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>
10
11#define LINE_SIZE 80
12
13#include <asm/mtrr.h>
14
15#include "mtrr.h"
16
17#define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
18
19static const char *const mtrr_strings[MTRR_NUM_TYPES] =
20{
21 "uncachable",
22 "write-combining",
23 "?",
24 "?",
25 "write-through",
26 "write-protect",
27 "write-back",
28};
29
30const char *mtrr_attrib_to_str(int x)
31{
32 return (x <= 6) ? mtrr_strings[x] : "?";
33}
34
35#ifdef CONFIG_PROC_FS
36
37static int
38mtrr_file_add(unsigned long base, unsigned long size,
39 unsigned int type, bool increment, struct file *file, int page)
40{
41 unsigned int *fcount = FILE_FCOUNT(file);
42 int reg, max;
43
44 max = num_var_ranges;
45 if (fcount == NULL) {
46 fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
47 if (!fcount)
48 return -ENOMEM;
49 FILE_FCOUNT(file) = fcount;
50 }
51 if (!page) {
52 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
53 return -EINVAL;
54 base >>= PAGE_SHIFT;
55 size >>= PAGE_SHIFT;
56 }
57 reg = mtrr_add_page(base, size, type, true);
58 if (reg >= 0)
59 ++fcount[reg];
60 return reg;
61}
62
63static int
64mtrr_file_del(unsigned long base, unsigned long size,
65 struct file *file, int page)
66{
67 unsigned int *fcount = FILE_FCOUNT(file);
68 int reg;
69
70 if (!page) {
71 if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
72 return -EINVAL;
73 base >>= PAGE_SHIFT;
74 size >>= PAGE_SHIFT;
75 }
76 reg = mtrr_del_page(-1, base, size);
77 if (reg < 0)
78 return reg;
79 if (fcount == NULL)
80 return reg;
81 if (fcount[reg] < 1)
82 return -EINVAL;
83 --fcount[reg];
84 return reg;
85}
86
87
88
89
90
91
92
93static ssize_t
94mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
95{
96 int i, err;
97 unsigned long reg;
98 unsigned long long base, size;
99 char *ptr;
100 char line[LINE_SIZE];
101 int length;
102 size_t linelen;
103
104 if (!capable(CAP_SYS_ADMIN))
105 return -EPERM;
106
107 memset(line, 0, LINE_SIZE);
108
109 length = len;
110 length--;
111
112 if (length > LINE_SIZE - 1)
113 length = LINE_SIZE - 1;
114
115 if (length < 0)
116 return -EINVAL;
117
118 if (copy_from_user(line, buf, length))
119 return -EFAULT;
120
121 linelen = strlen(line);
122 ptr = line + linelen - 1;
123 if (linelen && *ptr == '\n')
124 *ptr = '\0';
125
126 if (!strncmp(line, "disable=", 8)) {
127 reg = simple_strtoul(line + 8, &ptr, 0);
128 err = mtrr_del_page(reg, 0, 0);
129 if (err < 0)
130 return err;
131 return len;
132 }
133
134 if (strncmp(line, "base=", 5))
135 return -EINVAL;
136
137 base = simple_strtoull(line + 5, &ptr, 0);
138 ptr = skip_spaces(ptr);
139
140 if (strncmp(ptr, "size=", 5))
141 return -EINVAL;
142
143 size = simple_strtoull(ptr + 5, &ptr, 0);
144 if ((base & 0xfff) || (size & 0xfff))
145 return -EINVAL;
146 ptr = skip_spaces(ptr);
147
148 if (strncmp(ptr, "type=", 5))
149 return -EINVAL;
150 ptr = skip_spaces(ptr + 5);
151
152 for (i = 0; i < MTRR_NUM_TYPES; ++i) {
153 if (strcmp(ptr, mtrr_strings[i]))
154 continue;
155 base >>= PAGE_SHIFT;
156 size >>= PAGE_SHIFT;
157 err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
158 if (err < 0)
159 return err;
160 return len;
161 }
162 return -EINVAL;
163}
164
165static long
166mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
167{
168 int err = 0;
169 mtrr_type type;
170 unsigned long size;
171 struct mtrr_sentry sentry;
172 struct mtrr_gentry gentry;
173 void __user *arg = (void __user *) __arg;
174
175 switch (cmd) {
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))
185 return -EFAULT;
186 break;
187 case MTRRIOC_GET_ENTRY:
188 case MTRRIOC_GET_PAGE_ENTRY:
189 if (copy_from_user(&gentry, arg, sizeof gentry))
190 return -EFAULT;
191 break;
192#ifdef CONFIG_COMPAT
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;
202
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);
207 if (err)
208 return err;
209 break;
210 }
211 case MTRRIOC32_GET_ENTRY:
212 case MTRRIOC32_GET_PAGE_ENTRY: {
213 struct mtrr_gentry32 __user *g32;
214
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);
220 if (err)
221 return err;
222 break;
223 }
224#endif
225 }
226
227 switch (cmd) {
228 default:
229 return -ENOTTY;
230 case MTRRIOC_ADD_ENTRY:
231#ifdef CONFIG_COMPAT
232 case MTRRIOC32_ADD_ENTRY:
233#endif
234 if (!capable(CAP_SYS_ADMIN))
235 return -EPERM;
236 err =
237 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
238 file, 0);
239 break;
240 case MTRRIOC_SET_ENTRY:
241#ifdef CONFIG_COMPAT
242 case MTRRIOC32_SET_ENTRY:
243#endif
244 if (!capable(CAP_SYS_ADMIN))
245 return -EPERM;
246 err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
247 break;
248 case MTRRIOC_DEL_ENTRY:
249#ifdef CONFIG_COMPAT
250 case MTRRIOC32_DEL_ENTRY:
251#endif
252 if (!capable(CAP_SYS_ADMIN))
253 return -EPERM;
254 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
255 break;
256 case MTRRIOC_KILL_ENTRY:
257#ifdef CONFIG_COMPAT
258 case MTRRIOC32_KILL_ENTRY:
259#endif
260 if (!capable(CAP_SYS_ADMIN))
261 return -EPERM;
262 err = mtrr_del(-1, sentry.base, sentry.size);
263 break;
264 case MTRRIOC_GET_ENTRY:
265#ifdef CONFIG_COMPAT
266 case MTRRIOC32_GET_ENTRY:
267#endif
268 if (gentry.regnum >= num_var_ranges)
269 return -EINVAL;
270 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
271
272
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;
276 else {
277 gentry.base <<= PAGE_SHIFT;
278 gentry.size = size << PAGE_SHIFT;
279 gentry.type = type;
280 }
281
282 break;
283 case MTRRIOC_ADD_PAGE_ENTRY:
284#ifdef CONFIG_COMPAT
285 case MTRRIOC32_ADD_PAGE_ENTRY:
286#endif
287 if (!capable(CAP_SYS_ADMIN))
288 return -EPERM;
289 err =
290 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
291 file, 1);
292 break;
293 case MTRRIOC_SET_PAGE_ENTRY:
294#ifdef CONFIG_COMPAT
295 case MTRRIOC32_SET_PAGE_ENTRY:
296#endif
297 if (!capable(CAP_SYS_ADMIN))
298 return -EPERM;
299 err =
300 mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
301 break;
302 case MTRRIOC_DEL_PAGE_ENTRY:
303#ifdef CONFIG_COMPAT
304 case MTRRIOC32_DEL_PAGE_ENTRY:
305#endif
306 if (!capable(CAP_SYS_ADMIN))
307 return -EPERM;
308 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
309 break;
310 case MTRRIOC_KILL_PAGE_ENTRY:
311#ifdef CONFIG_COMPAT
312 case MTRRIOC32_KILL_PAGE_ENTRY:
313#endif
314 if (!capable(CAP_SYS_ADMIN))
315 return -EPERM;
316 err = mtrr_del_page(-1, sentry.base, sentry.size);
317 break;
318 case MTRRIOC_GET_PAGE_ENTRY:
319#ifdef CONFIG_COMPAT
320 case MTRRIOC32_GET_PAGE_ENTRY:
321#endif
322 if (gentry.regnum >= num_var_ranges)
323 return -EINVAL;
324 mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
325
326 if (size != (__typeof__(gentry.size))size)
327 gentry.base = gentry.size = gentry.type = 0;
328 else {
329 gentry.size = size;
330 gentry.type = type;
331 }
332 break;
333 }
334
335 if (err)
336 return err;
337
338 switch (cmd) {
339 case MTRRIOC_GET_ENTRY:
340 case MTRRIOC_GET_PAGE_ENTRY:
341 if (copy_to_user(arg, &gentry, sizeof gentry))
342 err = -EFAULT;
343 break;
344#ifdef CONFIG_COMPAT
345 case MTRRIOC32_GET_ENTRY:
346 case MTRRIOC32_GET_PAGE_ENTRY: {
347 struct mtrr_gentry32 __user *g32;
348
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);
354 break;
355 }
356#endif
357 }
358 return err;
359}
360
361static int mtrr_close(struct inode *ino, struct file *file)
362{
363 unsigned int *fcount = FILE_FCOUNT(file);
364 int i, max;
365
366 if (fcount != NULL) {
367 max = num_var_ranges;
368 for (i = 0; i < max; ++i) {
369 while (fcount[i] > 0) {
370 mtrr_del(i, 0, 0);
371 --fcount[i];
372 }
373 }
374 kfree(fcount);
375 FILE_FCOUNT(file) = NULL;
376 }
377 return single_release(ino, file);
378}
379
380static int mtrr_seq_show(struct seq_file *seq, void *offset);
381
382static int mtrr_open(struct inode *inode, struct file *file)
383{
384 if (!mtrr_if)
385 return -EIO;
386 if (!mtrr_if->get)
387 return -ENXIO;
388 return single_open(file, mtrr_seq_show, NULL);
389}
390
391static const struct file_operations mtrr_fops = {
392 .owner = THIS_MODULE,
393 .open = mtrr_open,
394 .read = seq_read,
395 .llseek = seq_lseek,
396 .write = mtrr_write,
397 .unlocked_ioctl = mtrr_ioctl,
398 .compat_ioctl = mtrr_ioctl,
399 .release = mtrr_close,
400};
401
402static int mtrr_seq_show(struct seq_file *seq, void *offset)
403{
404 char factor;
405 int i, max, len;
406 mtrr_type type;
407 unsigned long base, size;
408
409 len = 0;
410 max = num_var_ranges;
411 for (i = 0; i < max; i++) {
412 mtrr_if->get(i, &base, &size, &type);
413 if (size == 0) {
414 mtrr_usage_table[i] = 0;
415 continue;
416 }
417 if (size < (0x100000 >> PAGE_SHIFT)) {
418
419 factor = 'K';
420 size <<= PAGE_SHIFT - 10;
421 } else {
422 factor = 'M';
423 size >>= 20 - PAGE_SHIFT;
424 }
425
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));
431 }
432 return 0;
433}
434
435static int __init mtrr_if_init(void)
436{
437 struct cpuinfo_x86 *c = &boot_cpu_data;
438
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)))
443 return -ENODEV;
444
445 proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);
446 return 0;
447}
448arch_initcall(mtrr_if_init);
449#endif
450
