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/ctype.h>
6 #include <linux/string.h>
7 #include <linux/slab.h>
8 #include <linux/init.h>
16 #define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
18 static const char *const mtrr_strings[MTRR_NUM_TYPES] =
21 "write-combining", /* 1 */
24 "write-through", /* 4 */
25 "write-protect", /* 5 */
29 const char *mtrr_attrib_to_str(int x)
31 return (x <= 6) ? mtrr_strings[x] : "?";
37 mtrr_file_add(unsigned long base, unsigned long size,
38 unsigned int type, bool increment, struct file *file, int page)
40 unsigned int *fcount = FILE_FCOUNT(file);
45 fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
48 FILE_FCOUNT(file) = fcount;
51 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
56 reg = mtrr_add_page(base, size, type, true);
63 mtrr_file_del(unsigned long base, unsigned long size,
64 struct file *file, int page)
66 unsigned int *fcount = FILE_FCOUNT(file);
70 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
75 reg = mtrr_del_page(-1, base, size);
87 * seq_file can seek but we ignore it.
89 * Format of control line:
90 * "base=%Lx size=%Lx type=%s" or "disable=%d"
93 mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
97 unsigned long long base, size;
103 if (!capable(CAP_SYS_ADMIN))
106 memset(line, 0, LINE_SIZE);
111 if (length > LINE_SIZE - 1)
112 length = LINE_SIZE - 1;
117 if (copy_from_user(line, buf, length))
120 linelen = strlen(line);
121 ptr = line + linelen - 1;
122 if (linelen && *ptr == '\n')
125 if (!strncmp(line, "disable=", 8)) {
126 reg = simple_strtoul(line + 8, &ptr, 0);
127 err = mtrr_del_page(reg, 0, 0);
133 if (strncmp(line, "base=", 5))
136 base = simple_strtoull(line + 5, &ptr, 0);
137 ptr = skip_spaces(ptr);
139 if (strncmp(ptr, "size=", 5))
142 size = simple_strtoull(ptr + 5, &ptr, 0);
143 if ((base & 0xfff) || (size & 0xfff))
145 ptr = skip_spaces(ptr);
147 if (strncmp(ptr, "type=", 5))
149 ptr = skip_spaces(ptr + 5);
151 for (i = 0; i < MTRR_NUM_TYPES; ++i) {
152 if (strcmp(ptr, mtrr_strings[i]))
156 err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
165 mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
171 struct mtrr_sentry sentry;
172 struct mtrr_gentry gentry;
173 void __user *arg = (void __user *) __arg;
175 memset(&gentry, 0, sizeof(gentry));
178 case MTRRIOC_ADD_ENTRY:
179 case MTRRIOC_SET_ENTRY:
180 case MTRRIOC_DEL_ENTRY:
181 case MTRRIOC_KILL_ENTRY:
182 case MTRRIOC_ADD_PAGE_ENTRY:
183 case MTRRIOC_SET_PAGE_ENTRY:
184 case MTRRIOC_DEL_PAGE_ENTRY:
185 case MTRRIOC_KILL_PAGE_ENTRY:
186 if (copy_from_user(&sentry, arg, sizeof sentry))
189 case MTRRIOC_GET_ENTRY:
190 case MTRRIOC_GET_PAGE_ENTRY:
191 if (copy_from_user(&gentry, arg, sizeof gentry))
195 case MTRRIOC32_ADD_ENTRY:
196 case MTRRIOC32_SET_ENTRY:
197 case MTRRIOC32_DEL_ENTRY:
198 case MTRRIOC32_KILL_ENTRY:
199 case MTRRIOC32_ADD_PAGE_ENTRY:
200 case MTRRIOC32_SET_PAGE_ENTRY:
201 case MTRRIOC32_DEL_PAGE_ENTRY:
202 case MTRRIOC32_KILL_PAGE_ENTRY: {
203 struct mtrr_sentry32 __user *s32;
205 s32 = (struct mtrr_sentry32 __user *)__arg;
206 err = get_user(sentry.base, &s32->base);
207 err |= get_user(sentry.size, &s32->size);
208 err |= get_user(sentry.type, &s32->type);
213 case MTRRIOC32_GET_ENTRY:
214 case MTRRIOC32_GET_PAGE_ENTRY: {
215 struct mtrr_gentry32 __user *g32;
217 g32 = (struct mtrr_gentry32 __user *)__arg;
218 err = get_user(gentry.regnum, &g32->regnum);
219 err |= get_user(gentry.base, &g32->base);
220 err |= get_user(gentry.size, &g32->size);
221 err |= get_user(gentry.type, &g32->type);
232 case MTRRIOC_ADD_ENTRY:
234 case MTRRIOC32_ADD_ENTRY:
236 if (!capable(CAP_SYS_ADMIN))
239 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
242 case MTRRIOC_SET_ENTRY:
244 case MTRRIOC32_SET_ENTRY:
246 if (!capable(CAP_SYS_ADMIN))
248 err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
250 case MTRRIOC_DEL_ENTRY:
252 case MTRRIOC32_DEL_ENTRY:
254 if (!capable(CAP_SYS_ADMIN))
256 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
258 case MTRRIOC_KILL_ENTRY:
260 case MTRRIOC32_KILL_ENTRY:
262 if (!capable(CAP_SYS_ADMIN))
264 err = mtrr_del(-1, sentry.base, sentry.size);
266 case MTRRIOC_GET_ENTRY:
268 case MTRRIOC32_GET_ENTRY:
270 if (gentry.regnum >= num_var_ranges)
272 mtrr_if->get(gentry.regnum, &base, &size, &type);
274 /* Hide entries that go above 4GB */
275 if (base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
276 || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
277 gentry.base = gentry.size = gentry.type = 0;
279 gentry.base = base << PAGE_SHIFT;
280 gentry.size = size << PAGE_SHIFT;
285 case MTRRIOC_ADD_PAGE_ENTRY:
287 case MTRRIOC32_ADD_PAGE_ENTRY:
289 if (!capable(CAP_SYS_ADMIN))
292 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
295 case MTRRIOC_SET_PAGE_ENTRY:
297 case MTRRIOC32_SET_PAGE_ENTRY:
299 if (!capable(CAP_SYS_ADMIN))
302 mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
304 case MTRRIOC_DEL_PAGE_ENTRY:
306 case MTRRIOC32_DEL_PAGE_ENTRY:
308 if (!capable(CAP_SYS_ADMIN))
310 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
312 case MTRRIOC_KILL_PAGE_ENTRY:
314 case MTRRIOC32_KILL_PAGE_ENTRY:
316 if (!capable(CAP_SYS_ADMIN))
318 err = mtrr_del_page(-1, sentry.base, sentry.size);
320 case MTRRIOC_GET_PAGE_ENTRY:
322 case MTRRIOC32_GET_PAGE_ENTRY:
324 if (gentry.regnum >= num_var_ranges)
326 mtrr_if->get(gentry.regnum, &base, &size, &type);
327 /* Hide entries that would overflow */
328 if (size != (__typeof__(gentry.size))size)
329 gentry.base = gentry.size = gentry.type = 0;
342 case MTRRIOC_GET_ENTRY:
343 case MTRRIOC_GET_PAGE_ENTRY:
344 if (copy_to_user(arg, &gentry, sizeof gentry))
348 case MTRRIOC32_GET_ENTRY:
349 case MTRRIOC32_GET_PAGE_ENTRY: {
350 struct mtrr_gentry32 __user *g32;
352 g32 = (struct mtrr_gentry32 __user *)__arg;
353 err = put_user(gentry.base, &g32->base);
354 err |= put_user(gentry.size, &g32->size);
355 err |= put_user(gentry.regnum, &g32->regnum);
356 err |= put_user(gentry.type, &g32->type);
364 static int mtrr_close(struct inode *ino, struct file *file)
366 unsigned int *fcount = FILE_FCOUNT(file);
369 if (fcount != NULL) {
370 max = num_var_ranges;
371 for (i = 0; i < max; ++i) {
372 while (fcount[i] > 0) {
378 FILE_FCOUNT(file) = NULL;
380 return single_release(ino, file);
383 static int mtrr_seq_show(struct seq_file *seq, void *offset);
385 static int mtrr_open(struct inode *inode, struct file *file)
391 return single_open(file, mtrr_seq_show, NULL);
394 static const struct file_operations mtrr_fops = {
395 .owner = THIS_MODULE,
400 .unlocked_ioctl = mtrr_ioctl,
401 .compat_ioctl = mtrr_ioctl,
402 .release = mtrr_close,
405 static int mtrr_seq_show(struct seq_file *seq, void *offset)
410 unsigned long base, size;
412 max = num_var_ranges;
413 for (i = 0; i < max; i++) {
414 mtrr_if->get(i, &base, &size, &type);
416 mtrr_usage_table[i] = 0;
419 if (size < (0x100000 >> PAGE_SHIFT)) {
422 size <<= PAGE_SHIFT - 10;
425 size >>= 20 - PAGE_SHIFT;
427 /* Base can be > 32bit */
428 seq_printf(seq, "reg%02i: base=0x%06lx000 (%5luMB), size=%5lu%cB, count=%d: %s\n",
429 i, base, base >> (20 - PAGE_SHIFT),
431 mtrr_usage_table[i], mtrr_attrib_to_str(type));
436 static int __init mtrr_if_init(void)
438 struct cpuinfo_x86 *c = &boot_cpu_data;
440 if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
441 (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
442 (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
443 (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
446 proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);
449 arch_initcall(mtrr_if_init);
450 #endif /* CONFIG_PROC_FS */