1 #include <linux/capability.h> 2 #include <linux/seq_file.h> 3 #include <linux/uaccess.h> 4 #include <linux/proc_fs.h> 5 #include <linux/ctype.h> 6 #include <linux/string.h> 7 #include <linux/slab.h> 8 #include <linux/init.h> 9 10 #define LINE_SIZE 80 11 12 #include <asm/mtrr.h> 13 14 #include "mtrr.h" 15 16 #define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private) 17 18 static const char *const mtrr_strings[MTRR_NUM_TYPES] = 19 { 20 "uncachable", /* 0 */ 21 "write-combining", /* 1 */ 22 "?", /* 2 */ 23 "?", /* 3 */ 24 "write-through", /* 4 */ 25 "write-protect", /* 5 */ 26 "write-back", /* 6 */ 27 }; 28 29 const char *mtrr_attrib_to_str(int x) 30 { 31 return (x <= 6) ? mtrr_strings[x] : "?"; 32 } 33 34 #ifdef CONFIG_PROC_FS 35 36 static int 37 mtrr_file_add(unsigned long base, unsigned long size, 38 unsigned int type, bool increment, struct file *file, int page) 39 { 40 unsigned int *fcount = FILE_FCOUNT(file); 41 int reg, max; 42 43 max = num_var_ranges; 44 if (fcount == NULL) { 45 fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL); 46 if (!fcount) 47 return -ENOMEM; 48 FILE_FCOUNT(file) = fcount; 49 } 50 if (!page) { 51 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1))) 52 return -EINVAL; 53 base >>= PAGE_SHIFT; 54 size >>= PAGE_SHIFT; 55 } 56 reg = mtrr_add_page(base, size, type, true); 57 if (reg >= 0) 58 ++fcount[reg]; 59 return reg; 60 } 61 62 static int 63 mtrr_file_del(unsigned long base, unsigned long size, 64 struct file *file, int page) 65 { 66 unsigned int *fcount = FILE_FCOUNT(file); 67 int reg; 68 69 if (!page) { 70 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1))) 71 return -EINVAL; 72 base >>= PAGE_SHIFT; 73 size >>= PAGE_SHIFT; 74 } 75 reg = mtrr_del_page(-1, base, size); 76 if (reg < 0) 77 return reg; 78 if (fcount == NULL) 79 return reg; 80 if (fcount[reg] < 1) 81 return -EINVAL; 82 --fcount[reg]; 83 return reg; 84 } 85 86 /* 87 * seq_file can seek but we ignore it. 88 * 89 * Format of control line: 90 * "base=%Lx size=%Lx type=%s" or "disable=%d" 91 */ 92 static ssize_t 93 mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos) 94 { 95 int i, err; 96 unsigned long reg; 97 unsigned long long base, size; 98 char *ptr; 99 char line[LINE_SIZE]; 100 int length; 101 size_t linelen; 102 103 if (!capable(CAP_SYS_ADMIN)) 104 return -EPERM; 105 106 memset(line, 0, LINE_SIZE); 107 108 length = len; 109 length--; 110 111 if (length > LINE_SIZE - 1) 112 length = LINE_SIZE - 1; 113 114 if (length < 0) 115 return -EINVAL; 116 117 if (copy_from_user(line, buf, length)) 118 return -EFAULT; 119 120 linelen = strlen(line); 121 ptr = line + linelen - 1; 122 if (linelen && *ptr == '\n') 123 *ptr = '\0'; 124 125 if (!strncmp(line, "disable=", 8)) { 126 reg = simple_strtoul(line + 8, &ptr, 0); 127 err = mtrr_del_page(reg, 0, 0); 128 if (err < 0) 129 return err; 130 return len; 131 } 132 133 if (strncmp(line, "base=", 5)) 134 return -EINVAL; 135 136 base = simple_strtoull(line + 5, &ptr, 0); 137 ptr = skip_spaces(ptr); 138 139 if (strncmp(ptr, "size=", 5)) 140 return -EINVAL; 141 142 size = simple_strtoull(ptr + 5, &ptr, 0); 143 if ((base & 0xfff) || (size & 0xfff)) 144 return -EINVAL; 145 ptr = skip_spaces(ptr); 146 147 if (strncmp(ptr, "type=", 5)) 148 return -EINVAL; 149 ptr = skip_spaces(ptr + 5); 150 151 for (i = 0; i < MTRR_NUM_TYPES; ++i) { 152 if (strcmp(ptr, mtrr_strings[i])) 153 continue; 154 base >>= PAGE_SHIFT; 155 size >>= PAGE_SHIFT; 156 err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true); 157 if (err < 0) 158 return err; 159 return len; 160 } 161 return -EINVAL; 162 } 163 164 static long 165 mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg) 166 { 167 int err = 0; 168 mtrr_type type; 169 unsigned long base; 170 unsigned long size; 171 struct mtrr_sentry sentry; 172 struct mtrr_gentry gentry; 173 void __user *arg = (void __user *) __arg; 174 175 switch (cmd) { 176 case MTRRIOC_ADD_ENTRY: 177 case MTRRIOC_SET_ENTRY: 178 case MTRRIOC_DEL_ENTRY: 179 case MTRRIOC_KILL_ENTRY: 180 case MTRRIOC_ADD_PAGE_ENTRY: 181 case MTRRIOC_SET_PAGE_ENTRY: 182 case MTRRIOC_DEL_PAGE_ENTRY: 183 case MTRRIOC_KILL_PAGE_ENTRY: 184 if (copy_from_user(&sentry, arg, sizeof sentry)) 185 return -EFAULT; 186 break; 187 case MTRRIOC_GET_ENTRY: 188 case MTRRIOC_GET_PAGE_ENTRY: 189 if (copy_from_user(&gentry, arg, sizeof gentry)) 190 return -EFAULT; 191 break; 192 #ifdef CONFIG_COMPAT 193 case MTRRIOC32_ADD_ENTRY: 194 case MTRRIOC32_SET_ENTRY: 195 case MTRRIOC32_DEL_ENTRY: 196 case MTRRIOC32_KILL_ENTRY: 197 case MTRRIOC32_ADD_PAGE_ENTRY: 198 case MTRRIOC32_SET_PAGE_ENTRY: 199 case MTRRIOC32_DEL_PAGE_ENTRY: 200 case MTRRIOC32_KILL_PAGE_ENTRY: { 201 struct mtrr_sentry32 __user *s32; 202 203 s32 = (struct mtrr_sentry32 __user *)__arg; 204 err = get_user(sentry.base, &s32->base); 205 err |= get_user(sentry.size, &s32->size); 206 err |= get_user(sentry.type, &s32->type); 207 if (err) 208 return err; 209 break; 210 } 211 case MTRRIOC32_GET_ENTRY: 212 case MTRRIOC32_GET_PAGE_ENTRY: { 213 struct mtrr_gentry32 __user *g32; 214 215 g32 = (struct mtrr_gentry32 __user *)__arg; 216 err = get_user(gentry.regnum, &g32->regnum); 217 err |= get_user(gentry.base, &g32->base); 218 err |= get_user(gentry.size, &g32->size); 219 err |= get_user(gentry.type, &g32->type); 220 if (err) 221 return err; 222 break; 223 } 224 #endif 225 } 226 227 switch (cmd) { 228 default: 229 return -ENOTTY; 230 case MTRRIOC_ADD_ENTRY: 231 #ifdef CONFIG_COMPAT 232 case MTRRIOC32_ADD_ENTRY: 233 #endif 234 if (!capable(CAP_SYS_ADMIN)) 235 return -EPERM; 236 err = 237 mtrr_file_add(sentry.base, sentry.size, sentry.type, true, 238 file, 0); 239 break; 240 case MTRRIOC_SET_ENTRY: 241 #ifdef CONFIG_COMPAT 242 case MTRRIOC32_SET_ENTRY: 243 #endif 244 if (!capable(CAP_SYS_ADMIN)) 245 return -EPERM; 246 err = mtrr_add(sentry.base, sentry.size, sentry.type, false); 247 break; 248 case MTRRIOC_DEL_ENTRY: 249 #ifdef CONFIG_COMPAT 250 case MTRRIOC32_DEL_ENTRY: 251 #endif 252 if (!capable(CAP_SYS_ADMIN)) 253 return -EPERM; 254 err = mtrr_file_del(sentry.base, sentry.size, file, 0); 255 break; 256 case MTRRIOC_KILL_ENTRY: 257 #ifdef CONFIG_COMPAT 258 case MTRRIOC32_KILL_ENTRY: 259 #endif 260 if (!capable(CAP_SYS_ADMIN)) 261 return -EPERM; 262 err = mtrr_del(-1, sentry.base, sentry.size); 263 break; 264 case MTRRIOC_GET_ENTRY: 265 #ifdef CONFIG_COMPAT 266 case MTRRIOC32_GET_ENTRY: 267 #endif 268 if (gentry.regnum >= num_var_ranges) 269 return -EINVAL; 270 mtrr_if->get(gentry.regnum, &base, &size, &type); 271 272 /* Hide entries that go above 4GB */ 273 if (base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)) 274 || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))) 275 gentry.base = gentry.size = gentry.type = 0; 276 else { 277 gentry.base = base << PAGE_SHIFT; 278 gentry.size = size << PAGE_SHIFT; 279 gentry.type = type; 280 } 281 282 break; 283 case MTRRIOC_ADD_PAGE_ENTRY: 284 #ifdef CONFIG_COMPAT 285 case MTRRIOC32_ADD_PAGE_ENTRY: 286 #endif 287 if (!capable(CAP_SYS_ADMIN)) 288 return -EPERM; 289 err = 290 mtrr_file_add(sentry.base, sentry.size, sentry.type, true, 291 file, 1); 292 break; 293 case MTRRIOC_SET_PAGE_ENTRY: 294 #ifdef CONFIG_COMPAT 295 case MTRRIOC32_SET_PAGE_ENTRY: 296 #endif 297 if (!capable(CAP_SYS_ADMIN)) 298 return -EPERM; 299 err = 300 mtrr_add_page(sentry.base, sentry.size, sentry.type, false); 301 break; 302 case MTRRIOC_DEL_PAGE_ENTRY: 303 #ifdef CONFIG_COMPAT 304 case MTRRIOC32_DEL_PAGE_ENTRY: 305 #endif 306 if (!capable(CAP_SYS_ADMIN)) 307 return -EPERM; 308 err = mtrr_file_del(sentry.base, sentry.size, file, 1); 309 break; 310 case MTRRIOC_KILL_PAGE_ENTRY: 311 #ifdef CONFIG_COMPAT 312 case MTRRIOC32_KILL_PAGE_ENTRY: 313 #endif 314 if (!capable(CAP_SYS_ADMIN)) 315 return -EPERM; 316 err = mtrr_del_page(-1, sentry.base, sentry.size); 317 break; 318 case MTRRIOC_GET_PAGE_ENTRY: 319 #ifdef CONFIG_COMPAT 320 case MTRRIOC32_GET_PAGE_ENTRY: 321 #endif 322 if (gentry.regnum >= num_var_ranges) 323 return -EINVAL; 324 mtrr_if->get(gentry.regnum, &base, &size, &type); 325 /* Hide entries that would overflow */ 326 if (size != (__typeof__(gentry.size))size) 327 gentry.base = gentry.size = gentry.type = 0; 328 else { 329 gentry.base = base; 330 gentry.size = size; 331 gentry.type = type; 332 } 333 break; 334 } 335 336 if (err) 337 return err; 338 339 switch (cmd) { 340 case MTRRIOC_GET_ENTRY: 341 case MTRRIOC_GET_PAGE_ENTRY: 342 if (copy_to_user(arg, &gentry, sizeof gentry)) 343 err = -EFAULT; 344 break; 345 #ifdef CONFIG_COMPAT 346 case MTRRIOC32_GET_ENTRY: 347 case MTRRIOC32_GET_PAGE_ENTRY: { 348 struct mtrr_gentry32 __user *g32; 349 350 g32 = (struct mtrr_gentry32 __user *)__arg; 351 err = put_user(gentry.base, &g32->base); 352 err |= put_user(gentry.size, &g32->size); 353 err |= put_user(gentry.regnum, &g32->regnum); 354 err |= put_user(gentry.type, &g32->type); 355 break; 356 } 357 #endif 358 } 359 return err; 360 } 361 362 static int mtrr_close(struct inode *ino, struct file *file) 363 { 364 unsigned int *fcount = FILE_FCOUNT(file); 365 int i, max; 366 367 if (fcount != NULL) { 368 max = num_var_ranges; 369 for (i = 0; i < max; ++i) { 370 while (fcount[i] > 0) { 371 mtrr_del(i, 0, 0); 372 --fcount[i]; 373 } 374 } 375 kfree(fcount); 376 FILE_FCOUNT(file) = NULL; 377 } 378 return single_release(ino, file); 379 } 380 381 static int mtrr_seq_show(struct seq_file *seq, void *offset); 382 383 static int mtrr_open(struct inode *inode, struct file *file) 384 { 385 if (!mtrr_if) 386 return -EIO; 387 if (!mtrr_if->get) 388 return -ENXIO; 389 return single_open(file, mtrr_seq_show, NULL); 390 } 391 392 static const struct file_operations mtrr_fops = { 393 .owner = THIS_MODULE, 394 .open = mtrr_open, 395 .read = seq_read, 396 .llseek = seq_lseek, 397 .write = mtrr_write, 398 .unlocked_ioctl = mtrr_ioctl, 399 .compat_ioctl = mtrr_ioctl, 400 .release = mtrr_close, 401 }; 402 403 static int mtrr_seq_show(struct seq_file *seq, void *offset) 404 { 405 char factor; 406 int i, max; 407 mtrr_type type; 408 unsigned long base, size; 409 410 max = num_var_ranges; 411 for (i = 0; i < max; i++) { 412 mtrr_if->get(i, &base, &size, &type); 413 if (size == 0) { 414 mtrr_usage_table[i] = 0; 415 continue; 416 } 417 if (size < (0x100000 >> PAGE_SHIFT)) { 418 /* less than 1MB */ 419 factor = 'K'; 420 size <<= PAGE_SHIFT - 10; 421 } else { 422 factor = 'M'; 423 size >>= 20 - PAGE_SHIFT; 424 } 425 /* Base can be > 32bit */ 426 seq_printf(seq, "reg%02i: base=0x%06lx000 (%5luMB), size=%5lu%cB, count=%d: %s\n", 427 i, base, base >> (20 - PAGE_SHIFT), 428 size, factor, 429 mtrr_usage_table[i], mtrr_attrib_to_str(type)); 430 } 431 return 0; 432 } 433 434 static int __init mtrr_if_init(void) 435 { 436 struct cpuinfo_x86 *c = &boot_cpu_data; 437 438 if ((!cpu_has(c, X86_FEATURE_MTRR)) && 439 (!cpu_has(c, X86_FEATURE_K6_MTRR)) && 440 (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) && 441 (!cpu_has(c, X86_FEATURE_CENTAUR_MCR))) 442 return -ENODEV; 443 444 proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops); 445 return 0; 446 } 447 arch_initcall(mtrr_if_init); 448 #endif /* CONFIG_PROC_FS */ 449