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/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)
170 struct mtrr_sentry sentry;
171 struct mtrr_gentry gentry;
172 void __user *arg = (void __user *) __arg;
175 case MTRRIOC_ADD_ENTRY:
176 case MTRRIOC_SET_ENTRY:
177 case MTRRIOC_DEL_ENTRY:
178 case MTRRIOC_KILL_ENTRY:
179 case MTRRIOC_ADD_PAGE_ENTRY:
180 case MTRRIOC_SET_PAGE_ENTRY:
181 case MTRRIOC_DEL_PAGE_ENTRY:
182 case MTRRIOC_KILL_PAGE_ENTRY:
183 if (copy_from_user(&sentry, arg, sizeof sentry))
186 case MTRRIOC_GET_ENTRY:
187 case MTRRIOC_GET_PAGE_ENTRY:
188 if (copy_from_user(&gentry, arg, sizeof gentry))
192 case MTRRIOC32_ADD_ENTRY:
193 case MTRRIOC32_SET_ENTRY:
194 case MTRRIOC32_DEL_ENTRY:
195 case MTRRIOC32_KILL_ENTRY:
196 case MTRRIOC32_ADD_PAGE_ENTRY:
197 case MTRRIOC32_SET_PAGE_ENTRY:
198 case MTRRIOC32_DEL_PAGE_ENTRY:
199 case MTRRIOC32_KILL_PAGE_ENTRY: {
200 struct mtrr_sentry32 __user *s32;
202 s32 = (struct mtrr_sentry32 __user *)__arg;
203 err = get_user(sentry.base, &s32->base);
204 err |= get_user(sentry.size, &s32->size);
205 err |= get_user(sentry.type, &s32->type);
210 case MTRRIOC32_GET_ENTRY:
211 case MTRRIOC32_GET_PAGE_ENTRY: {
212 struct mtrr_gentry32 __user *g32;
214 g32 = (struct mtrr_gentry32 __user *)__arg;
215 err = get_user(gentry.regnum, &g32->regnum);
216 err |= get_user(gentry.base, &g32->base);
217 err |= get_user(gentry.size, &g32->size);
218 err |= get_user(gentry.type, &g32->type);
229 case MTRRIOC_ADD_ENTRY:
231 case MTRRIOC32_ADD_ENTRY:
233 if (!capable(CAP_SYS_ADMIN))
236 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
239 case MTRRIOC_SET_ENTRY:
241 case MTRRIOC32_SET_ENTRY:
243 if (!capable(CAP_SYS_ADMIN))
245 err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
247 case MTRRIOC_DEL_ENTRY:
249 case MTRRIOC32_DEL_ENTRY:
251 if (!capable(CAP_SYS_ADMIN))
253 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
255 case MTRRIOC_KILL_ENTRY:
257 case MTRRIOC32_KILL_ENTRY:
259 if (!capable(CAP_SYS_ADMIN))
261 err = mtrr_del(-1, sentry.base, sentry.size);
263 case MTRRIOC_GET_ENTRY:
265 case MTRRIOC32_GET_ENTRY:
267 if (gentry.regnum >= num_var_ranges)
269 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
271 /* Hide entries that go above 4GB */
272 if (gentry.base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
273 || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
274 gentry.base = gentry.size = gentry.type = 0;
276 gentry.base <<= PAGE_SHIFT;
277 gentry.size = size << PAGE_SHIFT;
282 case MTRRIOC_ADD_PAGE_ENTRY:
284 case MTRRIOC32_ADD_PAGE_ENTRY:
286 if (!capable(CAP_SYS_ADMIN))
289 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
292 case MTRRIOC_SET_PAGE_ENTRY:
294 case MTRRIOC32_SET_PAGE_ENTRY:
296 if (!capable(CAP_SYS_ADMIN))
299 mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
301 case MTRRIOC_DEL_PAGE_ENTRY:
303 case MTRRIOC32_DEL_PAGE_ENTRY:
305 if (!capable(CAP_SYS_ADMIN))
307 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
309 case MTRRIOC_KILL_PAGE_ENTRY:
311 case MTRRIOC32_KILL_PAGE_ENTRY:
313 if (!capable(CAP_SYS_ADMIN))
315 err = mtrr_del_page(-1, sentry.base, sentry.size);
317 case MTRRIOC_GET_PAGE_ENTRY:
319 case MTRRIOC32_GET_PAGE_ENTRY:
321 if (gentry.regnum >= num_var_ranges)
323 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
324 /* Hide entries that would overflow */
325 if (size != (__typeof__(gentry.size))size)
326 gentry.base = gentry.size = gentry.type = 0;
338 case MTRRIOC_GET_ENTRY:
339 case MTRRIOC_GET_PAGE_ENTRY:
340 if (copy_to_user(arg, &gentry, sizeof gentry))
344 case MTRRIOC32_GET_ENTRY:
345 case MTRRIOC32_GET_PAGE_ENTRY: {
346 struct mtrr_gentry32 __user *g32;
348 g32 = (struct mtrr_gentry32 __user *)__arg;
349 err = put_user(gentry.base, &g32->base);
350 err |= put_user(gentry.size, &g32->size);
351 err |= put_user(gentry.regnum, &g32->regnum);
352 err |= put_user(gentry.type, &g32->type);
360 static int mtrr_close(struct inode *ino, struct file *file)
362 unsigned int *fcount = FILE_FCOUNT(file);
365 if (fcount != NULL) {
366 max = num_var_ranges;
367 for (i = 0; i < max; ++i) {
368 while (fcount[i] > 0) {
374 FILE_FCOUNT(file) = NULL;
376 return single_release(ino, file);
379 static int mtrr_seq_show(struct seq_file *seq, void *offset);
381 static int mtrr_open(struct inode *inode, struct file *file)
387 return single_open(file, mtrr_seq_show, NULL);
390 static const struct file_operations mtrr_fops = {
391 .owner = THIS_MODULE,
396 .unlocked_ioctl = mtrr_ioctl,
397 .compat_ioctl = mtrr_ioctl,
398 .release = mtrr_close,
401 static int mtrr_seq_show(struct seq_file *seq, void *offset)
406 unsigned long base, size;
409 max = num_var_ranges;
410 for (i = 0; i < max; i++) {
411 mtrr_if->get(i, &base, &size, &type);
413 mtrr_usage_table[i] = 0;
416 if (size < (0x100000 >> PAGE_SHIFT)) {
419 size <<= PAGE_SHIFT - 10;
422 size >>= 20 - PAGE_SHIFT;
424 /* Base can be > 32bit */
425 len += seq_printf(seq, "reg%02i: base=0x%06lx000 "
426 "(%5luMB), size=%5lu%cB, count=%d: %s\n",
427 i, base, base >> (20 - PAGE_SHIFT), size,
428 factor, mtrr_usage_table[i],
429 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 */