// SPDX-License-Identifier: GPL-2.0-only
//
// Copyright(c) 2021-2022 Intel Corporation
//
// Authors: Cezary Rojewski <cezary.rojewski@intel.com>
//          Amadeusz Slawinski <amadeuszx.slawinski@linux.intel.com>
//

#include <linux/debugfs.h>
#include <linux/kfifo.h>
#include <linux/wait.h>
#include <linux/sched/signal.h>
#include <linux/string_helpers.h>
#include <sound/soc.h>
#include "avs.h"
#include "debug.h"
#include "messages.h"

static unsigned int __kfifo_fromio(struct kfifo *fifo, const void __iomem *src, unsigned int len)
{
        struct __kfifo *__fifo = &fifo->kfifo;
        unsigned int l, off;

        len = min(len, kfifo_avail(fifo));
        off = __fifo->in & __fifo->mask;
        l = min(len, kfifo_size(fifo) - off);

        memcpy_fromio(__fifo->data + off, src, l);
        memcpy_fromio(__fifo->data, src + l, len - l);
        /* Make sure data copied from SRAM is visible to all CPUs. */
        smp_mb();
        __fifo->in += len;

        return len;
}

bool avs_logging_fw(struct avs_dev *adev)
{
        return kfifo_initialized(&adev->trace_fifo);
}

void avs_dump_fw_log(struct avs_dev *adev, const void __iomem *src, unsigned int len)
{
        __kfifo_fromio(&adev->trace_fifo, src, len);
}

void avs_dump_fw_log_wakeup(struct avs_dev *adev, const void __iomem *src, unsigned int len)
{
        avs_dump_fw_log(adev, src, len);
        wake_up(&adev->trace_waitq);
}

static ssize_t fw_regs_read(struct file *file, char __user *to, size_t count, loff_t *ppos)
{
        struct avs_dev *adev = file->private_data;
        char *buf;
        int ret;

        buf = kzalloc(AVS_FW_REGS_SIZE, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        memcpy_fromio(buf, avs_sram_addr(adev, AVS_FW_REGS_WINDOW), AVS_FW_REGS_SIZE);

        ret = simple_read_from_buffer(to, count, ppos, buf, AVS_FW_REGS_SIZE);
        kfree(buf);
        return ret;
}

static const struct file_operations fw_regs_fops = {
        .open = simple_open,
        .read = fw_regs_read,
};

static ssize_t debug_window_read(struct file *file, char __user *to, size_t count, loff_t *ppos)
{
        struct avs_dev *adev = file->private_data;
        size_t size;
        char *buf;
        int ret;

        size = adev->hw_cfg.dsp_cores * AVS_WINDOW_CHUNK_SIZE;
        buf = kzalloc(size, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        memcpy_fromio(buf, avs_sram_addr(adev, AVS_DEBUG_WINDOW), size);

        ret = simple_read_from_buffer(to, count, ppos, buf, size);
        kfree(buf);
        return ret;
}

static const struct file_operations debug_window_fops = {
        .open = simple_open,
        .read = debug_window_read,
};

static ssize_t probe_points_read(struct file *file, char __user *to, size_t count, loff_t *ppos)
{
        struct avs_dev *adev = file->private_data;
        struct avs_probe_point_desc *desc;
        size_t num_desc, len = 0;
        char *buf;
        int i, ret;

        /* Prevent chaining, send and dump IPC value just once. */
        if (*ppos)
                return 0;

        buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        ret = avs_ipc_probe_get_points(adev, &desc, &num_desc);
        if (ret) {
                ret = AVS_IPC_RET(ret);
                goto exit;
        }

        for (i = 0; i < num_desc; i++) {
                ret = scnprintf(buf + len, PAGE_SIZE - len,
                                "Id: %#010x  Purpose: %d  Node id: %#x\n",
                                desc[i].id.value, desc[i].purpose, desc[i].node_id.val);
                len += ret;
        }

        ret = simple_read_from_buffer(to, count, ppos, buf, len);
        kfree(desc);
exit:
        kfree(buf);
        return ret;
}

static ssize_t probe_points_write(struct file *file, const char __user *from, size_t count,
                                  loff_t *ppos)
{
        struct avs_dev *adev = file->private_data;
        struct avs_probe_point_desc *desc;
        u32 *array, num_elems;
        size_t bytes;
        int ret;

        ret = parse_int_array_user(from, count, (int **)&array);
        if (ret)
                return ret;

        num_elems = *array;
        bytes = sizeof(*array) * num_elems;
        if (bytes % sizeof(*desc)) {
                ret = -EINVAL;
                goto exit;
        }

        desc = (struct avs_probe_point_desc *)&array[1];
        ret = avs_ipc_probe_connect_points(adev, desc, bytes / sizeof(*desc));
        if (ret)
                ret = AVS_IPC_RET(ret);
        else
                ret = count;
exit:
        kfree(array);
        return ret;
}

static const struct file_operations probe_points_fops = {
        .open = simple_open,
        .read = probe_points_read,
        .write = probe_points_write,
};

static ssize_t probe_points_disconnect_write(struct file *file, const char __user *from,
                                             size_t count, loff_t *ppos)
{
        struct avs_dev *adev = file->private_data;
        union avs_probe_point_id *id;
        u32 *array, num_elems;
        size_t bytes;
        int ret;

        ret = parse_int_array_user(from, count, (int **)&array);
        if (ret)
                return ret;

        num_elems = *array;
        bytes = sizeof(*array) * num_elems;
        if (bytes % sizeof(*id)) {
                ret = -EINVAL;
                goto exit;
        }

        id = (union avs_probe_point_id *)&array[1];
        ret = avs_ipc_probe_disconnect_points(adev, id, bytes / sizeof(*id));
        if (ret)
                ret = AVS_IPC_RET(ret);
        else
                ret = count;
exit:
        kfree(array);
        return ret;
}

static const struct file_operations probe_points_disconnect_fops = {
        .open = simple_open,
        .write = probe_points_disconnect_write,
        .llseek = default_llseek,
};

static ssize_t strace_read(struct file *file, char __user *to, size_t count, loff_t *ppos)
{
        struct avs_dev *adev = file->private_data;
        struct kfifo *fifo = &adev->trace_fifo;
        unsigned int copied;

        if (kfifo_is_empty(fifo)) {
                DEFINE_WAIT(wait);

                prepare_to_wait(&adev->trace_waitq, &wait, TASK_INTERRUPTIBLE);
                if (!signal_pending(current))
                        schedule();
                finish_wait(&adev->trace_waitq, &wait);
        }

        if (kfifo_to_user(fifo, to, count, &copied))
                return -EFAULT;
        *ppos += copied;
        return copied;
}

static int strace_open(struct inode *inode, struct file *file)
{
        struct avs_dev *adev = inode->i_private;
        int ret;

        if (!try_module_get(adev->dev->driver->owner))
                return -ENODEV;

        if (kfifo_initialized(&adev->trace_fifo))
                return -EBUSY;

        ret = kfifo_alloc(&adev->trace_fifo, PAGE_SIZE, GFP_KERNEL);
        if (ret < 0)
                return ret;

        file->private_data = adev;
        return 0;
}

static int strace_release(struct inode *inode, struct file *file)
{
        union avs_notify_msg msg = AVS_NOTIFICATION(LOG_BUFFER_STATUS);
        struct avs_dev *adev = file->private_data;
        unsigned long resource_mask;
        unsigned long flags, i;
        u32 num_cores;

        resource_mask = adev->logged_resources;
        num_cores = adev->hw_cfg.dsp_cores;

        spin_lock_irqsave(&adev->trace_lock, flags);

        /* Gather any remaining logs. */
        for_each_set_bit(i, &resource_mask, num_cores) {
                msg.log.core = i;
                avs_dsp_op(adev, log_buffer_status, &msg);
        }

        kfifo_free(&adev->trace_fifo);

        spin_unlock_irqrestore(&adev->trace_lock, flags);

        module_put(adev->dev->driver->owner);
        return 0;
}

static const struct file_operations strace_fops = {
        .llseek = default_llseek,
        .read = strace_read,
        .open = strace_open,
        .release = strace_release,
};

#define DISABLE_TIMERS  UINT_MAX

static int enable_logs(struct avs_dev *adev, u32 resource_mask, u32 *priorities)
{
        int ret;

        /* Logging demands D0i0 state from DSP. */
        if (!adev->logged_resources) {
                pm_runtime_get_sync(adev->dev);

                ret = avs_dsp_disable_d0ix(adev);
                if (ret)
                        goto err_d0ix;
        }

        ret = avs_ipc_set_system_time(adev);
        if (ret && ret != AVS_IPC_NOT_SUPPORTED) {
                ret = AVS_IPC_RET(ret);
                goto err_ipc;
        }

        ret = avs_dsp_op(adev, enable_logs, AVS_LOG_ENABLE, adev->aging_timer_period,
                         adev->fifo_full_timer_period, resource_mask, priorities);
        if (ret)
                goto err_ipc;

        adev->logged_resources |= resource_mask;
        return 0;

err_ipc:
        if (!adev->logged_resources) {
                avs_dsp_enable_d0ix(adev);
err_d0ix:
                pm_runtime_put_autosuspend(adev->dev);
        }

        return ret;
}

static int disable_logs(struct avs_dev *adev, u32 resource_mask)
{
        int ret;

        /* Check if there's anything to do. */
        if (!adev->logged_resources)
                return 0;

        ret = avs_dsp_op(adev, enable_logs, AVS_LOG_DISABLE, DISABLE_TIMERS, DISABLE_TIMERS,
                         resource_mask, NULL);

        /*
         * If IPC fails causing recovery, logged_resources is already zero
         * so unsetting bits is still safe.
         */
        adev->logged_resources &= ~resource_mask;

        /* If that's the last resource, allow for D3. */
        if (!adev->logged_resources) {
                avs_dsp_enable_d0ix(adev);
                pm_runtime_put_autosuspend(adev->dev);
        }

        return ret;
}

static ssize_t trace_control_read(struct file *file, char __user *to, size_t count, loff_t *ppos)
{
        struct avs_dev *adev = file->private_data;
        char buf[64];
        int len;

        len = snprintf(buf, sizeof(buf), "0x%08x\n", adev->logged_resources);

        return simple_read_from_buffer(to, count, ppos, buf, len);
}

static ssize_t trace_control_write(struct file *file, const char __user *from, size_t count,
                                   loff_t *ppos)
{
        struct avs_dev *adev = file->private_data;
        u32 *array, num_elems;
        u32 resource_mask;
        int ret;

        ret = parse_int_array_user(from, count, (int **)&array);
        if (ret)
                return ret;

        num_elems = *array;
        if (!num_elems) {
                ret = -EINVAL;
                goto free_array;
        }

        /*
         * Disable if just resource mask is provided - no log priority flags.
         *
         * Enable input format:   mask, prio1, .., prioN
         * Where 'N' equals number of bits set in the 'mask'.
         */
        resource_mask = array[1];
        if (num_elems == 1) {
                ret = disable_logs(adev, resource_mask);
        } else {
                if (num_elems != (hweight_long(resource_mask) + 1)) {
                        ret = -EINVAL;
                        goto free_array;
                }

                ret = enable_logs(adev, resource_mask, &array[2]);
        }

        if (!ret)
                ret = count;
free_array:
        kfree(array);
        return ret;
}

static const struct file_operations trace_control_fops = {
        .llseek = default_llseek,
        .read = trace_control_read,
        .write = trace_control_write,
        .open = simple_open,
};

void avs_debugfs_init(struct avs_dev *adev)
{
        init_waitqueue_head(&adev->trace_waitq);
        spin_lock_init(&adev->trace_lock);

        adev->debugfs_root = debugfs_create_dir("avs", snd_soc_debugfs_root);

        /* Initialize timer periods with recommended defaults. */
        adev->aging_timer_period = 10;
        adev->fifo_full_timer_period = 10;

        debugfs_create_file("strace", 0444, adev->debugfs_root, adev, &strace_fops);
        debugfs_create_file("trace_control", 0644, adev->debugfs_root, adev, &trace_control_fops);
        debugfs_create_file("fw_regs", 0444, adev->debugfs_root, adev, &fw_regs_fops);
        debugfs_create_file("debug_window", 0444, adev->debugfs_root, adev, &debug_window_fops);

        debugfs_create_u32("trace_aging_period", 0644, adev->debugfs_root,
                           &adev->aging_timer_period);
        debugfs_create_u32("trace_fifo_full_period", 0644, adev->debugfs_root,
                           &adev->fifo_full_timer_period);

        debugfs_create_file("probe_points", 0644, adev->debugfs_root, adev, &probe_points_fops);
        debugfs_create_file("probe_points_disconnect", 0200, adev->debugfs_root, adev,
                            &probe_points_disconnect_fops);
}

void avs_debugfs_exit(struct avs_dev *adev)
{
        debugfs_remove_recursive(adev->debugfs_root);
}