arch/i386/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 /* RED-PEN: this is accessed without any locking */
  15 extern unsigned int *usage_table;
  16
  17
  18 #define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
  19
  20 static const char *const mtrr_strings[MTRR_NUM_TYPES] =
  21 {
  22     "uncachable",               /* 0 */
  23     "write-combining",          /* 1 */
  24     "?",                        /* 2 */
  25     "?",                        /* 3 */
  26     "write-through",            /* 4 */
  27     "write-protect",            /* 5 */
  28     "write-back",               /* 6 */
  29 };
  30
  31 const char *mtrr_attrib_to_str(int x)
  32 {
  33         return (x <= 6) ? mtrr_strings[x] : "?";
  34 }
  35
  36 #ifdef CONFIG_PROC_FS
  37
  38 static int
  39 mtrr_file_add(unsigned long base, unsigned long size,
  40               unsigned int type, char increment, struct file *file, int page)
  41 {
  42         int reg, max;
  43         unsigned int *fcount = FILE_FCOUNT(file);
  44
  45         max = num_var_ranges;
  46         if (fcount == NULL) {
  47                 fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
  48                 if (!fcount)
  49                         return -ENOMEM;
  50                 FILE_FCOUNT(file) = fcount;
  51         }
  52         if (!page) {
  53                 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
  54                         return -EINVAL;
  55                 base >>= PAGE_SHIFT;
  56                 size >>= PAGE_SHIFT;
  57         }
  58         reg = mtrr_add_page(base, size, type, 1);
  59         if (reg >= 0)
  60                 ++fcount[reg];
  61         return reg;
  62 }
  63
  64 static int
  65 mtrr_file_del(unsigned long base, unsigned long size,
  66               struct file *file, int page)
  67 {
  68         int reg;
  69         unsigned int *fcount = FILE_FCOUNT(file);
  70
  71         if (!page) {
  72                 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
  73                         return -EINVAL;
  74                 base >>= PAGE_SHIFT;
  75                 size >>= PAGE_SHIFT;
  76         }
  77         reg = mtrr_del_page(-1, base, size);
  78         if (reg < 0)
  79                 return reg;
  80         if (fcount == NULL)
  81                 return reg;
  82         if (fcount[reg] < 1)
  83                 return -EINVAL;
  84         --fcount[reg];
  85         return reg;
  86 }
  87
  88 /* RED-PEN: seq_file can seek now. this is ignored. */
  89 static ssize_t
  90 mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
  91 /*  Format of control line:
  92     "base=%Lx size=%Lx type=%s"     OR:
  93     "disable=%d"
  94 */
  95 {
  96         int i, err;
  97         unsigned long reg;
  98         unsigned long long base, size;
  99         char *ptr;
 100         char line[LINE_SIZE];
 101         size_t linelen;
 102
 103         if (!capable(CAP_SYS_ADMIN))
 104                 return -EPERM;
 105         if (!len)
 106                 return -EINVAL;
 107         memset(line, 0, LINE_SIZE);
 108         if (len > LINE_SIZE)
 109                 len = LINE_SIZE;
 110         if (copy_from_user(line, buf, len - 1))
 111                 return -EFAULT;
 112         linelen = strlen(line);
 113         ptr = line + linelen - 1;
 114         if (linelen && *ptr == '\n')
 115                 *ptr = '\0';
 116         if (!strncmp(line, "disable=", 8)) {
 117                 reg = simple_strtoul(line + 8, &ptr, 0);
 118                 err = mtrr_del_page(reg, 0, 0);
 119                 if (err < 0)
 120                         return err;
 121                 return len;
 122         }
 123         if (strncmp(line, "base=", 5))
 124                 return -EINVAL;
 125         base = simple_strtoull(line + 5, &ptr, 0);
 126         for (; isspace(*ptr); ++ptr) ;
 127         if (strncmp(ptr, "size=", 5))
 128                 return -EINVAL;
 129         size = simple_strtoull(ptr + 5, &ptr, 0);
 130         if ((base & 0xfff) || (size & 0xfff))
 131                 return -EINVAL;
 132         for (; isspace(*ptr); ++ptr) ;
 133         if (strncmp(ptr, "type=", 5))
 134                 return -EINVAL;
 135         ptr += 5;
 136         for (; isspace(*ptr); ++ptr) ;
 137         for (i = 0; i < MTRR_NUM_TYPES; ++i) {
 138                 if (strcmp(ptr, mtrr_strings[i]))
 139                         continue;
 140                 base >>= PAGE_SHIFT;
 141                 size >>= PAGE_SHIFT;
 142                 err =
 143                     mtrr_add_page((unsigned long) base, (unsigned long) size, i,
 144                                   1);
 145                 if (err < 0)
 146                         return err;
 147                 return len;
 148         }
 149         return -EINVAL;
 150 }
 151
 152 static long
 153 mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
 154 {
 155         int err = 0;
 156         mtrr_type type;
 157         unsigned long size;
 158         struct mtrr_sentry sentry;
 159         struct mtrr_gentry gentry;
 160         void __user *arg = (void __user *) __arg;
 161
 162         switch (cmd) {
 163         case MTRRIOC_ADD_ENTRY:
 164         case MTRRIOC_SET_ENTRY:
 165         case MTRRIOC_DEL_ENTRY:
 166         case MTRRIOC_KILL_ENTRY:
 167         case MTRRIOC_ADD_PAGE_ENTRY:
 168         case MTRRIOC_SET_PAGE_ENTRY:
 169         case MTRRIOC_DEL_PAGE_ENTRY:
 170         case MTRRIOC_KILL_PAGE_ENTRY:
 171                 if (copy_from_user(&sentry, arg, sizeof sentry))
 172                         return -EFAULT;
 173                 break;
 174         case MTRRIOC_GET_ENTRY:
 175         case MTRRIOC_GET_PAGE_ENTRY:
 176                 if (copy_from_user(&gentry, arg, sizeof gentry))
 177                         return -EFAULT;
 178                 break;
 179 #ifdef CONFIG_COMPAT
 180         case MTRRIOC32_ADD_ENTRY:
 181         case MTRRIOC32_SET_ENTRY:
 182         case MTRRIOC32_DEL_ENTRY:
 183         case MTRRIOC32_KILL_ENTRY:
 184         case MTRRIOC32_ADD_PAGE_ENTRY:
 185         case MTRRIOC32_SET_PAGE_ENTRY:
 186         case MTRRIOC32_DEL_PAGE_ENTRY:
 187         case MTRRIOC32_KILL_PAGE_ENTRY: {
 188                 struct mtrr_sentry32 __user *s32 = (struct mtrr_sentry32 __user *)__arg;
 189                 err = get_user(sentry.base, &s32->base);
 190                 err |= get_user(sentry.size, &s32->size);
 191                 err |= get_user(sentry.type, &s32->type);
 192                 if (err)
 193                         return err;
 194                 break;
 195         }
 196         case MTRRIOC32_GET_ENTRY:
 197         case MTRRIOC32_GET_PAGE_ENTRY: {
 198                 struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
 199                 err = get_user(gentry.regnum, &g32->regnum);
 200                 err |= get_user(gentry.base, &g32->base);
 201                 err |= get_user(gentry.size, &g32->size);
 202                 err |= get_user(gentry.type, &g32->type);
 203                 if (err)
 204                         return err;
 205                 break;
 206         }
 207 #endif
 208         }
 209
 210         switch (cmd) {
 211         default:
 212                 return -ENOTTY;
 213         case MTRRIOC_ADD_ENTRY:
 214                 if (!capable(CAP_SYS_ADMIN))
 215                         return -EPERM;
 216                 err =
 217                     mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
 218                                   file, 0);
 219                 break;
 220         case MTRRIOC_SET_ENTRY:
 221                 if (!capable(CAP_SYS_ADMIN))
 222                         return -EPERM;
 223                 err = mtrr_add(sentry.base, sentry.size, sentry.type, 0);
 224                 break;
 225         case MTRRIOC_DEL_ENTRY:
 226                 if (!capable(CAP_SYS_ADMIN))
 227                         return -EPERM;
 228                 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
 229                 break;
 230         case MTRRIOC_KILL_ENTRY:
 231                 if (!capable(CAP_SYS_ADMIN))
 232                         return -EPERM;
 233                 err = mtrr_del(-1, sentry.base, sentry.size);
 234                 break;
 235         case MTRRIOC_GET_ENTRY:
 236                 if (gentry.regnum >= num_var_ranges)
 237                         return -EINVAL;
 238                 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
 239
 240                 /* Hide entries that go above 4GB */
 241                 if (gentry.base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
 242                     || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
 243                         gentry.base = gentry.size = gentry.type = 0;
 244                 else {
 245                         gentry.base <<= PAGE_SHIFT;
 246                         gentry.size = size << PAGE_SHIFT;
 247                         gentry.type = type;
 248                 }
 249
 250                 break;
 251         case MTRRIOC_ADD_PAGE_ENTRY:
 252                 if (!capable(CAP_SYS_ADMIN))
 253                         return -EPERM;
 254                 err =
 255                     mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
 256                                   file, 1);
 257                 break;
 258         case MTRRIOC_SET_PAGE_ENTRY:
 259                 if (!capable(CAP_SYS_ADMIN))
 260                         return -EPERM;
 261                 err = mtrr_add_page(sentry.base, sentry.size, sentry.type, 0);
 262                 break;
 263         case MTRRIOC_DEL_PAGE_ENTRY:
 264                 if (!capable(CAP_SYS_ADMIN))
 265                         return -EPERM;
 266                 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
 267                 break;
 268         case MTRRIOC_KILL_PAGE_ENTRY:
 269                 if (!capable(CAP_SYS_ADMIN))
 270                         return -EPERM;
 271                 err = mtrr_del_page(-1, sentry.base, sentry.size);
 272                 break;
 273         case MTRRIOC_GET_PAGE_ENTRY:
 274                 if (gentry.regnum >= num_var_ranges)
 275                         return -EINVAL;
 276                 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
 277                 /* Hide entries that would overflow */
 278                 if (size != (__typeof__(gentry.size))size)
 279                         gentry.base = gentry.size = gentry.type = 0;
 280                 else {
 281                         gentry.size = size;
 282                         gentry.type = type;
 283                 }
 284                 break;
 285         }
 286
 287         if (err)
 288                 return err;
 289
 290         switch(cmd) {
 291         case MTRRIOC_GET_ENTRY:
 292         case MTRRIOC_GET_PAGE_ENTRY:
 293                 if (copy_to_user(arg, &gentry, sizeof gentry))
 294                         err = -EFAULT;
 295                 break;
 296 #ifdef CONFIG_COMPAT
 297         case MTRRIOC32_GET_ENTRY:
 298         case MTRRIOC32_GET_PAGE_ENTRY: {
 299                 struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
 300                 err = put_user(gentry.base, &g32->base);
 301                 err |= put_user(gentry.size, &g32->size);
 302                 err |= put_user(gentry.regnum, &g32->regnum);
 303                 err |= put_user(gentry.type, &g32->type);
 304                 break;
 305         }
 306 #endif
 307         }
 308         return err;
 309 }
 310
 311 static int
 312 mtrr_close(struct inode *ino, struct file *file)
 313 {
 314         int i, max;
 315         unsigned int *fcount = FILE_FCOUNT(file);
 316
 317         if (fcount != NULL) {
 318                 max = num_var_ranges;
 319                 for (i = 0; i < max; ++i) {
 320                         while (fcount[i] > 0) {
 321                                 mtrr_del(i, 0, 0);
 322                                 --fcount[i];
 323                         }
 324                 }
 325                 kfree(fcount);
 326                 FILE_FCOUNT(file) = NULL;
 327         }
 328         return single_release(ino, file);
 329 }
 330
 331 static int mtrr_seq_show(struct seq_file *seq, void *offset);
 332
 333 static int mtrr_open(struct inode *inode, struct file *file)
 334 {
 335         if (!mtrr_if)
 336                 return -EIO;
 337         if (!mtrr_if->get)
 338                 return -ENXIO;
 339         return single_open(file, mtrr_seq_show, NULL);
 340 }
 341
 342 static struct file_operations mtrr_fops = {
 343         .owner   = THIS_MODULE,
 344         .open    = mtrr_open,
 345         .read    = seq_read,
 346         .llseek  = seq_lseek,
 347         .write   = mtrr_write,
 348         .unlocked_ioctl = mtrr_ioctl,
 349         .compat_ioctl = mtrr_ioctl,
 350         .release = mtrr_close,
 351 };
 352
 353
 354 static struct proc_dir_entry *proc_root_mtrr;
 355
 356
 357 static int mtrr_seq_show(struct seq_file *seq, void *offset)
 358 {
 359         char factor;
 360         int i, max, len;
 361         mtrr_type type;
 362         unsigned long base, size;
 363
 364         len = 0;
 365         max = num_var_ranges;
 366         for (i = 0; i < max; i++) {
 367                 mtrr_if->get(i, &base, &size, &type);
 368                 if (size == 0)
 369                         usage_table[i] = 0;
 370                 else {
 371                         if (size < (0x100000 >> PAGE_SHIFT)) {
 372                                 /* less than 1MB */
 373                                 factor = 'K';
 374                                 size <<= PAGE_SHIFT - 10;
 375                         } else {
 376                                 factor = 'M';
 377                                 size >>= 20 - PAGE_SHIFT;
 378                         }
 379                         /* RED-PEN: base can be > 32bit */
 380                         len += seq_printf(seq,
 381                                    "reg%02i: base=0x%05lx000 (%4luMB), size=%4lu%cB: %s, count=%d\n",
 382                              i, base, base >> (20 - PAGE_SHIFT), size, factor,
 383                              mtrr_attrib_to_str(type), usage_table[i]);
 384                 }
 385         }
 386         return 0;
 387 }
 388
 389 static int __init mtrr_if_init(void)
 390 {
 391         struct cpuinfo_x86 *c = &boot_cpu_data;
 392
 393         if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
 394             (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
 395             (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
 396             (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
 397                 return -ENODEV;
 398
 399         proc_root_mtrr =
 400             create_proc_entry("mtrr", S_IWUSR | S_IRUGO, &proc_root);
 401         if (proc_root_mtrr) {
 402                 proc_root_mtrr->owner = THIS_MODULE;
 403                 proc_root_mtrr->proc_fops = &mtrr_fops;
 404         }
 405         return 0;
 406 }
 407
 408 arch_initcall(mtrr_if_init);
 409 #endif                  /*  CONFIG_PROC_FS  */