/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>

#include <rte_memcpy.h>
#include <rte_string_fns.h>

#include "power_acpi_cpufreq.h"
#include "power_common.h"

#define STR_SIZE     1024
#define POWER_CONVERT_TO_DECIMAL 10

#define POWER_GOVERNOR_USERSPACE "userspace"
#define POWER_SYSFILE_AVAIL_FREQ \
                "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_available_frequencies"
#define POWER_SYSFILE_SETSPEED   \
                "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_setspeed"
#define POWER_ACPI_DRIVER "acpi-cpufreq"

/*
 * MSR related
 */
#define PLATFORM_INFO     0x0CE
#define TURBO_RATIO_LIMIT 0x1AD
#define IA32_PERF_CTL     0x199
#define CORE_TURBO_DISABLE_BIT ((uint64_t)1<<32)

enum power_state {
        POWER_IDLE = 0,
        POWER_ONGOING,
        POWER_USED,
        POWER_UNKNOWN
};

/**
 * Power info per lcore.
 */
struct acpi_power_info {
        unsigned int lcore_id;                   /**< Logical core id */
        uint32_t freqs[RTE_MAX_LCORE_FREQS]; /**< Frequency array */
        uint32_t nb_freqs;                   /**< number of available freqs */
        FILE *f;                             /**< FD of scaling_setspeed */
        char governor_ori[32];               /**< Original governor name */
        uint32_t curr_idx;                   /**< Freq index in freqs array */
        uint32_t state;                      /**< Power in use state */
        uint16_t turbo_available;            /**< Turbo Boost available */
        uint16_t turbo_enable;               /**< Turbo Boost enable/disable */
} __rte_cache_aligned;

static struct acpi_power_info lcore_power_info[RTE_MAX_LCORE];

/**
 * It is to set specific freq for specific logical core, according to the index
 * of supported frequencies.
 */
static int
set_freq_internal(struct acpi_power_info *pi, uint32_t idx)
{
        if (idx >= RTE_MAX_LCORE_FREQS || idx >= pi->nb_freqs) {
                RTE_LOG(ERR, POWER, "Invalid frequency index %u, which "
                                "should be less than %u\n", idx, pi->nb_freqs);
                return -1;
        }

        /* Check if it is the same as current */
        if (idx == pi->curr_idx)
                return 0;

        POWER_DEBUG_TRACE("Frequency[%u] %u to be set for lcore %u\n",
                        idx, pi->freqs[idx], pi->lcore_id);
        if (fseek(pi->f, 0, SEEK_SET) < 0) {
                RTE_LOG(ERR, POWER, "Fail to set file position indicator to 0 "
                                "for setting frequency for lcore %u\n", pi->lcore_id);
                return -1;
        }
        if (fprintf(pi->f, "%u", pi->freqs[idx]) < 0) {
                RTE_LOG(ERR, POWER, "Fail to write new frequency for "
                                "lcore %u\n", pi->lcore_id);
                return -1;
        }
        fflush(pi->f);
        pi->curr_idx = idx;

        return 1;
}

/**
 * It is to check the current scaling governor by reading sys file, and then
 * set it into 'userspace' if it is not by writing the sys file. The original
 * governor will be saved for rolling back.
 */
static int
power_set_governor_userspace(struct acpi_power_info *pi)
{
        return power_set_governor(pi->lcore_id, POWER_GOVERNOR_USERSPACE,
                        pi->governor_ori, sizeof(pi->governor_ori));
}

/**
 * It is to check the governor and then set the original governor back if
 * needed by writing the sys file.
 */
static int
power_set_governor_original(struct acpi_power_info *pi)
{
        return power_set_governor(pi->lcore_id, pi->governor_ori, NULL, 0);
}

/**
 * It is to get the available frequencies of the specific lcore by reading the
 * sys file.
 */
static int
power_get_available_freqs(struct acpi_power_info *pi)
{
        FILE *f;
        int ret = -1, i, count;
        char *p;
        char buf[BUFSIZ];
        char *freqs[RTE_MAX_LCORE_FREQS];

        open_core_sysfs_file(&f, "r", POWER_SYSFILE_AVAIL_FREQ, pi->lcore_id);
        if (f == NULL) {
                RTE_LOG(ERR, POWER, "failed to open %s\n",
                                POWER_SYSFILE_AVAIL_FREQ);
                goto out;
        }

        ret = read_core_sysfs_s(f, buf, sizeof(buf));
        if ((ret) < 0) {
                RTE_LOG(ERR, POWER, "Failed to read %s\n",
                                POWER_SYSFILE_AVAIL_FREQ);
                goto out;
        }

        /* Split string into at most RTE_MAX_LCORE_FREQS frequencies */
        count = rte_strsplit(buf, sizeof(buf), freqs,
                        RTE_MAX_LCORE_FREQS, ' ');
        if (count <= 0) {
                RTE_LOG(ERR, POWER, "No available frequency in "
                                ""POWER_SYSFILE_AVAIL_FREQ"\n", pi->lcore_id);
                goto out;
        }
        if (count >= RTE_MAX_LCORE_FREQS) {
                RTE_LOG(ERR, POWER, "Too many available frequencies : %d\n",
                                count);
                goto out;
        }

        /* Store the available frequencies into power context */
        for (i = 0, pi->nb_freqs = 0; i < count; i++) {
                POWER_DEBUG_TRACE("Lcore %u frequency[%d]: %s\n", pi->lcore_id,
                                i, freqs[i]);
                pi->freqs[pi->nb_freqs++] = strtoul(freqs[i], &p,
                                POWER_CONVERT_TO_DECIMAL);
        }

        if ((pi->freqs[0]-1000) == pi->freqs[1]) {
                pi->turbo_available = 1;
                pi->turbo_enable = 1;
                POWER_DEBUG_TRACE("Lcore %u Can do Turbo Boost\n",
                                pi->lcore_id);
        } else {
                pi->turbo_available = 0;
                pi->turbo_enable = 0;
                POWER_DEBUG_TRACE("Turbo Boost not available on Lcore %u\n",
                                pi->lcore_id);
        }

        ret = 0;
        POWER_DEBUG_TRACE("%d frequency(s) of lcore %u are available\n",
                        count, pi->lcore_id);
out:
        if (f != NULL)
                fclose(f);

        return ret;
}

/**
 * It is to fopen the sys file for the future setting the lcore frequency.
 */
static int
power_init_for_setting_freq(struct acpi_power_info *pi)
{
        FILE *f;
        char buf[BUFSIZ];
        uint32_t i, freq;
        int ret;

        open_core_sysfs_file(&f, "rw+", POWER_SYSFILE_SETSPEED, pi->lcore_id);
        if (f == NULL) {
                RTE_LOG(ERR, POWER, "Failed to open %s\n",
                                POWER_SYSFILE_SETSPEED);
                goto err;
        }

        ret = read_core_sysfs_s(f, buf, sizeof(buf));
        if ((ret) < 0) {
                RTE_LOG(ERR, POWER, "Failed to read %s\n",
                                POWER_SYSFILE_SETSPEED);
                goto err;
        }

        freq = strtoul(buf, NULL, POWER_CONVERT_TO_DECIMAL);
        for (i = 0; i < pi->nb_freqs; i++) {
                if (freq == pi->freqs[i]) {
                        pi->curr_idx = i;
                        pi->f = f;
                        return 0;
                }
        }

err:
        if (f != NULL)
                fclose(f);

        return -1;
}

int
power_acpi_cpufreq_check_supported(void)
{
        return cpufreq_check_scaling_driver(POWER_ACPI_DRIVER);
}

int
power_acpi_cpufreq_init(unsigned int lcore_id)
{
        struct acpi_power_info *pi;
        uint32_t exp_state;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Lcore id %u can not exceeds %u\n",
                                lcore_id, RTE_MAX_LCORE - 1U);
                return -1;
        }

        pi = &lcore_power_info[lcore_id];
        exp_state = POWER_IDLE;
        /* The power in use state works as a guard variable between
         * the CPU frequency control initialization and exit process.
         * The ACQUIRE memory ordering here pairs with the RELEASE
         * ordering below as lock to make sure the frequency operations
         * in the critical section are done under the correct state.
         */
        if (!__atomic_compare_exchange_n(&(pi->state), &exp_state,
                                        POWER_ONGOING, 0,
                                        __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) {
                RTE_LOG(INFO, POWER, "Power management of lcore %u is "
                                "in use\n", lcore_id);
                return -1;
        }

        pi->lcore_id = lcore_id;
        /* Check and set the governor */
        if (power_set_governor_userspace(pi) < 0) {
                RTE_LOG(ERR, POWER, "Cannot set governor of lcore %u to "
                                "userspace\n", lcore_id);
                goto fail;
        }

        /* Get the available frequencies */
        if (power_get_available_freqs(pi) < 0) {
                RTE_LOG(ERR, POWER, "Cannot get available frequencies of "
                                "lcore %u\n", lcore_id);
                goto fail;
        }

        /* Init for setting lcore frequency */
        if (power_init_for_setting_freq(pi) < 0) {
                RTE_LOG(ERR, POWER, "Cannot init for setting frequency for "
                                "lcore %u\n", lcore_id);
                goto fail;
        }

        /* Set freq to max by default */
        if (power_acpi_cpufreq_freq_max(lcore_id) < 0) {
                RTE_LOG(ERR, POWER, "Cannot set frequency of lcore %u "
                                "to max\n", lcore_id);
                goto fail;
        }

        RTE_LOG(INFO, POWER, "Initialized successfully for lcore %u "
                        "power management\n", lcore_id);
        exp_state = POWER_ONGOING;
        __atomic_compare_exchange_n(&(pi->state), &exp_state, POWER_USED,
                                    0, __ATOMIC_RELEASE, __ATOMIC_RELAXED);

        return 0;

fail:
        exp_state = POWER_ONGOING;
        __atomic_compare_exchange_n(&(pi->state), &exp_state, POWER_UNKNOWN,
                                    0, __ATOMIC_RELEASE, __ATOMIC_RELAXED);

        return -1;
}

int
power_acpi_cpufreq_exit(unsigned int lcore_id)
{
        struct acpi_power_info *pi;
        uint32_t exp_state;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Lcore id %u can not exceeds %u\n",
                                lcore_id, RTE_MAX_LCORE - 1U);
                return -1;
        }
        pi = &lcore_power_info[lcore_id];
        exp_state = POWER_USED;
        /* The power in use state works as a guard variable between
         * the CPU frequency control initialization and exit process.
         * The ACQUIRE memory ordering here pairs with the RELEASE
         * ordering below as lock to make sure the frequency operations
         * in the critical section are done under the correct state.
         */
        if (!__atomic_compare_exchange_n(&(pi->state), &exp_state,
                                        POWER_ONGOING, 0,
                                        __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) {
                RTE_LOG(INFO, POWER, "Power management of lcore %u is "
                                "not used\n", lcore_id);
                return -1;
        }

        /* Close FD of setting freq */
        fclose(pi->f);
        pi->f = NULL;

        /* Set the governor back to the original */
        if (power_set_governor_original(pi) < 0) {
                RTE_LOG(ERR, POWER, "Cannot set the governor of %u back "
                                "to the original\n", lcore_id);
                goto fail;
        }

        RTE_LOG(INFO, POWER, "Power management of lcore %u has exited from "
                        "'userspace' mode and been set back to the "
                        "original\n", lcore_id);
        exp_state = POWER_ONGOING;
        __atomic_compare_exchange_n(&(pi->state), &exp_state, POWER_IDLE,
                                    0, __ATOMIC_RELEASE, __ATOMIC_RELAXED);

        return 0;

fail:
        exp_state = POWER_ONGOING;
        __atomic_compare_exchange_n(&(pi->state), &exp_state, POWER_UNKNOWN,
                                    0, __ATOMIC_RELEASE, __ATOMIC_RELAXED);

        return -1;
}

uint32_t
power_acpi_cpufreq_freqs(unsigned int lcore_id, uint32_t *freqs, uint32_t num)
{
        struct acpi_power_info *pi;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return 0;
        }

        if (freqs == NULL) {
                RTE_LOG(ERR, POWER, "NULL buffer supplied\n");
                return 0;
        }

        pi = &lcore_power_info[lcore_id];
        if (num < pi->nb_freqs) {
                RTE_LOG(ERR, POWER, "Buffer size is not enough\n");
                return 0;
        }
        rte_memcpy(freqs, pi->freqs, pi->nb_freqs * sizeof(uint32_t));

        return pi->nb_freqs;
}

uint32_t
power_acpi_cpufreq_get_freq(unsigned int lcore_id)
{
        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return RTE_POWER_INVALID_FREQ_INDEX;
        }

        return lcore_power_info[lcore_id].curr_idx;
}

int
power_acpi_cpufreq_set_freq(unsigned int lcore_id, uint32_t index)
{
        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return -1;
        }

        return set_freq_internal(&(lcore_power_info[lcore_id]), index);
}

int
power_acpi_cpufreq_freq_down(unsigned int lcore_id)
{
        struct acpi_power_info *pi;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return -1;
        }

        pi = &lcore_power_info[lcore_id];
        if (pi->curr_idx + 1 == pi->nb_freqs)
                return 0;

        /* Frequencies in the array are from high to low. */
        return set_freq_internal(pi, pi->curr_idx + 1);
}

int
power_acpi_cpufreq_freq_up(unsigned int lcore_id)
{
        struct acpi_power_info *pi;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return -1;
        }

        pi = &lcore_power_info[lcore_id];
        if (pi->curr_idx == 0 ||
            (pi->curr_idx == 1 && pi->turbo_available && !pi->turbo_enable))
                return 0;

        /* Frequencies in the array are from high to low. */
        return set_freq_internal(pi, pi->curr_idx - 1);
}

int
power_acpi_cpufreq_freq_max(unsigned int lcore_id)
{
        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return -1;
        }

        /* Frequencies in the array are from high to low. */
        if (lcore_power_info[lcore_id].turbo_available) {
                if (lcore_power_info[lcore_id].turbo_enable)
                        /* Set to Turbo */
                        return set_freq_internal(
                                        &lcore_power_info[lcore_id], 0);
                else
                        /* Set to max non-turbo */
                        return set_freq_internal(
                                        &lcore_power_info[lcore_id], 1);
        } else
                return set_freq_internal(&lcore_power_info[lcore_id], 0);
}

int
power_acpi_cpufreq_freq_min(unsigned int lcore_id)
{
        struct acpi_power_info *pi;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return -1;
        }

        pi = &lcore_power_info[lcore_id];

        /* Frequencies in the array are from high to low. */
        return set_freq_internal(pi, pi->nb_freqs - 1);
}


int
power_acpi_turbo_status(unsigned int lcore_id)
{
        struct acpi_power_info *pi;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return -1;
        }

        pi = &lcore_power_info[lcore_id];

        return pi->turbo_enable;
}


int
power_acpi_enable_turbo(unsigned int lcore_id)
{
        struct acpi_power_info *pi;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return -1;
        }

        pi = &lcore_power_info[lcore_id];

        if (pi->turbo_available)
                pi->turbo_enable = 1;
        else {
                pi->turbo_enable = 0;
                RTE_LOG(ERR, POWER,
                        "Failed to enable turbo on lcore %u\n",
                        lcore_id);
                        return -1;
        }

        /* Max may have changed, so call to max function */
        if (power_acpi_cpufreq_freq_max(lcore_id) < 0) {
                RTE_LOG(ERR, POWER,
                        "Failed to set frequency of lcore %u to max\n",
                        lcore_id);
                        return -1;
        }

        return 0;
}

int
power_acpi_disable_turbo(unsigned int lcore_id)
{
        struct acpi_power_info *pi;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return -1;
        }

        pi = &lcore_power_info[lcore_id];

         pi->turbo_enable = 0;

        if ((pi->turbo_available) && (pi->curr_idx <= 1)) {
                /* Try to set freq to max by default coming out of turbo */
                if (power_acpi_cpufreq_freq_max(lcore_id) < 0) {
                        RTE_LOG(ERR, POWER,
                                "Failed to set frequency of lcore %u to max\n",
                                lcore_id);
                        return -1;
                }
        }

        return 0;
}

int power_acpi_get_capabilities(unsigned int lcore_id,
                struct rte_power_core_capabilities *caps)
{
        struct acpi_power_info *pi;

        if (lcore_id >= RTE_MAX_LCORE) {
                RTE_LOG(ERR, POWER, "Invalid lcore ID\n");
                return -1;
        }
        if (caps == NULL) {
                RTE_LOG(ERR, POWER, "Invalid argument\n");
                return -1;
        }

        pi = &lcore_power_info[lcore_id];
        caps->capabilities = 0;
        caps->turbo = !!(pi->turbo_available);

        return 0;
}