diff options
Diffstat (limited to 'lib/librte_eal/linuxapp/eal/eal_interrupts.c')
| -rw-r--r-- | lib/librte_eal/linuxapp/eal/eal_interrupts.c | 540 |
1 files changed, 540 insertions, 0 deletions
diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c b/lib/librte_eal/linuxapp/eal/eal_interrupts.c new file mode 100644 index 0000000..8ff2289 --- /dev/null +++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c @@ -0,0 +1,540 @@ +/*- + * BSD LICENSE + * + * Copyright(c) 2010-2012 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. + * + * version: DPDK.L.1.2.3-3 + */ + +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <pthread.h> +#include <sys/queue.h> +#include <malloc.h> +#include <stdarg.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> +#include <inttypes.h> +#include <sys/epoll.h> +#include <sys/signalfd.h> + +#include <rte_common.h> +#include <rte_interrupts.h> +#include <rte_memory.h> +#include <rte_memzone.h> +#include <rte_launch.h> +#include <rte_tailq.h> +#include <rte_eal.h> +#include <rte_per_lcore.h> +#include <rte_lcore.h> +#include <rte_atomic.h> +#include <rte_branch_prediction.h> +#include <rte_ring.h> +#include <rte_debug.h> +#include <rte_log.h> +#include <rte_mempool.h> +#include <rte_pci.h> +#include <rte_malloc.h> +#include <rte_errno.h> +#include <rte_spinlock.h> + +#include "eal_private.h" + +#define EAL_INTR_EPOLL_WAIT_FOREVER (-1) + +/** + * union for pipe fds. + */ +union intr_pipefds{ + struct { + int pipefd[2]; + }; + struct { + int readfd; + int writefd; + }; +}; + +/** + * union buffer for reading on different devices + */ +union rte_intr_read_buffer { + int uio_intr_count; /* for uio device */ + uint64_t timerfd_num; /* for timerfd */ + char charbuf[16]; /* for others */ +}; + +TAILQ_HEAD(rte_intr_cb_list, rte_intr_callback); +TAILQ_HEAD(rte_intr_source_list, rte_intr_source); + +struct rte_intr_callback { + TAILQ_ENTRY(rte_intr_callback) next; + rte_intr_callback_fn cb_fn; /**< callback address */ + void *cb_arg; /**< parameter for callback */ +}; + +struct rte_intr_source { + TAILQ_ENTRY(rte_intr_source) next; + struct rte_intr_handle intr_handle; /**< interrupt handle */ + struct rte_intr_cb_list callbacks; /**< user callbacks */ +}; + +/* global spinlock for interrupt data operation */ +static rte_spinlock_t intr_lock = RTE_SPINLOCK_INITIALIZER; + +/* union buffer for pipe read/write */ +static union intr_pipefds intr_pipe; + +/* interrupt sources list */ +static struct rte_intr_source_list intr_sources; + +/* interrupt handling thread */ +static pthread_t intr_thread; + +int +rte_intr_callback_register(struct rte_intr_handle *intr_handle, + rte_intr_callback_fn cb, void *cb_arg) +{ + int ret = -1; + struct rte_intr_source *src; + int wake_thread = 0; + + /* first do parameter checking */ + if (intr_handle == NULL || intr_handle->fd < 0 || cb == NULL) { + RTE_LOG(ERR, EAL, + "Registering with invalid input parameter\n"); + return -EINVAL; + } + + /* allocate a new interrupt callback entity */ + struct rte_intr_callback *callback = + rte_zmalloc("interrupt callback list", + sizeof(*callback), 0); + if (callback == NULL) { + RTE_LOG(ERR, EAL, "Can not allocate memory\n"); + return -ENOMEM; + } + callback->cb_fn = cb; + callback->cb_arg = cb_arg; + + rte_spinlock_lock(&intr_lock); + + /* check if there is at least one callback registered for the fd */ + TAILQ_FOREACH(src, &intr_sources, next) + if (src->intr_handle.fd == intr_handle->fd) { + if (src->callbacks.tqh_first == NULL) + /* we had no interrupts for this */ + wake_thread = 1; + + TAILQ_INSERT_TAIL(&(src->callbacks), callback, next); + break; + } + + /* No callback registered for this fd */ + if (src == NULL){ + /* no existing callbacks for this - add new source */ + src = rte_zmalloc("interrupt source list", sizeof(*src), 0); + if (src == NULL){ + RTE_LOG(ERR, EAL, "Can not allocate memory\n"); + ret = -ENOMEM; + goto error; + } + src->intr_handle = *intr_handle; + TAILQ_INIT(&src->callbacks); + + TAILQ_INSERT_TAIL(&intr_sources, src, next); + TAILQ_INSERT_TAIL(&(src->callbacks), callback, next); + wake_thread = 1; + } + + rte_spinlock_unlock(&intr_lock); + /** + * check if need to notify the pipe fd waited by epoll_wait to + * rebuild the wait list. + */ + if (wake_thread) + if (write(intr_pipe.writefd, "1", 1) < 0) + return -EPIPE; + + return 0; + +error: + rte_spinlock_unlock(&intr_lock); + + return ret; +} + +int +rte_intr_callback_unregister(struct rte_intr_handle *intr_handle, + rte_intr_callback_fn cb_fn, void *cb_arg) +{ + int ret = -1; + struct rte_intr_source *src; + struct rte_intr_callback *cb; + + /* do parameter checking first */ + if (intr_handle == NULL || intr_handle->fd < 0) { + RTE_LOG(ERR, EAL, + "Unregistering with invalid input parameter\n"); + return -EINVAL; + } + + rte_spinlock_lock(&intr_lock); + + /* check if the insterrupt source for the fd is existent */ + TAILQ_FOREACH(src, &intr_sources, next) + if (src->intr_handle.fd == intr_handle->fd) + break; + + /* No interrupt source registered for the fd */ + if (src == NULL) { + ret = -ENOENT; + goto error; + } + + ret = 0; + TAILQ_FOREACH(cb, &src->callbacks, next) { + if (cb->cb_fn != cb_fn) + continue; + if (cb_arg == (void *)-1 || cb->cb_arg == cb_arg) { + TAILQ_REMOVE(&src->callbacks, cb, next); + rte_free(cb); + ret ++; + } + + if (src->callbacks.tqh_first == NULL) { + TAILQ_REMOVE(&intr_sources, src, next); + rte_free(src); + } + } + + /* notify the pipe fd waited by epoll_wait to rebuild the wait list */ + if (write(intr_pipe.writefd, "1", 1) < 0) { + ret = -EPIPE; + goto error; + } + + rte_spinlock_unlock(&intr_lock); + + return ret; + +error: + rte_spinlock_unlock(&intr_lock); + + return ret; +} + +int +rte_intr_enable(struct rte_intr_handle *intr_handle) +{ + const int value = 1; + + if (!intr_handle || intr_handle->fd < 0) + return -1; + + switch (intr_handle->type){ + /* write to the uio fd to enable the interrupt */ + case RTE_INTR_HANDLE_UIO: + if (write(intr_handle->fd, &value, sizeof(value)) < 0) { + RTE_LOG(ERR, EAL, + "Error enabling interrupts for fd %d\n", + intr_handle->fd); + return -1; + } + break; + /* not used at this moment */ + case RTE_INTR_HANDLE_ALARM: + return -1; + /* unkown handle type */ + default: + RTE_LOG(ERR, EAL, + "Unknown handle type of fd %d\n", + intr_handle->fd); + return -1; + } + + return 0; +} + +int +rte_intr_disable(struct rte_intr_handle *intr_handle) +{ + const int value = 0; + + if (!intr_handle || intr_handle->fd < 0) + return -1; + + switch (intr_handle->type){ + /* write to the uio fd to disable the interrupt */ + case RTE_INTR_HANDLE_UIO: + if (write(intr_handle->fd, &value, sizeof(value)) < 0){ + RTE_LOG(ERR, EAL, + "Error enabling interrupts for fd %d\n", + intr_handle->fd); + return -1; + } + break; + /* not used at this moment */ + case RTE_INTR_HANDLE_ALARM: + return -1; + /* unkown handle type */ + default: + RTE_LOG(ERR, EAL, + "Unknown handle type of fd %d\n", + intr_handle->fd); + return -1; + } + + return 0; +} + +static int +eal_intr_process_interrupts(struct epoll_event *events, int nfds) +{ + int n, i, active_cb, bytes_read; + struct rte_intr_source *src; + struct rte_intr_callback *cb; + union rte_intr_read_buffer buf; + struct rte_intr_callback active_cbs[32]; + + for (n = 0; n < nfds; n++) { + /** + * if the pipe fd is ready to read, return out to + * rebuild the wait list. + */ + if (events[n].data.fd == intr_pipe.readfd){ + int r = read(intr_pipe.readfd, buf.charbuf, + sizeof(buf.charbuf)); + RTE_SET_USED(r); + return -1; + } + rte_spinlock_lock(&intr_lock); + TAILQ_FOREACH(src, &intr_sources, next) + if (src->intr_handle.fd == + events[n].data.fd) + break; + if (src == NULL){ + rte_spinlock_unlock(&intr_lock); + continue; + } + + /* for this source, make a copy of all the callbacks, + * then unlock the lock, so the callbacks can + * themselves manipulate the list for future + * instances. + */ + active_cb = 0; + memset(active_cbs, 0, sizeof(active_cbs)); + TAILQ_FOREACH(cb, &src->callbacks, next) + active_cbs[active_cb++] = *cb; + rte_spinlock_unlock(&intr_lock); + + /* set the length to be read dor different handle type */ + switch (src->intr_handle.type) { + case RTE_INTR_HANDLE_UIO: + bytes_read = 4; + break; + case RTE_INTR_HANDLE_ALARM: + bytes_read = sizeof(uint64_t); + break; + default: + bytes_read = 1; + break; + } + /** + * read out to clear the ready-to-be-read flag + * for epoll_wait. + */ + bytes_read = read(events[n].data.fd, &buf, bytes_read); + if (bytes_read < 0) { + RTE_LOG(ERR, EAL, "Error reading from file descriptor" + " %d, error: %d\n", events[n].data.fd, errno); + continue; + } + else if (bytes_read == 0) { + RTE_LOG(ERR, EAL, + "Read nothing from file descriptor %d.\n", + events[n].data.fd); + continue; + } + /** + * Finally, call all callbacks from the copy + * we made earlier. + */ + for (i = 0; i < active_cb; i++) { + if (active_cbs[i].cb_fn == NULL) + continue; + active_cbs[i].cb_fn(&src->intr_handle, + active_cbs[i].cb_arg); + } + } + + return 0; +} + +/** + * It handles all the interrupts. + * + * @param pfd + * epoll file descriptor. + * @param totalfds + * The number of file descriptors added in epoll. + * + * @return + * void + */ +static void +eal_intr_handle_interrupts(int pfd, unsigned totalfds) +{ + struct epoll_event events[totalfds]; + int nfds = 0; + + for(;;) { + nfds = epoll_wait(pfd, events, totalfds, + EAL_INTR_EPOLL_WAIT_FOREVER); + /* epoll_wait fail */ + if (nfds < 0) { + if (errno == EINTR) + continue; + RTE_LOG(ERR, EAL, + "epoll_wait returns with fail\n"); + return; + } + /* epoll_wait timeout, will never happens here */ + else if (nfds == 0) + continue; + /* epoll_wait has at least one fd ready to read */ + if (eal_intr_process_interrupts(events, nfds) < 0) + return; + } +} + +/** + * It builds/rebuilds up the epoll file descriptor with all the + * file descriptors being waited on. Then handles the interrupts. + * + * @param arg + * pointer. (unused) + * + * @return + * never return; + */ +static __attribute__((noreturn)) void * +eal_intr_thread_main(__rte_unused void *arg) +{ + struct epoll_event ev; + + /* host thread, never break out */ + for (;;) { + /* build up the epoll fd with all descriptors we are to + * wait on then pass it to the handle_interrupts function + */ + static struct epoll_event pipe_event = { + .events = EPOLLIN | EPOLLPRI, + }; + struct rte_intr_source *src; + unsigned numfds = 0; + + /* create epoll fd */ + int pfd = epoll_create(1); + if (pfd < 0) + rte_panic("Cannot create epoll instance\n"); + + pipe_event.data.fd = intr_pipe.readfd; + /** + * add pipe fd into wait list, this pipe is used to + * rebuild the wait list. + */ + if (epoll_ctl(pfd, EPOLL_CTL_ADD, intr_pipe.readfd, + &pipe_event) < 0) { + rte_panic("Error adding fd to %d epoll_ctl, %s\n", + intr_pipe.readfd, strerror(errno)); + } + numfds++; + + rte_spinlock_lock(&intr_lock); + + TAILQ_FOREACH(src, &intr_sources, next) { + if (src->callbacks.tqh_first == NULL) + continue; /* skip those with no callbacks */ + ev.events = EPOLLIN | EPOLLPRI; + ev.data.fd = src->intr_handle.fd; + + /** + * add all the uio device file descriptor + * into wait list. + */ + if (epoll_ctl(pfd, EPOLL_CTL_ADD, + src->intr_handle.fd, &ev) < 0){ + rte_panic("Error adding fd %d epoll_ctl, %s\n", + src->intr_handle.fd, strerror(errno)); + } + else + numfds++; + } + rte_spinlock_unlock(&intr_lock); + /* serve the interrupt */ + eal_intr_handle_interrupts(pfd, numfds); + + /** + * when we return, we need to rebuild the + * list of fds to monitor. + */ + close(pfd); + } +} + +int +rte_eal_intr_init(void) +{ + int ret = 0; + + /* init the global interrupt source head */ + TAILQ_INIT(&intr_sources); + + /** + * create a pipe which will be waited by epoll and notified to + * rebuild the wait list of epoll. + */ + if (pipe(intr_pipe.pipefd) < 0) + return -1; + + /* create the host thread to wait/handle the interrupt */ + ret = pthread_create(&intr_thread, NULL, + eal_intr_thread_main, NULL); + if (ret != 0) + RTE_LOG(ERR, EAL, + "Failed to create thread for interrupt handling\n"); + + return -ret; +} + |