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;
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, &base, &size, &type);
272 /* Hide entries that go above 4GB */
273 if (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 = 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, &base, &size, &type);
325 /* Hide entries that would overflow */
326 if (size != (__typeof__(gentry.size))size)
327 gentry.base = gentry.size = gentry.type = 0;
340 case MTRRIOC_GET_ENTRY:
341 case MTRRIOC_GET_PAGE_ENTRY:
342 if (copy_to_user(arg, &gentry, sizeof gentry))
346 case MTRRIOC32_GET_ENTRY:
347 case MTRRIOC32_GET_PAGE_ENTRY: {
348 struct mtrr_gentry32 __user *g32;
350 g32 = (struct mtrr_gentry32 __user *)__arg;
351 err = put_user(gentry.base, &g32->base);
352 err |= put_user(gentry.size, &g32->size);
353 err |= put_user(gentry.regnum, &g32->regnum);
354 err |= put_user(gentry.type, &g32->type);
362 static int mtrr_close(struct inode *ino, struct file *file)
364 unsigned int *fcount = FILE_FCOUNT(file);
367 if (fcount != NULL) {
368 max = num_var_ranges;
369 for (i = 0; i < max; ++i) {
370 while (fcount[i] > 0) {
376 FILE_FCOUNT(file) = NULL;
378 return single_release(ino, file);
381 static int mtrr_seq_show(struct seq_file *seq, void *offset);
383 static int mtrr_open(struct inode *inode, struct file *file)
389 return single_open(file, mtrr_seq_show, NULL);
392 static const struct file_operations mtrr_fops = {
393 .owner = THIS_MODULE,
398 .unlocked_ioctl = mtrr_ioctl,
399 .compat_ioctl = mtrr_ioctl,
400 .release = mtrr_close,
403 static int mtrr_seq_show(struct seq_file *seq, void *offset)
408 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 seq_printf(seq, "reg%02i: base=0x%06lx000 (%5luMB), size=%5lu%cB, count=%d: %s\n",
427 i, base, base >> (20 - PAGE_SHIFT),
429 mtrr_usage_table[i], mtrr_attrib_to_str(type));
434 static int __init mtrr_if_init(void)
436 struct cpuinfo_x86 *c = &boot_cpu_data;
438 if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
439 (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
440 (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
441 (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
444 proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);
447 arch_initcall(mtrr_if_init);
448 #endif /* CONFIG_PROC_FS */