// 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>
//
// Generic debug routines used to export DSP MMIO and memories to userspace
// for firmware debugging.
//

#include <linux/debugfs.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include "sof-priv.h"
#include "ops.h"

#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_PROBES)
#include "probe.h"

/**
 * strsplit_u32 - Split string into sequence of u32 tokens
 * @buf:        String to split into tokens.
 * @delim:      String containing delimiter characters.
 * @tkns:       Returned u32 sequence pointer.
 * @num_tkns:   Returned number of tokens obtained.
 */
static int
strsplit_u32(char **buf, const char *delim, u32 **tkns, size_t *num_tkns)
{
        char *s;
        u32 *data, *tmp;
        size_t count = 0;
        size_t cap = 32;
        int ret = 0;

        *tkns = NULL;
        *num_tkns = 0;
        data = kcalloc(cap, sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        while ((s = strsep(buf, delim)) != NULL) {
                ret = kstrtouint(s, 0, data + count);
                if (ret)
                        goto exit;
                if (++count >= cap) {
                        cap *= 2;
                        tmp = krealloc(data, cap * sizeof(*data), GFP_KERNEL);
                        if (!tmp) {
                                ret = -ENOMEM;
                                goto exit;
                        }
                        data = tmp;
                }
        }

        if (!count)
                goto exit;
        *tkns = kmemdup(data, count * sizeof(*data), GFP_KERNEL);
        if (*tkns == NULL) {
                ret = -ENOMEM;
                goto exit;
        }
        *num_tkns = count;

exit:
        kfree(data);
        return ret;
}

static int tokenize_input(const char __user *from, size_t count,
                loff_t *ppos, u32 **tkns, size_t *num_tkns)
{
        char *buf;
        int ret;

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

        ret = simple_write_to_buffer(buf, count, ppos, from, count);
        if (ret != count) {
                ret = ret >= 0 ? -EIO : ret;
                goto exit;
        }

        buf[count] = '\0';
        ret = strsplit_u32((char **)&buf, ",", tkns, num_tkns);
exit:
        kfree(buf);
        return ret;
}

static ssize_t probe_points_read(struct file *file,
                char __user *to, size_t count, loff_t *ppos)
{
        struct snd_sof_dfsentry *dfse = file->private_data;
        struct snd_sof_dev *sdev = dfse->sdev;
        struct sof_probe_point_desc *desc;
        size_t num_desc, len = 0;
        char *buf;
        int i, ret;

        if (sdev->extractor_stream_tag == SOF_PROBE_INVALID_NODE_ID) {
                dev_warn(sdev->dev, "no extractor stream running\n");
                return -ENOENT;
        }

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

        ret = sof_ipc_probe_points_info(sdev, &desc, &num_desc);
        if (ret < 0)
                goto exit;

        for (i = 0; i < num_desc; i++) {
                ret = snprintf(buf + len, PAGE_SIZE - len,
                        "Id: %#010x  Purpose: %d  Node id: %#x\n",
                        desc[i].buffer_id, desc[i].purpose, desc[i].stream_tag);
                if (ret < 0)
                        goto free_desc;
                len += ret;
        }

        ret = simple_read_from_buffer(to, count, ppos, buf, len);
free_desc:
        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 snd_sof_dfsentry *dfse = file->private_data;
        struct snd_sof_dev *sdev = dfse->sdev;
        struct sof_probe_point_desc *desc;
        size_t num_tkns, bytes;
        u32 *tkns;
        int ret;

        if (sdev->extractor_stream_tag == SOF_PROBE_INVALID_NODE_ID) {
                dev_warn(sdev->dev, "no extractor stream running\n");
                return -ENOENT;
        }

        ret = tokenize_input(from, count, ppos, &tkns, &num_tkns);
        if (ret < 0)
                return ret;
        bytes = sizeof(*tkns) * num_tkns;
        if (!num_tkns || (bytes % sizeof(*desc))) {
                ret = -EINVAL;
                goto exit;
        }

        desc = (struct sof_probe_point_desc *)tkns;
        ret = sof_ipc_probe_points_add(sdev,
                        desc, bytes / sizeof(*desc));
        if (!ret)
                ret = count;
exit:
        kfree(tkns);
        return ret;
}

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

static ssize_t probe_points_remove_write(struct file *file,
                const char __user *from, size_t count, loff_t *ppos)
{
        struct snd_sof_dfsentry *dfse = file->private_data;
        struct snd_sof_dev *sdev = dfse->sdev;
        size_t num_tkns;
        u32 *tkns;
        int ret;

        if (sdev->extractor_stream_tag == SOF_PROBE_INVALID_NODE_ID) {
                dev_warn(sdev->dev, "no extractor stream running\n");
                return -ENOENT;
        }

        ret = tokenize_input(from, count, ppos, &tkns, &num_tkns);
        if (ret < 0)
                return ret;
        if (!num_tkns) {
                ret = -EINVAL;
                goto exit;
        }

        ret = sof_ipc_probe_points_remove(sdev, tkns, num_tkns);
        if (!ret)
                ret = count;
exit:
        kfree(tkns);
        return ret;
}

static const struct file_operations probe_points_remove_fops = {
        .open = simple_open,
        .write = probe_points_remove_write,
        .llseek = default_llseek,
};

static int snd_sof_debugfs_probe_item(struct snd_sof_dev *sdev,
                                 const char *name, mode_t mode,
                                 const struct file_operations *fops)
{
        struct snd_sof_dfsentry *dfse;

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

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

        debugfs_create_file(name, mode, sdev->debugfs_root, dfse, fops);
        /* add to dfsentry list */
        list_add(&dfse->list, &sdev->dfsentry_list);

        return 0;
}
#endif

#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST)
#define MAX_IPC_FLOOD_DURATION_MS 1000
#define MAX_IPC_FLOOD_COUNT 10000
#define IPC_FLOOD_TEST_RESULT_LEN 512

static int sof_debug_ipc_flood_test(struct snd_sof_dev *sdev,
                                    struct snd_sof_dfsentry *dfse,
                                    bool flood_duration_test,
                                    unsigned long ipc_duration_ms,
                                    unsigned long ipc_count)
{
        struct sof_ipc_cmd_hdr hdr;
        struct sof_ipc_reply reply;
        u64 min_response_time = U64_MAX;
        ktime_t start, end, test_end;
        u64 avg_response_time = 0;
        u64 max_response_time = 0;
        u64 ipc_response_time;
        int i = 0;
        int ret;

        /* configure test IPC */
        hdr.cmd = SOF_IPC_GLB_TEST_MSG | SOF_IPC_TEST_IPC_FLOOD;
        hdr.size = sizeof(hdr);

        /* set test end time for duration flood test */
        if (flood_duration_test)
                test_end = ktime_get_ns() + ipc_duration_ms * NSEC_PER_MSEC;

        /* send test IPC's */
        while (1) {
                start = ktime_get();
                ret = sof_ipc_tx_message(sdev->ipc, hdr.cmd, &hdr, hdr.size,
                                         &reply, sizeof(reply));
                end = ktime_get();

                if (ret < 0)
                        break;

                /* compute min and max response times */
                ipc_response_time = ktime_to_ns(ktime_sub(end, start));
                min_response_time = min(min_response_time, ipc_response_time);
                max_response_time = max(max_response_time, ipc_response_time);

                /* sum up response times */
                avg_response_time += ipc_response_time;
                i++;

                /* test complete? */
                if (flood_duration_test) {
                        if (ktime_to_ns(end) >= test_end)
                                break;
                } else {
                        if (i == ipc_count)
                                break;
                }
        }

        if (ret < 0)
                dev_err(sdev->dev,
                        "error: ipc flood test failed at %d iterations\n", i);

        /* return if the first IPC fails */
        if (!i)
                return ret;

        /* compute average response time */
        do_div(avg_response_time, i);

        /* clear previous test output */
        memset(dfse->cache_buf, 0, IPC_FLOOD_TEST_RESULT_LEN);

        if (flood_duration_test) {
                dev_dbg(sdev->dev, "IPC Flood test duration: %lums\n",
                        ipc_duration_ms);
                snprintf(dfse->cache_buf, IPC_FLOOD_TEST_RESULT_LEN,
                         "IPC Flood test duration: %lums\n", ipc_duration_ms);
        }

        dev_dbg(sdev->dev,
                "IPC Flood count: %d, Avg response time: %lluns\n",
                i, avg_response_time);
        dev_dbg(sdev->dev, "Max response time: %lluns\n",
                max_response_time);
        dev_dbg(sdev->dev, "Min response time: %lluns\n",
                min_response_time);

        /* format output string */
        snprintf(dfse->cache_buf + strlen(dfse->cache_buf),
                 IPC_FLOOD_TEST_RESULT_LEN - strlen(dfse->cache_buf),
                 "IPC Flood count: %d\nAvg response time: %lluns\n",
                 i, avg_response_time);

        snprintf(dfse->cache_buf + strlen(dfse->cache_buf),
                 IPC_FLOOD_TEST_RESULT_LEN - strlen(dfse->cache_buf),
                 "Max response time: %lluns\nMin response time: %lluns\n",
                 max_response_time, min_response_time);

        return ret;
}
#endif

static ssize_t sof_dfsentry_write(struct file *file, const char __user *buffer,
                                  size_t count, loff_t *ppos)
{
#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST)
        struct snd_sof_dfsentry *dfse = file->private_data;
        struct snd_sof_dev *sdev = dfse->sdev;
        unsigned long ipc_duration_ms = 0;
        bool flood_duration_test = false;
        unsigned long ipc_count = 0;
        struct dentry *dentry;
        int err;
#endif
        size_t size;
        char *string;
        int ret;

        string = kzalloc(count, GFP_KERNEL);
        if (!string)
                return -ENOMEM;

        size = simple_write_to_buffer(string, count, ppos, buffer, count);
        ret = size;

#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST)
        /*
         * write op is only supported for ipc_flood_count or
         * ipc_flood_duration_ms debugfs entries atm.
         * ipc_flood_count floods the DSP with the number of IPC's specified.
         * ipc_duration_ms test floods the DSP for the time specified
         * in the debugfs entry.
         */
        dentry = file->f_path.dentry;
        if (strcmp(dentry->d_name.name, "ipc_flood_count") &&
            strcmp(dentry->d_name.name, "ipc_flood_duration_ms")) {
                ret = -EINVAL;
                goto out;
        }

        if (!strcmp(dentry->d_name.name, "ipc_flood_duration_ms"))
                flood_duration_test = true;

        /* test completion criterion */
        if (flood_duration_test)
                ret = kstrtoul(string, 0, &ipc_duration_ms);
        else
                ret = kstrtoul(string, 0, &ipc_count);
        if (ret < 0)
                goto out;

        /* limit max duration/ipc count for flood test */
        if (flood_duration_test) {
                if (!ipc_duration_ms) {
                        ret = size;
                        goto out;
                }

                /* find the minimum. min() is not used to avoid warnings */
                if (ipc_duration_ms > MAX_IPC_FLOOD_DURATION_MS)
                        ipc_duration_ms = MAX_IPC_FLOOD_DURATION_MS;
        } else {
                if (!ipc_count) {
                        ret = size;
                        goto out;
                }

                /* find the minimum. min() is not used to avoid warnings */
                if (ipc_count > MAX_IPC_FLOOD_COUNT)
                        ipc_count = MAX_IPC_FLOOD_COUNT;
        }

        ret = pm_runtime_get_sync(sdev->dev);
        if (ret < 0) {
                dev_err_ratelimited(sdev->dev,
                                    "error: debugfs write failed to resume %d\n",
                                    ret);
                pm_runtime_put_noidle(sdev->dev);
                goto out;
        }

        /* flood test */
        ret = sof_debug_ipc_flood_test(sdev, dfse, flood_duration_test,
                                       ipc_duration_ms, ipc_count);

        pm_runtime_mark_last_busy(sdev->dev);
        err = pm_runtime_put_autosuspend(sdev->dev);
        if (err < 0)
                dev_err_ratelimited(sdev->dev,
                                    "error: debugfs write failed to idle %d\n",
                                    err);

        /* return size if test is successful */
        if (ret >= 0)
                ret = size;
out:
#endif
        kfree(string);
        return ret;
}

static ssize_t sof_dfsentry_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;
        loff_t pos = *ppos;
        size_t size_ret;
        int skip = 0;
        int size;
        u8 *buf;

#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST)
        struct dentry *dentry;

        dentry = file->f_path.dentry;
        if ((!strcmp(dentry->d_name.name, "ipc_flood_count") ||
             !strcmp(dentry->d_name.name, "ipc_flood_duration_ms")) &&
            dfse->cache_buf) {
                if (*ppos)
                        return 0;

                count = strlen(dfse->cache_buf);
                size_ret = copy_to_user(buffer, dfse->cache_buf, count);
                if (size_ret)
                        return -EFAULT;

                *ppos += count;
                return count;
        }
#endif
        size = dfse->size;

        /* validate position & count */
        if (pos < 0)
                return -EINVAL;
        if (pos >= size || !count)
                return 0;
        /* find the minimum. min() is not used since it adds sparse warnings */
        if (count > size - pos)
                count = size - pos;

        /* align io read start to u32 multiple */
        pos = ALIGN_DOWN(pos, 4);

        /* intermediate buffer size must be u32 multiple */
        size = ALIGN(count, 4);

        /* if start position is unaligned, read extra u32 */
        if (unlikely(pos != *ppos)) {
                skip = *ppos - pos;
                if (pos + size + 4 < dfse->size)
                        size += 4;
        }

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

        if (dfse->type == SOF_DFSENTRY_TYPE_IOMEM) {
#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_ENABLE_DEBUGFS_CACHE)
                /*
                 * If the DSP is active: copy from IO.
                 * If the DSP is suspended:
                 *      - Copy from IO if the memory is always accessible.
                 *      - Otherwise, copy from cached buffer.
                 */
                if (pm_runtime_active(sdev->dev) ||
                    dfse->access_type == SOF_DEBUGFS_ACCESS_ALWAYS) {
                        memcpy_fromio(buf, dfse->io_mem + pos, size);
                } else {
                        dev_info(sdev->dev,
                                 "Copying cached debugfs data\n");
                        memcpy(buf, dfse->cache_buf + pos, size);
                }
#else
                /* if the DSP is in D3 */
                if (!pm_runtime_active(sdev->dev) &&
                    dfse->access_type == SOF_DEBUGFS_ACCESS_D0_ONLY) {
                        dev_err(sdev->dev,
                                "error: debugfs entry cannot be read in DSP D3\n");
                        kfree(buf);
                        return -EINVAL;
                }

                memcpy_fromio(buf, dfse->io_mem + pos, size);
#endif
        } else {
                memcpy(buf, ((u8 *)(dfse->buf) + pos), size);
        }

        /* copy to userspace */
        size_ret = copy_to_user(buffer, buf + skip, count);

        kfree(buf);

        /* update count & position if copy succeeded */
        if (size_ret)
                return -EFAULT;

        *ppos = pos + count;

        return count;
}

static const struct file_operations sof_dfs_fops = {
        .open = simple_open,
        .read = sof_dfsentry_read,
        .llseek = default_llseek,
        .write = sof_dfsentry_write,
};

/* create FS entry for debug files that can expose DSP memories, registers */
int snd_sof_debugfs_io_item(struct snd_sof_dev *sdev,
                            void __iomem *base, size_t size,
                            const char *name,
                            enum sof_debugfs_access_type access_type)
{
        struct snd_sof_dfsentry *dfse;

        if (!sdev)
                return -EINVAL;

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

        dfse->type = SOF_DFSENTRY_TYPE_IOMEM;
        dfse->io_mem = base;
        dfse->size = size;
        dfse->sdev = sdev;
        dfse->access_type = access_type;

#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_ENABLE_DEBUGFS_CACHE)
        /*
         * allocate cache buffer that will be used to save the mem window
         * contents prior to suspend
         */
        if (access_type == SOF_DEBUGFS_ACCESS_D0_ONLY) {
                dfse->cache_buf = devm_kzalloc(sdev->dev, size, GFP_KERNEL);
                if (!dfse->cache_buf)
                        return -ENOMEM;
        }
#endif

        debugfs_create_file(name, 0444, sdev->debugfs_root, dfse,
                            &sof_dfs_fops);

        /* add to dfsentry list */
        list_add(&dfse->list, &sdev->dfsentry_list);

        return 0;
}
EXPORT_SYMBOL_GPL(snd_sof_debugfs_io_item);

/* create FS entry for debug files to expose kernel memory */
int snd_sof_debugfs_buf_item(struct snd_sof_dev *sdev,
                             void *base, size_t size,
                             const char *name, mode_t mode)
{
        struct snd_sof_dfsentry *dfse;

        if (!sdev)
                return -EINVAL;

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

        dfse->type = SOF_DFSENTRY_TYPE_BUF;
        dfse->buf = base;
        dfse->size = size;
        dfse->sdev = sdev;

#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST)
        /*
         * cache_buf is unused for SOF_DFSENTRY_TYPE_BUF debugfs entries.
         * So, use it to save the results of the last IPC flood test.
         */
        dfse->cache_buf = devm_kzalloc(sdev->dev, IPC_FLOOD_TEST_RESULT_LEN,
                                       GFP_KERNEL);
        if (!dfse->cache_buf)
                return -ENOMEM;
#endif

        debugfs_create_file(name, mode, sdev->debugfs_root, dfse,
                            &sof_dfs_fops);
        /* add to dfsentry list */
        list_add(&dfse->list, &sdev->dfsentry_list);

        return 0;
}
EXPORT_SYMBOL_GPL(snd_sof_debugfs_buf_item);

int snd_sof_dbg_init(struct snd_sof_dev *sdev)
{
        const struct snd_sof_dsp_ops *ops = sof_ops(sdev);
        const struct snd_sof_debugfs_map *map;
        int i;
        int err;

        /* use "sof" as top level debugFS dir */
        sdev->debugfs_root = debugfs_create_dir("sof", NULL);

        /* init dfsentry list */
        INIT_LIST_HEAD(&sdev->dfsentry_list);

        /* create debugFS files for platform specific MMIO/DSP memories */
        for (i = 0; i < ops->debug_map_count; i++) {
                map = &ops->debug_map[i];

                err = snd_sof_debugfs_io_item(sdev, sdev->bar[map->bar] +
                                              map->offset, map->size,
                                              map->name, map->access_type);
                /* errors are only due to memory allocation, not debugfs */
                if (err < 0)
                        return err;
        }

#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_PROBES)
        err = snd_sof_debugfs_probe_item(sdev, "probe_points",
                        0644, &probe_points_fops);
        if (err < 0)
                return err;
        err = snd_sof_debugfs_probe_item(sdev, "probe_points_remove",
                        0200, &probe_points_remove_fops);
        if (err < 0)
                return err;
#endif

#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST)
        /* create read-write ipc_flood_count debugfs entry */
        err = snd_sof_debugfs_buf_item(sdev, NULL, 0,
                                       "ipc_flood_count", 0666);

        /* errors are only due to memory allocation, not debugfs */
        if (err < 0)
                return err;

        /* create read-write ipc_flood_duration_ms debugfs entry */
        err = snd_sof_debugfs_buf_item(sdev, NULL, 0,
                                       "ipc_flood_duration_ms", 0666);

        /* errors are only due to memory allocation, not debugfs */
        if (err < 0)
                return err;
#endif

        return 0;
}
EXPORT_SYMBOL_GPL(snd_sof_dbg_init);

void snd_sof_free_debug(struct snd_sof_dev *sdev)
{
        debugfs_remove_recursive(sdev->debugfs_root);
}
EXPORT_SYMBOL_GPL(snd_sof_free_debug);

void snd_sof_handle_fw_exception(struct snd_sof_dev *sdev)
{
        if (IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_RETAIN_DSP_CONTEXT) ||
            (sof_core_debug & SOF_DBG_RETAIN_CTX)) {
                /* should we prevent DSP entering D3 ? */
                dev_info(sdev->dev, "info: preventing DSP entering D3 state to preserve context\n");
                pm_runtime_get_noresume(sdev->dev);
        }

        /* dump vital information to the logs */
        snd_sof_dsp_dbg_dump(sdev, SOF_DBG_REGS | SOF_DBG_MBOX);
        snd_sof_ipc_dump(sdev);
        snd_sof_trace_notify_for_error(sdev);
}
EXPORT_SYMBOL(snd_sof_handle_fw_exception);