ASoC: SOF: Add driver debug support.

// 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);