Line data Source code
1 : /*
2 : * MTRR (Memory Type Range Register) cleanup
3 : *
4 : * Copyright (C) 2009 Yinghai Lu
5 : *
6 : * This library is free software; you can redistribute it and/or
7 : * modify it under the terms of the GNU Library General Public
8 : * License as published by the Free Software Foundation; either
9 : * version 2 of the License, or (at your option) any later version.
10 : *
11 : * This library is distributed in the hope that it will be useful,
12 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 : * Library General Public License for more details.
15 : *
16 : * You should have received a copy of the GNU Library General Public
17 : * License along with this library; if not, write to the Free
18 : * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 : */
20 : #include <linux/init.h>
21 : #include <linux/pci.h>
22 : #include <linux/smp.h>
23 : #include <linux/cpu.h>
24 : #include <linux/mutex.h>
25 : #include <linux/uaccess.h>
26 : #include <linux/kvm_para.h>
27 : #include <linux/range.h>
28 :
29 : #include <asm/processor.h>
30 : #include <asm/e820/api.h>
31 : #include <asm/mtrr.h>
32 : #include <asm/msr.h>
33 :
34 : #include "mtrr.h"
35 :
36 : struct var_mtrr_range_state {
37 : unsigned long base_pfn;
38 : unsigned long size_pfn;
39 : mtrr_type type;
40 : };
41 :
42 : struct var_mtrr_state {
43 : unsigned long range_startk;
44 : unsigned long range_sizek;
45 : unsigned long chunk_sizek;
46 : unsigned long gran_sizek;
47 : unsigned int reg;
48 : };
49 :
50 : /* Should be related to MTRR_VAR_RANGES nums */
51 : #define RANGE_NUM 256
52 :
53 : static struct range __initdata range[RANGE_NUM];
54 : static int __initdata nr_range;
55 :
56 : static struct var_mtrr_range_state __initdata range_state[RANGE_NUM];
57 :
58 : static int __initdata debug_print;
59 : #define Dprintk(x...) do { if (debug_print) pr_debug(x); } while (0)
60 :
61 : #define BIOS_BUG_MSG \
62 : "WARNING: BIOS bug: VAR MTRR %d contains strange UC entry under 1M, check with your system vendor!\n"
63 :
64 : static int __init
65 0 : x86_get_mtrr_mem_range(struct range *range, int nr_range,
66 : unsigned long extra_remove_base,
67 : unsigned long extra_remove_size)
68 : {
69 0 : unsigned long base, size;
70 0 : mtrr_type type;
71 0 : int i;
72 :
73 0 : for (i = 0; i < num_var_ranges; i++) {
74 0 : type = range_state[i].type;
75 0 : if (type != MTRR_TYPE_WRBACK)
76 0 : continue;
77 0 : base = range_state[i].base_pfn;
78 0 : size = range_state[i].size_pfn;
79 0 : nr_range = add_range_with_merge(range, RANGE_NUM, nr_range,
80 0 : base, base + size);
81 : }
82 0 : if (debug_print) {
83 : pr_debug("After WB checking\n");
84 : for (i = 0; i < nr_range; i++)
85 : pr_debug("MTRR MAP PFN: %016llx - %016llx\n",
86 : range[i].start, range[i].end);
87 : }
88 :
89 : /* Take out UC ranges: */
90 0 : for (i = 0; i < num_var_ranges; i++) {
91 0 : type = range_state[i].type;
92 0 : if (type != MTRR_TYPE_UNCACHABLE &&
93 0 : type != MTRR_TYPE_WRPROT)
94 0 : continue;
95 0 : size = range_state[i].size_pfn;
96 0 : if (!size)
97 0 : continue;
98 0 : base = range_state[i].base_pfn;
99 0 : if (base < (1<<(20-PAGE_SHIFT)) && mtrr_state.have_fixed &&
100 0 : (mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) &&
101 : (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) {
102 : /* Var MTRR contains UC entry below 1M? Skip it: */
103 0 : pr_warn(BIOS_BUG_MSG, i);
104 0 : if (base + size <= (1<<(20-PAGE_SHIFT)))
105 0 : continue;
106 0 : size -= (1<<(20-PAGE_SHIFT)) - base;
107 0 : base = 1<<(20-PAGE_SHIFT);
108 : }
109 0 : subtract_range(range, RANGE_NUM, base, base + size);
110 : }
111 0 : if (extra_remove_size)
112 0 : subtract_range(range, RANGE_NUM, extra_remove_base,
113 0 : extra_remove_base + extra_remove_size);
114 :
115 0 : if (debug_print) {
116 : pr_debug("After UC checking\n");
117 : for (i = 0; i < RANGE_NUM; i++) {
118 : if (!range[i].end)
119 : continue;
120 : pr_debug("MTRR MAP PFN: %016llx - %016llx\n",
121 : range[i].start, range[i].end);
122 : }
123 : }
124 :
125 : /* sort the ranges */
126 0 : nr_range = clean_sort_range(range, RANGE_NUM);
127 0 : if (debug_print) {
128 : pr_debug("After sorting\n");
129 : for (i = 0; i < nr_range; i++)
130 : pr_debug("MTRR MAP PFN: %016llx - %016llx\n",
131 : range[i].start, range[i].end);
132 : }
133 :
134 0 : return nr_range;
135 : }
136 :
137 : #ifdef CONFIG_MTRR_SANITIZER
138 :
139 : static unsigned long __init sum_ranges(struct range *range, int nr_range)
140 : {
141 : unsigned long sum = 0;
142 : int i;
143 :
144 : for (i = 0; i < nr_range; i++)
145 : sum += range[i].end - range[i].start;
146 :
147 : return sum;
148 : }
149 :
150 : static int enable_mtrr_cleanup __initdata =
151 : CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT;
152 :
153 : static int __init disable_mtrr_cleanup_setup(char *str)
154 : {
155 : enable_mtrr_cleanup = 0;
156 : return 0;
157 : }
158 : early_param("disable_mtrr_cleanup", disable_mtrr_cleanup_setup);
159 :
160 : static int __init enable_mtrr_cleanup_setup(char *str)
161 : {
162 : enable_mtrr_cleanup = 1;
163 : return 0;
164 : }
165 : early_param("enable_mtrr_cleanup", enable_mtrr_cleanup_setup);
166 :
167 : static int __init mtrr_cleanup_debug_setup(char *str)
168 : {
169 : debug_print = 1;
170 : return 0;
171 : }
172 : early_param("mtrr_cleanup_debug", mtrr_cleanup_debug_setup);
173 :
174 : static void __init
175 : set_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek,
176 : unsigned char type, unsigned int address_bits)
177 : {
178 : u32 base_lo, base_hi, mask_lo, mask_hi;
179 : u64 base, mask;
180 :
181 : if (!sizek) {
182 : fill_mtrr_var_range(reg, 0, 0, 0, 0);
183 : return;
184 : }
185 :
186 : mask = (1ULL << address_bits) - 1;
187 : mask &= ~((((u64)sizek) << 10) - 1);
188 :
189 : base = ((u64)basek) << 10;
190 :
191 : base |= type;
192 : mask |= 0x800;
193 :
194 : base_lo = base & ((1ULL<<32) - 1);
195 : base_hi = base >> 32;
196 :
197 : mask_lo = mask & ((1ULL<<32) - 1);
198 : mask_hi = mask >> 32;
199 :
200 : fill_mtrr_var_range(reg, base_lo, base_hi, mask_lo, mask_hi);
201 : }
202 :
203 : static void __init
204 : save_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek,
205 : unsigned char type)
206 : {
207 : range_state[reg].base_pfn = basek >> (PAGE_SHIFT - 10);
208 : range_state[reg].size_pfn = sizek >> (PAGE_SHIFT - 10);
209 : range_state[reg].type = type;
210 : }
211 :
212 : static void __init set_var_mtrr_all(unsigned int address_bits)
213 : {
214 : unsigned long basek, sizek;
215 : unsigned char type;
216 : unsigned int reg;
217 :
218 : for (reg = 0; reg < num_var_ranges; reg++) {
219 : basek = range_state[reg].base_pfn << (PAGE_SHIFT - 10);
220 : sizek = range_state[reg].size_pfn << (PAGE_SHIFT - 10);
221 : type = range_state[reg].type;
222 :
223 : set_var_mtrr(reg, basek, sizek, type, address_bits);
224 : }
225 : }
226 :
227 : static unsigned long to_size_factor(unsigned long sizek, char *factorp)
228 : {
229 : unsigned long base = sizek;
230 : char factor;
231 :
232 : if (base & ((1<<10) - 1)) {
233 : /* Not MB-aligned: */
234 : factor = 'K';
235 : } else if (base & ((1<<20) - 1)) {
236 : factor = 'M';
237 : base >>= 10;
238 : } else {
239 : factor = 'G';
240 : base >>= 20;
241 : }
242 :
243 : *factorp = factor;
244 :
245 : return base;
246 : }
247 :
248 : static unsigned int __init
249 : range_to_mtrr(unsigned int reg, unsigned long range_startk,
250 : unsigned long range_sizek, unsigned char type)
251 : {
252 : if (!range_sizek || (reg >= num_var_ranges))
253 : return reg;
254 :
255 : while (range_sizek) {
256 : unsigned long max_align, align;
257 : unsigned long sizek;
258 :
259 : /* Compute the maximum size with which we can make a range: */
260 : if (range_startk)
261 : max_align = __ffs(range_startk);
262 : else
263 : max_align = BITS_PER_LONG - 1;
264 :
265 : align = __fls(range_sizek);
266 : if (align > max_align)
267 : align = max_align;
268 :
269 : sizek = 1UL << align;
270 : if (debug_print) {
271 : char start_factor = 'K', size_factor = 'K';
272 : unsigned long start_base, size_base;
273 :
274 : start_base = to_size_factor(range_startk, &start_factor);
275 : size_base = to_size_factor(sizek, &size_factor);
276 :
277 : Dprintk("Setting variable MTRR %d, "
278 : "base: %ld%cB, range: %ld%cB, type %s\n",
279 : reg, start_base, start_factor,
280 : size_base, size_factor,
281 : (type == MTRR_TYPE_UNCACHABLE) ? "UC" :
282 : ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other")
283 : );
284 : }
285 : save_var_mtrr(reg++, range_startk, sizek, type);
286 : range_startk += sizek;
287 : range_sizek -= sizek;
288 : if (reg >= num_var_ranges)
289 : break;
290 : }
291 : return reg;
292 : }
293 :
294 : static unsigned __init
295 : range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek,
296 : unsigned long sizek)
297 : {
298 : unsigned long hole_basek, hole_sizek;
299 : unsigned long second_sizek;
300 : unsigned long range0_basek, range0_sizek;
301 : unsigned long range_basek, range_sizek;
302 : unsigned long chunk_sizek;
303 : unsigned long gran_sizek;
304 :
305 : hole_basek = 0;
306 : hole_sizek = 0;
307 : second_sizek = 0;
308 : chunk_sizek = state->chunk_sizek;
309 : gran_sizek = state->gran_sizek;
310 :
311 : /* Align with gran size, prevent small block used up MTRRs: */
312 : range_basek = ALIGN(state->range_startk, gran_sizek);
313 : if ((range_basek > basek) && basek)
314 : return second_sizek;
315 :
316 : state->range_sizek -= (range_basek - state->range_startk);
317 : range_sizek = ALIGN(state->range_sizek, gran_sizek);
318 :
319 : while (range_sizek > state->range_sizek) {
320 : range_sizek -= gran_sizek;
321 : if (!range_sizek)
322 : return 0;
323 : }
324 : state->range_sizek = range_sizek;
325 :
326 : /* Try to append some small hole: */
327 : range0_basek = state->range_startk;
328 : range0_sizek = ALIGN(state->range_sizek, chunk_sizek);
329 :
330 : /* No increase: */
331 : if (range0_sizek == state->range_sizek) {
332 : Dprintk("rangeX: %016lx - %016lx\n",
333 : range0_basek<<10,
334 : (range0_basek + state->range_sizek)<<10);
335 : state->reg = range_to_mtrr(state->reg, range0_basek,
336 : state->range_sizek, MTRR_TYPE_WRBACK);
337 : return 0;
338 : }
339 :
340 : /* Only cut back when it is not the last: */
341 : if (sizek) {
342 : while (range0_basek + range0_sizek > (basek + sizek)) {
343 : if (range0_sizek >= chunk_sizek)
344 : range0_sizek -= chunk_sizek;
345 : else
346 : range0_sizek = 0;
347 :
348 : if (!range0_sizek)
349 : break;
350 : }
351 : }
352 :
353 : second_try:
354 : range_basek = range0_basek + range0_sizek;
355 :
356 : /* One hole in the middle: */
357 : if (range_basek > basek && range_basek <= (basek + sizek))
358 : second_sizek = range_basek - basek;
359 :
360 : if (range0_sizek > state->range_sizek) {
361 :
362 : /* One hole in middle or at the end: */
363 : hole_sizek = range0_sizek - state->range_sizek - second_sizek;
364 :
365 : /* Hole size should be less than half of range0 size: */
366 : if (hole_sizek >= (range0_sizek >> 1) &&
367 : range0_sizek >= chunk_sizek) {
368 : range0_sizek -= chunk_sizek;
369 : second_sizek = 0;
370 : hole_sizek = 0;
371 :
372 : goto second_try;
373 : }
374 : }
375 :
376 : if (range0_sizek) {
377 : Dprintk("range0: %016lx - %016lx\n",
378 : range0_basek<<10,
379 : (range0_basek + range0_sizek)<<10);
380 : state->reg = range_to_mtrr(state->reg, range0_basek,
381 : range0_sizek, MTRR_TYPE_WRBACK);
382 : }
383 :
384 : if (range0_sizek < state->range_sizek) {
385 : /* Need to handle left over range: */
386 : range_sizek = state->range_sizek - range0_sizek;
387 :
388 : Dprintk("range: %016lx - %016lx\n",
389 : range_basek<<10,
390 : (range_basek + range_sizek)<<10);
391 :
392 : state->reg = range_to_mtrr(state->reg, range_basek,
393 : range_sizek, MTRR_TYPE_WRBACK);
394 : }
395 :
396 : if (hole_sizek) {
397 : hole_basek = range_basek - hole_sizek - second_sizek;
398 : Dprintk("hole: %016lx - %016lx\n",
399 : hole_basek<<10,
400 : (hole_basek + hole_sizek)<<10);
401 : state->reg = range_to_mtrr(state->reg, hole_basek,
402 : hole_sizek, MTRR_TYPE_UNCACHABLE);
403 : }
404 :
405 : return second_sizek;
406 : }
407 :
408 : static void __init
409 : set_var_mtrr_range(struct var_mtrr_state *state, unsigned long base_pfn,
410 : unsigned long size_pfn)
411 : {
412 : unsigned long basek, sizek;
413 : unsigned long second_sizek = 0;
414 :
415 : if (state->reg >= num_var_ranges)
416 : return;
417 :
418 : basek = base_pfn << (PAGE_SHIFT - 10);
419 : sizek = size_pfn << (PAGE_SHIFT - 10);
420 :
421 : /* See if I can merge with the last range: */
422 : if ((basek <= 1024) ||
423 : (state->range_startk + state->range_sizek == basek)) {
424 : unsigned long endk = basek + sizek;
425 : state->range_sizek = endk - state->range_startk;
426 : return;
427 : }
428 : /* Write the range mtrrs: */
429 : if (state->range_sizek != 0)
430 : second_sizek = range_to_mtrr_with_hole(state, basek, sizek);
431 :
432 : /* Allocate an msr: */
433 : state->range_startk = basek + second_sizek;
434 : state->range_sizek = sizek - second_sizek;
435 : }
436 :
437 : /* Mininum size of mtrr block that can take hole: */
438 : static u64 mtrr_chunk_size __initdata = (256ULL<<20);
439 :
440 : static int __init parse_mtrr_chunk_size_opt(char *p)
441 : {
442 : if (!p)
443 : return -EINVAL;
444 : mtrr_chunk_size = memparse(p, &p);
445 : return 0;
446 : }
447 : early_param("mtrr_chunk_size", parse_mtrr_chunk_size_opt);
448 :
449 : /* Granularity of mtrr of block: */
450 : static u64 mtrr_gran_size __initdata;
451 :
452 : static int __init parse_mtrr_gran_size_opt(char *p)
453 : {
454 : if (!p)
455 : return -EINVAL;
456 : mtrr_gran_size = memparse(p, &p);
457 : return 0;
458 : }
459 : early_param("mtrr_gran_size", parse_mtrr_gran_size_opt);
460 :
461 : static unsigned long nr_mtrr_spare_reg __initdata =
462 : CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT;
463 :
464 : static int __init parse_mtrr_spare_reg(char *arg)
465 : {
466 : if (arg)
467 : nr_mtrr_spare_reg = simple_strtoul(arg, NULL, 0);
468 : return 0;
469 : }
470 : early_param("mtrr_spare_reg_nr", parse_mtrr_spare_reg);
471 :
472 : static int __init
473 : x86_setup_var_mtrrs(struct range *range, int nr_range,
474 : u64 chunk_size, u64 gran_size)
475 : {
476 : struct var_mtrr_state var_state;
477 : int num_reg;
478 : int i;
479 :
480 : var_state.range_startk = 0;
481 : var_state.range_sizek = 0;
482 : var_state.reg = 0;
483 : var_state.chunk_sizek = chunk_size >> 10;
484 : var_state.gran_sizek = gran_size >> 10;
485 :
486 : memset(range_state, 0, sizeof(range_state));
487 :
488 : /* Write the range: */
489 : for (i = 0; i < nr_range; i++) {
490 : set_var_mtrr_range(&var_state, range[i].start,
491 : range[i].end - range[i].start);
492 : }
493 :
494 : /* Write the last range: */
495 : if (var_state.range_sizek != 0)
496 : range_to_mtrr_with_hole(&var_state, 0, 0);
497 :
498 : num_reg = var_state.reg;
499 : /* Clear out the extra MTRR's: */
500 : while (var_state.reg < num_var_ranges) {
501 : save_var_mtrr(var_state.reg, 0, 0, 0);
502 : var_state.reg++;
503 : }
504 :
505 : return num_reg;
506 : }
507 :
508 : struct mtrr_cleanup_result {
509 : unsigned long gran_sizek;
510 : unsigned long chunk_sizek;
511 : unsigned long lose_cover_sizek;
512 : unsigned int num_reg;
513 : int bad;
514 : };
515 :
516 : /*
517 : * gran_size: 64K, 128K, 256K, 512K, 1M, 2M, ..., 2G
518 : * chunk size: gran_size, ..., 2G
519 : * so we need (1+16)*8
520 : */
521 : #define NUM_RESULT 136
522 : #define PSHIFT (PAGE_SHIFT - 10)
523 :
524 : static struct mtrr_cleanup_result __initdata result[NUM_RESULT];
525 : static unsigned long __initdata min_loss_pfn[RANGE_NUM];
526 :
527 : static void __init print_out_mtrr_range_state(void)
528 : {
529 : char start_factor = 'K', size_factor = 'K';
530 : unsigned long start_base, size_base;
531 : mtrr_type type;
532 : int i;
533 :
534 : for (i = 0; i < num_var_ranges; i++) {
535 :
536 : size_base = range_state[i].size_pfn << (PAGE_SHIFT - 10);
537 : if (!size_base)
538 : continue;
539 :
540 : size_base = to_size_factor(size_base, &size_factor);
541 : start_base = range_state[i].base_pfn << (PAGE_SHIFT - 10);
542 : start_base = to_size_factor(start_base, &start_factor);
543 : type = range_state[i].type;
544 :
545 : pr_debug("reg %d, base: %ld%cB, range: %ld%cB, type %s\n",
546 : i, start_base, start_factor,
547 : size_base, size_factor,
548 : (type == MTRR_TYPE_UNCACHABLE) ? "UC" :
549 : ((type == MTRR_TYPE_WRPROT) ? "WP" :
550 : ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other"))
551 : );
552 : }
553 : }
554 :
555 : static int __init mtrr_need_cleanup(void)
556 : {
557 : int i;
558 : mtrr_type type;
559 : unsigned long size;
560 : /* Extra one for all 0: */
561 : int num[MTRR_NUM_TYPES + 1];
562 :
563 : /* Check entries number: */
564 : memset(num, 0, sizeof(num));
565 : for (i = 0; i < num_var_ranges; i++) {
566 : type = range_state[i].type;
567 : size = range_state[i].size_pfn;
568 : if (type >= MTRR_NUM_TYPES)
569 : continue;
570 : if (!size)
571 : type = MTRR_NUM_TYPES;
572 : num[type]++;
573 : }
574 :
575 : /* Check if we got UC entries: */
576 : if (!num[MTRR_TYPE_UNCACHABLE])
577 : return 0;
578 :
579 : /* Check if we only had WB and UC */
580 : if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] !=
581 : num_var_ranges - num[MTRR_NUM_TYPES])
582 : return 0;
583 :
584 : return 1;
585 : }
586 :
587 : static unsigned long __initdata range_sums;
588 :
589 : static void __init
590 : mtrr_calc_range_state(u64 chunk_size, u64 gran_size,
591 : unsigned long x_remove_base,
592 : unsigned long x_remove_size, int i)
593 : {
594 : /*
595 : * range_new should really be an automatic variable, but
596 : * putting 4096 bytes on the stack is frowned upon, to put it
597 : * mildly. It is safe to make it a static __initdata variable,
598 : * since mtrr_calc_range_state is only called during init and
599 : * there's no way it will call itself recursively.
600 : */
601 : static struct range range_new[RANGE_NUM] __initdata;
602 : unsigned long range_sums_new;
603 : int nr_range_new;
604 : int num_reg;
605 :
606 : /* Convert ranges to var ranges state: */
607 : num_reg = x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size);
608 :
609 : /* We got new setting in range_state, check it: */
610 : memset(range_new, 0, sizeof(range_new));
611 : nr_range_new = x86_get_mtrr_mem_range(range_new, 0,
612 : x_remove_base, x_remove_size);
613 : range_sums_new = sum_ranges(range_new, nr_range_new);
614 :
615 : result[i].chunk_sizek = chunk_size >> 10;
616 : result[i].gran_sizek = gran_size >> 10;
617 : result[i].num_reg = num_reg;
618 :
619 : if (range_sums < range_sums_new) {
620 : result[i].lose_cover_sizek = (range_sums_new - range_sums) << PSHIFT;
621 : result[i].bad = 1;
622 : } else {
623 : result[i].lose_cover_sizek = (range_sums - range_sums_new) << PSHIFT;
624 : }
625 :
626 : /* Double check it: */
627 : if (!result[i].bad && !result[i].lose_cover_sizek) {
628 : if (nr_range_new != nr_range || memcmp(range, range_new, sizeof(range)))
629 : result[i].bad = 1;
630 : }
631 :
632 : if (!result[i].bad && (range_sums - range_sums_new < min_loss_pfn[num_reg]))
633 : min_loss_pfn[num_reg] = range_sums - range_sums_new;
634 : }
635 :
636 : static void __init mtrr_print_out_one_result(int i)
637 : {
638 : unsigned long gran_base, chunk_base, lose_base;
639 : char gran_factor, chunk_factor, lose_factor;
640 :
641 : gran_base = to_size_factor(result[i].gran_sizek, &gran_factor);
642 : chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor);
643 : lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor);
644 :
645 : pr_info("%sgran_size: %ld%c \tchunk_size: %ld%c \t",
646 : result[i].bad ? "*BAD*" : " ",
647 : gran_base, gran_factor, chunk_base, chunk_factor);
648 : pr_cont("num_reg: %d \tlose cover RAM: %s%ld%c\n",
649 : result[i].num_reg, result[i].bad ? "-" : "",
650 : lose_base, lose_factor);
651 : }
652 :
653 : static int __init mtrr_search_optimal_index(void)
654 : {
655 : int num_reg_good;
656 : int index_good;
657 : int i;
658 :
659 : if (nr_mtrr_spare_reg >= num_var_ranges)
660 : nr_mtrr_spare_reg = num_var_ranges - 1;
661 :
662 : num_reg_good = -1;
663 : for (i = num_var_ranges - nr_mtrr_spare_reg; i > 0; i--) {
664 : if (!min_loss_pfn[i])
665 : num_reg_good = i;
666 : }
667 :
668 : index_good = -1;
669 : if (num_reg_good != -1) {
670 : for (i = 0; i < NUM_RESULT; i++) {
671 : if (!result[i].bad &&
672 : result[i].num_reg == num_reg_good &&
673 : !result[i].lose_cover_sizek) {
674 : index_good = i;
675 : break;
676 : }
677 : }
678 : }
679 :
680 : return index_good;
681 : }
682 :
683 : int __init mtrr_cleanup(unsigned address_bits)
684 : {
685 : unsigned long x_remove_base, x_remove_size;
686 : unsigned long base, size, def, dummy;
687 : u64 chunk_size, gran_size;
688 : mtrr_type type;
689 : int index_good;
690 : int i;
691 :
692 : if (!is_cpu(INTEL) || enable_mtrr_cleanup < 1)
693 : return 0;
694 :
695 : rdmsr(MSR_MTRRdefType, def, dummy);
696 : def &= 0xff;
697 : if (def != MTRR_TYPE_UNCACHABLE)
698 : return 0;
699 :
700 : /* Get it and store it aside: */
701 : memset(range_state, 0, sizeof(range_state));
702 : for (i = 0; i < num_var_ranges; i++) {
703 : mtrr_if->get(i, &base, &size, &type);
704 : range_state[i].base_pfn = base;
705 : range_state[i].size_pfn = size;
706 : range_state[i].type = type;
707 : }
708 :
709 : /* Check if we need handle it and can handle it: */
710 : if (!mtrr_need_cleanup())
711 : return 0;
712 :
713 : /* Print original var MTRRs at first, for debugging: */
714 : pr_debug("original variable MTRRs\n");
715 : print_out_mtrr_range_state();
716 :
717 : memset(range, 0, sizeof(range));
718 : x_remove_size = 0;
719 : x_remove_base = 1 << (32 - PAGE_SHIFT);
720 : if (mtrr_tom2)
721 : x_remove_size = (mtrr_tom2 >> PAGE_SHIFT) - x_remove_base;
722 :
723 : /*
724 : * [0, 1M) should always be covered by var mtrr with WB
725 : * and fixed mtrrs should take effect before var mtrr for it:
726 : */
727 : nr_range = add_range_with_merge(range, RANGE_NUM, 0, 0,
728 : 1ULL<<(20 - PAGE_SHIFT));
729 : /* add from var mtrr at last */
730 : nr_range = x86_get_mtrr_mem_range(range, nr_range,
731 : x_remove_base, x_remove_size);
732 :
733 : range_sums = sum_ranges(range, nr_range);
734 : pr_info("total RAM covered: %ldM\n",
735 : range_sums >> (20 - PAGE_SHIFT));
736 :
737 : if (mtrr_chunk_size && mtrr_gran_size) {
738 : i = 0;
739 : mtrr_calc_range_state(mtrr_chunk_size, mtrr_gran_size,
740 : x_remove_base, x_remove_size, i);
741 :
742 : mtrr_print_out_one_result(i);
743 :
744 : if (!result[i].bad) {
745 : set_var_mtrr_all(address_bits);
746 : pr_debug("New variable MTRRs\n");
747 : print_out_mtrr_range_state();
748 : return 1;
749 : }
750 : pr_info("invalid mtrr_gran_size or mtrr_chunk_size, will find optimal one\n");
751 : }
752 :
753 : i = 0;
754 : memset(min_loss_pfn, 0xff, sizeof(min_loss_pfn));
755 : memset(result, 0, sizeof(result));
756 : for (gran_size = (1ULL<<16); gran_size < (1ULL<<32); gran_size <<= 1) {
757 :
758 : for (chunk_size = gran_size; chunk_size < (1ULL<<32);
759 : chunk_size <<= 1) {
760 :
761 : if (i >= NUM_RESULT)
762 : continue;
763 :
764 : mtrr_calc_range_state(chunk_size, gran_size,
765 : x_remove_base, x_remove_size, i);
766 : if (debug_print) {
767 : mtrr_print_out_one_result(i);
768 : pr_info("\n");
769 : }
770 :
771 : i++;
772 : }
773 : }
774 :
775 : /* Try to find the optimal index: */
776 : index_good = mtrr_search_optimal_index();
777 :
778 : if (index_good != -1) {
779 : pr_info("Found optimal setting for mtrr clean up\n");
780 : i = index_good;
781 : mtrr_print_out_one_result(i);
782 :
783 : /* Convert ranges to var ranges state: */
784 : chunk_size = result[i].chunk_sizek;
785 : chunk_size <<= 10;
786 : gran_size = result[i].gran_sizek;
787 : gran_size <<= 10;
788 : x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size);
789 : set_var_mtrr_all(address_bits);
790 : pr_debug("New variable MTRRs\n");
791 : print_out_mtrr_range_state();
792 : return 1;
793 : } else {
794 : /* print out all */
795 : for (i = 0; i < NUM_RESULT; i++)
796 : mtrr_print_out_one_result(i);
797 : }
798 :
799 : pr_info("mtrr_cleanup: can not find optimal value\n");
800 : pr_info("please specify mtrr_gran_size/mtrr_chunk_size\n");
801 :
802 : return 0;
803 : }
804 : #else
805 1 : int __init mtrr_cleanup(unsigned address_bits)
806 : {
807 1 : return 0;
808 : }
809 : #endif
810 :
811 : static int disable_mtrr_trim;
812 :
813 0 : static int __init disable_mtrr_trim_setup(char *str)
814 : {
815 0 : disable_mtrr_trim = 1;
816 0 : return 0;
817 : }
818 : early_param("disable_mtrr_trim", disable_mtrr_trim_setup);
819 :
820 : /*
821 : * Newer AMD K8s and later CPUs have a special magic MSR way to force WB
822 : * for memory >4GB. Check for that here.
823 : * Note this won't check if the MTRRs < 4GB where the magic bit doesn't
824 : * apply to are wrong, but so far we don't know of any such case in the wild.
825 : */
826 : #define Tom2Enabled (1U << 21)
827 : #define Tom2ForceMemTypeWB (1U << 22)
828 :
829 1 : int __init amd_special_default_mtrr(void)
830 : {
831 1 : u32 l, h;
832 :
833 1 : if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
834 : boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
835 : return 0;
836 0 : if (boot_cpu_data.x86 < 0xf)
837 : return 0;
838 : /* In case some hypervisor doesn't pass SYSCFG through: */
839 0 : if (rdmsr_safe(MSR_K8_SYSCFG, &l, &h) < 0)
840 : return 0;
841 : /*
842 : * Memory between 4GB and top of mem is forced WB by this magic bit.
843 : * Reserved before K8RevF, but should be zero there.
844 : */
845 0 : if ((l & (Tom2Enabled | Tom2ForceMemTypeWB)) ==
846 : (Tom2Enabled | Tom2ForceMemTypeWB))
847 0 : return 1;
848 : return 0;
849 : }
850 :
851 : static u64 __init
852 0 : real_trim_memory(unsigned long start_pfn, unsigned long limit_pfn)
853 : {
854 0 : u64 trim_start, trim_size;
855 :
856 0 : trim_start = start_pfn;
857 0 : trim_start <<= PAGE_SHIFT;
858 :
859 0 : trim_size = limit_pfn;
860 0 : trim_size <<= PAGE_SHIFT;
861 0 : trim_size -= trim_start;
862 :
863 0 : return e820__range_update(trim_start, trim_size, E820_TYPE_RAM, E820_TYPE_RESERVED);
864 : }
865 :
866 : /**
867 : * mtrr_trim_uncached_memory - trim RAM not covered by MTRRs
868 : * @end_pfn: ending page frame number
869 : *
870 : * Some buggy BIOSes don't setup the MTRRs properly for systems with certain
871 : * memory configurations. This routine checks that the highest MTRR matches
872 : * the end of memory, to make sure the MTRRs having a write back type cover
873 : * all of the memory the kernel is intending to use. If not, it'll trim any
874 : * memory off the end by adjusting end_pfn, removing it from the kernel's
875 : * allocation pools, warning the user with an obnoxious message.
876 : */
877 1 : int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
878 : {
879 1 : unsigned long i, base, size, highest_pfn = 0, def, dummy;
880 1 : mtrr_type type;
881 1 : u64 total_trim_size;
882 : /* extra one for all 0 */
883 1 : int num[MTRR_NUM_TYPES + 1];
884 :
885 : /*
886 : * Make sure we only trim uncachable memory on machines that
887 : * support the Intel MTRR architecture:
888 : */
889 1 : if (!is_cpu(INTEL) || disable_mtrr_trim)
890 : return 0;
891 :
892 1 : rdmsr(MSR_MTRRdefType, def, dummy);
893 1 : def &= 0xff;
894 1 : if (def != MTRR_TYPE_UNCACHABLE)
895 : return 0;
896 :
897 : /* Get it and store it aside: */
898 1 : memset(range_state, 0, sizeof(range_state));
899 9 : for (i = 0; i < num_var_ranges; i++) {
900 8 : mtrr_if->get(i, &base, &size, &type);
901 8 : range_state[i].base_pfn = base;
902 8 : range_state[i].size_pfn = size;
903 8 : range_state[i].type = type;
904 : }
905 :
906 : /* Find highest cached pfn: */
907 9 : for (i = 0; i < num_var_ranges; i++) {
908 8 : type = range_state[i].type;
909 8 : if (type != MTRR_TYPE_WRBACK)
910 8 : continue;
911 0 : base = range_state[i].base_pfn;
912 0 : size = range_state[i].size_pfn;
913 0 : if (highest_pfn < base + size)
914 : highest_pfn = base + size;
915 : }
916 :
917 : /* kvm/qemu doesn't have mtrr set right, don't trim them all: */
918 1 : if (!highest_pfn) {
919 1 : pr_info("CPU MTRRs all blank - virtualized system.\n");
920 1 : return 0;
921 : }
922 :
923 : /* Check entries number: */
924 0 : memset(num, 0, sizeof(num));
925 0 : for (i = 0; i < num_var_ranges; i++) {
926 0 : type = range_state[i].type;
927 0 : if (type >= MTRR_NUM_TYPES)
928 0 : continue;
929 0 : size = range_state[i].size_pfn;
930 0 : if (!size)
931 0 : type = MTRR_NUM_TYPES;
932 0 : num[type]++;
933 : }
934 :
935 : /* No entry for WB? */
936 0 : if (!num[MTRR_TYPE_WRBACK])
937 : return 0;
938 :
939 : /* Check if we only had WB and UC: */
940 0 : if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] !=
941 0 : num_var_ranges - num[MTRR_NUM_TYPES])
942 : return 0;
943 :
944 0 : memset(range, 0, sizeof(range));
945 0 : nr_range = 0;
946 0 : if (mtrr_tom2) {
947 0 : range[nr_range].start = (1ULL<<(32 - PAGE_SHIFT));
948 0 : range[nr_range].end = mtrr_tom2 >> PAGE_SHIFT;
949 0 : if (highest_pfn < range[nr_range].end)
950 0 : highest_pfn = range[nr_range].end;
951 0 : nr_range++;
952 : }
953 0 : nr_range = x86_get_mtrr_mem_range(range, nr_range, 0, 0);
954 :
955 : /* Check the head: */
956 0 : total_trim_size = 0;
957 0 : if (range[0].start)
958 0 : total_trim_size += real_trim_memory(0, range[0].start);
959 :
960 : /* Check the holes: */
961 0 : for (i = 0; i < nr_range - 1; i++) {
962 0 : if (range[i].end < range[i+1].start)
963 0 : total_trim_size += real_trim_memory(range[i].end,
964 : range[i+1].start);
965 : }
966 :
967 : /* Check the top: */
968 0 : i = nr_range - 1;
969 0 : if (range[i].end < end_pfn)
970 0 : total_trim_size += real_trim_memory(range[i].end,
971 : end_pfn);
972 :
973 0 : if (total_trim_size) {
974 0 : pr_warn("WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing %lluMB of RAM.\n",
975 : total_trim_size >> 20);
976 :
977 0 : if (!changed_by_mtrr_cleanup)
978 0 : WARN_ON(1);
979 :
980 0 : pr_info("update e820 for mtrr\n");
981 0 : e820__update_table_print();
982 :
983 0 : return 1;
984 : }
985 :
986 : return 0;
987 : }
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