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

   1 #include <linux/init.h>
   2 #include <linux/proc_fs.h>
   3 #include <linux/capability.h>
   4 #include <linux/ctype.h>
   5 #include <linux/module.h>
   6 #include <linux/seq_file.h>
   7 #include <asm/uaccess.h>
   8
   9 #define LINE_SIZE 80
  10
  11 #include <asm/mtrr.h>
  12 #include "mtrr.h"
  13
  14 #define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
  15
  16 static const char *const mtrr_strings[MTRR_NUM_TYPES] =
  17 {
  18     "uncachable",               /* 0 */
  19     "write-combining",          /* 1 */
  20     "?",                        /* 2 */
  21     "?",                        /* 3 */
  22     "write-through",            /* 4 */
  23     "write-protect",            /* 5 */
  24     "write-back",               /* 6 */
  25 };
  26
  27 const char *mtrr_attrib_to_str(int x)
  28 {
  29         return (x <= 6) ? mtrr_strings[x] : "?";
  30 }
  31
  32 #ifdef CONFIG_PROC_FS
  33
  34 static int
  35 mtrr_file_add(unsigned long base, unsigned long size,
  36               unsigned int type, bool increment, struct file *file, int page)
  37 {
  38         int reg, max;
  39         unsigned int *fcount = FILE_FCOUNT(file);
  40
  41         max = num_var_ranges;
  42         if (fcount == NULL) {
  43                 fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
  44                 if (!fcount)
  45                         return -ENOMEM;
  46                 FILE_FCOUNT(file) = fcount;
  47         }
  48         if (!page) {
  49                 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
  50                         return -EINVAL;
  51                 base >>= PAGE_SHIFT;
  52                 size >>= PAGE_SHIFT;
  53         }
  54         reg = mtrr_add_page(base, size, type, true);
  55         if (reg >= 0)
  56                 ++fcount[reg];
  57         return reg;
  58 }
  59
  60 static int
  61 mtrr_file_del(unsigned long base, unsigned long size,
  62               struct file *file, int page)
  63 {
  64         int reg;
  65         unsigned int *fcount = FILE_FCOUNT(file);
  66
  67         if (!page) {
  68                 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
  69                         return -EINVAL;
  70                 base >>= PAGE_SHIFT;
  71                 size >>= PAGE_SHIFT;
  72         }
  73         reg = mtrr_del_page(-1, base, size);
  74         if (reg < 0)
  75                 return reg;
  76         if (fcount == NULL)
  77                 return reg;
  78         if (fcount[reg] < 1)
  79                 return -EINVAL;
  80         --fcount[reg];
  81         return reg;
  82 }
  83
  84 /* RED-PEN: seq_file can seek now. this is ignored. */
  85 static ssize_t
  86 mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
  87 /*  Format of control line:
  88     "base=%Lx size=%Lx type=%s"     OR:
  89     "disable=%d"
  90 */
  91 {
  92         int i, err;
  93         unsigned long reg;
  94         unsigned long long base, size;
  95         char *ptr;
  96         char line[LINE_SIZE];
  97         size_t linelen;
  98
  99         if (!capable(CAP_SYS_ADMIN))
 100                 return -EPERM;
 101         if (!len)
 102                 return -EINVAL;
 103         memset(line, 0, LINE_SIZE);
 104         if (len > LINE_SIZE)
 105                 len = LINE_SIZE;
 106         if (copy_from_user(line, buf, len - 1))
 107                 return -EFAULT;
 108         linelen = strlen(line);
 109         ptr = line + linelen - 1;
 110         if (linelen && *ptr == '\n')
 111                 *ptr = '\0';
 112         if (!strncmp(line, "disable=", 8)) {
 113                 reg = simple_strtoul(line + 8, &ptr, 0);
 114                 err = mtrr_del_page(reg, 0, 0);
 115                 if (err < 0)
 116                         return err;
 117                 return len;
 118         }
 119         if (strncmp(line, "base=", 5))
 120                 return -EINVAL;
 121         base = simple_strtoull(line + 5, &ptr, 0);
 122         for (; isspace(*ptr); ++ptr) ;
 123         if (strncmp(ptr, "size=", 5))
 124                 return -EINVAL;
 125         size = simple_strtoull(ptr + 5, &ptr, 0);
 126         if ((base & 0xfff) || (size & 0xfff))
 127                 return -EINVAL;
 128         for (; isspace(*ptr); ++ptr) ;
 129         if (strncmp(ptr, "type=", 5))
 130                 return -EINVAL;
 131         ptr += 5;
 132         for (; isspace(*ptr); ++ptr) ;
 133         for (i = 0; i < MTRR_NUM_TYPES; ++i) {
 134                 if (strcmp(ptr, mtrr_strings[i]))
 135                         continue;
 136                 base >>= PAGE_SHIFT;
 137                 size >>= PAGE_SHIFT;
 138                 err =
 139                     mtrr_add_page((unsigned long) base, (unsigned long) size, i,
 140                                   true);
 141                 if (err < 0)
 142                         return err;
 143                 return len;
 144         }
 145         return -EINVAL;
 146 }
 147
 148 static long
 149 mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
 150 {
 151         int err = 0;
 152         mtrr_type type;
 153         unsigned long size;
 154         struct mtrr_sentry sentry;
 155         struct mtrr_gentry gentry;
 156         void __user *arg = (void __user *) __arg;
 157
 158         switch (cmd) {
 159         case MTRRIOC_ADD_ENTRY:
 160         case MTRRIOC_SET_ENTRY:
 161         case MTRRIOC_DEL_ENTRY:
 162         case MTRRIOC_KILL_ENTRY:
 163         case MTRRIOC_ADD_PAGE_ENTRY:
 164         case MTRRIOC_SET_PAGE_ENTRY:
 165         case MTRRIOC_DEL_PAGE_ENTRY:
 166         case MTRRIOC_KILL_PAGE_ENTRY:
 167                 if (copy_from_user(&sentry, arg, sizeof sentry))
 168                         return -EFAULT;
 169                 break;
 170         case MTRRIOC_GET_ENTRY:
 171         case MTRRIOC_GET_PAGE_ENTRY:
 172                 if (copy_from_user(&gentry, arg, sizeof gentry))
 173                         return -EFAULT;
 174                 break;
 175 #ifdef CONFIG_COMPAT
 176         case MTRRIOC32_ADD_ENTRY:
 177         case MTRRIOC32_SET_ENTRY:
 178         case MTRRIOC32_DEL_ENTRY:
 179         case MTRRIOC32_KILL_ENTRY:
 180         case MTRRIOC32_ADD_PAGE_ENTRY:
 181         case MTRRIOC32_SET_PAGE_ENTRY:
 182         case MTRRIOC32_DEL_PAGE_ENTRY:
 183         case MTRRIOC32_KILL_PAGE_ENTRY: {
 184                 struct mtrr_sentry32 __user *s32 = (struct mtrr_sentry32 __user *)__arg;
 185                 err = get_user(sentry.base, &s32->base);
 186                 err |= get_user(sentry.size, &s32->size);
 187                 err |= get_user(sentry.type, &s32->type);
 188                 if (err)
 189                         return err;
 190                 break;
 191         }
 192         case MTRRIOC32_GET_ENTRY:
 193         case MTRRIOC32_GET_PAGE_ENTRY: {
 194                 struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
 195                 err = get_user(gentry.regnum, &g32->regnum);
 196                 err |= get_user(gentry.base, &g32->base);
 197                 err |= get_user(gentry.size, &g32->size);
 198                 err |= get_user(gentry.type, &g32->type);
 199                 if (err)
 200                         return err;
 201                 break;
 202         }
 203 #endif
 204         }
 205
 206         switch (cmd) {
 207         default:
 208                 return -ENOTTY;
 209         case MTRRIOC_ADD_ENTRY:
 210 #ifdef CONFIG_COMPAT
 211         case MTRRIOC32_ADD_ENTRY:
 212 #endif
 213                 if (!capable(CAP_SYS_ADMIN))
 214                         return -EPERM;
 215                 err =
 216                     mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
 217                                   file, 0);
 218                 break;
 219         case MTRRIOC_SET_ENTRY:
 220 #ifdef CONFIG_COMPAT
 221         case MTRRIOC32_SET_ENTRY:
 222 #endif
 223                 if (!capable(CAP_SYS_ADMIN))
 224                         return -EPERM;
 225                 err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
 226                 break;
 227         case MTRRIOC_DEL_ENTRY:
 228 #ifdef CONFIG_COMPAT
 229         case MTRRIOC32_DEL_ENTRY:
 230 #endif
 231                 if (!capable(CAP_SYS_ADMIN))
 232                         return -EPERM;
 233                 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
 234                 break;
 235         case MTRRIOC_KILL_ENTRY:
 236 #ifdef CONFIG_COMPAT
 237         case MTRRIOC32_KILL_ENTRY:
 238 #endif
 239                 if (!capable(CAP_SYS_ADMIN))
 240                         return -EPERM;
 241                 err = mtrr_del(-1, sentry.base, sentry.size);
 242                 break;
 243         case MTRRIOC_GET_ENTRY:
 244 #ifdef CONFIG_COMPAT
 245         case MTRRIOC32_GET_ENTRY:
 246 #endif
 247                 if (gentry.regnum >= num_var_ranges)
 248                         return -EINVAL;
 249                 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
 250
 251                 /* Hide entries that go above 4GB */
 252                 if (gentry.base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
 253                     || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
 254                         gentry.base = gentry.size = gentry.type = 0;
 255                 else {
 256                         gentry.base <<= PAGE_SHIFT;
 257                         gentry.size = size << PAGE_SHIFT;
 258                         gentry.type = type;
 259                 }
 260
 261                 break;
 262         case MTRRIOC_ADD_PAGE_ENTRY:
 263 #ifdef CONFIG_COMPAT
 264         case MTRRIOC32_ADD_PAGE_ENTRY:
 265 #endif
 266                 if (!capable(CAP_SYS_ADMIN))
 267                         return -EPERM;
 268                 err =
 269                     mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
 270                                   file, 1);
 271                 break;
 272         case MTRRIOC_SET_PAGE_ENTRY:
 273 #ifdef CONFIG_COMPAT
 274         case MTRRIOC32_SET_PAGE_ENTRY:
 275 #endif
 276                 if (!capable(CAP_SYS_ADMIN))
 277                         return -EPERM;
 278                 err =
 279                     mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
 280                 break;
 281         case MTRRIOC_DEL_PAGE_ENTRY:
 282 #ifdef CONFIG_COMPAT
 283         case MTRRIOC32_DEL_PAGE_ENTRY:
 284 #endif
 285                 if (!capable(CAP_SYS_ADMIN))
 286                         return -EPERM;
 287                 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
 288                 break;
 289         case MTRRIOC_KILL_PAGE_ENTRY:
 290 #ifdef CONFIG_COMPAT
 291         case MTRRIOC32_KILL_PAGE_ENTRY:
 292 #endif
 293                 if (!capable(CAP_SYS_ADMIN))
 294                         return -EPERM;
 295                 err = mtrr_del_page(-1, sentry.base, sentry.size);
 296                 break;
 297         case MTRRIOC_GET_PAGE_ENTRY:
 298 #ifdef CONFIG_COMPAT
 299         case MTRRIOC32_GET_PAGE_ENTRY:
 300 #endif
 301                 if (gentry.regnum >= num_var_ranges)
 302                         return -EINVAL;
 303                 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
 304                 /* Hide entries that would overflow */
 305                 if (size != (__typeof__(gentry.size))size)
 306                         gentry.base = gentry.size = gentry.type = 0;
 307                 else {
 308                         gentry.size = size;
 309                         gentry.type = type;
 310                 }
 311                 break;
 312         }
 313
 314         if (err)
 315                 return err;
 316
 317         switch(cmd) {
 318         case MTRRIOC_GET_ENTRY:
 319         case MTRRIOC_GET_PAGE_ENTRY:
 320                 if (copy_to_user(arg, &gentry, sizeof gentry))
 321                         err = -EFAULT;
 322                 break;
 323 #ifdef CONFIG_COMPAT
 324         case MTRRIOC32_GET_ENTRY:
 325         case MTRRIOC32_GET_PAGE_ENTRY: {
 326                 struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
 327                 err = put_user(gentry.base, &g32->base);
 328                 err |= put_user(gentry.size, &g32->size);
 329                 err |= put_user(gentry.regnum, &g32->regnum);
 330                 err |= put_user(gentry.type, &g32->type);
 331                 break;
 332         }
 333 #endif
 334         }
 335         return err;
 336 }
 337
 338 static int
 339 mtrr_close(struct inode *ino, struct file *file)
 340 {
 341         int i, max;
 342         unsigned int *fcount = FILE_FCOUNT(file);
 343
 344         if (fcount != NULL) {
 345                 max = num_var_ranges;
 346                 for (i = 0; i < max; ++i) {
 347                         while (fcount[i] > 0) {
 348                                 mtrr_del(i, 0, 0);
 349                                 --fcount[i];
 350                         }
 351                 }
 352                 kfree(fcount);
 353                 FILE_FCOUNT(file) = NULL;
 354         }
 355         return single_release(ino, file);
 356 }
 357
 358 static int mtrr_seq_show(struct seq_file *seq, void *offset);
 359
 360 static int mtrr_open(struct inode *inode, struct file *file)
 361 {
 362         if (!mtrr_if)
 363                 return -EIO;
 364         if (!mtrr_if->get)
 365                 return -ENXIO;
 366         return single_open(file, mtrr_seq_show, NULL);
 367 }
 368
 369 static const struct file_operations mtrr_fops = {
 370         .owner   = THIS_MODULE,
 371         .open    = mtrr_open,
 372         .read    = seq_read,
 373         .llseek  = seq_lseek,
 374         .write   = mtrr_write,
 375         .unlocked_ioctl = mtrr_ioctl,
 376         .compat_ioctl = mtrr_ioctl,
 377         .release = mtrr_close,
 378 };
 379
 380
 381 static struct proc_dir_entry *proc_root_mtrr;
 382
 383
 384 static int mtrr_seq_show(struct seq_file *seq, void *offset)
 385 {
 386         char factor;
 387         int i, max, len;
 388         mtrr_type type;
 389         unsigned long base, size;
 390
 391         len = 0;
 392         max = num_var_ranges;
 393         for (i = 0; i < max; i++) {
 394                 mtrr_if->get(i, &base, &size, &type);
 395                 if (size == 0)
 396                         mtrr_usage_table[i] = 0;
 397                 else {
 398                         if (size < (0x100000 >> PAGE_SHIFT)) {
 399                                 /* less than 1MB */
 400                                 factor = 'K';
 401                                 size <<= PAGE_SHIFT - 10;
 402                         } else {
 403                                 factor = 'M';
 404                                 size >>= 20 - PAGE_SHIFT;
 405                         }
 406                         /* RED-PEN: base can be > 32bit */
 407                         len += seq_printf(seq,
 408                                    "reg%02i: base=0x%05lx000 (%4luMB), size=%4lu%cB: %s, count=%d\n",
 409                              i, base, base >> (20 - PAGE_SHIFT), size, factor,
 410                              mtrr_attrib_to_str(type), mtrr_usage_table[i]);
 411                 }
 412         }
 413         return 0;
 414 }
 415
 416 static int __init mtrr_if_init(void)
 417 {
 418         struct cpuinfo_x86 *c = &boot_cpu_data;
 419
 420         if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
 421             (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
 422             (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
 423             (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
 424                 return -ENODEV;
 425
 426         proc_root_mtrr =
 427             create_proc_entry("mtrr", S_IWUSR | S_IRUGO, &proc_root);
 428         if (proc_root_mtrr) {
 429                 proc_root_mtrr->owner = THIS_MODULE;
 430                 proc_root_mtrr->proc_fops = &mtrr_fops;
 431         }
 432         return 0;
 433 }
 434
 435 arch_initcall(mtrr_if_init);
 436 #endif                  /*  CONFIG_PROC_FS  */