4903a03ae876338c2ad351f5db5988f35bb35d08
[linux-3.10.git] / arch / x86 / mm / init.c
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  */
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);
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
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
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
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  */
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
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         /* try to merge same page size and continuous */
281         for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
282                 unsigned long old_start;
283                 if (mr[i].end != mr[i+1].start ||
284                     mr[i].page_size_mask != mr[i+1].page_size_mask)
285                         continue;
286                 /* move it */
287                 old_start = mr[i].start;
288                 memmove(&mr[i], &mr[i+1],
289                         (nr_range - 1 - i) * sizeof(struct map_range));
290                 mr[i--].start = old_start;
291                 nr_range--;
292         }
293
294         if (!after_bootmem)
295                 adjust_range_page_size_mask(mr, nr_range);
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
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
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  */
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  * would have hole in the middle or ends, and only ram parts will be mapped.
363  */
364 static unsigned long __init init_range_memory_mapping(
365                                            unsigned long r_start,
366                                            unsigned long r_end)
367 {
368         unsigned long start_pfn, end_pfn;
369         unsigned long mapped_ram_size = 0;
370         int i;
371
372         for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
373                 u64 start = clamp_val(PFN_PHYS(start_pfn), r_start, r_end);
374                 u64 end = clamp_val(PFN_PHYS(end_pfn), r_start, r_end);
375                 if (start >= end)
376                         continue;
377
378                 /*
379                  * if it is overlapping with brk pgt, we need to
380                  * alloc pgt buf from memblock instead.
381                  */
382                 can_use_brk_pgt = max(start, (u64)pgt_buf_end<<PAGE_SHIFT) >=
383                                     min(end, (u64)pgt_buf_top<<PAGE_SHIFT);
384                 init_memory_mapping(start, end);
385                 mapped_ram_size += end - start;
386                 can_use_brk_pgt = true;
387         }
388
389         return mapped_ram_size;
390 }
391
392 /* (PUD_SHIFT-PMD_SHIFT)/2 */
393 #define STEP_SIZE_SHIFT 5
394 void __init init_mem_mapping(void)
395 {
396         unsigned long end, real_end, start, last_start;
397         unsigned long step_size;
398         unsigned long addr;
399         unsigned long mapped_ram_size = 0;
400         unsigned long new_mapped_ram_size;
401
402         probe_page_size_mask();
403
404 #ifdef CONFIG_X86_64
405         end = max_pfn << PAGE_SHIFT;
406 #else
407         end = max_low_pfn << PAGE_SHIFT;
408 #endif
409
410         /* the ISA range is always mapped regardless of memory holes */
411         init_memory_mapping(0, ISA_END_ADDRESS);
412
413         /* xen has big range in reserved near end of ram, skip it at first */
414         addr = memblock_find_in_range(ISA_END_ADDRESS, end, PMD_SIZE,
415                          PAGE_SIZE);
416         real_end = addr + PMD_SIZE;
417
418         /* step_size need to be small so pgt_buf from BRK could cover it */
419         step_size = PMD_SIZE;
420         max_pfn_mapped = 0; /* will get exact value next */
421         min_pfn_mapped = real_end >> PAGE_SHIFT;
422         last_start = start = real_end;
423         while (last_start > ISA_END_ADDRESS) {
424                 if (last_start > step_size) {
425                         start = round_down(last_start - 1, step_size);
426                         if (start < ISA_END_ADDRESS)
427                                 start = ISA_END_ADDRESS;
428                 } else
429                         start = ISA_END_ADDRESS;
430                 new_mapped_ram_size = init_range_memory_mapping(start,
431                                                         last_start);
432                 last_start = start;
433                 min_pfn_mapped = last_start >> PAGE_SHIFT;
434                 /* only increase step_size after big range get mapped */
435                 if (new_mapped_ram_size > mapped_ram_size)
436                         step_size <<= STEP_SIZE_SHIFT;
437                 mapped_ram_size += new_mapped_ram_size;
438         }
439
440         if (real_end < end)
441                 init_range_memory_mapping(real_end, end);
442
443 #ifdef CONFIG_X86_64
444         if (max_pfn > max_low_pfn) {
445                 /* can we preseve max_low_pfn ?*/
446                 max_low_pfn = max_pfn;
447         }
448 #else
449         early_ioremap_page_table_range_init();
450 #endif
451
452         load_cr3(swapper_pg_dir);
453         __flush_tlb_all();
454
455         early_memtest(0, max_pfn_mapped << PAGE_SHIFT);
456 }
457
458 /*
459  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
460  * is valid. The argument is a physical page number.
461  *
462  *
463  * On x86, access has to be given to the first megabyte of ram because that area
464  * contains bios code and data regions used by X and dosemu and similar apps.
465  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
466  * mmio resources as well as potential bios/acpi data regions.
467  */
468 int devmem_is_allowed(unsigned long pagenr)
469 {
470         if (pagenr < 256)
471                 return 1;
472         if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
473                 return 0;
474         if (!page_is_ram(pagenr))
475                 return 1;
476         return 0;
477 }
478
479 void free_init_pages(char *what, unsigned long begin, unsigned long end)
480 {
481         unsigned long addr;
482         unsigned long begin_aligned, end_aligned;
483
484         /* Make sure boundaries are page aligned */
485         begin_aligned = PAGE_ALIGN(begin);
486         end_aligned   = end & PAGE_MASK;
487
488         if (WARN_ON(begin_aligned != begin || end_aligned != end)) {
489                 begin = begin_aligned;
490                 end   = end_aligned;
491         }
492
493         if (begin >= end)
494                 return;
495
496         addr = begin;
497
498         /*
499          * If debugging page accesses then do not free this memory but
500          * mark them not present - any buggy init-section access will
501          * create a kernel page fault:
502          */
503 #ifdef CONFIG_DEBUG_PAGEALLOC
504         printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n",
505                 begin, end - 1);
506         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
507 #else
508         /*
509          * We just marked the kernel text read only above, now that
510          * we are going to free part of that, we need to make that
511          * writeable and non-executable first.
512          */
513         set_memory_nx(begin, (end - begin) >> PAGE_SHIFT);
514         set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
515
516         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
517
518         for (; addr < end; addr += PAGE_SIZE) {
519                 ClearPageReserved(virt_to_page(addr));
520                 init_page_count(virt_to_page(addr));
521                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
522                 free_page(addr);
523                 totalram_pages++;
524         }
525 #endif
526 }
527
528 void free_initmem(void)
529 {
530         free_init_pages("unused kernel memory",
531                         (unsigned long)(&__init_begin),
532                         (unsigned long)(&__init_end));
533 }
534
535 #ifdef CONFIG_BLK_DEV_INITRD
536 void __init free_initrd_mem(unsigned long start, unsigned long end)
537 {
538 #ifdef CONFIG_MICROCODE_EARLY
539         /*
540          * Remember, initrd memory may contain microcode or other useful things.
541          * Before we lose initrd mem, we need to find a place to hold them
542          * now that normal virtual memory is enabled.
543          */
544         save_microcode_in_initrd();
545 #endif
546
547         /*
548          * end could be not aligned, and We can not align that,
549          * decompresser could be confused by aligned initrd_end
550          * We already reserve the end partial page before in
551          *   - i386_start_kernel()
552          *   - x86_64_start_kernel()
553          *   - relocate_initrd()
554          * So here We can do PAGE_ALIGN() safely to get partial page to be freed
555          */
556         free_init_pages("initrd memory", start, PAGE_ALIGN(end));
557 }
558 #endif
559
560 void __init zone_sizes_init(void)
561 {
562         unsigned long max_zone_pfns[MAX_NR_ZONES];
563
564         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
565
566 #ifdef CONFIG_ZONE_DMA
567         max_zone_pfns[ZONE_DMA]         = MAX_DMA_PFN;
568 #endif
569 #ifdef CONFIG_ZONE_DMA32
570         max_zone_pfns[ZONE_DMA32]       = MAX_DMA32_PFN;
571 #endif
572         max_zone_pfns[ZONE_NORMAL]      = max_low_pfn;
573 #ifdef CONFIG_HIGHMEM
574         max_zone_pfns[ZONE_HIGHMEM]     = max_pfn;
575 #endif
576
577         free_area_init_nodes(max_zone_pfns);
578 }
579