1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * CMA DebugFS Interface
4 *
5 * Copyright (c) 2015 Sasha Levin <sasha.levin@oracle.com>
6 *
7 * Copyright (C) 2022 Rockchip Electronics Co. Ltd.
8 *
9 */
10
11 #include <linux/debugfs.h>
12 #include <linux/fs.h>
13 #include <linux/seq_file.h>
14 #include <linux/cma.h>
15 #include <linux/list.h>
16 #include <linux/kernel.h>
17 #include <linux/slab.h>
18 #include <linux/mm_types.h>
19
20 #include "cma.h"
21
22 static size_t
u32_format_array_hex(char * buf,size_t bufsize,u32 * array,int array_size)23 u32_format_array_hex(char *buf, size_t bufsize, u32 *array, int array_size)
24 {
25 int i = 0;
26
27 while (--array_size >= 0) {
28 size_t len;
29 char term = (array_size && (++i % 8)) ? ' ' : '\n';
30
31 len = snprintf(buf, bufsize, "%08X%c", *array++, term);
32 buf += len;
33 bufsize -= len;
34 }
35
36 return 0;
37 }
38
u32_array_open_hex(struct inode * inode,struct file * file)39 static int u32_array_open_hex(struct inode *inode, struct file *file)
40 {
41 struct debugfs_u32_array *data = inode->i_private;
42 int size, elements = data->n_elements;
43 char *buf;
44
45 /*
46 * Max size:
47 * - 8 digits + ' '/'\n' = 9 bytes per number
48 * - terminating NUL character
49 */
50 size = elements * 9;
51 buf = kmalloc(size + 1, GFP_KERNEL);
52 if (!buf)
53 return -ENOMEM;
54
55 buf[size] = 0;
56
57 file->private_data = buf;
58 u32_format_array_hex(buf, size + 1, data->array, data->n_elements);
59
60 return nonseekable_open(inode, file);
61 }
62
63 static ssize_t
u32_array_read(struct file * file,char __user * buf,size_t len,loff_t * ppos)64 u32_array_read(struct file *file, char __user *buf, size_t len, loff_t *ppos)
65 {
66 size_t size = strlen(file->private_data);
67
68 return simple_read_from_buffer(buf, len, ppos,
69 file->private_data, size);
70 }
71
u32_array_release(struct inode * inode,struct file * file)72 static int u32_array_release(struct inode *inode, struct file *file)
73 {
74 kfree(file->private_data);
75
76 return 0;
77 }
78
79 static const struct file_operations u32_array_hex_fops = {
80 .owner = THIS_MODULE,
81 .open = u32_array_open_hex,
82 .release = u32_array_release,
83 .read = u32_array_read,
84 .llseek = no_llseek,
85 };
86
debugfs_create_u32_array_hex(const char * name,umode_t mode,struct dentry * parent,struct debugfs_u32_array * array)87 static void debugfs_create_u32_array_hex(const char *name, umode_t mode,
88 struct dentry *parent,
89 struct debugfs_u32_array *array)
90 {
91 debugfs_create_file_unsafe(name, mode, parent, array, &u32_array_hex_fops);
92 }
93
cma_debugfs_add_one(struct cma * cma,struct dentry * root_dentry)94 static int cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry)
95 {
96 struct dentry *tmp;
97 char name[16];
98
99 scnprintf(name, sizeof(name), "cma-%s", cma->name);
100
101 tmp = debugfs_lookup(name, root_dentry);
102 if (!tmp)
103 return -EPROBE_DEFER;
104
105 debugfs_create_u32_array_hex("bitmap_hex", 0444, tmp, &cma->dfs_bitmap);
106
107 return 0;
108 }
109
rk_cma_debugfs_init(void)110 static int __init rk_cma_debugfs_init(void)
111 {
112 struct dentry *cma_debugfs_root;
113 int ret;
114 int i;
115
116 cma_debugfs_root = debugfs_lookup("cma", NULL);
117 if (!cma_debugfs_root)
118 return -EPROBE_DEFER;
119
120 for (i = 0; i < cma_area_count; i++) {
121 ret = cma_debugfs_add_one(&cma_areas[i], cma_debugfs_root);
122 if (ret)
123 return ret;
124 }
125
126 return 0;
127 }
128 late_initcall(rk_cma_debugfs_init);
129