Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * mtdram - a test mtd device
3 * Author: Alexander Larsson <alex@cendio.se>
4 *
5 * Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
6 * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
7 *
8 * This code is GPL
9 *
10 */
11
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/ioport.h>
15#include <linux/vmalloc.h>
16#include <linux/init.h>
17#include <linux/mtd/compatmac.h>
18#include <linux/mtd/mtd.h>
19#include <linux/mtd/mtdram.h>
20
21static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
22static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
23#define MTDRAM_TOTAL_SIZE (total_size * 1024)
24#define MTDRAM_ERASE_SIZE (erase_size * 1024)
25
26#ifdef MODULE
27module_param(total_size, ulong, 0);
28MODULE_PARM_DESC(total_size, "Total device size in KiB");
29module_param(erase_size, ulong, 0);
30MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
31#endif
32
33// We could store these in the mtd structure, but we only support 1 device..
34static struct mtd_info *mtd_info;
35
36static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
37{
38 if (instr->addr + instr->len > mtd->size)
39 return -EINVAL;
40
41 memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
42
43 instr->state = MTD_ERASE_DONE;
44 mtd_erase_callback(instr);
45
46 return 0;
47}
48
49static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
50 size_t *retlen, void **virt, resource_size_t *phys)
51{
52 if (from + len > mtd->size)
53 return -EINVAL;
54
55 /* can we return a physical address with this driver? */
56 if (phys)
57 return -EINVAL;
58
59 *virt = mtd->priv + from;
60 *retlen = len;
61 return 0;
62}
63
64static void ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
65{
66}
67
68/*
69 * Allow NOMMU mmap() to directly map the device (if not NULL)
70 * - return the address to which the offset maps
71 * - return -ENOSYS to indicate refusal to do the mapping
72 */
73static unsigned long ram_get_unmapped_area(struct mtd_info *mtd,
74 unsigned long len,
75 unsigned long offset,
76 unsigned long flags)
77{
78 return (unsigned long) mtd->priv + offset;
79}
80
81static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
82 size_t *retlen, u_char *buf)
83{
84 if (from + len > mtd->size)
85 return -EINVAL;
86
87 memcpy(buf, mtd->priv + from, len);
88
89 *retlen = len;
90 return 0;
91}
92
93static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
94 size_t *retlen, const u_char *buf)
95{
96 if (to + len > mtd->size)
97 return -EINVAL;
98
99 memcpy((char *)mtd->priv + to, buf, len);
100
101 *retlen = len;
102 return 0;
103}
104
105static void __exit cleanup_mtdram(void)
106{
107 if (mtd_info) {
108 del_mtd_device(mtd_info);
109 vfree(mtd_info->priv);
110 kfree(mtd_info);
111 }
112}
113
114int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
115 unsigned long size, char *name)
116{
117 memset(mtd, 0, sizeof(*mtd));
118
119 /* Setup the MTD structure */
120 mtd->name = name;
121 mtd->type = MTD_RAM;
122 mtd->flags = MTD_CAP_RAM;
123 mtd->size = size;
124 mtd->writesize = 1;
125 mtd->erasesize = MTDRAM_ERASE_SIZE;
126 mtd->priv = mapped_address;
127
128 mtd->owner = THIS_MODULE;
129 mtd->erase = ram_erase;
130 mtd->point = ram_point;
131 mtd->unpoint = ram_unpoint;
132 mtd->get_unmapped_area = ram_get_unmapped_area;
133 mtd->read = ram_read;
134 mtd->write = ram_write;
135
136 if (add_mtd_device(mtd)) {
137 return -EIO;
138 }
139
140 return 0;
141}
142
143static int __init init_mtdram(void)
144{
145 void *addr;
146 int err;
147
148 if (!total_size)
149 return -EINVAL;
150
151 /* Allocate some memory */
152 mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
153 if (!mtd_info)
154 return -ENOMEM;
155
156 addr = vmalloc(MTDRAM_TOTAL_SIZE);
157 if (!addr) {
158 kfree(mtd_info);
159 mtd_info = NULL;
160 return -ENOMEM;
161 }
162 err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
163 if (err) {
164 vfree(addr);
165 kfree(mtd_info);
166 mtd_info = NULL;
167 return err;
168 }
169 memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
170 return err;
171}
172
173module_init(init_mtdram);
174module_exit(cleanup_mtdram);
175
176MODULE_LICENSE("GPL");
177MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
178MODULE_DESCRIPTION("Simulated MTD driver for testing");