aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/cpu/mtrr/if.c
blob: 84c480bb3715af21405c6d55fab0f3160cbf3a59 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/capability.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>

#define LINE_SIZE 80

#include <asm/mtrr.h>
#include "mtrr.h"

#define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)

static const char *const mtrr_strings[MTRR_NUM_TYPES] =
{
    "uncachable",               /* 0 */
    "write-combining",          /* 1 */
    "?",                        /* 2 */
    "?",                        /* 3 */
    "write-through",            /* 4 */
    "write-protect",            /* 5 */
    "write-back",               /* 6 */
};

const char *mtrr_attrib_to_str(int x)
{
	return (x <= 6) ? mtrr_strings[x] : "?";
}

#ifdef CONFIG_PROC_FS

static int
mtrr_file_add(unsigned long base, unsigned long size,
	      unsigned int type, bool increment, struct file *file, int page)
{
	int reg, max;
	unsigned int *fcount = FILE_FCOUNT(file); 

	max = num_var_ranges;
	if (fcount == NULL) {
		fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
		if (!fcount)
			return -ENOMEM;
		FILE_FCOUNT(file) = fcount;
	}
	if (!page) {
		if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
			return -EINVAL;
		base >>= PAGE_SHIFT;
		size >>= PAGE_SHIFT;
	}
	reg = mtrr_add_page(base, size, type, true);
	if (reg >= 0)
		++fcount[reg];
	return reg;
}

static int
mtrr_file_del(unsigned long base, unsigned long size,
	      struct file *file, int page)
{
	int reg;
	unsigned int *fcount = FILE_FCOUNT(file);

	if (!page) {
		if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
			return -EINVAL;
		base >>= PAGE_SHIFT;
		size >>= PAGE_SHIFT;
	}
	reg = mtrr_del_page(-1, base, size);
	if (reg < 0)
		return reg;
	if (fcount == NULL)
		return reg;
	if (fcount[reg] < 1)
		return -EINVAL;
	--fcount[reg];
	return reg;
}

/* RED-PEN: seq_file can seek now. this is ignored. */
static ssize_t
mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
/*  Format of control line:
    "base=%Lx size=%Lx type=%s"     OR:
    "disable=%d"
*/
{
	int i, err;
	unsigned long reg;
	unsigned long long base, size;
	char *ptr;
	char line[LINE_SIZE];
	size_t linelen;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
	if (!len)
		return -EINVAL;
	memset(line, 0, LINE_SIZE);
	if (len > LINE_SIZE)
		len = LINE_SIZE;
	if (copy_from_user(line, buf, len - 1))
		return -EFAULT;
	linelen = strlen(line);
	ptr = line + linelen - 1;
	if (linelen && *ptr == '\n')
		*ptr = '\0';
	if (!strncmp(line, "disable=", 8)) {
		reg = simple_strtoul(line + 8, &ptr, 0);
		err = mtrr_del_page(reg, 0, 0);
		if (err < 0)
			return err;
		return len;
	}
	if (strncmp(line, "base=", 5))
		return -EINVAL;
	base = simple_strtoull(line + 5, &ptr, 0);
	for (; isspace(*ptr); ++ptr) ;
	if (strncmp(ptr, "size=", 5))
		return -EINVAL;
	size = simple_strtoull(ptr + 5, &ptr, 0);
	if ((base & 0xfff) || (size & 0xfff))
		return -EINVAL;
	for (; isspace(*ptr); ++ptr) ;
	if (strncmp(ptr, "type=", 5))
		return -EINVAL;
	ptr += 5;
	for (; isspace(*ptr); ++ptr) ;
	for (i = 0; i < MTRR_NUM_TYPES; ++i) {
		if (strcmp(ptr, mtrr_strings[i]))
			continue;
		base >>= PAGE_SHIFT;
		size >>= PAGE_SHIFT;
		err =
		    mtrr_add_page((unsigned long) base, (unsigned long) size, i,
				  true);
		if (err < 0)
			return err;
		return len;
	}
	return -EINVAL;
}

static long
mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
{
	int err = 0;
	mtrr_type type;
	unsigned long size;
	struct mtrr_sentry sentry;
	struct mtrr_gentry gentry;
	void __user *arg = (void __user *) __arg;

	switch (cmd) {
	case MTRRIOC_ADD_ENTRY:
	case MTRRIOC_SET_ENTRY:
	case MTRRIOC_DEL_ENTRY:
	case MTRRIOC_KILL_ENTRY:
	case MTRRIOC_ADD_PAGE_ENTRY:
	case MTRRIOC_SET_PAGE_ENTRY:
	case MTRRIOC_DEL_PAGE_ENTRY:
	case MTRRIOC_KILL_PAGE_ENTRY:
		if (copy_from_user(&sentry, arg, sizeof sentry))
			return -EFAULT;
		break;
	case MTRRIOC_GET_ENTRY:
	case MTRRIOC_GET_PAGE_ENTRY:
		if (copy_from_user(&gentry, arg, sizeof gentry))
			return -EFAULT;
		break;
#ifdef CONFIG_COMPAT
	case MTRRIOC32_ADD_ENTRY:
	case MTRRIOC32_SET_ENTRY:
	case MTRRIOC32_DEL_ENTRY:
	case MTRRIOC32_KILL_ENTRY:
	case MTRRIOC32_ADD_PAGE_ENTRY:
	case MTRRIOC32_SET_PAGE_ENTRY:
	case MTRRIOC32_DEL_PAGE_ENTRY:
	case MTRRIOC32_KILL_PAGE_ENTRY: {
		struct mtrr_sentry32 __user *s32 = (struct mtrr_sentry32 __user *)__arg;
		err = get_user(sentry.base, &s32->base);
		err |= get_user(sentry.size, &s32->size);
		err |= get_user(sentry.type, &s32->type);
		if (err)
			return err;
		break;
	}
	case MTRRIOC32_GET_ENTRY:
	case MTRRIOC32_GET_PAGE_ENTRY: {
		struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
		err = get_user(gentry.regnum, &g32->regnum);
		err |= get_user(gentry.base, &g32->base);
		err |= get_user(gentry.size, &g32->size);
		err |= get_user(gentry.type, &g32->type);
		if (err)
			return err;
		break;
	}
#endif
	}

	switch (cmd) {
	default:
		return -ENOTTY;
	case MTRRIOC_ADD_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_ADD_ENTRY:
#endif
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		err =
		    mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
				  file, 0);
		break;
	case MTRRIOC_SET_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_SET_ENTRY:
#endif
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
		break;
	case MTRRIOC_DEL_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_DEL_ENTRY:
#endif
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		err = mtrr_file_del(sentry.base, sentry.size, file, 0);
		break;
	case MTRRIOC_KILL_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_KILL_ENTRY:
#endif
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		err = mtrr_del(-1, sentry.base, sentry.size);
		break;
	case MTRRIOC_GET_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_GET_ENTRY:
#endif
		if (gentry.regnum >= num_var_ranges)
			return -EINVAL;
		mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);

		/* Hide entries that go above 4GB */
		if (gentry.base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
		    || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
			gentry.base = gentry.size = gentry.type = 0;
		else {
			gentry.base <<= PAGE_SHIFT;
			gentry.size = size << PAGE_SHIFT;
			gentry.type = type;
		}

		break;
	case MTRRIOC_ADD_PAGE_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_ADD_PAGE_ENTRY:
#endif
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		err =
		    mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
				  file, 1);
		break;
	case MTRRIOC_SET_PAGE_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_SET_PAGE_ENTRY:
#endif
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		err =
		    mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
		break;
	case MTRRIOC_DEL_PAGE_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_DEL_PAGE_ENTRY:
#endif
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		err = mtrr_file_del(sentry.base, sentry.size, file, 1);
		break;
	case MTRRIOC_KILL_PAGE_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_KILL_PAGE_ENTRY:
#endif
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		err = mtrr_del_page(-1, sentry.base, sentry.size);
		break;
	case MTRRIOC_GET_PAGE_ENTRY:
#ifdef CONFIG_COMPAT
	case MTRRIOC32_GET_PAGE_ENTRY:
#endif
		if (gentry.regnum >= num_var_ranges)
			return -EINVAL;
		mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
		/* Hide entries that would overflow */
		if (size != (__typeof__(gentry.size))size)
			gentry.base = gentry.size = gentry.type = 0;
		else {
			gentry.size = size;
			gentry.type = type;
		}
		break;
	}

	if (err)
		return err;

	switch(cmd) {
	case MTRRIOC_GET_ENTRY:
	case MTRRIOC_GET_PAGE_ENTRY:
		if (copy_to_user(arg, &gentry, sizeof gentry))
			err = -EFAULT;
		break;
#ifdef CONFIG_COMPAT
	case MTRRIOC32_GET_ENTRY:
	case MTRRIOC32_GET_PAGE_ENTRY: {
		struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
		err = put_user(gentry.base, &g32->base);
		err |= put_user(gentry.size, &g32->size);
		err |= put_user(gentry.regnum, &g32->regnum);
		err |= put_user(gentry.type, &g32->type);
		break;
	}
#endif
	}
	return err;
}

static int
mtrr_close(struct inode *ino, struct file *file)
{
	int i, max;
	unsigned int *fcount = FILE_FCOUNT(file);

	if (fcount != NULL) {
		max = num_var_ranges;
		for (i = 0; i < max; ++i) {
			while (fcount[i] > 0) {
				mtrr_del(i, 0, 0);
				--fcount[i];
			}
		}
		kfree(fcount);
		FILE_FCOUNT(file) = NULL;
	}
	return single_release(ino, file);
}

static int mtrr_seq_show(struct seq_file *seq, void *offset);

static int mtrr_open(struct inode *inode, struct file *file)
{
	if (!mtrr_if) 
		return -EIO;
	if (!mtrr_if->get) 
		return -ENXIO; 
	return single_open(file, mtrr_seq_show, NULL);
}

static const struct file_operations mtrr_fops = {
	.owner   = THIS_MODULE,
	.open	 = mtrr_open, 
	.read    = seq_read,
	.llseek  = seq_lseek,
	.write   = mtrr_write,
	.unlocked_ioctl = mtrr_ioctl,
	.compat_ioctl = mtrr_ioctl,
	.release = mtrr_close,
};


static struct proc_dir_entry *proc_root_mtrr;


static int mtrr_seq_show(struct seq_file *seq, void *offset)
{
	char factor;
	int i, max, len;
	mtrr_type type;
	unsigned long base, size;

	len = 0;
	max = num_var_ranges;
	for (i = 0; i < max; i++) {
		mtrr_if->get(i, &base, &size, &type);
		if (size == 0)
			mtrr_usage_table[i] = 0;
		else {
			if (size < (0x100000 >> PAGE_SHIFT)) {
				/* less than 1MB */
				factor = 'K';
				size <<= PAGE_SHIFT - 10;
			} else {
				factor = 'M';
				size >>= 20 - PAGE_SHIFT;
			}
			/* RED-PEN: base can be > 32bit */ 
			len += seq_printf(seq, 
				   "reg%02i: base=0x%05lx000 (%4luMB), size=%4lu%cB: %s, count=%d\n",
			     i, base, base >> (20 - PAGE_SHIFT), size, factor,
			     mtrr_attrib_to_str(type), mtrr_usage_table[i]);
		}
	}
	return 0;
}

static int __init mtrr_if_init(void)
{
	struct cpuinfo_x86 *c = &boot_cpu_data;

	if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
	    (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
	    (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
	    (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
		return -ENODEV;

	proc_root_mtrr =
		proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);

	if (proc_root_mtrr)
		proc_root_mtrr->owner = THIS_MODULE;
	return 0;
}

arch_initcall(mtrr_if_init);
#endif			/*  CONFIG_PROC_FS  */