec -= now.tv_sec;
 127                 atime.it_value.tv_nsec -= now.tv_usec * NS_PER_US;
 128                 timerfd_settime(intr_handle.fd, 0, &atime, NULL);
 129         }
 130         rte_spinlock_unlock(&alarm_list_lk);
 131 }
 132
 133 int
 134 rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb_fn, void *cb_arg)
 135 {
 136         struct timeval now;
 137         int ret = 0;
 138         struct alarm_entry *ap, *new_alarm;
 139
 140         /* Check parameters, including that us won't cause a uint64_t overflow */
 141         if (us < 1 || us > (UINT64_MAX - US_PER_S) || cb_fn == NULL)
 142                 return -EINVAL;
 143
 144         new_alarm = rte_malloc(NULL, sizeof(*new_alarm), 0);
 145         if (new_alarm == NULL)
 146                 return -ENOMEM;
 147
 148         /* use current time to calculate absolute time of alarm */
 149         gettimeofday(&now, NULL);
 150
 151         new_alarm->cb_fn = cb_fn;
 152         new_alarm->cb_arg = cb_arg;
 153         new_alarm->time.tv_usec = (now.tv_usec + us) % US_PER_S;
 154         new_alarm->time.tv_sec = now.tv_sec + ((now.tv_usec + us) / US_PER_S);
 155         new_alarm->executing = 0;
 156
 157         rte_spinlock_lock(&alarm_list_lk);
 158         if (!handler_registered) {
 159                 ret |= rte_intr_callback_register(&intr_handle,
 160                                 eal_alarm_callback, NULL);
 161                 handler_registered = (ret == 0) ? 1 : 0;
 162         }
 163
 164         if (LIST_EMPTY(&alarm_list))
 165                 LIST_INSERT_HEAD(&alarm_list, new_alarm, next);
 166         else {
 167                 LIST_FOREACH(ap, &alarm_list, next) {
 168                         if (ap->time.tv_sec > new_alarm->time.tv_sec ||
 169                                         (ap->time.tv_sec == new_alarm->time.tv_sec &&
 170                                                         ap->time.tv_usec > new_alarm->time.tv_usec)){
 171                                 LIST_INSERT_BEFORE(ap, new_alarm, next);
 172                                 break;
 173                         }
 174                         if (LIST_NEXT(ap, next) == NULL) {
 175                                 LIST_INSERT_AFTER(ap, new_alarm, next);
 176                                 break;
 177                         }
 178                 }
 179         }
 180
 181         if (LIST_FIRST(&alarm_list) == new_alarm) {
 182                 struct itimerspec alarm_time = {
 183                         .it_interval = {0, 0},
 184                         .it_value = {
 185                                 .tv_sec = us / US_PER_S,
 186                                 .tv_nsec = (us % US_PER_S) * NS_PER_US,
 187                         },
 188                 };
 189                 ret |= timerfd_settime(intr_handle.fd, 0, &alarm_time, NULL);
 190         }
 191         rte_spinlock_unlock(&alarm_list_lk);
 192
 193         return ret;
 194 }
 195
 196 int
 197 rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg)
 198 {
 199         struct alarm_entry *ap, *ap_prev;
 200         int count = 0;
 201
 202         if (!cb_fn)
 203                 return -1;
 204
 205         rte_spinlock_lock(&alarm_list_lk);
 206         /* remove any matches at the start of the list */
 207         while ((ap = LIST_FIRST(&alarm_list)) != NULL &&
 208                         cb_fn == ap->cb_fn && ap->executing == 0 &&
 209                         (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
 210                 LIST_REMOVE(ap, next);
 211                 rte_free(ap);
 212                 count++;
 213         }
 214         ap_prev = ap;
 215
 216         /* now go through list, removing entries not at start */
 217         LIST_FOREACH(ap, &alarm_list, next) {
 218                 /* this won't be true first time through */
 219                 if (cb_fn == ap->cb_fn &&  ap->executing == 0 &&
 220                                 (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
 221                         LIST_REMOVE(ap,next);
 222                         rte_free(ap);
 223                         count++;
 224                         ap = ap_prev;
 225                 }
 226                 ap_prev = ap;
 227         }
 228         rte_spinlock_unlock(&alarm_list_lk);
 229         return count;
 230 }
 231