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/string.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 size;
 170         struct mtrr_sentry sentry;
 171         struct mtrr_gentry gentry;
 172         void __user *arg = (void __user *) __arg;
 173
 174         switch (cmd) {
 175         case MTRRIOC_ADD_ENTRY:
 176         case MTRRIOC_SET_ENTRY:
 177         case MTRRIOC_DEL_ENTRY:
 178         case MTRRIOC_KILL_ENTRY:
 179         case MTRRIOC_ADD_PAGE_ENTRY:
 180         case MTRRIOC_SET_PAGE_ENTRY:
 181         case MTRRIOC_DEL_PAGE_ENTRY:
 182         case MTRRIOC_KILL_PAGE_ENTRY:
 183                 if (copy_from_user(&sentry, arg, sizeof sentry))
 184                         return -EFAULT;
 185                 break;
 186         case MTRRIOC_GET_ENTRY:
 187         case MTRRIOC_GET_PAGE_ENTRY:
 188                 if (copy_from_user(&gentry, arg, sizeof gentry))
 189                         return -EFAULT;
 190                 break;
 191 #ifdef CONFIG_COMPAT
 192         case MTRRIOC32_ADD_ENTRY:
 193         case MTRRIOC32_SET_ENTRY:
 194         case MTRRIOC32_DEL_ENTRY:
 195         case MTRRIOC32_KILL_ENTRY:
 196         case MTRRIOC32_ADD_PAGE_ENTRY:
 197         case MTRRIOC32_SET_PAGE_ENTRY:
 198         case MTRRIOC32_DEL_PAGE_ENTRY:
 199         case MTRRIOC32_KILL_PAGE_ENTRY: {
 200                 struct mtrr_sentry32 __user *s32;
 201
 202                 s32 = (struct mtrr_sentry32 __user *)__arg;
 203                 err = get_user(sentry.base, &s32->base);
 204                 err |= get_user(sentry.size, &s32->size);
 205                 err |= get_user(sentry.type, &s32->type);
 206                 if (err)
 207                         return err;
 208                 break;
 209         }
 210         case MTRRIOC32_GET_ENTRY:
 211         case MTRRIOC32_GET_PAGE_ENTRY: {
 212                 struct mtrr_gentry32 __user *g32;
 213
 214                 g32 = (struct mtrr_gentry32 __user *)__arg;
 215                 err = get_user(gentry.regnum, &g32->regnum);
 216                 err |= get_user(gentry.base, &g32->base);
 217                 err |= get_user(gentry.size, &g32->size);
 218                 err |= get_user(gentry.type, &g32->type);
 219                 if (err)
 220                         return err;
 221                 break;
 222         }
 223 #endif
 224         }
 225
 226         switch (cmd) {
 227         default:
 228                 return -ENOTTY;
 229         case MTRRIOC_ADD_ENTRY:
 230 #ifdef CONFIG_COMPAT
 231         case MTRRIOC32_ADD_ENTRY:
 232 #endif
 233                 if (!capable(CAP_SYS_ADMIN))
 234                         return -EPERM;
 235                 err =
 236                     mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
 237                                   file, 0);
 238                 break;
 239         case MTRRIOC_SET_ENTRY:
 240 #ifdef CONFIG_COMPAT
 241         case MTRRIOC32_SET_ENTRY:
 242 #endif
 243                 if (!capable(CAP_SYS_ADMIN))
 244                         return -EPERM;
 245                 err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
 246                 break;
 247         case MTRRIOC_DEL_ENTRY:
 248 #ifdef CONFIG_COMPAT
 249         case MTRRIOC32_DEL_ENTRY:
 250 #endif
 251                 if (!capable(CAP_SYS_ADMIN))
 252                         return -EPERM;
 253                 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
 254                 break;
 255         case MTRRIOC_KILL_ENTRY:
 256 #ifdef CONFIG_COMPAT
 257         case MTRRIOC32_KILL_ENTRY:
 258 #endif
 259                 if (!capable(CAP_SYS_ADMIN))
 260                         return -EPERM;
 261                 err = mtrr_del(-1, sentry.base, sentry.size);
 262                 break;
 263         case MTRRIOC_GET_ENTRY:
 264 #ifdef CONFIG_COMPAT
 265         case MTRRIOC32_GET_ENTRY:
 266 #endif
 267                 if (gentry.regnum >= num_var_ranges)
 268                         return -EINVAL;
 269                 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
 270
 271                 /* Hide entries that go above 4GB */
 272                 if (gentry.base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
 273                     || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
 274                         gentry.base = gentry.size = gentry.type = 0;
 275                 else {
 276                         gentry.base <<= PAGE_SHIFT;
 277                         gentry.size = size << PAGE_SHIFT;
 278                         gentry.type = type;
 279                 }
 280
 281                 break;
 282         case MTRRIOC_ADD_PAGE_ENTRY:
 283 #ifdef CONFIG_COMPAT
 284         case MTRRIOC32_ADD_PAGE_ENTRY:
 285 #endif
 286                 if (!capable(CAP_SYS_ADMIN))
 287                         return -EPERM;
 288                 err =
 289                     mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
 290                                   file, 1);
 291                 break;
 292         case MTRRIOC_SET_PAGE_ENTRY:
 293 #ifdef CONFIG_COMPAT
 294         case MTRRIOC32_SET_PAGE_ENTRY:
 295 #endif
 296                 if (!capable(CAP_SYS_ADMIN))
 297                         return -EPERM;
 298                 err =
 299                     mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
 300                 break;
 301         case MTRRIOC_DEL_PAGE_ENTRY:
 302 #ifdef CONFIG_COMPAT
 303         case MTRRIOC32_DEL_PAGE_ENTRY:
 304 #endif
 305                 if (!capable(CAP_SYS_ADMIN))
 306                         return -EPERM;
 307                 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
 308                 break;
 309         case MTRRIOC_KILL_PAGE_ENTRY:
 310 #ifdef CONFIG_COMPAT
 311         case MTRRIOC32_KILL_PAGE_ENTRY:
 312 #endif
 313                 if (!capable(CAP_SYS_ADMIN))
 314                         return -EPERM;
 315                 err = mtrr_del_page(-1, sentry.base, sentry.size);
 316                 break;
 317         case MTRRIOC_GET_PAGE_ENTRY:
 318 #ifdef CONFIG_COMPAT
 319         case MTRRIOC32_GET_PAGE_ENTRY:
 320 #endif
 321                 if (gentry.regnum >= num_var_ranges)
 322                         return -EINVAL;
 323                 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
 324                 /* Hide entries that would overflow */
 325                 if (size != (__typeof__(gentry.size))size)
 326                         gentry.base = gentry.size = gentry.type = 0;
 327                 else {
 328                         gentry.size = size;
 329                         gentry.type = type;
 330                 }
 331                 break;
 332         }
 333
 334         if (err)
 335                 return err;
 336
 337         switch (cmd) {
 338         case MTRRIOC_GET_ENTRY:
 339         case MTRRIOC_GET_PAGE_ENTRY:
 340                 if (copy_to_user(arg, &gentry, sizeof gentry))
 341                         err = -EFAULT;
 342                 break;
 343 #ifdef CONFIG_COMPAT
 344         case MTRRIOC32_GET_ENTRY:
 345         case MTRRIOC32_GET_PAGE_ENTRY: {
 346                 struct mtrr_gentry32 __user *g32;
 347
 348                 g32 = (struct mtrr_gentry32 __user *)__arg;
 349                 err = put_user(gentry.base, &g32->base);
 350                 err |= put_user(gentry.size, &g32->size);
 351                 err |= put_user(gentry.regnum, &g32->regnum);
 352                 err |= put_user(gentry.type, &g32->type);
 353                 break;
 354         }
 355 #endif
 356         }
 357         return err;
 358 }
 359
 360 static int mtrr_close(struct inode *ino, struct file *file)
 361 {
 362         unsigned int *fcount = FILE_FCOUNT(file);
 363         int i, max;
 364
 365         if (fcount != NULL) {
 366                 max = num_var_ranges;
 367                 for (i = 0; i < max; ++i) {
 368                         while (fcount[i] > 0) {
 369                                 mtrr_del(i, 0, 0);
 370                                 --fcount[i];
 371                         }
 372                 }
 373                 kfree(fcount);
 374                 FILE_FCOUNT(file) = NULL;
 375         }
 376         return single_release(ino, file);
 377 }
 378
 379 static int mtrr_seq_show(struct seq_file *seq, void *offset);
 380
 381 static int mtrr_open(struct inode *inode, struct file *file)
 382 {
 383         if (!mtrr_if)
 384                 return -EIO;
 385         if (!mtrr_if->get)
 386                 return -ENXIO;
 387         return single_open(file, mtrr_seq_show, NULL);
 388 }
 389
 390 static const struct file_operations mtrr_fops = {
 391         .owner                  = THIS_MODULE,
 392         .open                   = mtrr_open,
 393         .read                   = seq_read,
 394         .llseek                 = seq_lseek,
 395         .write                  = mtrr_write,
 396         .unlocked_ioctl         = mtrr_ioctl,
 397         .compat_ioctl           = mtrr_ioctl,
 398         .release                = mtrr_close,
 399 };
 400
 401 static int mtrr_seq_show(struct seq_file *seq, void *offset)
 402 {
 403         char factor;
 404         int i, max, len;
 405         mtrr_type type;
 406         unsigned long base, size;
 407
 408         len = 0;
 409         max = num_var_ranges;
 410         for (i = 0; i < max; i++) {
 411                 mtrr_if->get(i, &base, &size, &type);
 412                 if (size == 0) {
 413                         mtrr_usage_table[i] = 0;
 414                         continue;
 415                 }
 416                 if (size < (0x100000 >> PAGE_SHIFT)) {
 417                         /* less than 1MB */
 418                         factor = 'K';
 419                         size <<= PAGE_SHIFT - 10;
 420                 } else {
 421                         factor = 'M';
 422                         size >>= 20 - PAGE_SHIFT;
 423                 }
 424                 /* Base can be > 32bit */
 425                 len += seq_printf(seq, "reg%02i: base=0x%06lx000 "
 426                         "(%5luMB), size=%5lu%cB, count=%d: %s\n",
 427                         i, base, base >> (20 - PAGE_SHIFT), size,
 428                         factor, mtrr_usage_table[i],
 429                         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  */