linux/sound/soc/sof/debug.c

// SPDX-License-Identifier: (GPL-2.0 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"

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;

	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 %s cannot be read in DSP D3\n",
				dfse->dfsentry->d_name.name);
			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,
};

/* 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

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

	dfse->dfsentry = debugfs_create_file(name, 0444, sdev->debugfs_root,
					     dfse, &sof_dfs_fops);
	if (!dfse->dfsentry) {
		/* can't rely on debugfs, only log error and keep going */
		dev_err(sdev->dev, "error: cannot create debugfs entry %s\n",
			name);
	} else {
		/* 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);
	if (IS_ERR_OR_NULL(sdev->debugfs_root)) {
		dev_err(sdev->dev, "error: failed to create debugfs directory\n");
		return 0;
	}

	/* 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;
	}

	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);