1 #include <linux/gfp.h>
2 #include <linux/initrd.h>
3 #include <linux/ioport.h>
4 #include <linux/swap.h>
5 #include <linux/memblock.h>
6 #include <linux/bootmem.h> /* for max_low_pfn */
7
8 #include <asm/cacheflush.h>
9 #include <asm/e820.h>
10 #include <asm/init.h>
11 #include <asm/page.h>
12 #include <asm/page_types.h>
13 #include <asm/sections.h>
14 #include <asm/setup.h>
15 #include <asm/tlbflush.h>
16 #include <asm/tlb.h>
17 #include <asm/proto.h>
18 #include <asm/dma.h> /* for MAX_DMA_PFN */
19 #include <asm/microcode.h>
20
21 #include "mm_internal.h"
22
23 static unsigned long __initdata pgt_buf_start;
24 static unsigned long __initdata pgt_buf_end;
25 static unsigned long __initdata pgt_buf_top;
26
27 static unsigned long min_pfn_mapped;
28
29 static bool __initdata can_use_brk_pgt = true;
30
31 /*
32 * Pages returned are already directly mapped.
33 *
34 * Changing that is likely to break Xen, see commit:
35 *
36 * 279b706 x86,xen: introduce x86_init.mapping.pagetable_reserve
37 *
38 * for detailed information.
39 */
alloc_low_pages(unsigned int num)40 __ref void *alloc_low_pages(unsigned int num)
41 {
42 unsigned long pfn;
43 int i;
44
45 if (after_bootmem) {
46 unsigned int order;
47
48 order = get_order((unsigned long)num << PAGE_SHIFT);
49 return (void *)__get_free_pages(GFP_ATOMIC | __GFP_NOTRACK |
50 __GFP_ZERO, order);
51 }
52
53 if ((pgt_buf_end + num) > pgt_buf_top || !can_use_brk_pgt) {
54 unsigned long ret;
55 if (min_pfn_mapped >= max_pfn_mapped)
56 panic("alloc_low_page: ran out of memory");
57 ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT,
58 max_pfn_mapped << PAGE_SHIFT,
59 PAGE_SIZE * num , PAGE_SIZE);
60 if (!ret)
61 panic("alloc_low_page: can not alloc memory");
62 memblock_reserve(ret, PAGE_SIZE * num);
63 pfn = ret >> PAGE_SHIFT;
64 } else {
65 pfn = pgt_buf_end;
66 pgt_buf_end += num;
67 printk(KERN_DEBUG "BRK [%#010lx, %#010lx] PGTABLE\n",
68 pfn << PAGE_SHIFT, (pgt_buf_end << PAGE_SHIFT) - 1);
69 }
70
71 for (i = 0; i < num; i++) {
72 void *adr;
73
74 adr = __va((pfn + i) << PAGE_SHIFT);
75 clear_page(adr);
76 }
77
78 return __va(pfn << PAGE_SHIFT);
79 }
80
81 /* need 4 4k for initial PMD_SIZE, 4k for 0-ISA_END_ADDRESS */
82 #define INIT_PGT_BUF_SIZE (5 * PAGE_SIZE)
83 RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE);
early_alloc_pgt_buf(void)84 void __init early_alloc_pgt_buf(void)
85 {
86 unsigned long tables = INIT_PGT_BUF_SIZE;
87 phys_addr_t base;
88
89 base = __pa(extend_brk(tables, PAGE_SIZE));
90
91 pgt_buf_start = base >> PAGE_SHIFT;
92 pgt_buf_end = pgt_buf_start;
93 pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
94 }
95
96 int after_bootmem;
97
98 int direct_gbpages
99 #ifdef CONFIG_DIRECT_GBPAGES
100 = 1
101 #endif
102 ;
103
init_gbpages(void)104 static void __init init_gbpages(void)
105 {
106 #ifdef CONFIG_X86_64
107 if (direct_gbpages && cpu_has_gbpages)
108 printk(KERN_INFO "Using GB pages for direct mapping\n");
109 else
110 direct_gbpages = 0;
111 #endif
112 }
113
114 struct map_range {
115 unsigned long start;
116 unsigned long end;
117 unsigned page_size_mask;
118 };
119
120 static int page_size_mask;
121
probe_page_size_mask(void)122 static void __init probe_page_size_mask(void)
123 {
124 init_gbpages();
125
126 #if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK)
127 /*
128 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
129 * This will simplify cpa(), which otherwise needs to support splitting
130 * large pages into small in interrupt context, etc.
131 */
132 if (direct_gbpages)
133 page_size_mask |= 1 << PG_LEVEL_1G;
134 if (cpu_has_pse)
135 page_size_mask |= 1 << PG_LEVEL_2M;
136 #endif
137
138 /* Enable PSE if available */
139 if (cpu_has_pse)
140 set_in_cr4(X86_CR4_PSE);
141
142 /* Enable PGE if available */
143 if (cpu_has_pge) {
144 set_in_cr4(X86_CR4_PGE);
145 __supported_pte_mask |= _PAGE_GLOBAL;
146 }
147 }
148
149 #ifdef CONFIG_X86_32
150 #define NR_RANGE_MR 3
151 #else /* CONFIG_X86_64 */
152 #define NR_RANGE_MR 5
153 #endif
154
save_mr(struct map_range * mr,int nr_range,unsigned long start_pfn,unsigned long end_pfn,unsigned long page_size_mask)155 static int __meminit save_mr(struct map_range *mr, int nr_range,
156 unsigned long start_pfn, unsigned long end_pfn,
157 unsigned long page_size_mask)
158 {
159 if (start_pfn < end_pfn) {
160 if (nr_range >= NR_RANGE_MR)
161 panic("run out of range for init_memory_mapping\n");
162 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
163 mr[nr_range].end = end_pfn<<PAGE_SHIFT;
164 mr[nr_range].page_size_mask = page_size_mask;
165 nr_range++;
166 }
167
168 return nr_range;
169 }
170
171 /*
172 * adjust the page_size_mask for small range to go with
173 * big page size instead small one if nearby are ram too.
174 */
adjust_range_page_size_mask(struct map_range * mr,int nr_range)175 static void __init_refok adjust_range_page_size_mask(struct map_range *mr,
176 int nr_range)
177 {
178 int i;
179
180 for (i = 0; i < nr_range; i++) {
181 if ((page_size_mask & (1<<PG_LEVEL_2M)) &&
182 !(mr[i].page_size_mask & (1<<PG_LEVEL_2M))) {
183 unsigned long start = round_down(mr[i].start, PMD_SIZE);
184 unsigned long end = round_up(mr[i].end, PMD_SIZE);
185
186 #ifdef CONFIG_X86_32
187 if ((end >> PAGE_SHIFT) > max_low_pfn)
188 continue;
189 #endif
190
191 if (memblock_is_region_memory(start, end - start))
192 mr[i].page_size_mask |= 1<<PG_LEVEL_2M;
193 }
194 if ((page_size_mask & (1<<PG_LEVEL_1G)) &&
195 !(mr[i].page_size_mask & (1<<PG_LEVEL_1G))) {
196 unsigned long start = round_down(mr[i].start, PUD_SIZE);
197 unsigned long end = round_up(mr[i].end, PUD_SIZE);
198
199 if (memblock_is_region_memory(start, end - start))
200 mr[i].page_size_mask |= 1<<PG_LEVEL_1G;
201 }
202 }
203 }
204
split_mem_range(struct map_range * mr,int nr_range,unsigned long start,unsigned long end)205 static int __meminit split_mem_range(struct map_range *mr, int nr_range,
206 unsigned long start,
207 unsigned long end)
208 {
209 unsigned long start_pfn, end_pfn, limit_pfn;
210 unsigned long pfn;
211 int i;
212
213 limit_pfn = PFN_DOWN(end);
214
215 /* head if not big page alignment ? */
216 pfn = start_pfn = PFN_DOWN(start);
217 #ifdef CONFIG_X86_32
218 /*
219 * Don't use a large page for the first 2/4MB of memory
220 * because there are often fixed size MTRRs in there
221 * and overlapping MTRRs into large pages can cause
222 * slowdowns.
223 */
224 if (pfn == 0)
225 end_pfn = PFN_DOWN(PMD_SIZE);
226 else
227 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
228 #else /* CONFIG_X86_64 */
229 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
230 #endif
231 if (end_pfn > limit_pfn)
232 end_pfn = limit_pfn;
233 if (start_pfn < end_pfn) {
234 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
235 pfn = end_pfn;
236 }
237
238 /* big page (2M) range */
239 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
240 #ifdef CONFIG_X86_32
241 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
242 #else /* CONFIG_X86_64 */
243 end_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
244 if (end_pfn > round_down(limit_pfn, PFN_DOWN(PMD_SIZE)))
245 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
246 #endif
247
248 if (start_pfn < end_pfn) {
249 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
250 page_size_mask & (1<<PG_LEVEL_2M));
251 pfn = end_pfn;
252 }
253
254 #ifdef CONFIG_X86_64
255 /* big page (1G) range */
256 start_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
257 end_pfn = round_down(limit_pfn, PFN_DOWN(PUD_SIZE));
258 if (start_pfn < end_pfn) {
259 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
260 page_size_mask &
261 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
262 pfn = end_pfn;
263 }
264
265 /* tail is not big page (1G) alignment */
266 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
267 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
268 if (start_pfn < end_pfn) {
269 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
270 page_size_mask & (1<<PG_LEVEL_2M));
271 pfn = end_pfn;
272 }
273 #endif
274
275 /* tail is not big page (2M) alignment */
276 start_pfn = pfn;
277 end_pfn = limit_pfn;
278 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
279
280 if (!after_bootmem)
281 adjust_range_page_size_mask(mr, nr_range);
282
283 /* try to merge same page size and continuous */
284 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
285 unsigned long old_start;
286 if (mr[i].end != mr[i+1].start ||
287 mr[i].page_size_mask != mr[i+1].page_size_mask)
288 continue;
289 /* move it */
290 old_start = mr[i].start;
291 memmove(&mr[i], &mr[i+1],
292 (nr_range - 1 - i) * sizeof(struct map_range));
293 mr[i--].start = old_start;
294 nr_range--;
295 }
296
297 for (i = 0; i < nr_range; i++)
298 printk(KERN_DEBUG " [mem %#010lx-%#010lx] page %s\n",
299 mr[i].start, mr[i].end - 1,
300 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
301 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
302
303 return nr_range;
304 }
305
306 struct range pfn_mapped[E820_X_MAX];
307 int nr_pfn_mapped;
308
add_pfn_range_mapped(unsigned long start_pfn,unsigned long end_pfn)309 static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn)
310 {
311 nr_pfn_mapped = add_range_with_merge(pfn_mapped, E820_X_MAX,
312 nr_pfn_mapped, start_pfn, end_pfn);
313 nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_X_MAX);
314
315 max_pfn_mapped = max(max_pfn_mapped, end_pfn);
316
317 if (start_pfn < (1UL<<(32-PAGE_SHIFT)))
318 max_low_pfn_mapped = max(max_low_pfn_mapped,
319 min(end_pfn, 1UL<<(32-PAGE_SHIFT)));
320 }
321
pfn_range_is_mapped(unsigned long start_pfn,unsigned long end_pfn)322 bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn)
323 {
324 int i;
325
326 for (i = 0; i < nr_pfn_mapped; i++)
327 if ((start_pfn >= pfn_mapped[i].start) &&
328 (end_pfn <= pfn_mapped[i].end))
329 return true;
330
331 return false;
332 }
333
334 /*
335 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
336 * This runs before bootmem is initialized and gets pages directly from
337 * the physical memory. To access them they are temporarily mapped.
338 */
init_memory_mapping(unsigned long start,unsigned long end)339 unsigned long __init_refok init_memory_mapping(unsigned long start,
340 unsigned long end)
341 {
342 struct map_range mr[NR_RANGE_MR];
343 unsigned long ret = 0;
344 int nr_range, i;
345
346 pr_info("init_memory_mapping: [mem %#010lx-%#010lx]\n",
347 start, end - 1);
348
349 memset(mr, 0, sizeof(mr));
350 nr_range = split_mem_range(mr, 0, start, end);
351
352 for (i = 0; i < nr_range; i++)
353 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
354 mr[i].page_size_mask);
355
356 add_pfn_range_mapped(start >> PAGE_SHIFT, ret >> PAGE_SHIFT);
357
358 return ret >> PAGE_SHIFT;
359 }
360
361 /*
362 * We need to iterate through the E820 memory map and create direct mappings
363 * for only E820_RAM and E820_KERN_RESERVED regions. We cannot simply
364 * create direct mappings for all pfns from [0 to max_low_pfn) and
365 * [4GB to max_pfn) because of possible memory holes in high addresses
366 * that cannot be marked as UC by fixed/variable range MTRRs.
367 * Depending on the alignment of E820 ranges, this may possibly result
368 * in using smaller size (i.e. 4K instead of 2M or 1G) page tables.
369 *
370 * init_mem_mapping() calls init_range_memory_mapping() with big range.
371 * That range would have hole in the middle or ends, and only ram parts
372 * will be mapped in init_range_memory_mapping().
373 */
init_range_memory_mapping(unsigned long r_start,unsigned long r_end)374 static unsigned long __init init_range_memory_mapping(
375 unsigned long r_start,
376 unsigned long r_end)
377 {
378 unsigned long start_pfn, end_pfn;
379 unsigned long mapped_ram_size = 0;
380 int i;
381
382 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
383 u64 start = clamp_val(PFN_PHYS(start_pfn), r_start, r_end);
384 u64 end = clamp_val(PFN_PHYS(end_pfn), r_start, r_end);
385 if (start >= end)
386 continue;
387
388 /*
389 * if it is overlapping with brk pgt, we need to
390 * alloc pgt buf from memblock instead.
391 */
392 can_use_brk_pgt = max(start, (u64)pgt_buf_end<<PAGE_SHIFT) >=
393 min(end, (u64)pgt_buf_top<<PAGE_SHIFT);
394 init_memory_mapping(start, end);
395 mapped_ram_size += end - start;
396 can_use_brk_pgt = true;
397 }
398
399 return mapped_ram_size;
400 }
401
402 /* (PUD_SHIFT-PMD_SHIFT)/2 */
403 #define STEP_SIZE_SHIFT 5
init_mem_mapping(void)404 void __init init_mem_mapping(void)
405 {
406 unsigned long end, real_end, start, last_start;
407 unsigned long step_size;
408 unsigned long addr;
409 unsigned long mapped_ram_size = 0;
410 unsigned long new_mapped_ram_size;
411
412 probe_page_size_mask();
413
414 #ifdef CONFIG_X86_64
415 end = max_pfn << PAGE_SHIFT;
416 #else
417 end = max_low_pfn << PAGE_SHIFT;
418 #endif
419
420 /* the ISA range is always mapped regardless of memory holes */
421 init_memory_mapping(0, ISA_END_ADDRESS);
422
423 /* xen has big range in reserved near end of ram, skip it at first.*/
424 addr = memblock_find_in_range(ISA_END_ADDRESS, end, PMD_SIZE, PMD_SIZE);
425 real_end = addr + PMD_SIZE;
426
427 /* step_size need to be small so pgt_buf from BRK could cover it */
428 step_size = PMD_SIZE;
429 max_pfn_mapped = 0; /* will get exact value next */
430 min_pfn_mapped = real_end >> PAGE_SHIFT;
431 last_start = start = real_end;
432
433 /*
434 * We start from the top (end of memory) and go to the bottom.
435 * The memblock_find_in_range() gets us a block of RAM from the
436 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages
437 * for page table.
438 */
439 while (last_start > ISA_END_ADDRESS) {
440 if (last_start > step_size) {
441 start = round_down(last_start - 1, step_size);
442 if (start < ISA_END_ADDRESS)
443 start = ISA_END_ADDRESS;
444 } else
445 start = ISA_END_ADDRESS;
446 new_mapped_ram_size = init_range_memory_mapping(start,
447 last_start);
448 last_start = start;
449 min_pfn_mapped = last_start >> PAGE_SHIFT;
450 /* only increase step_size after big range get mapped */
451 if (new_mapped_ram_size > mapped_ram_size)
452 step_size <<= STEP_SIZE_SHIFT;
453 mapped_ram_size += new_mapped_ram_size;
454 }
455
456 if (real_end < end)
457 init_range_memory_mapping(real_end, end);
458
459 #ifdef CONFIG_X86_64
460 if (max_pfn > max_low_pfn) {
461 /* can we preseve max_low_pfn ?*/
462 max_low_pfn = max_pfn;
463 }
464 #else
465 early_ioremap_page_table_range_init();
466 #endif
467
468 load_cr3(swapper_pg_dir);
469 __flush_tlb_all();
470
471 early_memtest(0, max_pfn_mapped << PAGE_SHIFT);
472 }
473
474 /*
475 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
476 * is valid. The argument is a physical page number.
477 *
478 *
479 * On x86, access has to be given to the first megabyte of ram because that area
480 * contains bios code and data regions used by X and dosemu and similar apps.
481 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
482 * mmio resources as well as potential bios/acpi data regions.
483 */
devmem_is_allowed(unsigned long pagenr)484 int devmem_is_allowed(unsigned long pagenr)
485 {
486 if (pagenr < 256)
487 return 1;
488 if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
489 return 0;
490 if (!page_is_ram(pagenr))
491 return 1;
492 return 0;
493 }
494
free_init_pages(char * what,unsigned long begin,unsigned long end)495 void free_init_pages(char *what, unsigned long begin, unsigned long end)
496 {
497 unsigned long addr;
498 unsigned long begin_aligned, end_aligned;
499
500 /* Make sure boundaries are page aligned */
501 begin_aligned = PAGE_ALIGN(begin);
502 end_aligned = end & PAGE_MASK;
503
504 if (WARN_ON(begin_aligned != begin || end_aligned != end)) {
505 begin = begin_aligned;
506 end = end_aligned;
507 }
508
509 if (begin >= end)
510 return;
511
512 addr = begin;
513
514 /*
515 * If debugging page accesses then do not free this memory but
516 * mark them not present - any buggy init-section access will
517 * create a kernel page fault:
518 */
519 #ifdef CONFIG_DEBUG_PAGEALLOC
520 printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n",
521 begin, end - 1);
522 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
523 #else
524 /*
525 * We just marked the kernel text read only above, now that
526 * we are going to free part of that, we need to make that
527 * writeable and non-executable first.
528 */
529 set_memory_nx(begin, (end - begin) >> PAGE_SHIFT);
530 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
531
532 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
533
534 for (; addr < end; addr += PAGE_SIZE) {
535 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
536 free_reserved_page(virt_to_page(addr));
537 }
538 #endif
539 }
540
free_initmem(void)541 void free_initmem(void)
542 {
543 free_init_pages("unused kernel memory",
544 (unsigned long)(&__init_begin),
545 (unsigned long)(&__init_end));
546 }
547
548 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)549 void __init free_initrd_mem(unsigned long start, unsigned long end)
550 {
551 #ifdef CONFIG_MICROCODE_EARLY
552 /*
553 * Remember, initrd memory may contain microcode or other useful things.
554 * Before we lose initrd mem, we need to find a place to hold them
555 * now that normal virtual memory is enabled.
556 */
557 save_microcode_in_initrd();
558 #endif
559
560 /*
561 * end could be not aligned, and We can not align that,
562 * decompresser could be confused by aligned initrd_end
563 * We already reserve the end partial page before in
564 * - i386_start_kernel()
565 * - x86_64_start_kernel()
566 * - relocate_initrd()
567 * So here We can do PAGE_ALIGN() safely to get partial page to be freed
568 */
569 free_init_pages("initrd memory", start, PAGE_ALIGN(end));
570 }
571 #endif
572
zone_sizes_init(void)573 void __init zone_sizes_init(void)
574 {
575 unsigned long max_zone_pfns[MAX_NR_ZONES];
576
577 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
578
579 #ifdef CONFIG_ZONE_DMA
580 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
581 #endif
582 #ifdef CONFIG_ZONE_DMA32
583 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
584 #endif
585 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
586 #ifdef CONFIG_HIGHMEM
587 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
588 #endif
589
590 free_area_init_nodes(max_zone_pfns);
591 }
592
593