1
2#include <linux/capability.h>
3#include <linux/seq_file.h>
4#include <linux/uaccess.h>
5#include <linux/proc_fs.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 = kcalloc(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 len = min_t(size_t, len, LINE_SIZE - 1);
110 length = strncpy_from_user(line, buf, len);
111 if (length < 0)
112 return length;
113
114 linelen = strlen(line);
115 ptr = line + linelen - 1;
116 if (linelen && *ptr == '\n')
117 *ptr = '\0';
118
119 if (!strncmp(line, "disable=", 8)) {
120 reg = simple_strtoul(line + 8, &ptr, 0);
121 err = mtrr_del_page(reg, 0, 0);
122 if (err < 0)
123 return err;
124 return len;
125 }
126
127 if (strncmp(line, "base=", 5))
128 return -EINVAL;
129
130 base = simple_strtoull(line + 5, &ptr, 0);
131 ptr = skip_spaces(ptr);
132
133 if (strncmp(ptr, "size=", 5))
134 return -EINVAL;
135
136 size = simple_strtoull(ptr + 5, &ptr, 0);
137 if ((base & 0xfff) || (size & 0xfff))
138 return -EINVAL;
139 ptr = skip_spaces(ptr);
140
141 if (strncmp(ptr, "type=", 5))
142 return -EINVAL;
143 ptr = skip_spaces(ptr + 5);
144
145 i = match_string(mtrr_strings, MTRR_NUM_TYPES, ptr);
146 if (i < 0)
147 return i;
148
149 base >>= PAGE_SHIFT;
150 size >>= PAGE_SHIFT;
151 err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
152 if (err < 0)
153 return err;
154 return len;
155}
156
157static long
158mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
159{
160 int err = 0;
161 mtrr_type type;
162 unsigned long base;
163 unsigned long size;
164 struct mtrr_sentry sentry;
165 struct mtrr_gentry gentry;
166 void __user *arg = (void __user *) __arg;
167
168 memset(&gentry, 0, sizeof(gentry));
169
170 switch (cmd) {
171 case MTRRIOC_ADD_ENTRY:
172 case MTRRIOC_SET_ENTRY:
173 case MTRRIOC_DEL_ENTRY:
174 case MTRRIOC_KILL_ENTRY:
175 case MTRRIOC_ADD_PAGE_ENTRY:
176 case MTRRIOC_SET_PAGE_ENTRY:
177 case MTRRIOC_DEL_PAGE_ENTRY:
178 case MTRRIOC_KILL_PAGE_ENTRY:
179 if (copy_from_user(&sentry, arg, sizeof(sentry)))
180 return -EFAULT;
181 break;
182 case MTRRIOC_GET_ENTRY:
183 case MTRRIOC_GET_PAGE_ENTRY:
184 if (copy_from_user(&gentry, arg, sizeof(gentry)))
185 return -EFAULT;
186 break;
187#ifdef CONFIG_COMPAT
188 case MTRRIOC32_ADD_ENTRY:
189 case MTRRIOC32_SET_ENTRY:
190 case MTRRIOC32_DEL_ENTRY:
191 case MTRRIOC32_KILL_ENTRY:
192 case MTRRIOC32_ADD_PAGE_ENTRY:
193 case MTRRIOC32_SET_PAGE_ENTRY:
194 case MTRRIOC32_DEL_PAGE_ENTRY:
195 case MTRRIOC32_KILL_PAGE_ENTRY: {
196 struct mtrr_sentry32 __user *s32;
197
198 s32 = (struct mtrr_sentry32 __user *)__arg;
199 err = get_user(sentry.base, &s32->base);
200 err |= get_user(sentry.size, &s32->size);
201 err |= get_user(sentry.type, &s32->type);
202 if (err)
203 return err;
204 break;
205 }
206 case MTRRIOC32_GET_ENTRY:
207 case MTRRIOC32_GET_PAGE_ENTRY: {
208 struct mtrr_gentry32 __user *g32;
209
210 g32 = (struct mtrr_gentry32 __user *)__arg;
211 err = get_user(gentry.regnum, &g32->regnum);
212 err |= get_user(gentry.base, &g32->base);
213 err |= get_user(gentry.size, &g32->size);
214 err |= get_user(gentry.type, &g32->type);
215 if (err)
216 return err;
217 break;
218 }
219#endif
220 }
221
222 switch (cmd) {
223 default:
224 return -ENOTTY;
225 case MTRRIOC_ADD_ENTRY:
226#ifdef CONFIG_COMPAT
227 case MTRRIOC32_ADD_ENTRY:
228#endif
229 if (!capable(CAP_SYS_ADMIN))
230 return -EPERM;
231 err =
232 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
233 file, 0);
234 break;
235 case MTRRIOC_SET_ENTRY:
236#ifdef CONFIG_COMPAT
237 case MTRRIOC32_SET_ENTRY:
238#endif
239 if (!capable(CAP_SYS_ADMIN))
240 return -EPERM;
241 err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
242 break;
243 case MTRRIOC_DEL_ENTRY:
244#ifdef CONFIG_COMPAT
245 case MTRRIOC32_DEL_ENTRY:
246#endif
247 if (!capable(CAP_SYS_ADMIN))
248 return -EPERM;
249 err = mtrr_file_del(sentry.base, sentry.size, file, 0);
250 break;
251 case MTRRIOC_KILL_ENTRY:
252#ifdef CONFIG_COMPAT
253 case MTRRIOC32_KILL_ENTRY:
254#endif
255 if (!capable(CAP_SYS_ADMIN))
256 return -EPERM;
257 err = mtrr_del(-1, sentry.base, sentry.size);
258 break;
259 case MTRRIOC_GET_ENTRY:
260#ifdef CONFIG_COMPAT
261 case MTRRIOC32_GET_ENTRY:
262#endif
263 if (gentry.regnum >= num_var_ranges)
264 return -EINVAL;
265 mtrr_if->get(gentry.regnum, &base, &size, &type);
266
267
268 if (base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
269 || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
270 gentry.base = gentry.size = gentry.type = 0;
271 else {
272 gentry.base = base << PAGE_SHIFT;
273 gentry.size = size << PAGE_SHIFT;
274 gentry.type = type;
275 }
276
277 break;
278 case MTRRIOC_ADD_PAGE_ENTRY:
279#ifdef CONFIG_COMPAT
280 case MTRRIOC32_ADD_PAGE_ENTRY:
281#endif
282 if (!capable(CAP_SYS_ADMIN))
283 return -EPERM;
284 err =
285 mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
286 file, 1);
287 break;
288 case MTRRIOC_SET_PAGE_ENTRY:
289#ifdef CONFIG_COMPAT
290 case MTRRIOC32_SET_PAGE_ENTRY:
291#endif
292 if (!capable(CAP_SYS_ADMIN))
293 return -EPERM;
294 err =
295 mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
296 break;
297 case MTRRIOC_DEL_PAGE_ENTRY:
298#ifdef CONFIG_COMPAT
299 case MTRRIOC32_DEL_PAGE_ENTRY:
300#endif
301 if (!capable(CAP_SYS_ADMIN))
302 return -EPERM;
303 err = mtrr_file_del(sentry.base, sentry.size, file, 1);
304 break;
305 case MTRRIOC_KILL_PAGE_ENTRY:
306#ifdef CONFIG_COMPAT
307 case MTRRIOC32_KILL_PAGE_ENTRY:
308#endif
309 if (!capable(CAP_SYS_ADMIN))
310 return -EPERM;
311 err = mtrr_del_page(-1, sentry.base, sentry.size);
312 break;
313 case MTRRIOC_GET_PAGE_ENTRY:
314#ifdef CONFIG_COMPAT
315 case MTRRIOC32_GET_PAGE_ENTRY:
316#endif
317 if (gentry.regnum >= num_var_ranges)
318 return -EINVAL;
319 mtrr_if->get(gentry.regnum, &base, &size, &type);
320
321 if (size != (__typeof__(gentry.size))size)
322 gentry.base = gentry.size = gentry.type = 0;
323 else {
324 gentry.base = base;
325 gentry.size = size;
326 gentry.type = type;
327 }
328 break;
329 }
330
331 if (err)
332 return err;
333
334 switch (cmd) {
335 case MTRRIOC_GET_ENTRY:
336 case MTRRIOC_GET_PAGE_ENTRY:
337 if (copy_to_user(arg, &gentry, sizeof(gentry)))
338 err = -EFAULT;
339 break;
340#ifdef CONFIG_COMPAT
341 case MTRRIOC32_GET_ENTRY:
342 case MTRRIOC32_GET_PAGE_ENTRY: {
343 struct mtrr_gentry32 __user *g32;
344
345 g32 = (struct mtrr_gentry32 __user *)__arg;
346 err = put_user(gentry.base, &g32->base);
347 err |= put_user(gentry.size, &g32->size);
348 err |= put_user(gentry.regnum, &g32->regnum);
349 err |= put_user(gentry.type, &g32->type);
350 break;
351 }
352#endif
353 }
354 return err;
355}
356
357static int mtrr_close(struct inode *ino, struct file *file)
358{
359 unsigned int *fcount = FILE_FCOUNT(file);
360 int i, max;
361
362 if (fcount != NULL) {
363 max = num_var_ranges;
364 for (i = 0; i < max; ++i) {
365 while (fcount[i] > 0) {
366 mtrr_del(i, 0, 0);
367 --fcount[i];
368 }
369 }
370 kfree(fcount);
371 FILE_FCOUNT(file) = NULL;
372 }
373 return single_release(ino, file);
374}
375
376static int mtrr_seq_show(struct seq_file *seq, void *offset);
377
378static int mtrr_open(struct inode *inode, struct file *file)
379{
380 if (!mtrr_if)
381 return -EIO;
382 if (!mtrr_if->get)
383 return -ENXIO;
384 return single_open(file, mtrr_seq_show, NULL);
385}
386
387static const struct file_operations mtrr_fops = {
388 .owner = THIS_MODULE,
389 .open = mtrr_open,
390 .read = seq_read,
391 .llseek = seq_lseek,
392 .write = mtrr_write,
393 .unlocked_ioctl = mtrr_ioctl,
394 .compat_ioctl = mtrr_ioctl,
395 .release = mtrr_close,
396};
397
398static int mtrr_seq_show(struct seq_file *seq, void *offset)
399{
400 char factor;
401 int i, max;
402 mtrr_type type;
403 unsigned long base, size;
404
405 max = num_var_ranges;
406 for (i = 0; i < max; i++) {
407 mtrr_if->get(i, &base, &size, &type);
408 if (size == 0) {
409 mtrr_usage_table[i] = 0;
410 continue;
411 }
412 if (size < (0x100000 >> PAGE_SHIFT)) {
413
414 factor = 'K';
415 size <<= PAGE_SHIFT - 10;
416 } else {
417 factor = 'M';
418 size >>= 20 - PAGE_SHIFT;
419 }
420
421 seq_printf(seq, "reg%02i: base=0x%06lx000 (%5luMB), size=%5lu%cB, count=%d: %s\n",
422 i, base, base >> (20 - PAGE_SHIFT),
423 size, factor,
424 mtrr_usage_table[i], mtrr_attrib_to_str(type));
425 }
426 return 0;
427}
428
429static int __init mtrr_if_init(void)
430{
431 struct cpuinfo_x86 *c = &boot_cpu_data;
432
433 if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
434 (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
435 (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
436 (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
437 return -ENODEV;
438
439 proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);
440 return 0;
441}
442arch_initcall(mtrr_if_init);
443#endif
444
