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>
8
9#define LINE_SIZE 80
10
11#include <asm/mtrr.h>
12
13#include "mtrr.h"
14
15#define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
16
17static const char *const mtrr_strings[MTRR_NUM_TYPES] =
18{
19 "uncachable",
20 "write-combining",
21 "?",
22 "?",
23 "write-through",
24 "write-protect",
25 "write-back",
26};
27
28const char *mtrr_attrib_to_str(int x)
29{
30 return (x <= 6) ? mtrr_strings[x] : "?";
31}
32
33#ifdef CONFIG_PROC_FS
34
35static int
36mtrr_file_add(unsigned long base, unsigned long size,
37 unsigned int type, bool increment, struct file *file, int page)
38{
39 unsigned int *fcount = FILE_FCOUNT(file);
40 int reg, max;
41
42 max = num_var_ranges;
43 if (fcount == NULL) {
44 fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
45 if (!fcount)
46 return -ENOMEM;
47 FILE_FCOUNT(file) = fcount;
48 }
49 if (!page) {
50 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
51 return -EINVAL;
52 base >>= PAGE_SHIFT;
53 size >>= PAGE_SHIFT;
54 }
55 reg = mtrr_add_page(base, size, type, true);
56 if (reg >= 0)
57 ++fcount[reg];
58 return reg;
59}
60
61static int
62mtrr_file_del(unsigned long base, unsigned long size,
63 struct file *file, int page)
64{
65 unsigned int *fcount = FILE_FCOUNT(file);
66 int reg;
67
68 if (!page) {
69 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
70 return -EINVAL;
71 base >>= PAGE_SHIFT;
72 size >>= PAGE_SHIFT;
73 }
74 reg = mtrr_del_page(-1, base, size);
75 if (reg < 0)
76 return reg;
77 if (fcount == NULL)
78 return reg;
79 if (fcount[reg] < 1)
80 return -EINVAL;
81 --fcount[reg];
82 return reg;
83}
84
85
86
87
88
89
90
91static ssize_t
92mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
93{
94 int i, err;
95 unsigned long reg;
96 unsigned long long base, size;
97 char *ptr;
98 char line[LINE_SIZE];
99 int length;
100 size_t linelen;
101
102 if (!capable(CAP_SYS_ADMIN))
103 return -EPERM;
104
105 memset(line, 0, LINE_SIZE);
106
107 length = len;
108 length--;
109
110 if (length > LINE_SIZE - 1)
111 length = LINE_SIZE - 1;
112
113 if (length < 0)
114 return -EINVAL;
115
116 if (copy_from_user(line, buf, length))
117 return -EFAULT;
118
119 linelen = strlen(line);
120 ptr = line + linelen - 1;
121 if (linelen && *ptr == '\n')
122 *ptr = '\0';
123
124 if (!strncmp(line, "disable=", 8)) {
125 reg = simple_strtoul(line + 8, &ptr, 0);
126 err = mtrr_del_page(reg, 0, 0);
127 if (err < 0)
128 return err;
129 return len;
130 }
131
132 if (strncmp(line, "base=", 5))
133 return -EINVAL;
134
135 base = simple_strtoull(line + 5, &ptr, 0);
136 while (isspace(*ptr))
137 ptr++;
138
139 if (strncmp(ptr, "size=", 5))
140 return -EINVAL;
141
142 size = simple_strtoull(ptr + 5, &ptr, 0);
143 if ((base & 0xfff) || (size & 0xfff))
144 return -EINVAL;
145 while (isspace(*ptr))
146 ptr++;
147
148 if (strncmp(ptr, "type=", 5))
149 return -EINVAL;
150 ptr += 5;
151 while (isspace(*ptr))
152 ptr++;
153
154 for (i = 0; i < MTRR_NUM_TYPES; ++i) {
155 if (strcmp(ptr, mtrr_strings[i]))
156 continue;
157 base >>= PAGE_SHIFT;
158 size >>= PAGE_SHIFT;
159 err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
160 if (err < 0)
161 return err;
162 return len;
163 }
164 return -EINVAL;
165}
166
167static long
168mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
169{
170 int err = 0;
171 mtrr_type type;
172 unsigned long size;
173 struct mtrr_sentry sentry;
174 struct mtrr_gentry gentry;
175 void __user *arg = (void __user *) __arg;
176
177 switch (cmd) {
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))
187 return -EFAULT;
188 break;
189 case MTRRIOC_GET_ENTRY:
190 case MTRRIOC_GET_PAGE_ENTRY:
191 if (copy_from_user(&gentry, arg, sizeof gentry))
192 return -EFAULT;
193 break;
194#ifdef CONFIG_COMPAT
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;
204
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);
209 if (err)
210 return err;
211 break;
212 }
213 case MTRRIOC32_GET_ENTRY:
214 case MTRRIOC32_GET_PAGE_ENTRY: {
215 struct mtrr_gentry32 __user *g32;
216
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);
222 if (err)
223 return err;
224 break;
225 }
226#endif
227 }
228
229 switch (cmd) {
230 default:
231 return -ENOTTY;
232 case MTRRIOC_ADD_ENTRY:
233#ifdef CONFIG_COMPAT
234 case MTRRIOC32_ADD_ENTRY:
235#endif
236 if (!capable(CAP_SYS_ADMIN))
237 return -EPERM;
238 err =
239 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
240 file, 0);
241 break;
242 case MTRRIOC_SET_ENTRY:
243#ifdef CONFIG_COMPAT
244 case MTRRIOC32_SET_ENTRY:
245#endif
246 if (!capable(CAP_SYS_ADMIN))
247 return -EPERM;
248 err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
249 break;
250 case MTRRIOC_DEL_ENTRY:
251#ifdef CONFIG_COMPAT
252 case MTRRIOC32_DEL_ENTRY:
253#endif
254 if (!capable(CAP_SYS_ADMIN))
255 return -EPERM;
256 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
257 break;
258 case MTRRIOC_KILL_ENTRY:
259#ifdef CONFIG_COMPAT
260 case MTRRIOC32_KILL_ENTRY:
261#endif
262 if (!capable(CAP_SYS_ADMIN))
263 return -EPERM;
264 err = mtrr_del(-1, sentry.base, sentry.size);
265 break;
266 case MTRRIOC_GET_ENTRY:
267#ifdef CONFIG_COMPAT
268 case MTRRIOC32_GET_ENTRY:
269#endif
270 if (gentry.regnum >= num_var_ranges)
271 return -EINVAL;
272 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
273
274
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;
278 else {
279 gentry.base <<= PAGE_SHIFT;
280 gentry.size = size << PAGE_SHIFT;
281 gentry.type = type;
282 }
283
284 break;
285 case MTRRIOC_ADD_PAGE_ENTRY:
286#ifdef CONFIG_COMPAT
287 case MTRRIOC32_ADD_PAGE_ENTRY:
288#endif
289 if (!capable(CAP_SYS_ADMIN))
290 return -EPERM;
291 err =
292 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
293 file, 1);
294 break;
295 case MTRRIOC_SET_PAGE_ENTRY:
296#ifdef CONFIG_COMPAT
297 case MTRRIOC32_SET_PAGE_ENTRY:
298#endif
299 if (!capable(CAP_SYS_ADMIN))
300 return -EPERM;
301 err =
302 mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
303 break;
304 case MTRRIOC_DEL_PAGE_ENTRY:
305#ifdef CONFIG_COMPAT
306 case MTRRIOC32_DEL_PAGE_ENTRY:
307#endif
308 if (!capable(CAP_SYS_ADMIN))
309 return -EPERM;
310 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
311 break;
312 case MTRRIOC_KILL_PAGE_ENTRY:
313#ifdef CONFIG_COMPAT
314 case MTRRIOC32_KILL_PAGE_ENTRY:
315#endif
316 if (!capable(CAP_SYS_ADMIN))
317 return -EPERM;
318 err = mtrr_del_page(-1, sentry.base, sentry.size);
319 break;
320 case MTRRIOC_GET_PAGE_ENTRY:
321#ifdef CONFIG_COMPAT
322 case MTRRIOC32_GET_PAGE_ENTRY:
323#endif
324 if (gentry.regnum >= num_var_ranges)
325 return -EINVAL;
326 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
327
328 if (size != (__typeof__(gentry.size))size)
329 gentry.base = gentry.size = gentry.type = 0;
330 else {
331 gentry.size = size;
332 gentry.type = type;
333 }
334 break;
335 }
336
337 if (err)
338 return err;
339
340 switch (cmd) {
341 case MTRRIOC_GET_ENTRY:
342 case MTRRIOC_GET_PAGE_ENTRY:
343 if (copy_to_user(arg, &gentry, sizeof gentry))
344 err = -EFAULT;
345 break;
346#ifdef CONFIG_COMPAT
347 case MTRRIOC32_GET_ENTRY:
348 case MTRRIOC32_GET_PAGE_ENTRY: {
349 struct mtrr_gentry32 __user *g32;
350
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);
356 break;
357 }
358#endif
359 }
360 return err;
361}
362
363static int mtrr_close(struct inode *ino, struct file *file)
364{
365 unsigned int *fcount = FILE_FCOUNT(file);
366 int i, max;
367
368 if (fcount != NULL) {
369 max = num_var_ranges;
370 for (i = 0; i < max; ++i) {
371 while (fcount[i] > 0) {
372 mtrr_del(i, 0, 0);
373 --fcount[i];
374 }
375 }
376 kfree(fcount);
377 FILE_FCOUNT(file) = NULL;
378 }
379 return single_release(ino, file);
380}
381
382static int mtrr_seq_show(struct seq_file *seq, void *offset);
383
384static int mtrr_open(struct inode *inode, struct file *file)
385{
386 if (!mtrr_if)
387 return -EIO;
388 if (!mtrr_if->get)
389 return -ENXIO;
390 return single_open(file, mtrr_seq_show, NULL);
391}
392
393static const struct file_operations mtrr_fops = {
394 .owner = THIS_MODULE,
395 .open = mtrr_open,
396 .read = seq_read,
397 .llseek = seq_lseek,
398 .write = mtrr_write,
399 .unlocked_ioctl = mtrr_ioctl,
400 .compat_ioctl = mtrr_ioctl,
401 .release = mtrr_close,
402};
403
404static int mtrr_seq_show(struct seq_file *seq, void *offset)
405{
406 char factor;
407 int i, max, len;
408 mtrr_type type;
409 unsigned long base, size;
410
411 len = 0;
412 max = num_var_ranges;
413 for (i = 0; i < max; i++) {
414 mtrr_if->get(i, &base, &size, &type);
415 if (size == 0) {
416 mtrr_usage_table[i] = 0;
417 continue;
418 }
419 if (size < (0x100000 >> PAGE_SHIFT)) {
420
421 factor = 'K';
422 size <<= PAGE_SHIFT - 10;
423 } else {
424 factor = 'M';
425 size >>= 20 - PAGE_SHIFT;
426 }
427
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));
433 }
434 return 0;
435}
436
437static int __init mtrr_if_init(void)
438{
439 struct cpuinfo_x86 *c = &boot_cpu_data;
440
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)))
445 return -ENODEV;
446
447 proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);
448 return 0;
449}
450arch_initcall(mtrr_if_init);
451#endif
452
