arch/i386/kernel/cpu/mtrr/if.c

   1 #include <linux/init.h>
   2 #include <linux/proc_fs.h>
   3 #include <linux/ctype.h>
   4 #include <linux/module.h>
   5 #include <linux/seq_file.h>
   6 #include <asm/uaccess.h>
   7
   8 #define LINE_SIZE 80
   9
  10 #include <asm/mtrr.h>
  11 #include "mtrr.h"
  12
  13 /* RED-PEN: this is accessed without any locking */
  14 extern unsigned int *usage_table;
  15
  16
  17 #define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
  18
  19 static char *mtrr_strings[MTRR_NUM_TYPES] =
  20 {
  21     "uncachable",               /* 0 */
  22     "write-combining",          /* 1 */
  23     "?",                        /* 2 */
  24     "?",                        /* 3 */
  25     "write-through",            /* 4 */
  26     "write-protect",            /* 5 */
  27     "write-back",               /* 6 */
  28 };
  29
  30 char *mtrr_attrib_to_str(int x)
  31 {
  32         return (x <= 6) ? mtrr_strings[x] : "?";
  33 }
  34
  35 #ifdef CONFIG_PROC_FS
  36
  37 static int
  38 mtrr_file_add(unsigned long base, unsigned long size,
  39               unsigned int type, char increment, struct file *file, int page)
  40 {
  41         int reg, max;
  42         unsigned int *fcount = FILE_FCOUNT(file);
  43
  44         max = num_var_ranges;
  45         if (fcount == NULL) {
  46                 fcount = kmalloc(max * sizeof *fcount, GFP_KERNEL);
  47                 if (!fcount)
  48                         return -ENOMEM;
  49                 memset(fcount, 0, max * sizeof *fcount);
  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 int
 153 mtrr_ioctl(struct inode *inode, struct file *file,
 154            unsigned int cmd, unsigned long __arg)
 155 {
 156         int err;
 157         mtrr_type type;
 158         struct mtrr_sentry sentry;
 159         struct mtrr_gentry gentry;
 160         void __user *arg = (void __user *) __arg;
 161
 162         switch (cmd) {
 163         default:
 164                 return -ENOTTY;
 165         case MTRRIOC_ADD_ENTRY:
 166                 if (!capable(CAP_SYS_ADMIN))
 167                         return -EPERM;
 168                 if (copy_from_user(&sentry, arg, sizeof sentry))
 169                         return -EFAULT;
 170                 err =
 171                     mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
 172                                   file, 0);
 173                 if (err < 0)
 174                         return err;
 175                 break;
 176         case MTRRIOC_SET_ENTRY:
 177                 if (!capable(CAP_SYS_ADMIN))
 178                         return -EPERM;
 179                 if (copy_from_user(&sentry, arg, sizeof sentry))
 180                         return -EFAULT;
 181                 err = mtrr_add(sentry.base, sentry.size, sentry.type, 0);
 182                 if (err < 0)
 183                         return err;
 184                 break;
 185         case MTRRIOC_DEL_ENTRY:
 186                 if (!capable(CAP_SYS_ADMIN))
 187                         return -EPERM;
 188                 if (copy_from_user(&sentry, arg, sizeof sentry))
 189                         return -EFAULT;
 190                 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
 191                 if (err < 0)
 192                         return err;
 193                 break;
 194         case MTRRIOC_KILL_ENTRY:
 195                 if (!capable(CAP_SYS_ADMIN))
 196                         return -EPERM;
 197                 if (copy_from_user(&sentry, arg, sizeof sentry))
 198                         return -EFAULT;
 199                 err = mtrr_del(-1, sentry.base, sentry.size);
 200                 if (err < 0)
 201                         return err;
 202                 break;
 203         case MTRRIOC_GET_ENTRY:
 204                 if (copy_from_user(&gentry, arg, sizeof gentry))
 205                         return -EFAULT;
 206                 if (gentry.regnum >= num_var_ranges)
 207                         return -EINVAL;
 208                 mtrr_if->get(gentry.regnum, &gentry.base, &gentry.size, &type);
 209
 210                 /* Hide entries that go above 4GB */
 211                 if (gentry.base + gentry.size > 0x100000
 212                     || gentry.size == 0x100000)
 213                         gentry.base = gentry.size = gentry.type = 0;
 214                 else {
 215                         gentry.base <<= PAGE_SHIFT;
 216                         gentry.size <<= PAGE_SHIFT;
 217                         gentry.type = type;
 218                 }
 219
 220                 if (copy_to_user(arg, &gentry, sizeof gentry))
 221                         return -EFAULT;
 222                 break;
 223         case MTRRIOC_ADD_PAGE_ENTRY:
 224                 if (!capable(CAP_SYS_ADMIN))
 225                         return -EPERM;
 226                 if (copy_from_user(&sentry, arg, sizeof sentry))
 227                         return -EFAULT;
 228                 err =
 229                     mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
 230                                   file, 1);
 231                 if (err < 0)
 232                         return err;
 233                 break;
 234         case MTRRIOC_SET_PAGE_ENTRY:
 235                 if (!capable(CAP_SYS_ADMIN))
 236                         return -EPERM;
 237                 if (copy_from_user(&sentry, arg, sizeof sentry))
 238                         return -EFAULT;
 239                 err = mtrr_add_page(sentry.base, sentry.size, sentry.type, 0);
 240                 if (err < 0)
 241                         return err;
 242                 break;
 243         case MTRRIOC_DEL_PAGE_ENTRY:
 244                 if (!capable(CAP_SYS_ADMIN))
 245                         return -EPERM;
 246                 if (copy_from_user(&sentry, arg, sizeof sentry))
 247                         return -EFAULT;
 248                 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
 249                 if (err < 0)
 250                         return err;
 251                 break;
 252         case MTRRIOC_KILL_PAGE_ENTRY:
 253                 if (!capable(CAP_SYS_ADMIN))
 254                         return -EPERM;
 255                 if (copy_from_user(&sentry, arg, sizeof sentry))
 256                         return -EFAULT;
 257                 err = mtrr_del_page(-1, sentry.base, sentry.size);
 258                 if (err < 0)
 259                         return err;
 260                 break;
 261         case MTRRIOC_GET_PAGE_ENTRY:
 262                 if (copy_from_user(&gentry, arg, sizeof gentry))
 263                         return -EFAULT;
 264                 if (gentry.regnum >= num_var_ranges)
 265                         return -EINVAL;
 266                 mtrr_if->get(gentry.regnum, &gentry.base, &gentry.size, &type);
 267                 gentry.type = type;
 268
 269                 if (copy_to_user(arg, &gentry, sizeof gentry))
 270                         return -EFAULT;
 271                 break;
 272         }
 273         return 0;
 274 }
 275
 276 static int
 277 mtrr_close(struct inode *ino, struct file *file)
 278 {
 279         int i, max;
 280         unsigned int *fcount = FILE_FCOUNT(file);
 281
 282         if (fcount != NULL) {
 283                 max = num_var_ranges;
 284                 for (i = 0; i < max; ++i) {
 285                         while (fcount[i] > 0) {
 286                                 mtrr_del(i, 0, 0);
 287                                 --fcount[i];
 288                         }
 289                 }
 290                 kfree(fcount);
 291                 FILE_FCOUNT(file) = NULL;
 292         }
 293         return single_release(ino, file);
 294 }
 295
 296 static int mtrr_seq_show(struct seq_file *seq, void *offset);
 297
 298 static int mtrr_open(struct inode *inode, struct file *file)
 299 {
 300         if (!mtrr_if)
 301                 return -EIO;
 302         if (!mtrr_if->get)
 303                 return -ENXIO;
 304         return single_open(file, mtrr_seq_show, NULL);
 305 }
 306
 307 static struct file_operations mtrr_fops = {
 308         .owner   = THIS_MODULE,
 309         .open    = mtrr_open,
 310         .read    = seq_read,
 311         .llseek  = seq_lseek,
 312         .write   = mtrr_write,
 313         .ioctl   = mtrr_ioctl,
 314         .release = mtrr_close,
 315 };
 316
 317
 318 static struct proc_dir_entry *proc_root_mtrr;
 319
 320
 321 static int mtrr_seq_show(struct seq_file *seq, void *offset)
 322 {
 323         char factor;
 324         int i, max, len;
 325         mtrr_type type;
 326         unsigned long base;
 327         unsigned int size;
 328
 329         len = 0;
 330         max = num_var_ranges;
 331         for (i = 0; i < max; i++) {
 332                 mtrr_if->get(i, &base, &size, &type);
 333                 if (size == 0)
 334                         usage_table[i] = 0;
 335                 else {
 336                         if (size < (0x100000 >> PAGE_SHIFT)) {
 337                                 /* less than 1MB */
 338                                 factor = 'K';
 339                                 size <<= PAGE_SHIFT - 10;
 340                         } else {
 341                                 factor = 'M';
 342                                 size >>= 20 - PAGE_SHIFT;
 343                         }
 344                         /* RED-PEN: base can be > 32bit */
 345                         len += seq_printf(seq,
 346                                    "reg%02i: base=0x%05lx000 (%4liMB), size=%4i%cB: %s, count=%d\n",
 347                              i, base, base >> (20 - PAGE_SHIFT), size, factor,
 348                              mtrr_attrib_to_str(type), usage_table[i]);
 349                 }
 350         }
 351         return 0;
 352 }
 353
 354 static int __init mtrr_if_init(void)
 355 {
 356         struct cpuinfo_x86 *c = &boot_cpu_data;
 357
 358         if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
 359             (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
 360             (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
 361             (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
 362                 return -ENODEV;
 363
 364         proc_root_mtrr =
 365             create_proc_entry("mtrr", S_IWUSR | S_IRUGO, &proc_root);
 366         if (proc_root_mtrr) {
 367                 proc_root_mtrr->owner = THIS_MODULE;
 368                 proc_root_mtrr->proc_fops = &mtrr_fops;
 369         }
 370         return 0;
 371 }
 372
 373 arch_initcall(mtrr_if_init);
 374 #endif                  /*  CONFIG_PROC_FS  */