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