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/init.h>
15 #define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
17 static const char *const mtrr_strings[MTRR_NUM_TYPES] =
20 "write-combining", /* 1 */
23 "write-through", /* 4 */
24 "write-protect", /* 5 */
28 const char *mtrr_attrib_to_str(int x)
30 return (x <= 6) ? mtrr_strings[x] : "?";
36 mtrr_file_add(unsigned long base, unsigned long size,
37 unsigned int type, bool increment, struct file *file, int page)
39 unsigned int *fcount = FILE_FCOUNT(file);
44 fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
47 FILE_FCOUNT(file) = fcount;
50 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
55 reg = mtrr_add_page(base, size, type, true);
62 mtrr_file_del(unsigned long base, unsigned long size,
63 struct file *file, int page)
65 unsigned int *fcount = FILE_FCOUNT(file);
69 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
74 reg = mtrr_del_page(-1, base, size);
86 * seq_file can seek but we ignore it.
88 * Format of control line:
89 * "base=%Lx size=%Lx type=%s" or "disable=%d"
92 mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
96 unsigned long long base, size;
102 if (!capable(CAP_SYS_ADMIN))
105 memset(line, 0, LINE_SIZE);
110 if (length > LINE_SIZE - 1)
111 length = LINE_SIZE - 1;
116 if (copy_from_user(line, buf, length))
119 linelen = strlen(line);
120 ptr = line + linelen - 1;
121 if (linelen && *ptr == '\n')
124 if (!strncmp(line, "disable=", 8)) {
125 reg = simple_strtoul(line + 8, &ptr, 0);
126 err = mtrr_del_page(reg, 0, 0);
132 if (strncmp(line, "base=", 5))
135 base = simple_strtoull(line + 5, &ptr, 0);
136 while (isspace(*ptr))
139 if (strncmp(ptr, "size=", 5))
142 size = simple_strtoull(ptr + 5, &ptr, 0);
143 if ((base & 0xfff) || (size & 0xfff))
145 while (isspace(*ptr))
148 if (strncmp(ptr, "type=", 5))
151 while (isspace(*ptr))
154 for (i = 0; i < MTRR_NUM_TYPES; ++i) {
155 if (strcmp(ptr, mtrr_strings[i]))
159 err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
168 mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
173 struct mtrr_sentry sentry;
174 struct mtrr_gentry gentry;
175 void __user *arg = (void __user *) __arg;
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, &gentry.base, &size, &type);
274 /* Hide entries that go above 4GB */
275 if (gentry.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 <<= 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, &gentry.base, &size, &type);
327 /* Hide entries that would overflow */
328 if (size != (__typeof__(gentry.size))size)
329 gentry.base = gentry.size = gentry.type = 0;
341 case MTRRIOC_GET_ENTRY:
342 case MTRRIOC_GET_PAGE_ENTRY:
343 if (copy_to_user(arg, &gentry, sizeof gentry))
347 case MTRRIOC32_GET_ENTRY:
348 case MTRRIOC32_GET_PAGE_ENTRY: {
349 struct mtrr_gentry32 __user *g32;
351 g32 = (struct mtrr_gentry32 __user *)__arg;
352 err = put_user(gentry.base, &g32->base);
353 err |= put_user(gentry.size, &g32->size);
354 err |= put_user(gentry.regnum, &g32->regnum);
355 err |= put_user(gentry.type, &g32->type);
363 static int mtrr_close(struct inode *ino, struct file *file)
365 unsigned int *fcount = FILE_FCOUNT(file);
368 if (fcount != NULL) {
369 max = num_var_ranges;
370 for (i = 0; i < max; ++i) {
371 while (fcount[i] > 0) {
377 FILE_FCOUNT(file) = NULL;
379 return single_release(ino, file);
382 static int mtrr_seq_show(struct seq_file *seq, void *offset);
384 static int mtrr_open(struct inode *inode, struct file *file)
390 return single_open(file, mtrr_seq_show, NULL);
393 static const struct file_operations mtrr_fops = {
394 .owner = THIS_MODULE,
399 .unlocked_ioctl = mtrr_ioctl,
400 .compat_ioctl = mtrr_ioctl,
401 .release = mtrr_close,
404 static int mtrr_seq_show(struct seq_file *seq, void *offset)
409 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 len += seq_printf(seq, "reg%02i: base=0x%06lx000 "
429 "(%5luMB), size=%5lu%cB, count=%d: %s\n",
430 i, base, base >> (20 - PAGE_SHIFT), size,
431 factor, mtrr_usage_table[i],
432 mtrr_attrib_to_str(type));
437 static int __init mtrr_if_init(void)
439 struct cpuinfo_x86 *c = &boot_cpu_data;
441 if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
442 (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
443 (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
444 (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
447 proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);
450 arch_initcall(mtrr_if_init);
451 #endif /* CONFIG_PROC_FS */