// SPDX-License-Identifier: GPL-2.0-only
//
// Copyright(c) 2022 Intel Corporation
//
// Author: Liam Girdwood <liam.r.girdwood@linux.intel.com>

#include <linux/debugfs.h>
#include <linux/sched/signal.h>
#include "sof-priv.h"
#include "sof-audio.h"
#include "ops.h"
#include "sof-utils.h"
#include "ipc3-priv.h"

#define TRACE_FILTER_ELEMENTS_PER_ENTRY 4
#define TRACE_FILTER_MAX_CONFIG_STRING_LENGTH 1024

enum sof_dtrace_state {
        SOF_DTRACE_DISABLED,
        SOF_DTRACE_STOPPED,
        SOF_DTRACE_INITIALIZING,
        SOF_DTRACE_ENABLED,
};

struct sof_dtrace_priv {
        struct snd_dma_buffer dmatb;
        struct snd_dma_buffer dmatp;
        int dma_trace_pages;
        wait_queue_head_t trace_sleep;
        u32 host_offset;
        bool dtrace_error;
        bool dtrace_draining;
        enum sof_dtrace_state dtrace_state;
};

static bool trace_pos_update_expected(struct sof_dtrace_priv *priv)
{
        if (priv->dtrace_state == SOF_DTRACE_ENABLED ||
            priv->dtrace_state == SOF_DTRACE_INITIALIZING)
                return true;

        return false;
}

static int trace_filter_append_elem(struct snd_sof_dev *sdev, u32 key, u32 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 log_level, pipe_id, comp_id, read, ret;
        int len = strlen(line);
        int cnt = *counter;
        u32 uuid_id;

        /* 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, "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_objs(**out, capacity);
        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,
                                "Parsing filter entry '%s' failed with %d\n",
                                entry, entry_len);
                        return -EINVAL;
                }
        }

        *out_elem_cnt = cnt;

        return 0;
}

static int ipc3_trace_update_filter(struct snd_sof_dev *sdev, int num_elems,
                                    struct sof_ipc_trace_filter_elem *elems)
{
        struct sof_ipc_trace_filter *msg;
        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_resume_and_get(sdev->dev);
        if (ret < 0 && ret != -EACCES) {
                dev_err(sdev->dev, "enabling device failed: %d\n", ret);
                goto error;
        }

        /* Make sure the DSP/firmware is booted up */
        ret = snd_sof_boot_dsp_firmware(sdev);
        if (!ret)
                ret = sof_ipc_tx_message_no_reply(sdev->ipc, msg, msg->hdr.size);

        pm_runtime_put_autosuspend(sdev->dev);

error:
        kfree(msg);
        return ret;
}

static ssize_t 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;
        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 = memdup_user_nul(from, count);
        if (IS_ERR(string))
                return PTR_ERR(string);

        ret = trace_filter_parse(sdev, string, &num_elems, &elems);
        if (ret < 0)
                goto error;

        if (num_elems) {
                ret = ipc3_trace_update_filter(sdev, num_elems, elems);
                if (ret < 0) {
                        dev_err(sdev->dev, "Filter update failed: %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 = dfsentry_trace_filter_write,
        .llseek = default_llseek,
};

static int debugfs_create_trace_filter(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 bool sof_dtrace_set_host_offset(struct sof_dtrace_priv *priv, u32 new_offset)
{
        u32 host_offset = READ_ONCE(priv->host_offset);

        if (host_offset != new_offset) {
                /* This is a bit paranoid and unlikely that it is needed */
                u32 ret = cmpxchg(&priv->host_offset, host_offset, new_offset);

                if (ret == host_offset)
                        return true;
        }

        return false;
}

static size_t sof_dtrace_avail(struct snd_sof_dev *sdev,
                               loff_t pos, size_t buffer_size)
{
        struct sof_dtrace_priv *priv = sdev->fw_trace_data;
        loff_t host_offset = READ_ONCE(priv->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_dtrace_avail(struct snd_sof_dev *sdev, loff_t pos,
                                    size_t buffer_size)
{
        size_t ret = sof_dtrace_avail(sdev, pos, buffer_size);
        struct sof_dtrace_priv *priv = sdev->fw_trace_data;
        wait_queue_entry_t wait;

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

        if (priv->dtrace_draining && !trace_pos_update_expected(priv)) {
                /*
                 * tracing has ended and all traces have been
                 * read by client, return EOF
                 */
                priv->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(&priv->trace_sleep, &wait);

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

        return sof_dtrace_avail(sdev, pos, buffer_size);
}

static ssize_t dfsentry_dtrace_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;
        struct sof_dtrace_priv *priv = sdev->fw_trace_data;
        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 */
        priv->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);

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

        /* no new trace data */
        if (!avail)
                return 0;

        /* make sure count is <= avail */
        if (count > avail)
                count = avail;

        /*
         * make sure that all trace data is available for the CPU as the trace
         * data buffer might be allocated from non consistent memory.
         * Note: snd_dma_buffer_sync() is called for normal audio playback and
         *       capture streams also.
         */
        snd_dma_buffer_sync(&priv->dmatb, SNDRV_DMA_SYNC_CPU);
        /* 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 dfsentry_dtrace_release(struct inode *inode, struct file *file)
{
        struct snd_sof_dfsentry *dfse = inode->i_private;
        struct snd_sof_dev *sdev = dfse->sdev;
        struct sof_dtrace_priv *priv = sdev->fw_trace_data;

        /* avoid duplicate traces at next open */
        if (priv->dtrace_state != SOF_DTRACE_ENABLED)
                sof_dtrace_set_host_offset(priv, 0);

        return 0;
}

static const struct file_operations sof_dfs_dtrace_fops = {
        .open = simple_open,
        .read = dfsentry_dtrace_read,
        .llseek = default_llseek,
        .release = dfsentry_dtrace_release,
};

static int debugfs_create_dtrace(struct snd_sof_dev *sdev)
{
        struct sof_dtrace_priv *priv;
        struct snd_sof_dfsentry *dfse;
        int ret;

        if (!sdev)
                return -EINVAL;

        priv = sdev->fw_trace_data;

        ret = debugfs_create_trace_filter(sdev);
        if (ret < 0)
                dev_warn(sdev->dev, "failed to create filter debugfs file: %d", ret);

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

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

        debugfs_create_file("trace", 0444, sdev->debugfs_root, dfse,
                            &sof_dfs_dtrace_fops);

        return 0;
}

static int ipc3_dtrace_enable(struct snd_sof_dev *sdev)
{
        struct sof_dtrace_priv *priv = sdev->fw_trace_data;
        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;
        int ret;

        if (!sdev->fw_trace_is_supported)
                return 0;

        if (priv->dtrace_state == SOF_DTRACE_ENABLED || !priv->dma_trace_pages)
                return -EINVAL;

        if (priv->dtrace_state == SOF_DTRACE_STOPPED)
                goto start;

        /* 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 = priv->dmatp.addr;
        params.buffer.size = priv->dmatb.bytes;
        params.buffer.pages = priv->dma_trace_pages;
        params.stream_tag = 0;

        sof_dtrace_set_host_offset(priv, 0);
        priv->dtrace_draining = false;

        ret = sof_dtrace_host_init(sdev, &priv->dmatb, &params);
        if (ret < 0) {
                dev_err(sdev->dev, "Host dtrace init failed: %d\n", ret);
                return ret;
        }
        dev_dbg(sdev->dev, "stream_tag: %d\n", params.stream_tag);

        /* send IPC to the DSP */
        priv->dtrace_state = SOF_DTRACE_INITIALIZING;
        ret = sof_ipc_tx_message_no_reply(sdev->ipc, &params, sizeof(params));
        if (ret < 0) {
                dev_err(sdev->dev, "can't set params for DMA for trace %d\n", ret);
                goto trace_release;
        }

start:
        priv->dtrace_state = SOF_DTRACE_ENABLED;

        ret = sof_dtrace_host_trigger(sdev, SNDRV_PCM_TRIGGER_START);
        if (ret < 0) {
                dev_err(sdev->dev, "Host dtrace trigger start failed: %d\n", ret);
                goto trace_release;
        }

        return 0;

trace_release:
        priv->dtrace_state = SOF_DTRACE_DISABLED;
        sof_dtrace_host_release(sdev);
        return ret;
}

static int ipc3_dtrace_init(struct snd_sof_dev *sdev)
{
        struct sof_dtrace_priv *priv;
        int ret;

        /* dtrace is only supported with SOF_IPC */
        if (sdev->pdata->ipc_type != SOF_IPC_TYPE_3)
                return -EOPNOTSUPP;

        if (sdev->fw_trace_data) {
                dev_err(sdev->dev, "fw_trace_data has been already allocated\n");
                return -EBUSY;
        }

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

        sdev->fw_trace_data = priv;

        /* set false before start initialization */
        priv->dtrace_state = SOF_DTRACE_DISABLED;

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

        /* allocate trace data buffer */
        ret = snd_dma_alloc_dir_pages(SNDRV_DMA_TYPE_DEV_SG, sdev->dev,
                                      DMA_FROM_DEVICE, DMA_BUF_SIZE_FOR_TRACE,
                                      &priv->dmatb);
        if (ret < 0) {
                dev_err(sdev->dev, "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, &priv->dmatb,
                                        priv->dmatp.area, priv->dmatb.bytes);
        if (ret < 0)
                goto table_err;

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

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

        init_waitqueue_head(&priv->trace_sleep);

        ret = ipc3_dtrace_enable(sdev);
        if (ret < 0)
                goto table_err;

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

int ipc3_dtrace_posn_update(struct snd_sof_dev *sdev,
                            struct sof_ipc_dma_trace_posn *posn)
{
        struct sof_dtrace_priv *priv = sdev->fw_trace_data;

        if (!sdev->fw_trace_is_supported)
                return 0;

        if (trace_pos_update_expected(priv) &&
            sof_dtrace_set_host_offset(priv, posn->host_offset))
                wake_up(&priv->trace_sleep);

        if (posn->overflow != 0)
                dev_err(sdev->dev,
                        "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 */
static void ipc3_dtrace_fw_crashed(struct snd_sof_dev *sdev)
{
        struct sof_dtrace_priv *priv = sdev->fw_trace_data;

        if (priv->dtrace_state == SOF_DTRACE_ENABLED) {
                priv->dtrace_error = true;
                wake_up(&priv->trace_sleep);
        }
}

static void ipc3_dtrace_release(struct snd_sof_dev *sdev, bool only_stop)
{
        struct sof_dtrace_priv *priv = sdev->fw_trace_data;
        struct sof_ipc_fw_ready *ready = &sdev->fw_ready;
        struct sof_ipc_fw_version *v = &ready->version;
        struct sof_ipc_cmd_hdr hdr;
        int ret;

        if (!sdev->fw_trace_is_supported || priv->dtrace_state == SOF_DTRACE_DISABLED)
                return;

        ret = sof_dtrace_host_trigger(sdev, SNDRV_PCM_TRIGGER_STOP);
        if (ret < 0)
                dev_err(sdev->dev, "Host dtrace trigger stop failed: %d\n", ret);
        priv->dtrace_state = SOF_DTRACE_STOPPED;

        /*
         * stop and free trace DMA in the DSP. TRACE_DMA_FREE is only supported from
         * ABI 3.20.0 onwards
         */
        if (v->abi_version >= SOF_ABI_VER(3, 20, 0)) {
                hdr.size = sizeof(hdr);
                hdr.cmd = SOF_IPC_GLB_TRACE_MSG | SOF_IPC_TRACE_DMA_FREE;

                ret = sof_ipc_tx_message_no_reply(sdev->ipc, &hdr, hdr.size);
                if (ret < 0)
                        dev_err(sdev->dev, "DMA_TRACE_FREE failed with error: %d\n", ret);
        }

        if (only_stop)
                goto out;

        ret = sof_dtrace_host_release(sdev);
        if (ret < 0)
                dev_err(sdev->dev, "Host dtrace release failed %d\n", ret);

        priv->dtrace_state = SOF_DTRACE_DISABLED;

out:
        priv->dtrace_draining = true;
        wake_up(&priv->trace_sleep);
}

static void ipc3_dtrace_suspend(struct snd_sof_dev *sdev, pm_message_t pm_state)
{
        ipc3_dtrace_release(sdev, pm_state.event == SOF_DSP_PM_D0);
}

static int ipc3_dtrace_resume(struct snd_sof_dev *sdev)
{
        return ipc3_dtrace_enable(sdev);
}

static void ipc3_dtrace_free(struct snd_sof_dev *sdev)
{
        struct sof_dtrace_priv *priv = sdev->fw_trace_data;

        /* release trace */
        ipc3_dtrace_release(sdev, false);

        if (priv->dma_trace_pages) {
                snd_dma_free_pages(&priv->dmatb);
                snd_dma_free_pages(&priv->dmatp);
                priv->dma_trace_pages = 0;
        }
}

const struct sof_ipc_fw_tracing_ops ipc3_dtrace_ops = {
        .init = ipc3_dtrace_init,
        .free = ipc3_dtrace_free,
        .fw_crashed = ipc3_dtrace_fw_crashed,
        .suspend = ipc3_dtrace_suspend,
        .resume = ipc3_dtrace_resume,
};