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/string.h>
8 #include <linux/slab.h>
9 #include <linux/init.h>
17 #define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
19 static const char *const mtrr_strings[MTRR_NUM_TYPES] =
22 "write-combining", /* 1 */
25 "write-through", /* 4 */
26 "write-protect", /* 5 */
30 const char *mtrr_attrib_to_str(int x)
32 return (x <= 6) ? mtrr_strings[x] : "?";
38 mtrr_file_add(unsigned long base, unsigned long size,
39 unsigned int type, bool increment, struct file *file, int page)
41 unsigned int *fcount = FILE_FCOUNT(file);
46 fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
49 FILE_FCOUNT(file) = fcount;
52 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
57 reg = mtrr_add_page(base, size, type, true);
64 mtrr_file_del(unsigned long base, unsigned long size,
65 struct file *file, int page)
67 unsigned int *fcount = FILE_FCOUNT(file);
71 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
76 reg = mtrr_del_page(-1, base, size);
88 * seq_file can seek but we ignore it.
90 * Format of control line:
91 * "base=%Lx size=%Lx type=%s" or "disable=%d"
94 mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
98 unsigned long long base, size;
100 char line[LINE_SIZE];
104 if (!capable(CAP_SYS_ADMIN))
107 memset(line, 0, LINE_SIZE);
112 if (length > LINE_SIZE - 1)
113 length = LINE_SIZE - 1;
118 if (copy_from_user(line, buf, length))
121 linelen = strlen(line);
122 ptr = line + linelen - 1;
123 if (linelen && *ptr == '\n')
126 if (!strncmp(line, "disable=", 8)) {
127 reg = simple_strtoul(line + 8, &ptr, 0);
128 err = mtrr_del_page(reg, 0, 0);
134 if (strncmp(line, "base=", 5))
137 base = simple_strtoull(line + 5, &ptr, 0);
138 ptr = skip_spaces(ptr);
140 if (strncmp(ptr, "size=", 5))
143 size = simple_strtoull(ptr + 5, &ptr, 0);
144 if ((base & 0xfff) || (size & 0xfff))
146 ptr = skip_spaces(ptr);
148 if (strncmp(ptr, "type=", 5))
150 ptr = skip_spaces(ptr + 5);
152 for (i = 0; i < MTRR_NUM_TYPES; ++i) {
153 if (strcmp(ptr, mtrr_strings[i]))
157 err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
166 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;
176 case MTRRIOC_ADD_ENTRY:
177 case MTRRIOC_SET_ENTRY:
178 case MTRRIOC_DEL_ENTRY:
179 case MTRRIOC_KILL_ENTRY:
180 case MTRRIOC_ADD_PAGE_ENTRY:
181 case MTRRIOC_SET_PAGE_ENTRY:
182 case MTRRIOC_DEL_PAGE_ENTRY:
183 case MTRRIOC_KILL_PAGE_ENTRY:
184 if (copy_from_user(&sentry, arg, sizeof sentry))
187 case MTRRIOC_GET_ENTRY:
188 case MTRRIOC_GET_PAGE_ENTRY:
189 if (copy_from_user(&gentry, arg, sizeof gentry))
193 case MTRRIOC32_ADD_ENTRY:
194 case MTRRIOC32_SET_ENTRY:
195 case MTRRIOC32_DEL_ENTRY:
196 case MTRRIOC32_KILL_ENTRY:
197 case MTRRIOC32_ADD_PAGE_ENTRY:
198 case MTRRIOC32_SET_PAGE_ENTRY:
199 case MTRRIOC32_DEL_PAGE_ENTRY:
200 case MTRRIOC32_KILL_PAGE_ENTRY: {
201 struct mtrr_sentry32 __user *s32;
203 s32 = (struct mtrr_sentry32 __user *)__arg;
204 err = get_user(sentry.base, &s32->base);
205 err |= get_user(sentry.size, &s32->size);
206 err |= get_user(sentry.type, &s32->type);
211 case MTRRIOC32_GET_ENTRY:
212 case MTRRIOC32_GET_PAGE_ENTRY: {
213 struct mtrr_gentry32 __user *g32;
215 g32 = (struct mtrr_gentry32 __user *)__arg;
216 err = get_user(gentry.regnum, &g32->regnum);
217 err |= get_user(gentry.base, &g32->base);
218 err |= get_user(gentry.size, &g32->size);
219 err |= get_user(gentry.type, &g32->type);
230 case MTRRIOC_ADD_ENTRY:
232 case MTRRIOC32_ADD_ENTRY:
234 if (!capable(CAP_SYS_ADMIN))
237 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
240 case MTRRIOC_SET_ENTRY:
242 case MTRRIOC32_SET_ENTRY:
244 if (!capable(CAP_SYS_ADMIN))
246 err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
248 case MTRRIOC_DEL_ENTRY:
250 case MTRRIOC32_DEL_ENTRY:
252 if (!capable(CAP_SYS_ADMIN))
254 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
256 case MTRRIOC_KILL_ENTRY:
258 case MTRRIOC32_KILL_ENTRY:
260 if (!capable(CAP_SYS_ADMIN))
262 err = mtrr_del(-1, sentry.base, sentry.size);
264 case MTRRIOC_GET_ENTRY:
266 case MTRRIOC32_GET_ENTRY:
268 if (gentry.regnum >= num_var_ranges)
270 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
272 /* Hide entries that go above 4GB */
273 if (gentry.base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
274 || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
275 gentry.base = gentry.size = gentry.type = 0;
277 gentry.base <<= PAGE_SHIFT;
278 gentry.size = size << PAGE_SHIFT;
283 case MTRRIOC_ADD_PAGE_ENTRY:
285 case MTRRIOC32_ADD_PAGE_ENTRY:
287 if (!capable(CAP_SYS_ADMIN))
290 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
293 case MTRRIOC_SET_PAGE_ENTRY:
295 case MTRRIOC32_SET_PAGE_ENTRY:
297 if (!capable(CAP_SYS_ADMIN))
300 mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
302 case MTRRIOC_DEL_PAGE_ENTRY:
304 case MTRRIOC32_DEL_PAGE_ENTRY:
306 if (!capable(CAP_SYS_ADMIN))
308 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
310 case MTRRIOC_KILL_PAGE_ENTRY:
312 case MTRRIOC32_KILL_PAGE_ENTRY:
314 if (!capable(CAP_SYS_ADMIN))
316 err = mtrr_del_page(-1, sentry.base, sentry.size);
318 case MTRRIOC_GET_PAGE_ENTRY:
320 case MTRRIOC32_GET_PAGE_ENTRY:
322 if (gentry.regnum >= num_var_ranges)
324 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
325 /* Hide entries that would overflow */
326 if (size != (__typeof__(gentry.size))size)
327 gentry.base = gentry.size = gentry.type = 0;
339 case MTRRIOC_GET_ENTRY:
340 case MTRRIOC_GET_PAGE_ENTRY:
341 if (copy_to_user(arg, &gentry, sizeof gentry))
345 case MTRRIOC32_GET_ENTRY:
346 case MTRRIOC32_GET_PAGE_ENTRY: {
347 struct mtrr_gentry32 __user *g32;
349 g32 = (struct mtrr_gentry32 __user *)__arg;
350 err = put_user(gentry.base, &g32->base);
351 err |= put_user(gentry.size, &g32->size);
352 err |= put_user(gentry.regnum, &g32->regnum);
353 err |= put_user(gentry.type, &g32->type);
361 static int mtrr_close(struct inode *ino, struct file *file)
363 unsigned int *fcount = FILE_FCOUNT(file);
366 if (fcount != NULL) {
367 max = num_var_ranges;
368 for (i = 0; i < max; ++i) {
369 while (fcount[i] > 0) {
375 FILE_FCOUNT(file) = NULL;
377 return single_release(ino, file);
380 static int mtrr_seq_show(struct seq_file *seq, void *offset);
382 static int mtrr_open(struct inode *inode, struct file *file)
388 return single_open(file, mtrr_seq_show, NULL);
391 static const struct file_operations mtrr_fops = {
392 .owner = THIS_MODULE,
397 .unlocked_ioctl = mtrr_ioctl,
398 .compat_ioctl = mtrr_ioctl,
399 .release = mtrr_close,
402 static int mtrr_seq_show(struct seq_file *seq, void *offset)
407 unsigned long base, size;
410 max = num_var_ranges;
411 for (i = 0; i < max; i++) {
412 mtrr_if->get(i, &base, &size, &type);
414 mtrr_usage_table[i] = 0;
417 if (size < (0x100000 >> PAGE_SHIFT)) {
420 size <<= PAGE_SHIFT - 10;
423 size >>= 20 - PAGE_SHIFT;
425 /* Base can be > 32bit */
426 len += seq_printf(seq, "reg%02i: base=0x%06lx000 "
427 "(%5luMB), size=%5lu%cB, count=%d: %s\n",
428 i, base, base >> (20 - PAGE_SHIFT), size,
429 factor, mtrr_usage_table[i],
430 mtrr_attrib_to_str(type));
435 static int __init mtrr_if_init(void)
437 struct cpuinfo_x86 *c = &boot_cpu_data;
439 if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
440 (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
441 (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
442 (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
445 proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);
448 arch_initcall(mtrr_if_init);
449 #endif /* CONFIG_PROC_FS */