xref: /openbmc/linux/sound/soc/sof/debug.c (revision 3fc41476)
1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 //
3 // This file is provided under a dual BSD/GPLv2 license.  When using or
4 // redistributing this file, you may do so under either license.
5 //
6 // Copyright(c) 2018 Intel Corporation. All rights reserved.
7 //
8 // Author: Liam Girdwood <liam.r.girdwood@linux.intel.com>
9 //
10 // Generic debug routines used to export DSP MMIO and memories to userspace
11 // for firmware debugging.
12 //
13 
14 #include <linux/debugfs.h>
15 #include <linux/io.h>
16 #include <linux/pm_runtime.h>
17 #include "sof-priv.h"
18 #include "ops.h"
19 
20 static ssize_t sof_dfsentry_read(struct file *file, char __user *buffer,
21 				 size_t count, loff_t *ppos)
22 {
23 	struct snd_sof_dfsentry *dfse = file->private_data;
24 	struct snd_sof_dev *sdev = dfse->sdev;
25 	loff_t pos = *ppos;
26 	size_t size_ret;
27 	int skip = 0;
28 	int size;
29 	u8 *buf;
30 
31 	size = dfse->size;
32 
33 	/* validate position & count */
34 	if (pos < 0)
35 		return -EINVAL;
36 	if (pos >= size || !count)
37 		return 0;
38 	/* find the minimum. min() is not used since it adds sparse warnings */
39 	if (count > size - pos)
40 		count = size - pos;
41 
42 	/* align io read start to u32 multiple */
43 	pos = ALIGN_DOWN(pos, 4);
44 
45 	/* intermediate buffer size must be u32 multiple */
46 	size = ALIGN(count, 4);
47 
48 	/* if start position is unaligned, read extra u32 */
49 	if (unlikely(pos != *ppos)) {
50 		skip = *ppos - pos;
51 		if (pos + size + 4 < dfse->size)
52 			size += 4;
53 	}
54 
55 	buf = kzalloc(size, GFP_KERNEL);
56 	if (!buf)
57 		return -ENOMEM;
58 
59 	if (dfse->type == SOF_DFSENTRY_TYPE_IOMEM) {
60 #if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_ENABLE_DEBUGFS_CACHE)
61 		/*
62 		 * If the DSP is active: copy from IO.
63 		 * If the DSP is suspended:
64 		 *	- Copy from IO if the memory is always accessible.
65 		 *	- Otherwise, copy from cached buffer.
66 		 */
67 		if (pm_runtime_active(sdev->dev) ||
68 		    dfse->access_type == SOF_DEBUGFS_ACCESS_ALWAYS) {
69 			memcpy_fromio(buf, dfse->io_mem + pos, size);
70 		} else {
71 			dev_info(sdev->dev,
72 				 "Copying cached debugfs data\n");
73 			memcpy(buf, dfse->cache_buf + pos, size);
74 		}
75 #else
76 		/* if the DSP is in D3 */
77 		if (!pm_runtime_active(sdev->dev) &&
78 		    dfse->access_type == SOF_DEBUGFS_ACCESS_D0_ONLY) {
79 			dev_err(sdev->dev,
80 				"error: debugfs entry %s cannot be read in DSP D3\n",
81 				dfse->dfsentry->d_name.name);
82 			kfree(buf);
83 			return -EINVAL;
84 		}
85 
86 		memcpy_fromio(buf, dfse->io_mem + pos, size);
87 #endif
88 	} else {
89 		memcpy(buf, ((u8 *)(dfse->buf) + pos), size);
90 	}
91 
92 	/* copy to userspace */
93 	size_ret = copy_to_user(buffer, buf + skip, count);
94 
95 	kfree(buf);
96 
97 	/* update count & position if copy succeeded */
98 	if (size_ret)
99 		return -EFAULT;
100 
101 	*ppos = pos + count;
102 
103 	return count;
104 }
105 
106 static const struct file_operations sof_dfs_fops = {
107 	.open = simple_open,
108 	.read = sof_dfsentry_read,
109 	.llseek = default_llseek,
110 };
111 
112 /* create FS entry for debug files that can expose DSP memories, registers */
113 int snd_sof_debugfs_io_item(struct snd_sof_dev *sdev,
114 			    void __iomem *base, size_t size,
115 			    const char *name,
116 			    enum sof_debugfs_access_type access_type)
117 {
118 	struct snd_sof_dfsentry *dfse;
119 
120 	if (!sdev)
121 		return -EINVAL;
122 
123 	dfse = devm_kzalloc(sdev->dev, sizeof(*dfse), GFP_KERNEL);
124 	if (!dfse)
125 		return -ENOMEM;
126 
127 	dfse->type = SOF_DFSENTRY_TYPE_IOMEM;
128 	dfse->io_mem = base;
129 	dfse->size = size;
130 	dfse->sdev = sdev;
131 	dfse->access_type = access_type;
132 
133 #if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_ENABLE_DEBUGFS_CACHE)
134 	/*
135 	 * allocate cache buffer that will be used to save the mem window
136 	 * contents prior to suspend
137 	 */
138 	if (access_type == SOF_DEBUGFS_ACCESS_D0_ONLY) {
139 		dfse->cache_buf = devm_kzalloc(sdev->dev, size, GFP_KERNEL);
140 		if (!dfse->cache_buf)
141 			return -ENOMEM;
142 	}
143 #endif
144 
145 	dfse->dfsentry = debugfs_create_file(name, 0444, sdev->debugfs_root,
146 					     dfse, &sof_dfs_fops);
147 	if (!dfse->dfsentry) {
148 		/* can't rely on debugfs, only log error and keep going */
149 		dev_err(sdev->dev, "error: cannot create debugfs entry %s\n",
150 			name);
151 	} else {
152 		/* add to dfsentry list */
153 		list_add(&dfse->list, &sdev->dfsentry_list);
154 
155 	}
156 
157 	return 0;
158 }
159 EXPORT_SYMBOL_GPL(snd_sof_debugfs_io_item);
160 
161 /* create FS entry for debug files to expose kernel memory */
162 int snd_sof_debugfs_buf_item(struct snd_sof_dev *sdev,
163 			     void *base, size_t size,
164 			     const char *name)
165 {
166 	struct snd_sof_dfsentry *dfse;
167 
168 	if (!sdev)
169 		return -EINVAL;
170 
171 	dfse = devm_kzalloc(sdev->dev, sizeof(*dfse), GFP_KERNEL);
172 	if (!dfse)
173 		return -ENOMEM;
174 
175 	dfse->type = SOF_DFSENTRY_TYPE_BUF;
176 	dfse->buf = base;
177 	dfse->size = size;
178 	dfse->sdev = sdev;
179 
180 	dfse->dfsentry = debugfs_create_file(name, 0444, sdev->debugfs_root,
181 					     dfse, &sof_dfs_fops);
182 	if (!dfse->dfsentry) {
183 		/* can't rely on debugfs, only log error and keep going */
184 		dev_err(sdev->dev, "error: cannot create debugfs entry %s\n",
185 			name);
186 	} else {
187 		/* add to dfsentry list */
188 		list_add(&dfse->list, &sdev->dfsentry_list);
189 	}
190 
191 	return 0;
192 }
193 EXPORT_SYMBOL_GPL(snd_sof_debugfs_buf_item);
194 
195 int snd_sof_dbg_init(struct snd_sof_dev *sdev)
196 {
197 	const struct snd_sof_dsp_ops *ops = sof_ops(sdev);
198 	const struct snd_sof_debugfs_map *map;
199 	int i;
200 	int err;
201 
202 	/* use "sof" as top level debugFS dir */
203 	sdev->debugfs_root = debugfs_create_dir("sof", NULL);
204 	if (IS_ERR_OR_NULL(sdev->debugfs_root)) {
205 		dev_err(sdev->dev, "error: failed to create debugfs directory\n");
206 		return 0;
207 	}
208 
209 	/* init dfsentry list */
210 	INIT_LIST_HEAD(&sdev->dfsentry_list);
211 
212 	/* create debugFS files for platform specific MMIO/DSP memories */
213 	for (i = 0; i < ops->debug_map_count; i++) {
214 		map = &ops->debug_map[i];
215 
216 		err = snd_sof_debugfs_io_item(sdev, sdev->bar[map->bar] +
217 					      map->offset, map->size,
218 					      map->name, map->access_type);
219 		/* errors are only due to memory allocation, not debugfs */
220 		if (err < 0)
221 			return err;
222 	}
223 
224 	return 0;
225 }
226 EXPORT_SYMBOL_GPL(snd_sof_dbg_init);
227 
228 void snd_sof_free_debug(struct snd_sof_dev *sdev)
229 {
230 	debugfs_remove_recursive(sdev->debugfs_root);
231 }
232 EXPORT_SYMBOL_GPL(snd_sof_free_debug);
233