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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/**
David Woodhouse151e7652006-05-14 01:51:54 +01002 * Copyright (c) ???? Jochen Schäuble <psionic@psionic.de>
Joern Engel2b54aae2008-02-06 01:38:02 -08003 * Copyright (c) 2003-2004 Joern Engel <joern@wh.fh-wedel.de>
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * Usage:
6 *
7 * one commend line parameter per device, each in the form:
8 * phram=<name>,<start>,<len>
9 * <name> may be up to 63 characters.
10 * <start> and <len> can be octal, decimal or hexadecimal. If followed
11 * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
12 * gigabytes.
13 *
14 * Example:
15 * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 */
Mike Frysinger64da3922009-06-16 19:20:40 +000017
Joe Perches1cd844f2010-10-20 10:39:22 -070018#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
Mike Frysinger64da3922009-06-16 19:20:40 +000019
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/io.h>
21#include <linux/init.h>
22#include <linux/kernel.h>
23#include <linux/list.h>
24#include <linux/module.h>
25#include <linux/moduleparam.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080026#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/mtd/mtd.h>
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029struct phram_mtd_list {
30 struct mtd_info mtd;
31 struct list_head list;
32};
33
34static LIST_HEAD(phram_list);
35
Linus Torvalds1da177e2005-04-16 15:20:36 -070036static int phram_erase(struct mtd_info *mtd, struct erase_info *instr)
37{
38 u_char *start = mtd->priv;
39
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 memset(start + instr->addr, 0xff, instr->len);
41
Hervé Facheb2a2a842012-03-13 16:07:53 +010042 /*
43 * This'll catch a few races. Free the thing before returning :)
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 * I don't feel at all ashamed. This kind of thing is possible anyway
45 * with flash, but unlikely.
46 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 instr->state = MTD_ERASE_DONE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 mtd_erase_callback(instr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 return 0;
50}
51
52static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
Jared Hulberta98889f2008-04-29 23:26:49 -070053 size_t *retlen, void **virt, resource_size_t *phys)
Linus Torvalds1da177e2005-04-16 15:20:36 -070054{
Jared Hulberta98889f2008-04-29 23:26:49 -070055 *virt = mtd->priv + from;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 *retlen = len;
57 return 0;
58}
59
Artem Bityutskiy5e4e6e32012-02-03 13:20:43 +020060static int phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070061{
Artem Bityutskiy5e4e6e32012-02-03 13:20:43 +020062 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063}
64
65static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
66 size_t *retlen, u_char *buf)
67{
68 u_char *start = mtd->priv;
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 memcpy(buf, start + from, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 *retlen = len;
72 return 0;
73}
74
75static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
76 size_t *retlen, const u_char *buf)
77{
78 u_char *start = mtd->priv;
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 memcpy(start + to, buf, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 *retlen = len;
82 return 0;
83}
84
Linus Torvalds1da177e2005-04-16 15:20:36 -070085static void unregister_devices(void)
86{
Joern Engeld30f11d2005-02-23 19:37:11 +000087 struct phram_mtd_list *this, *safe;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
Joern Engeld30f11d2005-02-23 19:37:11 +000089 list_for_each_entry_safe(this, safe, &phram_list, list) {
Jamie Ilesee0e87b2011-05-23 10:23:40 +010090 mtd_device_unregister(&this->mtd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 iounmap(this->mtd.priv);
Mathias Krausef17f12c2011-01-30 10:31:48 +010092 kfree(this->mtd.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 kfree(this);
94 }
95}
96
97static int register_device(char *name, unsigned long start, unsigned long len)
98{
99 struct phram_mtd_list *new;
100 int ret = -ENOMEM;
101
Burman Yan95b93a02006-11-15 21:10:29 +0200102 new = kzalloc(sizeof(*new), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 if (!new)
104 goto out0;
105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 ret = -EIO;
107 new->mtd.priv = ioremap(start, len);
108 if (!new->mtd.priv) {
Mike Frysinger64da3922009-06-16 19:20:40 +0000109 pr_err("ioremap failed\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 goto out1;
111 }
112
113
114 new->mtd.name = name;
115 new->mtd.size = len;
Jörn Engela6c591e2006-04-13 18:54:34 +0200116 new->mtd.flags = MTD_CAP_RAM;
Artem Bityutskiy3c3c10b2012-01-30 14:58:32 +0200117 new->mtd._erase = phram_erase;
118 new->mtd._point = phram_point;
119 new->mtd._unpoint = phram_unpoint;
120 new->mtd._read = phram_read;
121 new->mtd._write = phram_write;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 new->mtd.owner = THIS_MODULE;
David Woodhouse21c8db92006-06-14 21:39:48 +0100123 new->mtd.type = MTD_RAM;
Joern Engel663259a2005-03-07 21:43:42 +0000124 new->mtd.erasesize = PAGE_SIZE;
Artem B. Bityutskiy17ffc7b2006-06-22 18:15:48 +0400125 new->mtd.writesize = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127 ret = -EAGAIN;
Jamie Ilesee0e87b2011-05-23 10:23:40 +0100128 if (mtd_device_register(&new->mtd, NULL, 0)) {
Mike Frysinger64da3922009-06-16 19:20:40 +0000129 pr_err("Failed to register new device\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 goto out2;
131 }
132
133 list_add_tail(&new->list, &phram_list);
Thomas Gleixnere5580fb2005-11-07 11:15:40 +0000134 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
136out2:
137 iounmap(new->mtd.priv);
138out1:
139 kfree(new);
140out0:
141 return ret;
142}
143
144static int ustrtoul(const char *cp, char **endp, unsigned int base)
145{
146 unsigned long result = simple_strtoul(cp, endp, base);
147
148 switch (**endp) {
149 case 'G':
150 result *= 1024;
151 case 'M':
152 result *= 1024;
153 case 'k':
154 result *= 1024;
155 /* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
156 if ((*endp)[1] == 'i')
157 (*endp) += 2;
158 }
159 return result;
160}
161
162static int parse_num32(uint32_t *num32, const char *token)
163{
164 char *endp;
165 unsigned long n;
166
167 n = ustrtoul(token, &endp, 0);
168 if (*endp)
169 return -EINVAL;
170
171 *num32 = n;
172 return 0;
173}
174
175static int parse_name(char **pname, const char *token)
176{
177 size_t len;
178 char *name;
179
180 len = strlen(token) + 1;
181 if (len > 64)
182 return -ENOSPC;
183
184 name = kmalloc(len, GFP_KERNEL);
185 if (!name)
186 return -ENOMEM;
187
188 strcpy(name, token);
189
190 *pname = name;
191 return 0;
192}
193
Joern Engel663259a2005-03-07 21:43:42 +0000194
195static inline void kill_final_newline(char *str)
196{
197 char *newline = strrchr(str, '\n');
198 if (newline && !newline[1])
199 *newline = 0;
200}
201
202
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203#define parse_err(fmt, args...) do { \
Mike Frysinger64da3922009-06-16 19:20:40 +0000204 pr_err(fmt , ## args); \
205 return 1; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206} while (0)
207
Hervé Facheb2a2a842012-03-13 16:07:53 +0100208/*
209 * This shall contain the module parameter if any. It is of the form:
210 * - phram=<device>,<address>,<size> for module case
211 * - phram.phram=<device>,<address>,<size> for built-in case
212 * We leave 64 bytes for the device name, 12 for the address and 12 for the
213 * size.
214 * Example: phram.phram=rootfs,0xa0000000,512Mi
215 */
216static __initdata char phram_paramline[64+12+12];
217
Ryosuke Saitob11ec572012-03-21 18:47:47 +0900218static int __init phram_setup(const char *val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219{
220 char buf[64+12+12], *str = buf;
221 char *token[3];
222 char *name;
223 uint32_t start;
224 uint32_t len;
225 int i, ret;
226
227 if (strnlen(val, sizeof(buf)) >= sizeof(buf))
228 parse_err("parameter too long\n");
229
230 strcpy(str, val);
Joern Engel663259a2005-03-07 21:43:42 +0000231 kill_final_newline(str);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
233 for (i=0; i<3; i++)
234 token[i] = strsep(&str, ",");
235
236 if (str)
237 parse_err("too many arguments\n");
238
239 if (!token[2])
240 parse_err("not enough arguments\n");
241
242 ret = parse_name(&name, token[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 if (ret)
Mike Frysinger64da3922009-06-16 19:20:40 +0000244 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
246 ret = parse_num32(&start, token[1]);
Jesper Juhl4f678a52006-05-14 01:07:18 +0200247 if (ret) {
248 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 parse_err("illegal start address\n");
Jesper Juhl4f678a52006-05-14 01:07:18 +0200250 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 ret = parse_num32(&len, token[2]);
Jesper Juhl4f678a52006-05-14 01:07:18 +0200253 if (ret) {
254 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 parse_err("illegal device length\n");
Jesper Juhl4f678a52006-05-14 01:07:18 +0200256 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Mike Frysinger64da3922009-06-16 19:20:40 +0000258 ret = register_device(name, start, len);
259 if (!ret)
260 pr_info("%s device: %#x at %#x\n", name, len, start);
Mathias Krausef17f12c2011-01-30 10:31:48 +0100261 else
262 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
Mike Frysinger64da3922009-06-16 19:20:40 +0000264 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
Hervé Facheb2a2a842012-03-13 16:07:53 +0100267static int __init phram_param_call(const char *val, struct kernel_param *kp)
268{
269 /*
270 * This function is always called before 'init_phram()', whether
271 * built-in or module.
272 */
273 if (strlen(val) >= sizeof(phram_paramline))
274 return -ENOSPC;
275 strcpy(phram_paramline, val);
276
277 return 0;
278}
279
280module_param_call(phram, phram_param_call, NULL, NULL, 000);
Mark Hindleyf72561cf2008-03-31 14:25:03 +0100281MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>\"");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
283
284static int __init init_phram(void)
285{
Hervé Facheb2a2a842012-03-13 16:07:53 +0100286 if (phram_paramline[0])
287 return phram_setup(phram_paramline);
288
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 return 0;
290}
291
292static void __exit cleanup_phram(void)
293{
294 unregister_devices();
295}
296
297module_init(init_phram);
298module_exit(cleanup_phram);
299
300MODULE_LICENSE("GPL");
Joern Engel2b54aae2008-02-06 01:38:02 -0800301MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302MODULE_DESCRIPTION("MTD driver for physical RAM");