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[linux-rt-nao.git] / arch / x86 / kernel / cpu / mtrr / cleanup.c
blobce0fe4b5c04f6cfef4c14109124d55bd13f90cbe
1 /* MTRR (Memory Type Range Register) cleanup
2
3 Copyright (C) 2009 Yinghai Lu
4
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 of the License, or (at your option) any later version.
9
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
14
15 You should have received a copy of the GNU Library General Public
16 License along with this library; if not, write to the Free
17 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/pci.h>
23 #include <linux/smp.h>
24 #include <linux/cpu.h>
25 #include <linux/mutex.h>
26 #include <linux/sort.h>
27
28 #include <asm/e820.h>
29 #include <asm/mtrr.h>
30 #include <asm/uaccess.h>
31 #include <asm/processor.h>
32 #include <asm/msr.h>
33 #include <asm/kvm_para.h>
34 #include "mtrr.h"
35
36 /* should be related to MTRR_VAR_RANGES nums */
37 #define RANGE_NUM 256
38
39 struct res_range {
40 unsigned long start;
41 unsigned long end;
42 };
43
44 static int __init
45 add_range(struct res_range *range, int nr_range, unsigned long start,
46 unsigned long end)
47 {
48 /* out of slots */
49 if (nr_range >= RANGE_NUM)
50 return nr_range;
51
52 range[nr_range].start = start;
53 range[nr_range].end = end;
54
55 nr_range++;
56
57 return nr_range;
58 }
59
60 static int __init
61 add_range_with_merge(struct res_range *range, int nr_range, unsigned long start,
62 unsigned long end)
63 {
64 int i;
65
66 /* try to merge it with old one */
67 for (i = 0; i < nr_range; i++) {
68 unsigned long final_start, final_end;
69 unsigned long common_start, common_end;
70
71 if (!range[i].end)
72 continue;
73
74 common_start = max(range[i].start, start);
75 common_end = min(range[i].end, end);
76 if (common_start > common_end + 1)
77 continue;
78
79 final_start = min(range[i].start, start);
80 final_end = max(range[i].end, end);
81
82 range[i].start = final_start;
83 range[i].end = final_end;
84 return nr_range;
85 }
86
87 /* need to add that */
88 return add_range(range, nr_range, start, end);
89 }
90
91 static void __init
92 subtract_range(struct res_range *range, unsigned long start, unsigned long end)
93 {
94 int i, j;
95
96 for (j = 0; j < RANGE_NUM; j++) {
97 if (!range[j].end)
98 continue;
99
100 if (start <= range[j].start && end >= range[j].end) {
101 range[j].start = 0;
102 range[j].end = 0;
103 continue;
104 }
105
106 if (start <= range[j].start && end < range[j].end &&
107 range[j].start < end + 1) {
108 range[j].start = end + 1;
109 continue;
110 }
111
112
113 if (start > range[j].start && end >= range[j].end &&
114 range[j].end > start - 1) {
115 range[j].end = start - 1;
116 continue;
117 }
118
119 if (start > range[j].start && end < range[j].end) {
120 /* find the new spare */
121 for (i = 0; i < RANGE_NUM; i++) {
122 if (range[i].end == 0)
123 break;
124 }
125 if (i < RANGE_NUM) {
126 range[i].end = range[j].end;
127 range[i].start = end + 1;
128 } else {
129 printk(KERN_ERR "run of slot in ranges\n");
130 }
131 range[j].end = start - 1;
132 continue;
133 }
134 }
135 }
136
137 static int __init cmp_range(const void *x1, const void *x2)
138 {
139 const struct res_range *r1 = x1;
140 const struct res_range *r2 = x2;
141 long start1, start2;
142
143 start1 = r1->start;
144 start2 = r2->start;
145
146 return start1 - start2;
147 }
148
149 struct var_mtrr_range_state {
150 unsigned long base_pfn;
151 unsigned long size_pfn;
152 mtrr_type type;
153 };
154
155 static struct var_mtrr_range_state __initdata range_state[RANGE_NUM];
156 static int __initdata debug_print;
157
158 static int __init
159 x86_get_mtrr_mem_range(struct res_range *range, int nr_range,
160 unsigned long extra_remove_base,
161 unsigned long extra_remove_size)
162 {
163 unsigned long base, size;
164 mtrr_type type;
165 int i;
166
167 for (i = 0; i < num_var_ranges; i++) {
168 type = range_state[i].type;
169 if (type != MTRR_TYPE_WRBACK)
170 continue;
171 base = range_state[i].base_pfn;
172 size = range_state[i].size_pfn;
173 nr_range = add_range_with_merge(range, nr_range, base,
174 base + size - 1);
175 }
176 if (debug_print) {
177 printk(KERN_DEBUG "After WB checking\n");
178 for (i = 0; i < nr_range; i++)
179 printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",
180 range[i].start, range[i].end + 1);
181 }
182
183 /* take out UC ranges */
184 for (i = 0; i < num_var_ranges; i++) {
185 type = range_state[i].type;
186 if (type != MTRR_TYPE_UNCACHABLE &&
187 type != MTRR_TYPE_WRPROT)
188 continue;
189 size = range_state[i].size_pfn;
190 if (!size)
191 continue;
192 base = range_state[i].base_pfn;
193 if (base < (1<<(20-PAGE_SHIFT)) && mtrr_state.have_fixed &&
194 (mtrr_state.enabled & 1)) {
195 /* Var MTRR contains UC entry below 1M? Skip it: */
196 printk(KERN_WARNING "WARNING: BIOS bug: VAR MTRR %d "
197 "contains strange UC entry under 1M, check "
198 "with your system vendor!\n", i);
199 if (base + size <= (1<<(20-PAGE_SHIFT)))
200 continue;
201 size -= (1<<(20-PAGE_SHIFT)) - base;
202 base = 1<<(20-PAGE_SHIFT);
203 }
204 subtract_range(range, base, base + size - 1);
205 }
206 if (extra_remove_size)
207 subtract_range(range, extra_remove_base,
208 extra_remove_base + extra_remove_size - 1);
209
210 /* get new range num */
211 nr_range = 0;
212 for (i = 0; i < RANGE_NUM; i++) {
213 if (!range[i].end)
214 continue;
215 nr_range++;
216 }
217 if (debug_print) {
218 printk(KERN_DEBUG "After UC checking\n");
219 for (i = 0; i < nr_range; i++)
220 printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",
221 range[i].start, range[i].end + 1);
222 }
223
224 /* sort the ranges */
225 sort(range, nr_range, sizeof(struct res_range), cmp_range, NULL);
226 if (debug_print) {
227 printk(KERN_DEBUG "After sorting\n");
228 for (i = 0; i < nr_range; i++)
229 printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",
230 range[i].start, range[i].end + 1);
231 }
232
233 /* clear those is not used */
234 for (i = nr_range; i < RANGE_NUM; i++)
235 memset(&range[i], 0, sizeof(range[i]));
236
237 return nr_range;
238 }
239
240 static struct res_range __initdata range[RANGE_NUM];
241 static int __initdata nr_range;
242
243 #ifdef CONFIG_MTRR_SANITIZER
244
245 static unsigned long __init sum_ranges(struct res_range *range, int nr_range)
246 {
247 unsigned long sum;
248 int i;
249
250 sum = 0;
251 for (i = 0; i < nr_range; i++)
252 sum += range[i].end + 1 - range[i].start;
253
254 return sum;
255 }
256
257 static int enable_mtrr_cleanup __initdata =
258 CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT;
259
260 static int __init disable_mtrr_cleanup_setup(char *str)
261 {
262 enable_mtrr_cleanup = 0;
263 return 0;
264 }
265 early_param("disable_mtrr_cleanup", disable_mtrr_cleanup_setup);
266
267 static int __init enable_mtrr_cleanup_setup(char *str)
268 {
269 enable_mtrr_cleanup = 1;
270 return 0;
271 }
272 early_param("enable_mtrr_cleanup", enable_mtrr_cleanup_setup);
273
274 static int __init mtrr_cleanup_debug_setup(char *str)
275 {
276 debug_print = 1;
277 return 0;
278 }
279 early_param("mtrr_cleanup_debug", mtrr_cleanup_debug_setup);
280
281 struct var_mtrr_state {
282 unsigned long range_startk;
283 unsigned long range_sizek;
284 unsigned long chunk_sizek;
285 unsigned long gran_sizek;
286 unsigned int reg;
287 };
288
289 static void __init
290 set_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek,
291 unsigned char type, unsigned int address_bits)
292 {
293 u32 base_lo, base_hi, mask_lo, mask_hi;
294 u64 base, mask;
295
296 if (!sizek) {
297 fill_mtrr_var_range(reg, 0, 0, 0, 0);
298 return;
299 }
300
301 mask = (1ULL << address_bits) - 1;
302 mask &= ~((((u64)sizek) << 10) - 1);
303
304 base = ((u64)basek) << 10;
305
306 base |= type;
307 mask |= 0x800;
308
309 base_lo = base & ((1ULL<<32) - 1);
310 base_hi = base >> 32;
311
312 mask_lo = mask & ((1ULL<<32) - 1);
313 mask_hi = mask >> 32;
314
315 fill_mtrr_var_range(reg, base_lo, base_hi, mask_lo, mask_hi);
316 }
317
318 static void __init
319 save_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek,
320 unsigned char type)
321 {
322 range_state[reg].base_pfn = basek >> (PAGE_SHIFT - 10);
323 range_state[reg].size_pfn = sizek >> (PAGE_SHIFT - 10);
324 range_state[reg].type = type;
325 }
326
327 static void __init
328 set_var_mtrr_all(unsigned int address_bits)
329 {
330 unsigned long basek, sizek;
331 unsigned char type;
332 unsigned int reg;
333
334 for (reg = 0; reg < num_var_ranges; reg++) {
335 basek = range_state[reg].base_pfn << (PAGE_SHIFT - 10);
336 sizek = range_state[reg].size_pfn << (PAGE_SHIFT - 10);
337 type = range_state[reg].type;
338
339 set_var_mtrr(reg, basek, sizek, type, address_bits);
340 }
341 }
342
343 static unsigned long to_size_factor(unsigned long sizek, char *factorp)
344 {
345 char factor;
346 unsigned long base = sizek;
347
348 if (base & ((1<<10) - 1)) {
349 /* not MB alignment */
350 factor = 'K';
351 } else if (base & ((1<<20) - 1)) {
352 factor = 'M';
353 base >>= 10;
354 } else {
355 factor = 'G';
356 base >>= 20;
357 }
358
359 *factorp = factor;
360
361 return base;
362 }
363
364 static unsigned int __init
365 range_to_mtrr(unsigned int reg, unsigned long range_startk,
366 unsigned long range_sizek, unsigned char type)
367 {
368 if (!range_sizek || (reg >= num_var_ranges))
369 return reg;
370
371 while (range_sizek) {
372 unsigned long max_align, align;
373 unsigned long sizek;
374
375 /* Compute the maximum size I can make a range */
376 if (range_startk)
377 max_align = ffs(range_startk) - 1;
378 else
379 max_align = 32;
380 align = fls(range_sizek) - 1;
381 if (align > max_align)
382 align = max_align;
383
384 sizek = 1 << align;
385 if (debug_print) {
386 char start_factor = 'K', size_factor = 'K';
387 unsigned long start_base, size_base;
388
389 start_base = to_size_factor(range_startk,
390 &start_factor),
391 size_base = to_size_factor(sizek, &size_factor),
392
393 printk(KERN_DEBUG "Setting variable MTRR %d, "
394 "base: %ld%cB, range: %ld%cB, type %s\n",
395 reg, start_base, start_factor,
396 size_base, size_factor,
397 (type == MTRR_TYPE_UNCACHABLE) ? "UC" :
398 ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other")
399 );
400 }
401 save_var_mtrr(reg++, range_startk, sizek, type);
402 range_startk += sizek;
403 range_sizek -= sizek;
404 if (reg >= num_var_ranges)
405 break;
406 }
407 return reg;
408 }
409
410 static unsigned __init
411 range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek,
412 unsigned long sizek)
413 {
414 unsigned long hole_basek, hole_sizek;
415 unsigned long second_basek, second_sizek;
416 unsigned long range0_basek, range0_sizek;
417 unsigned long range_basek, range_sizek;
418 unsigned long chunk_sizek;
419 unsigned long gran_sizek;
420
421 hole_basek = 0;
422 hole_sizek = 0;
423 second_basek = 0;
424 second_sizek = 0;
425 chunk_sizek = state->chunk_sizek;
426 gran_sizek = state->gran_sizek;
427
428 /* align with gran size, prevent small block used up MTRRs */
429 range_basek = ALIGN(state->range_startk, gran_sizek);
430 if ((range_basek > basek) && basek)
431 return second_sizek;
432 state->range_sizek -= (range_basek - state->range_startk);
433 range_sizek = ALIGN(state->range_sizek, gran_sizek);
434
435 while (range_sizek > state->range_sizek) {
436 range_sizek -= gran_sizek;
437 if (!range_sizek)
438 return 0;
439 }
440 state->range_sizek = range_sizek;
441
442 /* try to append some small hole */
443 range0_basek = state->range_startk;
444 range0_sizek = ALIGN(state->range_sizek, chunk_sizek);
445
446 /* no increase */
447 if (range0_sizek == state->range_sizek) {
448 if (debug_print)
449 printk(KERN_DEBUG "rangeX: %016lx - %016lx\n",
450 range0_basek<<10,
451 (range0_basek + state->range_sizek)<<10);
452 state->reg = range_to_mtrr(state->reg, range0_basek,
453 state->range_sizek, MTRR_TYPE_WRBACK);
454 return 0;
455 }
456
457 /* only cut back, when it is not the last */
458 if (sizek) {
459 while (range0_basek + range0_sizek > (basek + sizek)) {
460 if (range0_sizek >= chunk_sizek)
461 range0_sizek -= chunk_sizek;
462 else
463 range0_sizek = 0;
464
465 if (!range0_sizek)
466 break;
467 }
468 }
469
470 second_try:
471 range_basek = range0_basek + range0_sizek;
472
473 /* one hole in the middle */
474 if (range_basek > basek && range_basek <= (basek + sizek))
475 second_sizek = range_basek - basek;
476
477 if (range0_sizek > state->range_sizek) {
478
479 /* one hole in middle or at end */
480 hole_sizek = range0_sizek - state->range_sizek - second_sizek;
481
482 /* hole size should be less than half of range0 size */
483 if (hole_sizek >= (range0_sizek >> 1) &&
484 range0_sizek >= chunk_sizek) {
485 range0_sizek -= chunk_sizek;
486 second_sizek = 0;
487 hole_sizek = 0;
488
489 goto second_try;
490 }
491 }
492
493 if (range0_sizek) {
494 if (debug_print)
495 printk(KERN_DEBUG "range0: %016lx - %016lx\n",
496 range0_basek<<10,
497 (range0_basek + range0_sizek)<<10);
498 state->reg = range_to_mtrr(state->reg, range0_basek,
499 range0_sizek, MTRR_TYPE_WRBACK);
500 }
501
502 if (range0_sizek < state->range_sizek) {
503 /* need to handle left over */
504 range_sizek = state->range_sizek - range0_sizek;
505
506 if (debug_print)
507 printk(KERN_DEBUG "range: %016lx - %016lx\n",
508 range_basek<<10,
509 (range_basek + range_sizek)<<10);
510 state->reg = range_to_mtrr(state->reg, range_basek,
511 range_sizek, MTRR_TYPE_WRBACK);
512 }
513
514 if (hole_sizek) {
515 hole_basek = range_basek - hole_sizek - second_sizek;
516 if (debug_print)
517 printk(KERN_DEBUG "hole: %016lx - %016lx\n",
518 hole_basek<<10,
519 (hole_basek + hole_sizek)<<10);
520 state->reg = range_to_mtrr(state->reg, hole_basek,
521 hole_sizek, MTRR_TYPE_UNCACHABLE);
522 }
523
524 return second_sizek;
525 }
526
527 static void __init
528 set_var_mtrr_range(struct var_mtrr_state *state, unsigned long base_pfn,
529 unsigned long size_pfn)
530 {
531 unsigned long basek, sizek;
532 unsigned long second_sizek = 0;
533
534 if (state->reg >= num_var_ranges)
535 return;
536
537 basek = base_pfn << (PAGE_SHIFT - 10);
538 sizek = size_pfn << (PAGE_SHIFT - 10);
539
540 /* See if I can merge with the last range */
541 if ((basek <= 1024) ||
542 (state->range_startk + state->range_sizek == basek)) {
543 unsigned long endk = basek + sizek;
544 state->range_sizek = endk - state->range_startk;
545 return;
546 }
547 /* Write the range mtrrs */
548 if (state->range_sizek != 0)
549 second_sizek = range_to_mtrr_with_hole(state, basek, sizek);
550
551 /* Allocate an msr */
552 state->range_startk = basek + second_sizek;
553 state->range_sizek = sizek - second_sizek;
554 }
555
556 /* mininum size of mtrr block that can take hole */
557 static u64 mtrr_chunk_size __initdata = (256ULL<<20);
558
559 static int __init parse_mtrr_chunk_size_opt(char *p)
560 {
561 if (!p)
562 return -EINVAL;
563 mtrr_chunk_size = memparse(p, &p);
564 return 0;
565 }
566 early_param("mtrr_chunk_size", parse_mtrr_chunk_size_opt);
567
568 /* granity of mtrr of block */
569 static u64 mtrr_gran_size __initdata;
570
571 static int __init parse_mtrr_gran_size_opt(char *p)
572 {
573 if (!p)
574 return -EINVAL;
575 mtrr_gran_size = memparse(p, &p);
576 return 0;
577 }
578 early_param("mtrr_gran_size", parse_mtrr_gran_size_opt);
579
580 static int nr_mtrr_spare_reg __initdata =
581 CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT;
582
583 static int __init parse_mtrr_spare_reg(char *arg)
584 {
585 if (arg)
586 nr_mtrr_spare_reg = simple_strtoul(arg, NULL, 0);
587 return 0;
588 }
589
590 early_param("mtrr_spare_reg_nr", parse_mtrr_spare_reg);
591
592 static int __init
593 x86_setup_var_mtrrs(struct res_range *range, int nr_range,
594 u64 chunk_size, u64 gran_size)
595 {
596 struct var_mtrr_state var_state;
597 int i;
598 int num_reg;
599
600 var_state.range_startk = 0;
601 var_state.range_sizek = 0;
602 var_state.reg = 0;
603 var_state.chunk_sizek = chunk_size >> 10;
604 var_state.gran_sizek = gran_size >> 10;
605
606 memset(range_state, 0, sizeof(range_state));
607
608 /* Write the range etc */
609 for (i = 0; i < nr_range; i++)
610 set_var_mtrr_range(&var_state, range[i].start,
611 range[i].end - range[i].start + 1);
612
613 /* Write the last range */
614 if (var_state.range_sizek != 0)
615 range_to_mtrr_with_hole(&var_state, 0, 0);
616
617 num_reg = var_state.reg;
618 /* Clear out the extra MTRR's */
619 while (var_state.reg < num_var_ranges) {
620 save_var_mtrr(var_state.reg, 0, 0, 0);
621 var_state.reg++;
622 }
623
624 return num_reg;
625 }
626
627 struct mtrr_cleanup_result {
628 unsigned long gran_sizek;
629 unsigned long chunk_sizek;
630 unsigned long lose_cover_sizek;
631 unsigned int num_reg;
632 int bad;
633 };
634
635 /*
636 * gran_size: 64K, 128K, 256K, 512K, 1M, 2M, ..., 2G
637 * chunk size: gran_size, ..., 2G
638 * so we need (1+16)*8
639 */
640 #define NUM_RESULT 136
641 #define PSHIFT (PAGE_SHIFT - 10)
642
643 static struct mtrr_cleanup_result __initdata result[NUM_RESULT];
644 static unsigned long __initdata min_loss_pfn[RANGE_NUM];
645
646 static void __init print_out_mtrr_range_state(void)
647 {
648 int i;
649 char start_factor = 'K', size_factor = 'K';
650 unsigned long start_base, size_base;
651 mtrr_type type;
652
653 for (i = 0; i < num_var_ranges; i++) {
654
655 size_base = range_state[i].size_pfn << (PAGE_SHIFT - 10);
656 if (!size_base)
657 continue;
658
659 size_base = to_size_factor(size_base, &size_factor),
660 start_base = range_state[i].base_pfn << (PAGE_SHIFT - 10);
661 start_base = to_size_factor(start_base, &start_factor),
662 type = range_state[i].type;
663
664 printk(KERN_DEBUG "reg %d, base: %ld%cB, range: %ld%cB, type %s\n",
665 i, start_base, start_factor,
666 size_base, size_factor,
667 (type == MTRR_TYPE_UNCACHABLE) ? "UC" :
668 ((type == MTRR_TYPE_WRPROT) ? "WP" :
669 ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other"))
670 );
671 }
672 }
673
674 static int __init mtrr_need_cleanup(void)
675 {
676 int i;
677 mtrr_type type;
678 unsigned long size;
679 /* extra one for all 0 */
680 int num[MTRR_NUM_TYPES + 1];
681
682 /* check entries number */
683 memset(num, 0, sizeof(num));
684 for (i = 0; i < num_var_ranges; i++) {
685 type = range_state[i].type;
686 size = range_state[i].size_pfn;
687 if (type >= MTRR_NUM_TYPES)
688 continue;
689 if (!size)
690 type = MTRR_NUM_TYPES;
691 if (type == MTRR_TYPE_WRPROT)
692 type = MTRR_TYPE_UNCACHABLE;
693 num[type]++;
694 }
695
696 /* check if we got UC entries */
697 if (!num[MTRR_TYPE_UNCACHABLE])
698 return 0;
699
700 /* check if we only had WB and UC */
701 if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] !=
702 num_var_ranges - num[MTRR_NUM_TYPES])
703 return 0;
704
705 return 1;
706 }
707
708 static unsigned long __initdata range_sums;
709 static void __init mtrr_calc_range_state(u64 chunk_size, u64 gran_size,
710 unsigned long extra_remove_base,
711 unsigned long extra_remove_size,
712 int i)
713 {
714 int num_reg;
715 static struct res_range range_new[RANGE_NUM];
716 static int nr_range_new;
717 unsigned long range_sums_new;
718
719 /* convert ranges to var ranges state */
720 num_reg = x86_setup_var_mtrrs(range, nr_range,
721 chunk_size, gran_size);
722
723 /* we got new setting in range_state, check it */
724 memset(range_new, 0, sizeof(range_new));
725 nr_range_new = x86_get_mtrr_mem_range(range_new, 0,
726 extra_remove_base, extra_remove_size);
727 range_sums_new = sum_ranges(range_new, nr_range_new);
728
729 result[i].chunk_sizek = chunk_size >> 10;
730 result[i].gran_sizek = gran_size >> 10;
731 result[i].num_reg = num_reg;
732 if (range_sums < range_sums_new) {
733 result[i].lose_cover_sizek =
734 (range_sums_new - range_sums) << PSHIFT;
735 result[i].bad = 1;
736 } else
737 result[i].lose_cover_sizek =
738 (range_sums - range_sums_new) << PSHIFT;
739
740 /* double check it */
741 if (!result[i].bad && !result[i].lose_cover_sizek) {
742 if (nr_range_new != nr_range ||
743 memcmp(range, range_new, sizeof(range)))
744 result[i].bad = 1;
745 }
746
747 if (!result[i].bad && (range_sums - range_sums_new <
748 min_loss_pfn[num_reg])) {
749 min_loss_pfn[num_reg] =
750 range_sums - range_sums_new;
751 }
752 }
753
754 static void __init mtrr_print_out_one_result(int i)
755 {
756 char gran_factor, chunk_factor, lose_factor;
757 unsigned long gran_base, chunk_base, lose_base;
758
759 gran_base = to_size_factor(result[i].gran_sizek, &gran_factor),
760 chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor),
761 lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor),
762 printk(KERN_INFO "%sgran_size: %ld%c \tchunk_size: %ld%c \t",
763 result[i].bad ? "*BAD*" : " ",
764 gran_base, gran_factor, chunk_base, chunk_factor);
765 printk(KERN_CONT "num_reg: %d \tlose cover RAM: %s%ld%c\n",
766 result[i].num_reg, result[i].bad ? "-" : "",
767 lose_base, lose_factor);
768 }
769
770 static int __init mtrr_search_optimal_index(void)
771 {
772 int i;
773 int num_reg_good;
774 int index_good;
775
776 if (nr_mtrr_spare_reg >= num_var_ranges)
777 nr_mtrr_spare_reg = num_var_ranges - 1;
778 num_reg_good = -1;
779 for (i = num_var_ranges - nr_mtrr_spare_reg; i > 0; i--) {
780 if (!min_loss_pfn[i])
781 num_reg_good = i;
782 }
783
784 index_good = -1;
785 if (num_reg_good != -1) {
786 for (i = 0; i < NUM_RESULT; i++) {
787 if (!result[i].bad &&
788 result[i].num_reg == num_reg_good &&
789 !result[i].lose_cover_sizek) {
790 index_good = i;
791 break;
792 }
793 }
794 }
795
796 return index_good;
797 }
798
799
800 int __init mtrr_cleanup(unsigned address_bits)
801 {
802 unsigned long extra_remove_base, extra_remove_size;
803 unsigned long base, size, def, dummy;
804 mtrr_type type;
805 u64 chunk_size, gran_size;
806 int index_good;
807 int i;
808
809 if (!is_cpu(INTEL) || enable_mtrr_cleanup < 1)
810 return 0;
811 rdmsr(MTRRdefType_MSR, def, dummy);
812 def &= 0xff;
813 if (def != MTRR_TYPE_UNCACHABLE)
814 return 0;
815
816 /* get it and store it aside */
817 memset(range_state, 0, sizeof(range_state));
818 for (i = 0; i < num_var_ranges; i++) {
819 mtrr_if->get(i, &base, &size, &type);
820 range_state[i].base_pfn = base;
821 range_state[i].size_pfn = size;
822 range_state[i].type = type;
823 }
824
825 /* check if we need handle it and can handle it */
826 if (!mtrr_need_cleanup())
827 return 0;
828
829 /* print original var MTRRs at first, for debugging: */
830 printk(KERN_DEBUG "original variable MTRRs\n");
831 print_out_mtrr_range_state();
832
833 memset(range, 0, sizeof(range));
834 extra_remove_size = 0;
835 extra_remove_base = 1 << (32 - PAGE_SHIFT);
836 if (mtrr_tom2)
837 extra_remove_size =
838 (mtrr_tom2 >> PAGE_SHIFT) - extra_remove_base;
839 nr_range = x86_get_mtrr_mem_range(range, 0, extra_remove_base,
840 extra_remove_size);
841 /*
842 * [0, 1M) should always be coverred by var mtrr with WB
843 * and fixed mtrrs should take effective before var mtrr for it
844 */
845 nr_range = add_range_with_merge(range, nr_range, 0,
846 (1ULL<<(20 - PAGE_SHIFT)) - 1);
847 /* sort the ranges */
848 sort(range, nr_range, sizeof(struct res_range), cmp_range, NULL);
849
850 range_sums = sum_ranges(range, nr_range);
851 printk(KERN_INFO "total RAM coverred: %ldM\n",
852 range_sums >> (20 - PAGE_SHIFT));
853
854 if (mtrr_chunk_size && mtrr_gran_size) {
855 i = 0;
856 mtrr_calc_range_state(mtrr_chunk_size, mtrr_gran_size,
857 extra_remove_base, extra_remove_size, i);
858
859 mtrr_print_out_one_result(i);
860
861 if (!result[i].bad) {
862 set_var_mtrr_all(address_bits);
863 printk(KERN_DEBUG "New variable MTRRs\n");
864 print_out_mtrr_range_state();
865 return 1;
866 }
867 printk(KERN_INFO "invalid mtrr_gran_size or mtrr_chunk_size, "
868 "will find optimal one\n");
869 }
870
871 i = 0;
872 memset(min_loss_pfn, 0xff, sizeof(min_loss_pfn));
873 memset(result, 0, sizeof(result));
874 for (gran_size = (1ULL<<16); gran_size < (1ULL<<32); gran_size <<= 1) {
875
876 for (chunk_size = gran_size; chunk_size < (1ULL<<32);
877 chunk_size <<= 1) {
878
879 if (i >= NUM_RESULT)
880 continue;
881
882 mtrr_calc_range_state(chunk_size, gran_size,
883 extra_remove_base, extra_remove_size, i);
884 if (debug_print) {
885 mtrr_print_out_one_result(i);
886 printk(KERN_INFO "\n");
887 }
888
889 i++;
890 }
891 }
892
893 /* try to find the optimal index */
894 index_good = mtrr_search_optimal_index();
895
896 if (index_good != -1) {
897 printk(KERN_INFO "Found optimal setting for mtrr clean up\n");
898 i = index_good;
899 mtrr_print_out_one_result(i);
900
901 /* convert ranges to var ranges state */
902 chunk_size = result[i].chunk_sizek;
903 chunk_size <<= 10;
904 gran_size = result[i].gran_sizek;
905 gran_size <<= 10;
906 x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size);
907 set_var_mtrr_all(address_bits);
908 printk(KERN_DEBUG "New variable MTRRs\n");
909 print_out_mtrr_range_state();
910 return 1;
911 } else {
912 /* print out all */
913 for (i = 0; i < NUM_RESULT; i++)
914 mtrr_print_out_one_result(i);
915 }
916
917 printk(KERN_INFO "mtrr_cleanup: can not find optimal value\n");
918 printk(KERN_INFO "please specify mtrr_gran_size/mtrr_chunk_size\n");
919
920 return 0;
921 }
922 #else
923 int __init mtrr_cleanup(unsigned address_bits)
924 {
925 return 0;
926 }
927 #endif
928
929 static int disable_mtrr_trim;
930
931 static int __init disable_mtrr_trim_setup(char *str)
932 {
933 disable_mtrr_trim = 1;
934 return 0;
935 }
936 early_param("disable_mtrr_trim", disable_mtrr_trim_setup);
937
938 /*
939 * Newer AMD K8s and later CPUs have a special magic MSR way to force WB
940 * for memory >4GB. Check for that here.
941 * Note this won't check if the MTRRs < 4GB where the magic bit doesn't
942 * apply to are wrong, but so far we don't know of any such case in the wild.
943 */
944 #define Tom2Enabled (1U << 21)
945 #define Tom2ForceMemTypeWB (1U << 22)
946
947 int __init amd_special_default_mtrr(void)
948 {
949 u32 l, h;
950
951 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
952 return 0;
953 if (boot_cpu_data.x86 < 0xf || boot_cpu_data.x86 > 0x11)
954 return 0;
955 /* In case some hypervisor doesn't pass SYSCFG through */
956 if (rdmsr_safe(MSR_K8_SYSCFG, &l, &h) < 0)
957 return 0;
958 /*
959 * Memory between 4GB and top of mem is forced WB by this magic bit.
960 * Reserved before K8RevF, but should be zero there.
961 */
962 if ((l & (Tom2Enabled | Tom2ForceMemTypeWB)) ==
963 (Tom2Enabled | Tom2ForceMemTypeWB))
964 return 1;
965 return 0;
966 }
967
968 static u64 __init real_trim_memory(unsigned long start_pfn,
969 unsigned long limit_pfn)
970 {
971 u64 trim_start, trim_size;
972 trim_start = start_pfn;
973 trim_start <<= PAGE_SHIFT;
974 trim_size = limit_pfn;
975 trim_size <<= PAGE_SHIFT;
976 trim_size -= trim_start;
977
978 return e820_update_range(trim_start, trim_size, E820_RAM,
979 E820_RESERVED);
980 }
981 /**
982 * mtrr_trim_uncached_memory - trim RAM not covered by MTRRs
983 * @end_pfn: ending page frame number
984 *
985 * Some buggy BIOSes don't setup the MTRRs properly for systems with certain
986 * memory configurations. This routine checks that the highest MTRR matches
987 * the end of memory, to make sure the MTRRs having a write back type cover
988 * all of the memory the kernel is intending to use. If not, it'll trim any
989 * memory off the end by adjusting end_pfn, removing it from the kernel's
990 * allocation pools, warning the user with an obnoxious message.
991 */
992 int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
993 {
994 unsigned long i, base, size, highest_pfn = 0, def, dummy;
995 mtrr_type type;
996 u64 total_trim_size;
997
998 /* extra one for all 0 */
999 int num[MTRR_NUM_TYPES + 1];
1000 /*
1001 * Make sure we only trim uncachable memory on machines that
1002 * support the Intel MTRR architecture:
1003 */
1004 if (!is_cpu(INTEL) || disable_mtrr_trim)
1005 return 0;
1006 rdmsr(MTRRdefType_MSR, def, dummy);
1007 def &= 0xff;
1008 if (def != MTRR_TYPE_UNCACHABLE)
1009 return 0;
1010
1011 /* get it and store it aside */
1012 memset(range_state, 0, sizeof(range_state));
1013 for (i = 0; i < num_var_ranges; i++) {
1014 mtrr_if->get(i, &base, &size, &type);
1015 range_state[i].base_pfn = base;
1016 range_state[i].size_pfn = size;
1017 range_state[i].type = type;
1018 }
1019
1020 /* Find highest cached pfn */
1021 for (i = 0; i < num_var_ranges; i++) {
1022 type = range_state[i].type;
1023 if (type != MTRR_TYPE_WRBACK)
1024 continue;
1025 base = range_state[i].base_pfn;
1026 size = range_state[i].size_pfn;
1027 if (highest_pfn < base + size)
1028 highest_pfn = base + size;
1029 }
1030
1031 /* kvm/qemu doesn't have mtrr set right, don't trim them all */
1032 if (!highest_pfn) {
1033 printk(KERN_INFO "CPU MTRRs all blank - virtualized system.\n");
1034 return 0;
1035 }
1036
1037 /* check entries number */
1038 memset(num, 0, sizeof(num));
1039 for (i = 0; i < num_var_ranges; i++) {
1040 type = range_state[i].type;
1041 if (type >= MTRR_NUM_TYPES)
1042 continue;
1043 size = range_state[i].size_pfn;
1044 if (!size)
1045 type = MTRR_NUM_TYPES;
1046 num[type]++;
1047 }
1048
1049 /* no entry for WB? */
1050 if (!num[MTRR_TYPE_WRBACK])
1051 return 0;
1052
1053 /* check if we only had WB and UC */
1054 if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] !=
1055 num_var_ranges - num[MTRR_NUM_TYPES])
1056 return 0;
1057
1058 memset(range, 0, sizeof(range));
1059 nr_range = 0;
1060 if (mtrr_tom2) {
1061 range[nr_range].start = (1ULL<<(32 - PAGE_SHIFT));
1062 range[nr_range].end = (mtrr_tom2 >> PAGE_SHIFT) - 1;
1063 if (highest_pfn < range[nr_range].end + 1)
1064 highest_pfn = range[nr_range].end + 1;
1065 nr_range++;
1066 }
1067 nr_range = x86_get_mtrr_mem_range(range, nr_range, 0, 0);
1068
1069 total_trim_size = 0;
1070 /* check the head */
1071 if (range[0].start)
1072 total_trim_size += real_trim_memory(0, range[0].start);
1073 /* check the holes */
1074 for (i = 0; i < nr_range - 1; i++) {
1075 if (range[i].end + 1 < range[i+1].start)
1076 total_trim_size += real_trim_memory(range[i].end + 1,
1077 range[i+1].start);
1078 }
1079 /* check the top */
1080 i = nr_range - 1;
1081 if (range[i].end + 1 < end_pfn)
1082 total_trim_size += real_trim_memory(range[i].end + 1,
1083 end_pfn);
1084
1085 if (total_trim_size) {
1086 printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover"
1087 " all of memory, losing %lluMB of RAM.\n",
1088 total_trim_size >> 20);
1089
1090 if (!changed_by_mtrr_cleanup)
1091 WARN_ON(1);
1092
1093 printk(KERN_INFO "update e820 for mtrr\n");
1094 update_e820();
1095
1096 return 1;
1097 }
1098
1099 return 0;
1100 }
1101
(Inofficial) Linux kernel tree running on the Nao robot