/*
 * Copyright (c) 2012-2013,2015-2018, The Linux Foundation. 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 The Linux Foundation 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 "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
 * 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.
 */
#define LOG_NIDEBUG 0

#include <dlfcn.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "hint-data.h"
#include "list.h"
#include "power-common.h"
#include "utils.h"

#define LOG_TAG "QTI PowerHAL"
#include <log/log.h>

#define USINSEC 1000000L
#define NSINUS 1000L

#define SOC_ID_0 "/sys/devices/soc0/soc_id"
#define SOC_ID_1 "/sys/devices/system/soc/soc0/id"

const char* scaling_gov_path[8] = {"/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor",
                                   "/sys/devices/system/cpu/cpu1/cpufreq/scaling_governor",
                                   "/sys/devices/system/cpu/cpu2/cpufreq/scaling_governor",
                                   "/sys/devices/system/cpu/cpu3/cpufreq/scaling_governor",
                                   "/sys/devices/system/cpu/cpu4/cpufreq/scaling_governor",
                                   "/sys/devices/system/cpu/cpu5/cpufreq/scaling_governor",
                                   "/sys/devices/system/cpu/cpu6/cpufreq/scaling_governor",
                                   "/sys/devices/system/cpu/cpu7/cpufreq/scaling_governor"};

#define PERF_HAL_PATH "libqti-perfd-client.so"
static void* qcopt_handle;
static int (*perf_lock_acq)(int handle, int duration, int list[], int numArgs);
static int (*perf_lock_rel)(int handle);
static int (*perf_hint)(int, const char*, int, int);
static struct list_node active_hint_list_head;
const char* pkg = "QTI PowerHAL";

static void* get_qcopt_handle() {
    char qcopt_lib_path[PATH_MAX] = {0};
    void* handle = NULL;

    dlerror();

    if (property_get("ro.vendor.extension_library", qcopt_lib_path, NULL)) {
        handle = dlopen(qcopt_lib_path, RTLD_NOW);
        if (!handle) {
            ALOGE("Unable to open %s: %s\n", qcopt_lib_path, dlerror());
        }
    }
    if (!handle) {
        handle = dlopen(PERF_HAL_PATH, RTLD_NOW);
        if (!handle) {
            ALOGE("Unable to open %s: %s\n", PERF_HAL_PATH, dlerror());
        }
    }

    return handle;
}

static void __attribute__((constructor)) initialize(void) {
    qcopt_handle = get_qcopt_handle();

    if (!qcopt_handle) {
        ALOGE("Failed to get qcopt handle.\n");
    } else {
        /*
         * qc-opt handle obtained. Get the perflock acquire/release
         * function pointers.
         */
        perf_lock_acq = dlsym(qcopt_handle, "perf_lock_acq");

        if (!perf_lock_acq) {
            ALOGE("Unable to get perf_lock_acq function handle.\n");
        }

        perf_lock_rel = dlsym(qcopt_handle, "perf_lock_rel");

        if (!perf_lock_rel) {
            ALOGE("Unable to get perf_lock_rel function handle.\n");
        }

        perf_hint = dlsym(qcopt_handle, "perf_hint");

        if (!perf_hint) {
            ALOGE("Unable to get perf_hint function handle.\n");
        }
    }
}

static void __attribute__((destructor)) cleanup(void) {
    if (qcopt_handle) {
        if (dlclose(qcopt_handle)) ALOGE("Error occurred while closing qc-opt library.");
    }
}

int sysfs_read(const char* path, char* s, int num_bytes) {
    char buf[80];
    int count;
    int ret = 0;
    int fd = open(path, O_RDONLY);

    if (fd < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error opening %s: %s\n", path, buf);

        return -1;
    }

    if ((count = read(fd, s, num_bytes - 1)) < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error writing to %s: %s\n", path, buf);

        ret = -1;
    } else {
        s[count] = '\0';
    }

    close(fd);

    return ret;
}

int sysfs_write(const char* path, char* s) {
    char buf[80];
    int len;
    int ret = 0;
    int fd = open(path, O_WRONLY);

    if (fd < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error opening %s: %s\n", path, buf);
        return -1;
    }

    len = write(fd, s, strlen(s));
    if (len < 0) {
        strerror_r(errno, buf, sizeof(buf));
        ALOGE("Error writing to %s: %s\n", path, buf);

        ret = -1;
    }

    close(fd);

    return ret;
}

int get_scaling_governor(char governor[], int size) {
    for (size_t i = 0; i < ARRAY_SIZE(scaling_gov_path); i++) {
        if (get_scaling_governor_check_cores(governor, size, i) == 0) {
            // Obtained the scaling governor. Return.
            return 0;
        }
    }

    return -1;
}

int get_scaling_governor_check_cores(char governor[], int size, int core_num) {
    if (sysfs_read(scaling_gov_path[core_num], governor, size) == -1) {
        // Can't obtain the scaling governor. Return.
        return -1;
    }

    // Strip newline at the end.
    int len = strlen(governor);
    len--;
    while (len >= 0 && (governor[len] == '\n' || governor[len] == '\r')) governor[len--] = '\0';

    return 0;
}

int is_interactive_governor(char* governor) {
    if (strncmp(governor, INTERACTIVE_GOVERNOR, (strlen(INTERACTIVE_GOVERNOR) + 1)) == 0) return 1;
    return 0;
}

int is_schedutil_governor(char* governor) {
    if (strncmp(governor, SCHEDUTIL_GOVERNOR, (strlen(SCHEDUTIL_GOVERNOR) + 1)) == 0) return 1;
    return 0;
}

#ifndef INTERACTION_BOOST
void interaction(int duration, int num_args, int opt_list[]) {
#else
void interaction(int duration, int num_args, int opt_list[]) {
    static int lock_handle = 0;

    if (duration < 0 || num_args < 1 || opt_list[0] == 0) return;

    if (qcopt_handle) {
        if (perf_lock_acq) {
            lock_handle = perf_lock_acq(lock_handle, duration, opt_list, num_args);
            if (lock_handle == -1) ALOGE("Failed to acquire lock.");
        }
    }
#endif
}

int interaction_with_handle(int lock_handle, int duration, int num_args, int opt_list[]) {
    if (duration < 0 || num_args < 1 || opt_list[0] == 0) return 0;

    if (qcopt_handle) {
        if (perf_lock_acq) {
            lock_handle = perf_lock_acq(lock_handle, duration, opt_list, num_args);
            if (lock_handle == -1) ALOGE("Failed to acquire lock.");
        }
    }
    return lock_handle;
}

// this is interaction_with_handle using perf_hint instead of
// perf_lock_acq
int perf_hint_enable(int hint_id, int duration) {
    int lock_handle = 0;

    if (duration < 0) return 0;

    if (qcopt_handle) {
        if (perf_hint) {
            lock_handle = perf_hint(hint_id, pkg, duration, -1);
            if (lock_handle == -1) ALOGE("Failed to acquire lock for hint_id: %X.", hint_id);
        }
    }
    return lock_handle;
}

// Same as perf_hint_enable, but with the ability to
// choose the type
int perf_hint_enable_with_type(int hint_id, int duration, int type) {
    int lock_handle = 0;

    if (qcopt_handle) {
        if (perf_hint) {
            lock_handle = perf_hint(hint_id, NULL, duration, type);
            if (lock_handle == -1) ALOGE("Failed to acquire lock.");
        }
    }
    return lock_handle;
}

void release_request(int lock_handle) {
    if (qcopt_handle && perf_lock_rel) perf_lock_rel(lock_handle);
}

int perform_hint_action(int hint_id, int resource_values[], int num_resources) {
    if (qcopt_handle && perf_lock_acq) {
        /* Acquire an indefinite lock for the requested resources. */
        int lock_handle = perf_lock_acq(0, 0, resource_values, num_resources);

        if (lock_handle == -1) {
            ALOGE("Failed to acquire lock.");
            return -EINVAL;
        }

        /* Add this handle to our internal hint-list. */
        struct hint_data* new_hint = (struct hint_data*)malloc(sizeof(struct hint_data));

        if (!new_hint) {
            /* Can't keep track of this lock. Release it. */
            if (perf_lock_rel) perf_lock_rel(lock_handle);
            ALOGE("Failed to process hint.");
            return -ENOMEM;
        }

        if (!active_hint_list_head.compare) {
            active_hint_list_head.compare = (int (*)(void*, void*))hint_compare;
            active_hint_list_head.dump = (void (*)(void*))hint_dump;
        }

        new_hint->hint_id = hint_id;
        new_hint->perflock_handle = lock_handle;

        if (add_list_node(&active_hint_list_head, new_hint) == NULL) {
            free(new_hint);
            /* Can't keep track of this lock. Release it. */
            if (perf_lock_rel) perf_lock_rel(lock_handle);
            ALOGE("Failed to process hint.");
            return -ENOMEM;
        }
    }
    return 0;
}

void undo_hint_action(int hint_id) {
    if (qcopt_handle) {
        if (perf_lock_rel) {
            /* Get hint-data associated with this hint-id */
            struct list_node* found_node;
            struct hint_data temp_hint_data = {.hint_id = hint_id};

            found_node = find_node(&active_hint_list_head, &temp_hint_data);

            if (found_node) {
                /* Release this lock. */
                struct hint_data* found_hint_data = (struct hint_data*)(found_node->data);

                if (found_hint_data) {
                    if (perf_lock_rel(found_hint_data->perflock_handle) == -1)
                        ALOGE("Perflock release failed.");
                }

                if (found_node->data) {
                    /* We can free the hint-data for this node. */
                    free(found_node->data);
                }

                remove_list_node(&active_hint_list_head, found_node);
            } else {
                ALOGE("Invalid hint ID.");
            }
        }
    }
}

/*
 * Used to release initial lock holding
 * two cores online when the display is on
 */
void undo_initial_hint_action() {
    if (qcopt_handle) {
        if (perf_lock_rel) {
            perf_lock_rel(1);
        }
    }
}

int get_soc_id(void) {
    int fd;
    int soc_id = -1;
    char buf[10] = {0};

    if (!access(SOC_ID_0, F_OK))
        fd = open(SOC_ID_0, O_RDONLY);
    else
        fd = open(SOC_ID_1, O_RDONLY);

    if (fd >= 0) {
        if (read(fd, buf, sizeof(buf) - 1) == -1)
            ALOGW("Unable to read soc_id");
        else
            soc_id = atoi(buf);
    }

    close(fd);
    return soc_id;
}

long long calc_timespan_us(struct timespec start, struct timespec end) {
    long long diff_in_us = 0;
    diff_in_us += (end.tv_sec - start.tv_sec) * USINSEC;
    diff_in_us += (end.tv_nsec - start.tv_nsec) / NSINUS;
    return diff_in_us;
}