arch/x86/kernel/cpu/mtrr/if.c

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