1 2 3 4#include <linux/module.h> 5#include <asm/uaccess.h> 6#include <linux/types.h> 7#include <linux/kernel.h> 8#include <linux/ptrace.h> 9#include <linux/slab.h> 10#include <linux/string.h> 11#include <linux/timer.h> 12#include <linux/major.h> 13#include <linux/fs.h> 14#include <linux/ioctl.h> 15#include <linux/init.h> 16#include <asm/io.h> 17#include <asm/system.h> 18 19#include <linux/mtd/mtd.h> 20 21#define SLRAM_MAX_DEVICES_PARAMS 6 /* 3 parameters / device */ 22#define SLRAM_BLK_SZ 0x4000 23 24#define T(fmt, args...) printk(KERN_DEBUG fmt, ## args) 25#define E(fmt, args...) printk(KERN_NOTICE fmt, ## args) 26 27typedef struct slram_priv { 28 u_char *start; 29 u_char *end; 30} slram_priv_t; 31 32typedef struct slram_mtd_list { 33 struct mtd_info *mtdinfo; 34 struct slram_mtd_list *next; 35} slram_mtd_list_t; 36 37#ifdef MODULE 38static char *map[SLRAM_MAX_DEVICES_PARAMS]; 39 40module_param_array(map, charp, NULL, 0); 41MODULE_PARM_DESC(map, "List of memory regions to map. \"map=<name>, <start>, <length / end>\""); 42#else 43static char *map; 44#endif 45 46static slram_mtd_list_t *slram_mtdlist = NULL; 47 48static int slram_erase(struct mtd_info *, struct erase_info *); 49static int slram_point(struct mtd_info *, loff_t, size_t, size_t *, void **, 50 resource_size_t *); 51static void slram_unpoint(struct mtd_info *, loff_t, size_t); 52static int slram_read(struct mtd_info *, loff_t, size_t, size_t *, u_char *); 53static int slram_write(struct mtd_info *, loff_t, size_t, size_t *, const u_char *); 54 55static int slram_erase(struct mtd_info *mtd, struct erase_info *instr) 56{ 57 slram_priv_t *priv = mtd->priv; 58 59 if (instr->addr + instr->len > mtd->size) { 60 return(-EINVAL); 61 } 62 63 memset(priv->start + instr->addr, 0xff, instr->len); 64 65 /* This'll catch a few races. Free the thing before returning :) 66 * I don't feel at all ashamed. This kind of thing is possible anyway 67 * with flash, but unlikely. 68 */ 69 70 instr->state = MTD_ERASE_DONE; 71 72 mtd_erase_callback(instr); 73 74 return(0); 75} 76 77static int slram_point(struct mtd_info *mtd, loff_t from, size_t len, 78 size_t *retlen, void **virt, resource_size_t *phys) 79{ 80 slram_priv_t *priv = mtd->priv; 81 82 /* can we return a physical address with this driver? */ 83 if (phys) 84 return -EINVAL; 85 86 if (from + len > mtd->size) 87 return -EINVAL; 88 89 *virt = priv->start + from; 90 *retlen = len; 91 return(0); 92} 93 94static void slram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) 95{ 96} 97 98static int slram_read(struct mtd_info *mtd, loff_t from, size_t len, 99 size_t *retlen, u_char *buf) 100{ 101 slram_priv_t *priv = mtd->priv; 102 103 if (from > mtd->size) 104 return -EINVAL; 105 106 if (from + len > mtd->size) 107 len = mtd->size - from; 108 109 memcpy(buf, priv->start + from, len); 110 111 *retlen = len; 112 return(0); 113} 114 115static int slram_write(struct mtd_info *mtd, loff_t to, size_t len, 116 size_t *retlen, const u_char *buf) 117{ 118 slram_priv_t *priv = mtd->priv; 119 120 if (to + len > mtd->size) 121 return -EINVAL; 122 123 memcpy(priv->start + to, buf, len); 124 125 *retlen = len; 126 return(0); 127} 128 129/*====================================================================*/ 130 131static int register_device(char *name, unsigned long start, unsigned long length) 132{ 133 slram_mtd_list_t **curmtd; 134 135 curmtd = &slram_mtdlist; 136 while (*curmtd) { 137 curmtd = &(*curmtd)->next; 138 } 139 140 *curmtd = kmalloc(sizeof(slram_mtd_list_t), GFP_KERNEL); 141 if (!(*curmtd)) { 142 E("slram: Cannot allocate new MTD device.\n"); 143 return(-ENOMEM); 144 } 145 (*curmtd)->mtdinfo = kzalloc(sizeof(struct mtd_info), GFP_KERNEL); 146 (*curmtd)->next = NULL; 147 148 if ((*curmtd)->mtdinfo) { 149 (*curmtd)->mtdinfo->priv = 150 kzalloc(sizeof(slram_priv_t), GFP_KERNEL); 151 152 if (!(*curmtd)->mtdinfo->priv) { 153 kfree((*curmtd)->mtdinfo); 154 (*curmtd)->mtdinfo = NULL; 155 } 156 } 157 158 if (!(*curmtd)->mtdinfo) { 159 E("slram: Cannot allocate new MTD device.\n"); 160 return(-ENOMEM); 161 } 162 163 if (!(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start = 164 ioremap(start, length))) { 165 E("slram: ioremap failed\n"); 166 return -EIO; 167 } 168 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end = 169 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start + length; 170 171 172 (*curmtd)->mtdinfo->name = name; 173 (*curmtd)->mtdinfo->size = length; 174 (*curmtd)->mtdinfo->flags = MTD_CAP_RAM; 175 (*curmtd)->mtdinfo->erase = slram_erase; 176 (*curmtd)->mtdinfo->point = slram_point; 177 (*curmtd)->mtdinfo->unpoint = slram_unpoint; 178 (*curmtd)->mtdinfo->read = slram_read; 179 (*curmtd)->mtdinfo->write = slram_write; 180 (*curmtd)->mtdinfo->owner = THIS_MODULE; 181 (*curmtd)->mtdinfo->type = MTD_RAM; 182 (*curmtd)->mtdinfo->erasesize = SLRAM_BLK_SZ; 183 (*curmtd)->mtdinfo->writesize = 1; 184 185 if (add_mtd_device((*curmtd)->mtdinfo)) { 186 E("slram: Failed to register new device\n"); 187 iounmap(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start); 188 kfree((*curmtd)->mtdinfo->priv); 189 kfree((*curmtd)->mtdinfo); 190 return(-EAGAIN); 191 } 192 T("slram: Registered device %s from %luKiB to %luKiB\n", name, 193 (start / 1024), ((start + length) / 1024)); 194 T("slram: Mapped from 0x%p to 0x%p\n", 195 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start, 196 ((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end); 197 return(0); 198} 199 200static void unregister_devices(void) 201{ 202 slram_mtd_list_t *nextitem; 203 204 while (slram_mtdlist) { 205 nextitem = slram_mtdlist->next; 206 del_mtd_device(slram_mtdlist->mtdinfo); 207 iounmap(((slram_priv_t *)slram_mtdlist->mtdinfo->priv)->start); 208 kfree(slram_mtdlist->mtdinfo->priv); 209 kfree(slram_mtdlist->mtdinfo); 210 kfree(slram_mtdlist); 211 slram_mtdlist = nextitem; 212 } 213} 214 215static unsigned long handle_unit(unsigned long value, char *unit) 216{ 217 if ((*unit == 'M') || (*unit == 'm')) { 218 return(value * 1024 * 1024); 219 } else if ((*unit == 'K') || (*unit == 'k')) { 220 return(value * 1024); 221 } 222 return(value); 223} 224 225static int parse_cmdline(char *devname, char *szstart, char *szlength) 226{ 227 char *buffer; 228 unsigned long devstart; 229 unsigned long devlength; 230 231 if ((!devname) || (!szstart) || (!szlength)) { 232 unregister_devices(); 233 return(-EINVAL); 234 } 235 236 devstart = simple_strtoul(szstart, &buffer, 0); 237 devstart = handle_unit(devstart, buffer); 238 239 if (*(szlength) != '+') { 240 devlength = simple_strtoul(szlength, &buffer, 0); 241 devlength = handle_unit(devlength, buffer) - devstart; 242 if (devlength < devstart) 243 goto err_out; 244 245 devlength -= devstart; 246 } else { 247 devlength = simple_strtoul(szlength + 1, &buffer, 0); 248 devlength = handle_unit(devlength, buffer); 249 } 250 T("slram: devname=%s, devstart=0x%lx, devlength=0x%lx\n", 251 devname, devstart, devlength); 252 if (devlength % SLRAM_BLK_SZ != 0) 253 goto err_out; 254 255 if ((devstart = register_device(devname, devstart, devlength))){ 256 unregister_devices(); 257 return((int)devstart); 258 } 259 return(0); 260 261err_out: 262 E("slram: Illegal length parameter.\n"); 263 return(-EINVAL); 264} 265 266#ifndef MODULE 267 268static int __init mtd_slram_setup(char *str) 269{ 270 map = str; 271 return(1); 272} 273 274__setup("slram=", mtd_slram_setup); 275 276#endif 277 278static int __init init_slram(void) 279{ 280 char *devname; 281 int i; 282 283#ifndef MODULE 284 char *devstart; 285 char *devlength; 286 287 i = 0; 288 289 if (!map) { 290 E("slram: not enough parameters.\n"); 291 return(-EINVAL); 292 } 293 while (map) { 294 devname = devstart = devlength = NULL; 295 296 if (!(devname = strsep(&map, ","))) { 297 E("slram: No devicename specified.\n"); 298 break; 299 } 300 T("slram: devname = %s\n", devname); 301 if ((!map) || (!(devstart = strsep(&map, ",")))) { 302 E("slram: No devicestart specified.\n"); 303 } 304 T("slram: devstart = %s\n", devstart); 305 if ((!map) || (!(devlength = strsep(&map, ",")))) { 306 E("slram: No devicelength / -end specified.\n"); 307 } 308 T("slram: devlength = %s\n", devlength); 309 if (parse_cmdline(devname, devstart, devlength) != 0) { 310 return(-EINVAL); 311 } 312 } 313#else 314 int count; 315 316 for (count = 0; count < SLRAM_MAX_DEVICES_PARAMS && map[count]; 317 count++) { 318 } 319 320 if ((count % 3 != 0) || (count == 0)) { 321 E("slram: not enough parameters.\n"); 322 return(-EINVAL); 323 } 324 for (i = 0; i < (count / 3); i++) { 325 devname = map[i * 3]; 326 327 if (parse_cmdline(devname, map[i * 3 + 1], map[i * 3 + 2])!=0) { 328 return(-EINVAL); 329 } 330 331 } 332#endif /* !MODULE */ 333 334 return(0); 335} 336 337static void __exit cleanup_slram(void) 338{ 339 unregister_devices(); 340} 341 342module_init(init_slram); 343module_exit(cleanup_slram); 344 345MODULE_LICENSE("GPL"); 346MODULE_AUTHOR("Jochen Schaeuble <psionic@psionic.de>"); 347MODULE_DESCRIPTION("MTD driver for uncached system RAM"); 348