// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
//
// This file is provided under a dual BSD/GPLv2 license.  When using or
// redistributing this file, you may do so under either license.
//
// Copyright(c) 2018 Intel Corporation. All rights reserved.
//
// Author: Liam Girdwood <liam.r.girdwood@linux.intel.com>
//

#include <linux/debugfs.h>
#include <linux/sched/signal.h>
#include "sof-priv.h"
#include "ops.h"

#define TRACE_FILTER_ELEMENTS_PER_ENTRY 4
#define TRACE_FILTER_MAX_CONFIG_STRING_LENGTH 1024

static int trace_filter_append_elem(struct snd_sof_dev *sdev, uint32_t key, uint32_t value,
                                    struct sof_ipc_trace_filter_elem *elem_list,
                                    int capacity, int *counter)
{
        if (*counter >= capacity)
                return -ENOMEM;

        elem_list[*counter].key = key;
        elem_list[*counter].value = value;
        ++*counter;

        return 0;
}

static int trace_filter_parse_entry(struct snd_sof_dev *sdev, const char *line,
                                    struct sof_ipc_trace_filter_elem *elem,
                                    int capacity, int *counter)
{
        int len = strlen(line);
        int cnt = *counter;
        uint32_t uuid_id;
        int log_level;
        int pipe_id;
        int comp_id;
        int read;
        int ret;

        /* ignore empty content */
        ret = sscanf(line, " %n", &read);
        if (!ret && read == len)
                return len;

        ret = sscanf(line, " %d %x %d %d %n", &log_level, &uuid_id, &pipe_id, &comp_id, &read);
        if (ret != TRACE_FILTER_ELEMENTS_PER_ENTRY || read != len) {
                dev_err(sdev->dev, "error: invalid trace filter entry '%s'\n", line);
                return -EINVAL;
        }

        if (uuid_id > 0) {
                ret = trace_filter_append_elem(sdev, SOF_IPC_TRACE_FILTER_ELEM_BY_UUID,
                                               uuid_id, elem, capacity, &cnt);
                if (ret)
                        return ret;
        }
        if (pipe_id >= 0) {
                ret = trace_filter_append_elem(sdev, SOF_IPC_TRACE_FILTER_ELEM_BY_PIPE,
                                               pipe_id, elem, capacity, &cnt);
                if (ret)
                        return ret;
        }
        if (comp_id >= 0) {
                ret = trace_filter_append_elem(sdev, SOF_IPC_TRACE_FILTER_ELEM_BY_COMP,
                                               comp_id, elem, capacity, &cnt);
                if (ret)
                        return ret;
        }

        ret = trace_filter_append_elem(sdev, SOF_IPC_TRACE_FILTER_ELEM_SET_LEVEL |
                                       SOF_IPC_TRACE_FILTER_ELEM_FIN,
                                       log_level, elem, capacity, &cnt);
        if (ret)
                return ret;

        /* update counter only when parsing whole entry passed */
        *counter = cnt;

        return len;
}

static int trace_filter_parse(struct snd_sof_dev *sdev, char *string,
                              int *out_elem_cnt,
                              struct sof_ipc_trace_filter_elem **out)
{
        static const char entry_delimiter[] = ";";
        char *entry = string;
        int capacity = 0;
        int entry_len;
        int cnt = 0;

        /*
         * Each entry contains at least 1, up to TRACE_FILTER_ELEMENTS_PER_ENTRY
         * IPC elements, depending on content. Calculate IPC elements capacity
         * for the input string where each element is set.
         */
        while (entry) {
                capacity += TRACE_FILTER_ELEMENTS_PER_ENTRY;
                entry = strchr(entry + 1, entry_delimiter[0]);
        }
        *out = kmalloc(capacity * sizeof(**out), GFP_KERNEL);
        if (!*out)
                return -ENOMEM;

        /* split input string by ';', and parse each entry separately in trace_filter_parse_entry */
        while ((entry = strsep(&string, entry_delimiter))) {
                entry_len = trace_filter_parse_entry(sdev, entry, *out, capacity, &cnt);
                if (entry_len < 0) {
                        dev_err(sdev->dev, "error: %s failed for '%s', %d\n", __func__, entry,
                                entry_len);
                        return -EINVAL;
                }
        }

        *out_elem_cnt = cnt;

        return 0;
}

static int sof_ipc_trace_update_filter(struct snd_sof_dev *sdev, int num_elems,
                                       struct sof_ipc_trace_filter_elem *elems)
{
        struct sof_ipc_trace_filter *msg;
        struct sof_ipc_reply reply;
        size_t size;
        int ret;

        size = struct_size(msg, elems, num_elems);
        if (size > SOF_IPC_MSG_MAX_SIZE)
                return -EINVAL;

        msg = kmalloc(size, GFP_KERNEL);
        if (!msg)
                return -ENOMEM;

        msg->hdr.size = size;
        msg->hdr.cmd = SOF_IPC_GLB_TRACE_MSG | SOF_IPC_TRACE_FILTER_UPDATE;
        msg->elem_cnt = num_elems;
        memcpy(&msg->elems[0], elems, num_elems * sizeof(*elems));

        ret = pm_runtime_get_sync(sdev->dev);
        if (ret < 0 && ret != -EACCES) {
                pm_runtime_put_noidle(sdev->dev);
                dev_err(sdev->dev, "error: enabling device failed: %d\n", ret);
                goto error;
        }
        ret = sof_ipc_tx_message(sdev->ipc, msg->hdr.cmd, msg, msg->hdr.size,
                                 &reply, sizeof(reply));
        pm_runtime_mark_last_busy(sdev->dev);
        pm_runtime_put_autosuspend(sdev->dev);

error:
        kfree(msg);
        return ret ? ret : reply.error;
}

static ssize_t sof_dfsentry_trace_filter_write(struct file *file, const char __user *from,
                                               size_t count, loff_t *ppos)
{
        struct snd_sof_dfsentry *dfse = file->private_data;
        struct sof_ipc_trace_filter_elem *elems = NULL;
        struct snd_sof_dev *sdev = dfse->sdev;
        loff_t pos = 0;
        int num_elems;
        char *string;
        int ret;

        if (count > TRACE_FILTER_MAX_CONFIG_STRING_LENGTH) {
                dev_err(sdev->dev, "%s too long input, %zu > %d\n", __func__, count,
                        TRACE_FILTER_MAX_CONFIG_STRING_LENGTH);
                return -EINVAL;
        }

        string = kmalloc(count + 1, GFP_KERNEL);
        if (!string)
                return -ENOMEM;

        /* assert null termination */
        string[count] = 0;
        ret = simple_write_to_buffer(string, count, &pos, from, count);
        if (ret < 0)
                goto error;

        ret = trace_filter_parse(sdev, string, &num_elems, &elems);
        if (ret < 0) {
                dev_err(sdev->dev, "error: fail in trace_filter_parse, %d\n", ret);
                goto error;
        }

        if (num_elems) {
                ret = sof_ipc_trace_update_filter(sdev, num_elems, elems);
                if (ret < 0) {
                        dev_err(sdev->dev, "error: fail in sof_ipc_trace_update_filter %d\n", ret);
                        goto error;
                }
        }
        ret = count;
error:
        kfree(string);
        kfree(elems);
        return ret;
}

static const struct file_operations sof_dfs_trace_filter_fops = {
        .open = simple_open,
        .write = sof_dfsentry_trace_filter_write,
        .llseek = default_llseek,
};

static int trace_debugfs_filter_create(struct snd_sof_dev *sdev)
{
        struct snd_sof_dfsentry *dfse;

        dfse = devm_kzalloc(sdev->dev, sizeof(*dfse), GFP_KERNEL);
        if (!dfse)
                return -ENOMEM;

        dfse->sdev = sdev;
        dfse->type = SOF_DFSENTRY_TYPE_BUF;

        debugfs_create_file("filter", 0200, sdev->debugfs_root, dfse,
                            &sof_dfs_trace_filter_fops);
        /* add to dfsentry list */
        list_add(&dfse->list, &sdev->dfsentry_list);

        return 0;
}

static size_t sof_trace_avail(struct snd_sof_dev *sdev,
                              loff_t pos, size_t buffer_size)
{
        loff_t host_offset = READ_ONCE(sdev->host_offset);

        /*
         * If host offset is less than local pos, it means write pointer of
         * host DMA buffer has been wrapped. We should output the trace data
         * at the end of host DMA buffer at first.
         */
        if (host_offset < pos)
                return buffer_size - pos;

        /* If there is available trace data now, it is unnecessary to wait. */
        if (host_offset > pos)
                return host_offset - pos;

        return 0;
}

static size_t sof_wait_trace_avail(struct snd_sof_dev *sdev,
                                   loff_t pos, size_t buffer_size)
{
        wait_queue_entry_t wait;
        size_t ret = sof_trace_avail(sdev, pos, buffer_size);

        /* data immediately available */
        if (ret)
                return ret;

        if (!sdev->dtrace_is_enabled && sdev->dtrace_draining) {
                /*
                 * tracing has ended and all traces have been
                 * read by client, return EOF
                 */
                sdev->dtrace_draining = false;
                return 0;
        }

        /* wait for available trace data from FW */
        init_waitqueue_entry(&wait, current);
        set_current_state(TASK_INTERRUPTIBLE);
        add_wait_queue(&sdev->trace_sleep, &wait);

        if (!signal_pending(current)) {
                /* set timeout to max value, no error code */
                schedule_timeout(MAX_SCHEDULE_TIMEOUT);
        }
        remove_wait_queue(&sdev->trace_sleep, &wait);

        return sof_trace_avail(sdev, pos, buffer_size);
}

static ssize_t sof_dfsentry_trace_read(struct file *file, char __user *buffer,
                                       size_t count, loff_t *ppos)
{
        struct snd_sof_dfsentry *dfse = file->private_data;
        struct snd_sof_dev *sdev = dfse->sdev;
        unsigned long rem;
        loff_t lpos = *ppos;
        size_t avail, buffer_size = dfse->size;
        u64 lpos_64;

        /* make sure we know about any failures on the DSP side */
        sdev->dtrace_error = false;

        /* check pos and count */
        if (lpos < 0)
                return -EINVAL;
        if (!count)
                return 0;

        /* check for buffer wrap and count overflow */
        lpos_64 = lpos;
        lpos = do_div(lpos_64, buffer_size);

        if (count > buffer_size - lpos) /* min() not used to avoid sparse warnings */
                count = buffer_size - lpos;

        /* get available count based on current host offset */
        avail = sof_wait_trace_avail(sdev, lpos, buffer_size);
        if (sdev->dtrace_error) {
                dev_err(sdev->dev, "error: trace IO error\n");
                return -EIO;
        }

        /* make sure count is <= avail */
        count = avail > count ? count : avail;

        /* copy available trace data to debugfs */
        rem = copy_to_user(buffer, ((u8 *)(dfse->buf) + lpos), count);
        if (rem)
                return -EFAULT;

        *ppos += count;

        /* move debugfs reading position */
        return count;
}

static int sof_dfsentry_trace_release(struct inode *inode, struct file *file)
{
        struct snd_sof_dfsentry *dfse = inode->i_private;
        struct snd_sof_dev *sdev = dfse->sdev;

        /* avoid duplicate traces at next open */
        if (!sdev->dtrace_is_enabled)
                sdev->host_offset = 0;

        return 0;
}

static const struct file_operations sof_dfs_trace_fops = {
        .open = simple_open,
        .read = sof_dfsentry_trace_read,
        .llseek = default_llseek,
        .release = sof_dfsentry_trace_release,
};

static int trace_debugfs_create(struct snd_sof_dev *sdev)
{
        struct snd_sof_dfsentry *dfse;
        int ret;

        if (!sdev)
                return -EINVAL;

        ret = trace_debugfs_filter_create(sdev);
        if (ret < 0)
                dev_err(sdev->dev, "error: fail in %s, %d", __func__, ret);

        dfse = devm_kzalloc(sdev->dev, sizeof(*dfse), GFP_KERNEL);
        if (!dfse)
                return -ENOMEM;

        dfse->type = SOF_DFSENTRY_TYPE_BUF;
        dfse->buf = sdev->dmatb.area;
        dfse->size = sdev->dmatb.bytes;
        dfse->sdev = sdev;

        dfse->dfsentry = debugfs_create_file("trace", 0444, sdev->debugfs_root,
                                             dfse, &sof_dfs_trace_fops);
        if (!dfse->dfsentry) {
                /* can't rely on debugfs, only log error and keep going */
                dev_err(sdev->dev,
                        "error: cannot create debugfs entry for trace\n");
        }

        return 0;
}

int snd_sof_init_trace_ipc(struct snd_sof_dev *sdev)
{
        struct sof_ipc_fw_ready *ready = &sdev->fw_ready;
        struct sof_ipc_fw_version *v = &ready->version;
        struct sof_ipc_dma_trace_params_ext params;
        struct sof_ipc_reply ipc_reply;
        int ret;

        if (!sdev->dtrace_is_supported)
                return 0;

        if (sdev->dtrace_is_enabled || !sdev->dma_trace_pages)
                return -EINVAL;

        /* set IPC parameters */
        params.hdr.cmd = SOF_IPC_GLB_TRACE_MSG;
        /* PARAMS_EXT is only supported from ABI 3.7.0 onwards */
        if (v->abi_version >= SOF_ABI_VER(3, 7, 0)) {
                params.hdr.size = sizeof(struct sof_ipc_dma_trace_params_ext);
                params.hdr.cmd |= SOF_IPC_TRACE_DMA_PARAMS_EXT;
                params.timestamp_ns = ktime_get(); /* in nanosecond */
        } else {
                params.hdr.size = sizeof(struct sof_ipc_dma_trace_params);
                params.hdr.cmd |= SOF_IPC_TRACE_DMA_PARAMS;
        }
        params.buffer.phy_addr = sdev->dmatp.addr;
        params.buffer.size = sdev->dmatb.bytes;
        params.buffer.pages = sdev->dma_trace_pages;
        params.stream_tag = 0;

        sdev->host_offset = 0;
        sdev->dtrace_draining = false;

        ret = snd_sof_dma_trace_init(sdev, &params.stream_tag);
        if (ret < 0) {
                dev_err(sdev->dev,
                        "error: fail in snd_sof_dma_trace_init %d\n", ret);
                return ret;
        }
        dev_dbg(sdev->dev, "stream_tag: %d\n", params.stream_tag);

        /* send IPC to the DSP */
        ret = sof_ipc_tx_message(sdev->ipc,
                                 params.hdr.cmd, &params, sizeof(params),
                                 &ipc_reply, sizeof(ipc_reply));
        if (ret < 0) {
                dev_err(sdev->dev,
                        "error: can't set params for DMA for trace %d\n", ret);
                goto trace_release;
        }

        ret = snd_sof_dma_trace_trigger(sdev, SNDRV_PCM_TRIGGER_START);
        if (ret < 0) {
                dev_err(sdev->dev,
                        "error: snd_sof_dma_trace_trigger: start: %d\n", ret);
                goto trace_release;
        }

        sdev->dtrace_is_enabled = true;

        return 0;

trace_release:
        snd_sof_dma_trace_release(sdev);
        return ret;
}

int snd_sof_init_trace(struct snd_sof_dev *sdev)
{
        int ret;

        if (!sdev->dtrace_is_supported)
                return 0;

        /* set false before start initialization */
        sdev->dtrace_is_enabled = false;

        /* allocate trace page table buffer */
        ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, sdev->dev,
                                  PAGE_SIZE, &sdev->dmatp);
        if (ret < 0) {
                dev_err(sdev->dev,
                        "error: can't alloc page table for trace %d\n", ret);
                return ret;
        }

        /* allocate trace data buffer */
        ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV_SG, sdev->dev,
                                  DMA_BUF_SIZE_FOR_TRACE, &sdev->dmatb);
        if (ret < 0) {
                dev_err(sdev->dev,
                        "error: can't alloc buffer for trace %d\n", ret);
                goto page_err;
        }

        /* create compressed page table for audio firmware */
        ret = snd_sof_create_page_table(sdev->dev, &sdev->dmatb,
                                        sdev->dmatp.area, sdev->dmatb.bytes);
        if (ret < 0)
                goto table_err;

        sdev->dma_trace_pages = ret;
        dev_dbg(sdev->dev, "dma_trace_pages: %d\n", sdev->dma_trace_pages);

        if (sdev->first_boot) {
                ret = trace_debugfs_create(sdev);
                if (ret < 0)
                        goto table_err;
        }

        init_waitqueue_head(&sdev->trace_sleep);

        ret = snd_sof_init_trace_ipc(sdev);
        if (ret < 0)
                goto table_err;

        return 0;
table_err:
        sdev->dma_trace_pages = 0;
        snd_dma_free_pages(&sdev->dmatb);
page_err:
        snd_dma_free_pages(&sdev->dmatp);
        return ret;
}
EXPORT_SYMBOL(snd_sof_init_trace);

int snd_sof_trace_update_pos(struct snd_sof_dev *sdev,
                             struct sof_ipc_dma_trace_posn *posn)
{
        if (!sdev->dtrace_is_supported)
                return 0;

        if (sdev->dtrace_is_enabled && sdev->host_offset != posn->host_offset) {
                sdev->host_offset = posn->host_offset;
                wake_up(&sdev->trace_sleep);
        }

        if (posn->overflow != 0)
                dev_err(sdev->dev,
                        "error: DSP trace buffer overflow %u bytes. Total messages %d\n",
                        posn->overflow, posn->messages);

        return 0;
}

/* an error has occurred within the DSP that prevents further trace */
void snd_sof_trace_notify_for_error(struct snd_sof_dev *sdev)
{
        if (!sdev->dtrace_is_supported)
                return;

        if (sdev->dtrace_is_enabled) {
                dev_err(sdev->dev, "error: waking up any trace sleepers\n");
                sdev->dtrace_error = true;
                wake_up(&sdev->trace_sleep);
        }
}
EXPORT_SYMBOL(snd_sof_trace_notify_for_error);

void snd_sof_release_trace(struct snd_sof_dev *sdev)
{
        int ret;

        if (!sdev->dtrace_is_supported || !sdev->dtrace_is_enabled)
                return;

        ret = snd_sof_dma_trace_trigger(sdev, SNDRV_PCM_TRIGGER_STOP);
        if (ret < 0)
                dev_err(sdev->dev,
                        "error: snd_sof_dma_trace_trigger: stop: %d\n", ret);

        ret = snd_sof_dma_trace_release(sdev);
        if (ret < 0)
                dev_err(sdev->dev,
                        "error: fail in snd_sof_dma_trace_release %d\n", ret);

        sdev->dtrace_is_enabled = false;
        sdev->dtrace_draining = true;
        wake_up(&sdev->trace_sleep);
}
EXPORT_SYMBOL(snd_sof_release_trace);

void snd_sof_free_trace(struct snd_sof_dev *sdev)
{
        if (!sdev->dtrace_is_supported)
                return;

        snd_sof_release_trace(sdev);

        if (sdev->dma_trace_pages) {
                snd_dma_free_pages(&sdev->dmatb);
                snd_dma_free_pages(&sdev->dmatp);
                sdev->dma_trace_pages = 0;
        }
}
EXPORT_SYMBOL(snd_sof_free_trace);