Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
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 :
19 : static const char *const mtrr_strings[MTRR_NUM_TYPES] =
20 : {
21 : "uncachable", /* 0 */
22 : "write-combining", /* 1 */
23 : "?", /* 2 */
24 : "?", /* 3 */
25 : "write-through", /* 4 */
26 : "write-protect", /* 5 */
27 : "write-back", /* 6 */
28 : };
29 :
30 0 : const char *mtrr_attrib_to_str(int x)
31 : {
32 0 : return (x <= 6) ? mtrr_strings[x] : "?";
33 : }
34 :
35 : #ifdef CONFIG_PROC_FS
36 :
37 : static int
38 0 : mtrr_file_add(unsigned long base, unsigned long size,
39 : unsigned int type, bool increment, struct file *file, int page)
40 : {
41 0 : unsigned int *fcount = FILE_FCOUNT(file);
42 0 : int reg, max;
43 :
44 0 : max = num_var_ranges;
45 0 : if (fcount == NULL) {
46 0 : fcount = kcalloc(max, sizeof(*fcount), GFP_KERNEL);
47 0 : if (!fcount)
48 : return -ENOMEM;
49 0 : FILE_FCOUNT(file) = fcount;
50 : }
51 0 : if (!page) {
52 0 : if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
53 : return -EINVAL;
54 0 : base >>= PAGE_SHIFT;
55 0 : size >>= PAGE_SHIFT;
56 : }
57 0 : reg = mtrr_add_page(base, size, type, true);
58 0 : if (reg >= 0)
59 0 : ++fcount[reg];
60 : return reg;
61 : }
62 :
63 : static int
64 0 : mtrr_file_del(unsigned long base, unsigned long size,
65 : struct file *file, int page)
66 : {
67 0 : unsigned int *fcount = FILE_FCOUNT(file);
68 0 : int reg;
69 :
70 0 : if (!page) {
71 0 : if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
72 : return -EINVAL;
73 0 : base >>= PAGE_SHIFT;
74 0 : size >>= PAGE_SHIFT;
75 : }
76 0 : reg = mtrr_del_page(-1, base, size);
77 0 : if (reg < 0)
78 : return reg;
79 0 : if (fcount == NULL)
80 : return reg;
81 0 : if (fcount[reg] < 1)
82 : return -EINVAL;
83 0 : --fcount[reg];
84 0 : return reg;
85 : }
86 :
87 : /*
88 : * seq_file can seek but we ignore it.
89 : *
90 : * Format of control line:
91 : * "base=%Lx size=%Lx type=%s" or "disable=%d"
92 : */
93 : static ssize_t
94 0 : mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
95 : {
96 0 : int i, err;
97 0 : unsigned long reg;
98 0 : unsigned long long base, size;
99 0 : char *ptr;
100 0 : char line[LINE_SIZE];
101 0 : int length;
102 0 : size_t linelen;
103 :
104 0 : memset(line, 0, LINE_SIZE);
105 :
106 0 : len = min_t(size_t, len, LINE_SIZE - 1);
107 0 : length = strncpy_from_user(line, buf, len);
108 0 : if (length < 0)
109 0 : return length;
110 :
111 0 : linelen = strlen(line);
112 0 : ptr = line + linelen - 1;
113 0 : if (linelen && *ptr == '\n')
114 0 : *ptr = '\0';
115 :
116 0 : if (!strncmp(line, "disable=", 8)) {
117 0 : reg = simple_strtoul(line + 8, &ptr, 0);
118 0 : err = mtrr_del_page(reg, 0, 0);
119 0 : if (err < 0)
120 0 : return err;
121 : return len;
122 : }
123 :
124 0 : if (strncmp(line, "base=", 5))
125 : return -EINVAL;
126 :
127 0 : base = simple_strtoull(line + 5, &ptr, 0);
128 0 : ptr = skip_spaces(ptr);
129 :
130 0 : if (strncmp(ptr, "size=", 5))
131 : return -EINVAL;
132 :
133 0 : size = simple_strtoull(ptr + 5, &ptr, 0);
134 0 : if ((base & 0xfff) || (size & 0xfff))
135 : return -EINVAL;
136 0 : ptr = skip_spaces(ptr);
137 :
138 0 : if (strncmp(ptr, "type=", 5))
139 : return -EINVAL;
140 0 : ptr = skip_spaces(ptr + 5);
141 :
142 0 : i = match_string(mtrr_strings, MTRR_NUM_TYPES, ptr);
143 0 : if (i < 0)
144 0 : return i;
145 :
146 0 : base >>= PAGE_SHIFT;
147 0 : size >>= PAGE_SHIFT;
148 0 : err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
149 0 : if (err < 0)
150 0 : return err;
151 : return len;
152 : }
153 :
154 : static long
155 0 : mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
156 : {
157 0 : int err = 0;
158 0 : mtrr_type type;
159 0 : unsigned long base;
160 0 : unsigned long size;
161 0 : struct mtrr_sentry sentry;
162 0 : struct mtrr_gentry gentry;
163 0 : void __user *arg = (void __user *) __arg;
164 :
165 0 : memset(&gentry, 0, sizeof(gentry));
166 :
167 0 : switch (cmd) {
168 : case MTRRIOC_ADD_ENTRY:
169 : case MTRRIOC_SET_ENTRY:
170 : case MTRRIOC_DEL_ENTRY:
171 : case MTRRIOC_KILL_ENTRY:
172 : case MTRRIOC_ADD_PAGE_ENTRY:
173 : case MTRRIOC_SET_PAGE_ENTRY:
174 : case MTRRIOC_DEL_PAGE_ENTRY:
175 : case MTRRIOC_KILL_PAGE_ENTRY:
176 0 : if (copy_from_user(&sentry, arg, sizeof(sentry)))
177 : return -EFAULT;
178 : break;
179 : case MTRRIOC_GET_ENTRY:
180 : case MTRRIOC_GET_PAGE_ENTRY:
181 0 : if (copy_from_user(&gentry, arg, sizeof(gentry)))
182 : return -EFAULT;
183 : break;
184 : #ifdef CONFIG_COMPAT
185 0 : case MTRRIOC32_ADD_ENTRY:
186 : case MTRRIOC32_SET_ENTRY:
187 : case MTRRIOC32_DEL_ENTRY:
188 : case MTRRIOC32_KILL_ENTRY:
189 : case MTRRIOC32_ADD_PAGE_ENTRY:
190 : case MTRRIOC32_SET_PAGE_ENTRY:
191 : case MTRRIOC32_DEL_PAGE_ENTRY:
192 : case MTRRIOC32_KILL_PAGE_ENTRY: {
193 0 : struct mtrr_sentry32 __user *s32;
194 :
195 0 : s32 = (struct mtrr_sentry32 __user *)__arg;
196 0 : err = get_user(sentry.base, &s32->base);
197 0 : err |= get_user(sentry.size, &s32->size);
198 0 : err |= get_user(sentry.type, &s32->type);
199 0 : if (err)
200 0 : return err;
201 : break;
202 : }
203 0 : case MTRRIOC32_GET_ENTRY:
204 : case MTRRIOC32_GET_PAGE_ENTRY: {
205 0 : struct mtrr_gentry32 __user *g32;
206 :
207 0 : g32 = (struct mtrr_gentry32 __user *)__arg;
208 0 : err = get_user(gentry.regnum, &g32->regnum);
209 0 : err |= get_user(gentry.base, &g32->base);
210 0 : err |= get_user(gentry.size, &g32->size);
211 0 : err |= get_user(gentry.type, &g32->type);
212 0 : if (err)
213 0 : return err;
214 : break;
215 : }
216 : #endif
217 : }
218 :
219 0 : switch (cmd) {
220 : default:
221 : return -ENOTTY;
222 0 : case MTRRIOC_ADD_ENTRY:
223 : #ifdef CONFIG_COMPAT
224 : case MTRRIOC32_ADD_ENTRY:
225 : #endif
226 0 : err =
227 0 : mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
228 : file, 0);
229 0 : break;
230 0 : case MTRRIOC_SET_ENTRY:
231 : #ifdef CONFIG_COMPAT
232 : case MTRRIOC32_SET_ENTRY:
233 : #endif
234 0 : err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
235 0 : break;
236 0 : case MTRRIOC_DEL_ENTRY:
237 : #ifdef CONFIG_COMPAT
238 : case MTRRIOC32_DEL_ENTRY:
239 : #endif
240 0 : err = mtrr_file_del(sentry.base, sentry.size, file, 0);
241 0 : break;
242 0 : case MTRRIOC_KILL_ENTRY:
243 : #ifdef CONFIG_COMPAT
244 : case MTRRIOC32_KILL_ENTRY:
245 : #endif
246 0 : err = mtrr_del(-1, sentry.base, sentry.size);
247 0 : break;
248 0 : case MTRRIOC_GET_ENTRY:
249 : #ifdef CONFIG_COMPAT
250 : case MTRRIOC32_GET_ENTRY:
251 : #endif
252 0 : if (gentry.regnum >= num_var_ranges)
253 : return -EINVAL;
254 0 : mtrr_if->get(gentry.regnum, &base, &size, &type);
255 :
256 : /* Hide entries that go above 4GB */
257 0 : if (base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
258 0 : || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
259 0 : gentry.base = gentry.size = gentry.type = 0;
260 : else {
261 0 : gentry.base = base << PAGE_SHIFT;
262 0 : gentry.size = size << PAGE_SHIFT;
263 0 : gentry.type = type;
264 : }
265 :
266 : break;
267 0 : case MTRRIOC_ADD_PAGE_ENTRY:
268 : #ifdef CONFIG_COMPAT
269 : case MTRRIOC32_ADD_PAGE_ENTRY:
270 : #endif
271 0 : err =
272 0 : mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
273 : file, 1);
274 0 : break;
275 0 : case MTRRIOC_SET_PAGE_ENTRY:
276 : #ifdef CONFIG_COMPAT
277 : case MTRRIOC32_SET_PAGE_ENTRY:
278 : #endif
279 0 : err =
280 0 : mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
281 0 : break;
282 0 : case MTRRIOC_DEL_PAGE_ENTRY:
283 : #ifdef CONFIG_COMPAT
284 : case MTRRIOC32_DEL_PAGE_ENTRY:
285 : #endif
286 0 : err = mtrr_file_del(sentry.base, sentry.size, file, 1);
287 0 : break;
288 0 : case MTRRIOC_KILL_PAGE_ENTRY:
289 : #ifdef CONFIG_COMPAT
290 : case MTRRIOC32_KILL_PAGE_ENTRY:
291 : #endif
292 0 : err = mtrr_del_page(-1, sentry.base, sentry.size);
293 0 : break;
294 0 : case MTRRIOC_GET_PAGE_ENTRY:
295 : #ifdef CONFIG_COMPAT
296 : case MTRRIOC32_GET_PAGE_ENTRY:
297 : #endif
298 0 : if (gentry.regnum >= num_var_ranges)
299 : return -EINVAL;
300 0 : mtrr_if->get(gentry.regnum, &base, &size, &type);
301 : /* Hide entries that would overflow */
302 0 : if (size != (__typeof__(gentry.size))size)
303 0 : gentry.base = gentry.size = gentry.type = 0;
304 : else {
305 0 : gentry.base = base;
306 0 : gentry.size = size;
307 0 : gentry.type = type;
308 : }
309 : break;
310 : }
311 :
312 0 : if (err)
313 0 : return err;
314 :
315 0 : switch (cmd) {
316 : case MTRRIOC_GET_ENTRY:
317 : case MTRRIOC_GET_PAGE_ENTRY:
318 0 : if (copy_to_user(arg, &gentry, sizeof(gentry)))
319 0 : err = -EFAULT;
320 : break;
321 : #ifdef CONFIG_COMPAT
322 0 : case MTRRIOC32_GET_ENTRY:
323 : case MTRRIOC32_GET_PAGE_ENTRY: {
324 0 : struct mtrr_gentry32 __user *g32;
325 :
326 0 : g32 = (struct mtrr_gentry32 __user *)__arg;
327 0 : err = put_user(gentry.base, &g32->base);
328 0 : err |= put_user(gentry.size, &g32->size);
329 0 : err |= put_user(gentry.regnum, &g32->regnum);
330 0 : err |= put_user(gentry.type, &g32->type);
331 0 : break;
332 : }
333 : #endif
334 : }
335 0 : return err;
336 : }
337 :
338 0 : static int mtrr_close(struct inode *ino, struct file *file)
339 : {
340 0 : unsigned int *fcount = FILE_FCOUNT(file);
341 0 : int i, max;
342 :
343 0 : if (fcount != NULL) {
344 0 : max = num_var_ranges;
345 0 : for (i = 0; i < max; ++i) {
346 0 : while (fcount[i] > 0) {
347 0 : mtrr_del(i, 0, 0);
348 0 : --fcount[i];
349 : }
350 : }
351 0 : kfree(fcount);
352 0 : FILE_FCOUNT(file) = NULL;
353 : }
354 0 : return single_release(ino, file);
355 : }
356 :
357 0 : static int mtrr_seq_show(struct seq_file *seq, void *offset)
358 : {
359 0 : char factor;
360 0 : int i, max;
361 0 : mtrr_type type;
362 0 : unsigned long base, size;
363 :
364 0 : max = num_var_ranges;
365 0 : for (i = 0; i < max; i++) {
366 0 : mtrr_if->get(i, &base, &size, &type);
367 0 : if (size == 0) {
368 0 : mtrr_usage_table[i] = 0;
369 0 : continue;
370 : }
371 0 : if (size < (0x100000 >> PAGE_SHIFT)) {
372 : /* less than 1MB */
373 0 : factor = 'K';
374 0 : size <<= PAGE_SHIFT - 10;
375 : } else {
376 0 : factor = 'M';
377 0 : size >>= 20 - PAGE_SHIFT;
378 : }
379 : /* Base can be > 32bit */
380 0 : seq_printf(seq, "reg%02i: base=0x%06lx000 (%5luMB), size=%5lu%cB, count=%d: %s\n",
381 : i, base, base >> (20 - PAGE_SHIFT),
382 : size, factor,
383 : mtrr_usage_table[i], mtrr_attrib_to_str(type));
384 : }
385 0 : return 0;
386 : }
387 :
388 0 : static int mtrr_open(struct inode *inode, struct file *file)
389 : {
390 0 : if (!mtrr_if)
391 : return -EIO;
392 0 : if (!mtrr_if->get)
393 : return -ENXIO;
394 0 : if (!capable(CAP_SYS_ADMIN))
395 : return -EPERM;
396 0 : return single_open(file, mtrr_seq_show, NULL);
397 : }
398 :
399 : static const struct proc_ops mtrr_proc_ops = {
400 : .proc_open = mtrr_open,
401 : .proc_read = seq_read,
402 : .proc_lseek = seq_lseek,
403 : .proc_write = mtrr_write,
404 : .proc_ioctl = mtrr_ioctl,
405 : #ifdef CONFIG_COMPAT
406 : .proc_compat_ioctl = mtrr_ioctl,
407 : #endif
408 : .proc_release = mtrr_close,
409 : };
410 :
411 1 : static int __init mtrr_if_init(void)
412 : {
413 1 : struct cpuinfo_x86 *c = &boot_cpu_data;
414 :
415 1 : if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
416 0 : (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
417 0 : (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
418 0 : (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
419 : return -ENODEV;
420 :
421 1 : proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_proc_ops);
422 1 : return 0;
423 : }
424 : arch_initcall(mtrr_if_init);
425 : #endif /* CONFIG_PROC_FS */
|
