vm_power_manager/channel_monitor.c

/*-
 *   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 <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <signal.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/epoll.h>
#include <sys/queue.h>

#include <rte_log.h>
#include <rte_memory.h>
#include <rte_malloc.h>
#include <rte_atomic.h>


#include "channel_monitor.h"
#include "channel_commands.h"
#include "channel_manager.h"
#include "power_manager.h"

#define RTE_LOGTYPE_CHANNEL_MONITOR RTE_LOGTYPE_USER1

#define MAX_EVENTS 256


static volatile unsigned run_loop = 1;
static int global_event_fd;
static struct epoll_event *global_events_list;

void channel_monitor_exit(void)
{
    run_loop = 0;
    rte_free(global_events_list);
}

static int
process_request(struct channel_packet *pkt, struct channel_info *chan_info)
{
    uint64_t core_mask;

    if (chan_info == NULL)
        return -1;

    if (rte_atomic32_cmpset(&(chan_info->status), CHANNEL_MGR_CHANNEL_CONNECTED,
            CHANNEL_MGR_CHANNEL_PROCESSING) == 0)
        return -1;

    if (pkt->command == CPU_POWER) {
        core_mask = get_pcpus_mask(chan_info, pkt->resource_id);
        if (core_mask == 0) {
            RTE_LOG(ERR, CHANNEL_MONITOR, "Error get physical CPU mask for "
                "channel '%s' using vCPU(%u)\n", chan_info->channel_path,
                (unsigned)pkt->unit);
            return -1;
        }
        if (__builtin_popcountll(core_mask) == 1) {

            unsigned core_num = __builtin_ffsll(core_mask) - 1;

            switch (pkt->unit) {
            case(CPU_POWER_SCALE_MIN):
                    power_manager_scale_core_min(core_num);
            break;
            case(CPU_POWER_SCALE_MAX):
                    power_manager_scale_core_max(core_num);
            break;
            case(CPU_POWER_SCALE_DOWN):
                    power_manager_scale_core_down(core_num);
            break;
            case(CPU_POWER_SCALE_UP):
                    power_manager_scale_core_up(core_num);
            break;
            default:
                break;
            }
        } else {
            switch (pkt->unit) {
            case(CPU_POWER_SCALE_MIN):
                    power_manager_scale_mask_min(core_mask);
            break;
            case(CPU_POWER_SCALE_MAX):
                    power_manager_scale_mask_max(core_mask);
            break;
            case(CPU_POWER_SCALE_DOWN):
                    power_manager_scale_mask_down(core_mask);
            break;
            case(CPU_POWER_SCALE_UP):
                    power_manager_scale_mask_up(core_mask);
            break;
            default:
                break;
            }

        }
    }
    /* Return is not checked as channel status may have been set to DISABLED
     * from management thread
     */
    rte_atomic32_cmpset(&(chan_info->status), CHANNEL_MGR_CHANNEL_PROCESSING,
            CHANNEL_MGR_CHANNEL_CONNECTED);
    return 0;

}

int
add_channel_to_monitor(struct channel_info **chan_info)
{
    struct channel_info *info = *chan_info;
    struct epoll_event event;

    event.events = EPOLLIN;
    event.data.ptr = info;
    if (epoll_ctl(global_event_fd, EPOLL_CTL_ADD, info->fd, &event) < 0) {
        RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to add channel '%s' "
                "to epoll\n", info->channel_path);
        return -1;
    }
    return 0;
}

int
remove_channel_from_monitor(struct channel_info *chan_info)
{
    if (epoll_ctl(global_event_fd, EPOLL_CTL_DEL, chan_info->fd, NULL) < 0) {
        RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to remove channel '%s' "
                "from epoll\n", chan_info->channel_path);
        return -1;
    }
    return 0;
}

int
channel_monitor_init(void)
{
    global_event_fd = epoll_create1(0);
    if (global_event_fd == 0) {
        RTE_LOG(ERR, CHANNEL_MONITOR, "Error creating epoll context with "
                "error %s\n", strerror(errno));
        return -1;
    }
    global_events_list = rte_malloc("epoll_events", sizeof(*global_events_list)
            * MAX_EVENTS, RTE_CACHE_LINE_SIZE);
    if (global_events_list == NULL) {
        RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to rte_malloc for "
                "epoll events\n");
        return -1;
    }
    return 0;
}

void
run_channel_monitor(void)
{
    while (run_loop) {
        int n_events, i;

        n_events = epoll_wait(global_event_fd, global_events_list,
                MAX_EVENTS, 1);
        if (!run_loop)
            break;
        for (i = 0; i < n_events; i++) {
            struct channel_info *chan_info = (struct channel_info *)
                    global_events_list[i].data.ptr;
            if ((global_events_list[i].events & EPOLLERR) ||
                    (global_events_list[i].events & EPOLLHUP)) {
                RTE_LOG(DEBUG, CHANNEL_MONITOR, "Remote closed connection for "
                        "channel '%s'\n", chan_info->channel_path);
                remove_channel(&chan_info);
                continue;
            }
            if (global_events_list[i].events & EPOLLIN) {

                int n_bytes, err = 0;
                struct channel_packet pkt;
                void *buffer = &pkt;
                int buffer_len = sizeof(pkt);

                while (buffer_len > 0) {
                    n_bytes = read(chan_info->fd, buffer, buffer_len);
                    if (n_bytes == buffer_len)
                        break;
                    if (n_bytes == -1) {
                        err = errno;
                        RTE_LOG(DEBUG, CHANNEL_MONITOR, "Received error on "
                                "channel '%s' read: %s\n",
                                chan_info->channel_path, strerror(err));
                        remove_channel(&chan_info);
                        break;
                    }
                    buffer = (char *)buffer + n_bytes;
                    buffer_len -= n_bytes;
                }
                if (!err)
                    process_request(&pkt, chan_info);
            }
        }
    }
}