// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2023 Intel Corporation */
#include <linux/bitops.h>
#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/seq_file.h>
#include <linux/types.h>

#include "adf_accel_devices.h"
#include "adf_admin.h"
#include "adf_common_drv.h"
#include "adf_fw_counters.h"

#define ADF_FW_COUNTERS_MAX_PADDING 16

enum adf_fw_counters_types {
        ADF_FW_REQUESTS,
        ADF_FW_RESPONSES,
        ADF_FW_COUNTERS_COUNT
};

static const char * const adf_fw_counter_names[] = {
        [ADF_FW_REQUESTS] = "Requests",
        [ADF_FW_RESPONSES] = "Responses",
};

static_assert(ARRAY_SIZE(adf_fw_counter_names) == ADF_FW_COUNTERS_COUNT);

struct adf_ae_counters {
        u16 ae;
        u64 values[ADF_FW_COUNTERS_COUNT];
};

struct adf_fw_counters {
        u16 ae_count;
        struct adf_ae_counters ae_counters[] __counted_by(ae_count);
};

static void adf_fw_counters_parse_ae_values(struct adf_ae_counters *ae_counters, u32 ae,
                                            u64 req_count, u64 resp_count)
{
        ae_counters->ae = ae;
        ae_counters->values[ADF_FW_REQUESTS] = req_count;
        ae_counters->values[ADF_FW_RESPONSES] = resp_count;
}

static int adf_fw_counters_load_from_device(struct adf_accel_dev *accel_dev,
                                            struct adf_fw_counters *fw_counters)
{
        struct adf_hw_device_data *hw_data = GET_HW_DATA(accel_dev);
        unsigned long ae_mask;
        unsigned int i;
        unsigned long ae;

        /* Ignore the admin AEs */
        ae_mask = hw_data->ae_mask & ~hw_data->admin_ae_mask;

        if (hweight_long(ae_mask) > fw_counters->ae_count)
                return -EINVAL;

        i = 0;
        for_each_set_bit(ae, &ae_mask, GET_MAX_ACCELENGINES(accel_dev)) {
                u64 req_count, resp_count;
                int ret;

                ret = adf_get_ae_fw_counters(accel_dev, ae, &req_count, &resp_count);
                if (ret)
                        return ret;

                adf_fw_counters_parse_ae_values(&fw_counters->ae_counters[i++], ae,
                                                req_count, resp_count);
        }

        return 0;
}

static struct adf_fw_counters *adf_fw_counters_allocate(unsigned long ae_count)
{
        struct adf_fw_counters *fw_counters;

        if (unlikely(!ae_count))
                return ERR_PTR(-EINVAL);

        fw_counters = kmalloc_flex(*fw_counters, ae_counters, ae_count);
        if (!fw_counters)
                return ERR_PTR(-ENOMEM);

        fw_counters->ae_count = ae_count;

        return fw_counters;
}

/**
 * adf_fw_counters_get() - Return FW counters for the provided device.
 * @accel_dev: Pointer to a QAT acceleration device
 *
 * Allocates and returns a table of counters containing execution statistics
 * for each non-admin AE available through the supplied acceleration device.
 * The caller becomes the owner of such memory and is responsible for
 * the deallocation through a call to kfree().
 *
 * Returns: a pointer to a dynamically allocated struct adf_fw_counters
 *          on success, or a negative value on error.
 */
static struct adf_fw_counters *adf_fw_counters_get(struct adf_accel_dev *accel_dev)
{
        struct adf_hw_device_data *hw_data = GET_HW_DATA(accel_dev);
        struct adf_fw_counters *fw_counters;
        unsigned long ae_count;
        int ret;

        if (!adf_dev_started(accel_dev)) {
                dev_err(&GET_DEV(accel_dev), "QAT Device not started\n");
                return ERR_PTR(-EFAULT);
        }

        /* Ignore the admin AEs */
        ae_count = hweight_long(hw_data->ae_mask & ~hw_data->admin_ae_mask);

        fw_counters = adf_fw_counters_allocate(ae_count);
        if (IS_ERR(fw_counters))
                return fw_counters;

        ret = adf_fw_counters_load_from_device(accel_dev, fw_counters);
        if (ret) {
                kfree(fw_counters);
                dev_err(&GET_DEV(accel_dev),
                        "Failed to create QAT fw_counters file table [%d].\n", ret);
                return ERR_PTR(ret);
        }

        return fw_counters;
}

static void *qat_fw_counters_seq_start(struct seq_file *sfile, loff_t *pos)
{
        struct adf_fw_counters *fw_counters = sfile->private;

        if (*pos == 0)
                return SEQ_START_TOKEN;

        if (*pos > fw_counters->ae_count)
                return NULL;

        return &fw_counters->ae_counters[*pos - 1];
}

static void *qat_fw_counters_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
{
        struct adf_fw_counters *fw_counters = sfile->private;

        (*pos)++;

        if (*pos > fw_counters->ae_count)
                return NULL;

        return &fw_counters->ae_counters[*pos - 1];
}

static void qat_fw_counters_seq_stop(struct seq_file *sfile, void *v) {}

static int qat_fw_counters_seq_show(struct seq_file *sfile, void *v)
{
        int i;

        if (v == SEQ_START_TOKEN) {
                seq_puts(sfile, "AE ");
                for (i = 0; i < ADF_FW_COUNTERS_COUNT; ++i)
                        seq_printf(sfile, " %*s", ADF_FW_COUNTERS_MAX_PADDING,
                                   adf_fw_counter_names[i]);
        } else {
                struct adf_ae_counters *ae_counters = (struct adf_ae_counters *)v;

                seq_printf(sfile, "%2d:", ae_counters->ae);
                for (i = 0; i < ADF_FW_COUNTERS_COUNT; ++i)
                        seq_printf(sfile, " %*llu", ADF_FW_COUNTERS_MAX_PADDING,
                                   ae_counters->values[i]);
        }
        seq_putc(sfile, '\n');

        return 0;
}

static const struct seq_operations qat_fw_counters_sops = {
        .start = qat_fw_counters_seq_start,
        .next = qat_fw_counters_seq_next,
        .stop = qat_fw_counters_seq_stop,
        .show = qat_fw_counters_seq_show,
};

static int qat_fw_counters_file_open(struct inode *inode, struct file *file)
{
        struct adf_accel_dev *accel_dev = inode->i_private;
        struct seq_file *fw_counters_seq_file;
        struct adf_fw_counters *fw_counters;
        int ret;

        fw_counters = adf_fw_counters_get(accel_dev);
        if (IS_ERR(fw_counters))
                return PTR_ERR(fw_counters);

        ret = seq_open(file, &qat_fw_counters_sops);
        if (unlikely(ret)) {
                kfree(fw_counters);
                return ret;
        }

        fw_counters_seq_file = file->private_data;
        fw_counters_seq_file->private = fw_counters;
        return ret;
}

static int qat_fw_counters_file_release(struct inode *inode, struct file *file)
{
        struct seq_file *seq = file->private_data;

        kfree(seq->private);
        seq->private = NULL;

        return seq_release(inode, file); }

static const struct file_operations qat_fw_counters_fops = {
        .owner = THIS_MODULE,
        .open = qat_fw_counters_file_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = qat_fw_counters_file_release,
};

/**
 * adf_fw_counters_dbgfs_add() - Create a debugfs file containing FW
 * execution counters.
 * @accel_dev:  Pointer to a QAT acceleration device
 *
 * Function creates a file to display a table with statistics for the given
 * QAT acceleration device. The table stores device specific execution values
 * for each AE, such as the number of requests sent to the FW and responses
 * received from the FW.
 *
 * Return: void
 */
void adf_fw_counters_dbgfs_add(struct adf_accel_dev *accel_dev)
{
        accel_dev->fw_cntr_dbgfile = debugfs_create_file("fw_counters", 0400,
                                                         accel_dev->debugfs_dir,
                                                         accel_dev,
                                                         &qat_fw_counters_fops);
}

/**
 * adf_fw_counters_dbgfs_rm() - Remove the debugfs file containing FW counters.
 * @accel_dev:  Pointer to a QAT acceleration device.
 *
 * Function removes the file providing the table of statistics for the given
 * QAT acceleration device.
 *
 * Return: void
 */
void adf_fw_counters_dbgfs_rm(struct adf_accel_dev *accel_dev)
{
        debugfs_remove(accel_dev->fw_cntr_dbgfile);
        accel_dev->fw_cntr_dbgfile = NULL;
}