Imported Upstream version 16.04
[deb_dpdk.git] / lib / librte_eal / linuxapp / eal / eal_alarm.c
diff --git a/lib/librte_eal/linuxapp/eal/eal_alarm.c b/lib/librte_eal/linuxapp/eal/eal_alarm.c
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+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <signal.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/queue.h>
+#include <sys/time.h>
+#include <sys/timerfd.h>
+
+#include <rte_memory.h>
+#include <rte_memzone.h>
+#include <rte_interrupts.h>
+#include <rte_alarm.h>
+#include <rte_common.h>
+#include <rte_per_lcore.h>
+#include <rte_eal.h>
+#include <rte_launch.h>
+#include <rte_lcore.h>
+#include <rte_errno.h>
+#include <rte_malloc.h>
+#include <rte_spinlock.h>
+#include <eal_private.h>
+
+#ifndef        TFD_NONBLOCK
+#include <fcntl.h>
+#define        TFD_NONBLOCK    O_NONBLOCK
+#endif
+
+#define NS_PER_US 1000
+#define US_PER_MS 1000
+#define MS_PER_S 1000
+#define US_PER_S (US_PER_MS * MS_PER_S)
+
+#ifdef CLOCK_MONOTONIC_RAW /* Defined in glibc bits/time.h */
+#define CLOCK_TYPE_ID CLOCK_MONOTONIC_RAW
+#else
+#define CLOCK_TYPE_ID CLOCK_MONOTONIC
+#endif
+
+struct alarm_entry {
+       LIST_ENTRY(alarm_entry) next;
+       struct timeval time;
+       rte_eal_alarm_callback cb_fn;
+       void *cb_arg;
+       volatile uint8_t executing;
+       volatile pthread_t executing_id;
+};
+
+static LIST_HEAD(alarm_list, alarm_entry) alarm_list = LIST_HEAD_INITIALIZER();
+static rte_spinlock_t alarm_list_lk = RTE_SPINLOCK_INITIALIZER;
+
+static struct rte_intr_handle intr_handle = {.fd = -1 };
+static int handler_registered = 0;
+static void eal_alarm_callback(struct rte_intr_handle *hdl, void *arg);
+
+int
+rte_eal_alarm_init(void)
+{
+       intr_handle.type = RTE_INTR_HANDLE_ALARM;
+       /* create a timerfd file descriptor */
+       intr_handle.fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
+       if (intr_handle.fd == -1)
+               goto error;
+
+       return 0;
+
+error:
+       rte_errno = errno;
+       return -1;
+}
+
+static void
+eal_alarm_callback(struct rte_intr_handle *hdl __rte_unused,
+               void *arg __rte_unused)
+{
+       struct timespec now;
+       struct alarm_entry *ap;
+
+       rte_spinlock_lock(&alarm_list_lk);
+       while ((ap = LIST_FIRST(&alarm_list)) !=NULL &&
+                       clock_gettime(CLOCK_TYPE_ID, &now) == 0 &&
+                       (ap->time.tv_sec < now.tv_sec || (ap->time.tv_sec == now.tv_sec &&
+                                               (ap->time.tv_usec * NS_PER_US) <= now.tv_nsec))) {
+               ap->executing = 1;
+               ap->executing_id = pthread_self();
+               rte_spinlock_unlock(&alarm_list_lk);
+
+               ap->cb_fn(ap->cb_arg);
+
+               rte_spinlock_lock(&alarm_list_lk);
+
+               LIST_REMOVE(ap, next);
+               rte_free(ap);
+       }
+
+       if (!LIST_EMPTY(&alarm_list)) {
+               struct itimerspec atime = { .it_interval = { 0, 0 } };
+
+               ap = LIST_FIRST(&alarm_list);
+               atime.it_value.tv_sec = ap->time.tv_sec;
+               atime.it_value.tv_nsec = ap->time.tv_usec * NS_PER_US;
+               /* perform borrow for subtraction if necessary */
+               if (now.tv_nsec > (ap->time.tv_usec * NS_PER_US))
+                       atime.it_value.tv_sec--, atime.it_value.tv_nsec += US_PER_S * NS_PER_US;
+
+               atime.it_value.tv_sec -= now.tv_sec;
+               atime.it_value.tv_nsec -= now.tv_nsec;
+               timerfd_settime(intr_handle.fd, 0, &atime, NULL);
+       }
+       rte_spinlock_unlock(&alarm_list_lk);
+}
+
+int
+rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb_fn, void *cb_arg)
+{
+       struct timespec now;
+       int ret = 0;
+       struct alarm_entry *ap, *new_alarm;
+
+       /* Check parameters, including that us won't cause a uint64_t overflow */
+       if (us < 1 || us > (UINT64_MAX - US_PER_S) || cb_fn == NULL)
+               return -EINVAL;
+
+       new_alarm = rte_zmalloc(NULL, sizeof(*new_alarm), 0);
+       if (new_alarm == NULL)
+               return -ENOMEM;
+
+       /* use current time to calculate absolute time of alarm */
+       clock_gettime(CLOCK_TYPE_ID, &now);
+
+       new_alarm->cb_fn = cb_fn;
+       new_alarm->cb_arg = cb_arg;
+       new_alarm->time.tv_usec = ((now.tv_nsec / NS_PER_US) + us) % US_PER_S;
+       new_alarm->time.tv_sec = now.tv_sec + (((now.tv_nsec / NS_PER_US) + us) / US_PER_S);
+
+       rte_spinlock_lock(&alarm_list_lk);
+       if (!handler_registered) {
+               ret |= rte_intr_callback_register(&intr_handle,
+                               eal_alarm_callback, NULL);
+               handler_registered = (ret == 0) ? 1 : 0;
+       }
+
+       if (LIST_EMPTY(&alarm_list))
+               LIST_INSERT_HEAD(&alarm_list, new_alarm, next);
+       else {
+               LIST_FOREACH(ap, &alarm_list, next) {
+                       if (ap->time.tv_sec > new_alarm->time.tv_sec ||
+                                       (ap->time.tv_sec == new_alarm->time.tv_sec &&
+                                                       ap->time.tv_usec > new_alarm->time.tv_usec)){
+                               LIST_INSERT_BEFORE(ap, new_alarm, next);
+                               break;
+                       }
+                       if (LIST_NEXT(ap, next) == NULL) {
+                               LIST_INSERT_AFTER(ap, new_alarm, next);
+                               break;
+                       }
+               }
+       }
+
+       if (LIST_FIRST(&alarm_list) == new_alarm) {
+               struct itimerspec alarm_time = {
+                       .it_interval = {0, 0},
+                       .it_value = {
+                               .tv_sec = us / US_PER_S,
+                               .tv_nsec = (us % US_PER_S) * NS_PER_US,
+                       },
+               };
+               ret |= timerfd_settime(intr_handle.fd, 0, &alarm_time, NULL);
+       }
+       rte_spinlock_unlock(&alarm_list_lk);
+
+       return ret;
+}
+
+int
+rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, void *cb_arg)
+{
+       struct alarm_entry *ap, *ap_prev;
+       int count = 0;
+       int err = 0;
+       int executing;
+
+       if (!cb_fn) {
+               rte_errno = EINVAL;
+               return -1;
+       }
+
+       do {
+               executing = 0;
+               rte_spinlock_lock(&alarm_list_lk);
+               /* remove any matches at the start of the list */
+               while ((ap = LIST_FIRST(&alarm_list)) != NULL &&
+                               cb_fn == ap->cb_fn &&
+                               (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
+
+                       if (ap->executing == 0) {
+                               LIST_REMOVE(ap, next);
+                               rte_free(ap);
+                               count++;
+                       } else {
+                               /* If calling from other context, mark that alarm is executing
+                                * so loop can spin till it finish. Otherwise we are trying to
+                                * cancel our self - mark it by EINPROGRESS */
+                               if (pthread_equal(ap->executing_id, pthread_self()) == 0)
+                                       executing++;
+                               else
+                                       err = EINPROGRESS;
+
+                               break;
+                       }
+               }
+               ap_prev = ap;
+
+               /* now go through list, removing entries not at start */
+               LIST_FOREACH(ap, &alarm_list, next) {
+                       /* this won't be true first time through */
+                       if (cb_fn == ap->cb_fn &&
+                                       (cb_arg == (void *)-1 || cb_arg == ap->cb_arg)) {
+
+                               if (ap->executing == 0) {
+                                       LIST_REMOVE(ap, next);
+                                       rte_free(ap);
+                                       count++;
+                                       ap = ap_prev;
+                               } else if (pthread_equal(ap->executing_id, pthread_self()) == 0)
+                                       executing++;
+                               else
+                                       err = EINPROGRESS;
+                       }
+                       ap_prev = ap;
+               }
+               rte_spinlock_unlock(&alarm_list_lk);
+       } while (executing != 0);
+
+       if (count == 0 && err == 0)
+               rte_errno = ENOENT;
+       else if (err)
+               rte_errno = err;
+
+       return count;
+}