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 */
8 #include <asm/cacheflush.h>
12 #include <asm/page_types.h>
13 #include <asm/sections.h>
14 #include <asm/setup.h>
15 #include <asm/tlbflush.h>
17 #include <asm/proto.h>
18 #include <asm/dma.h> /* for MAX_DMA_PFN */
19 #include <asm/microcode.h>
22 * We need to define the tracepoints somewhere, and tlb.c
23 * is only compied when SMP=y.
25 #define CREATE_TRACE_POINTS
26 #include <trace/events/tlb.h>
28 #include "mm_internal.h"
30 static unsigned long __initdata pgt_buf_start;
31 static unsigned long __initdata pgt_buf_end;
32 static unsigned long __initdata pgt_buf_top;
34 static unsigned long min_pfn_mapped;
36 static bool __initdata can_use_brk_pgt = true;
39 * Pages returned are already directly mapped.
41 * Changing that is likely to break Xen, see commit:
43 * 279b706 x86,xen: introduce x86_init.mapping.pagetable_reserve
45 * for detailed information.
47 __ref void *alloc_low_pages(unsigned int num)
55 order = get_order((unsigned long)num << PAGE_SHIFT);
56 return (void *)__get_free_pages(GFP_ATOMIC | __GFP_NOTRACK |
60 if ((pgt_buf_end + num) > pgt_buf_top || !can_use_brk_pgt) {
62 if (min_pfn_mapped >= max_pfn_mapped)
63 panic("alloc_low_pages: ran out of memory");
64 ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT,
65 max_pfn_mapped << PAGE_SHIFT,
66 PAGE_SIZE * num , PAGE_SIZE);
68 panic("alloc_low_pages: can not alloc memory");
69 memblock_reserve(ret, PAGE_SIZE * num);
70 pfn = ret >> PAGE_SHIFT;
74 printk(KERN_DEBUG "BRK [%#010lx, %#010lx] PGTABLE\n",
75 pfn << PAGE_SHIFT, (pgt_buf_end << PAGE_SHIFT) - 1);
78 for (i = 0; i < num; i++) {
81 adr = __va((pfn + i) << PAGE_SHIFT);
85 return __va(pfn << PAGE_SHIFT);
88 /* need 3 4k for initial PMD_SIZE, 3 4k for 0-ISA_END_ADDRESS */
89 #define INIT_PGT_BUF_SIZE (6 * PAGE_SIZE)
90 RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE);
91 void __init early_alloc_pgt_buf(void)
93 unsigned long tables = INIT_PGT_BUF_SIZE;
96 base = __pa(extend_brk(tables, PAGE_SIZE));
98 pgt_buf_start = base >> PAGE_SHIFT;
99 pgt_buf_end = pgt_buf_start;
100 pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
106 #ifdef CONFIG_DIRECT_GBPAGES
111 static void __init init_gbpages(void)
114 if (direct_gbpages && cpu_has_gbpages)
115 printk(KERN_INFO "Using GB pages for direct mapping\n");
124 unsigned page_size_mask;
127 static int page_size_mask;
129 static void __init probe_page_size_mask(void)
133 #if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK)
135 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
136 * This will simplify cpa(), which otherwise needs to support splitting
137 * large pages into small in interrupt context, etc.
140 page_size_mask |= 1 << PG_LEVEL_1G;
142 page_size_mask |= 1 << PG_LEVEL_2M;
145 /* Enable PSE if available */
147 set_in_cr4(X86_CR4_PSE);
149 /* Enable PGE if available */
151 set_in_cr4(X86_CR4_PGE);
152 __supported_pte_mask |= _PAGE_GLOBAL;
157 #define NR_RANGE_MR 3
158 #else /* CONFIG_X86_64 */
159 #define NR_RANGE_MR 5
162 static int __meminit save_mr(struct map_range *mr, int nr_range,
163 unsigned long start_pfn, unsigned long end_pfn,
164 unsigned long page_size_mask)
166 if (start_pfn < end_pfn) {
167 if (nr_range >= NR_RANGE_MR)
168 panic("run out of range for init_memory_mapping\n");
169 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
170 mr[nr_range].end = end_pfn<<PAGE_SHIFT;
171 mr[nr_range].page_size_mask = page_size_mask;
179 * adjust the page_size_mask for small range to go with
180 * big page size instead small one if nearby are ram too.
182 static void __init_refok adjust_range_page_size_mask(struct map_range *mr,
187 for (i = 0; i < nr_range; i++) {
188 if ((page_size_mask & (1<<PG_LEVEL_2M)) &&
189 !(mr[i].page_size_mask & (1<<PG_LEVEL_2M))) {
190 unsigned long start = round_down(mr[i].start, PMD_SIZE);
191 unsigned long end = round_up(mr[i].end, PMD_SIZE);
194 if ((end >> PAGE_SHIFT) > max_low_pfn)
198 if (memblock_is_region_memory(start, end - start))
199 mr[i].page_size_mask |= 1<<PG_LEVEL_2M;
201 if ((page_size_mask & (1<<PG_LEVEL_1G)) &&
202 !(mr[i].page_size_mask & (1<<PG_LEVEL_1G))) {
203 unsigned long start = round_down(mr[i].start, PUD_SIZE);
204 unsigned long end = round_up(mr[i].end, PUD_SIZE);
206 if (memblock_is_region_memory(start, end - start))
207 mr[i].page_size_mask |= 1<<PG_LEVEL_1G;
212 static int __meminit split_mem_range(struct map_range *mr, int nr_range,
216 unsigned long start_pfn, end_pfn, limit_pfn;
220 limit_pfn = PFN_DOWN(end);
222 /* head if not big page alignment ? */
223 pfn = start_pfn = PFN_DOWN(start);
226 * Don't use a large page for the first 2/4MB of memory
227 * because there are often fixed size MTRRs in there
228 * and overlapping MTRRs into large pages can cause
232 end_pfn = PFN_DOWN(PMD_SIZE);
234 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
235 #else /* CONFIG_X86_64 */
236 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
238 if (end_pfn > limit_pfn)
240 if (start_pfn < end_pfn) {
241 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
245 /* big page (2M) range */
246 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
248 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
249 #else /* CONFIG_X86_64 */
250 end_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
251 if (end_pfn > round_down(limit_pfn, PFN_DOWN(PMD_SIZE)))
252 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
255 if (start_pfn < end_pfn) {
256 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
257 page_size_mask & (1<<PG_LEVEL_2M));
262 /* big page (1G) range */
263 start_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
264 end_pfn = round_down(limit_pfn, PFN_DOWN(PUD_SIZE));
265 if (start_pfn < end_pfn) {
266 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
268 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
272 /* tail is not big page (1G) alignment */
273 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
274 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
275 if (start_pfn < end_pfn) {
276 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
277 page_size_mask & (1<<PG_LEVEL_2M));
282 /* tail is not big page (2M) alignment */
285 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
288 adjust_range_page_size_mask(mr, nr_range);
290 /* try to merge same page size and continuous */
291 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
292 unsigned long old_start;
293 if (mr[i].end != mr[i+1].start ||
294 mr[i].page_size_mask != mr[i+1].page_size_mask)
297 old_start = mr[i].start;
298 memmove(&mr[i], &mr[i+1],
299 (nr_range - 1 - i) * sizeof(struct map_range));
300 mr[i--].start = old_start;
304 for (i = 0; i < nr_range; i++)
305 printk(KERN_DEBUG " [mem %#010lx-%#010lx] page %s\n",
306 mr[i].start, mr[i].end - 1,
307 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
308 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
313 struct range pfn_mapped[E820_X_MAX];
316 static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn)
318 nr_pfn_mapped = add_range_with_merge(pfn_mapped, E820_X_MAX,
319 nr_pfn_mapped, start_pfn, end_pfn);
320 nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_X_MAX);
322 max_pfn_mapped = max(max_pfn_mapped, end_pfn);
324 if (start_pfn < (1UL<<(32-PAGE_SHIFT)))
325 max_low_pfn_mapped = max(max_low_pfn_mapped,
326 min(end_pfn, 1UL<<(32-PAGE_SHIFT)));
329 bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn)
333 for (i = 0; i < nr_pfn_mapped; i++)
334 if ((start_pfn >= pfn_mapped[i].start) &&
335 (end_pfn <= pfn_mapped[i].end))
342 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
343 * This runs before bootmem is initialized and gets pages directly from
344 * the physical memory. To access them they are temporarily mapped.
346 unsigned long __init_refok init_memory_mapping(unsigned long start,
349 struct map_range mr[NR_RANGE_MR];
350 unsigned long ret = 0;
353 pr_info("init_memory_mapping: [mem %#010lx-%#010lx]\n",
356 memset(mr, 0, sizeof(mr));
357 nr_range = split_mem_range(mr, 0, start, end);
359 for (i = 0; i < nr_range; i++)
360 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
361 mr[i].page_size_mask);
363 add_pfn_range_mapped(start >> PAGE_SHIFT, ret >> PAGE_SHIFT);
365 return ret >> PAGE_SHIFT;
369 * We need to iterate through the E820 memory map and create direct mappings
370 * for only E820_RAM and E820_KERN_RESERVED regions. We cannot simply
371 * create direct mappings for all pfns from [0 to max_low_pfn) and
372 * [4GB to max_pfn) because of possible memory holes in high addresses
373 * that cannot be marked as UC by fixed/variable range MTRRs.
374 * Depending on the alignment of E820 ranges, this may possibly result
375 * in using smaller size (i.e. 4K instead of 2M or 1G) page tables.
377 * init_mem_mapping() calls init_range_memory_mapping() with big range.
378 * That range would have hole in the middle or ends, and only ram parts
379 * will be mapped in init_range_memory_mapping().
381 static unsigned long __init init_range_memory_mapping(
382 unsigned long r_start,
385 unsigned long start_pfn, end_pfn;
386 unsigned long mapped_ram_size = 0;
389 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
390 u64 start = clamp_val(PFN_PHYS(start_pfn), r_start, r_end);
391 u64 end = clamp_val(PFN_PHYS(end_pfn), r_start, r_end);
396 * if it is overlapping with brk pgt, we need to
397 * alloc pgt buf from memblock instead.
399 can_use_brk_pgt = max(start, (u64)pgt_buf_end<<PAGE_SHIFT) >=
400 min(end, (u64)pgt_buf_top<<PAGE_SHIFT);
401 init_memory_mapping(start, end);
402 mapped_ram_size += end - start;
403 can_use_brk_pgt = true;
406 return mapped_ram_size;
409 static unsigned long __init get_new_step_size(unsigned long step_size)
412 * Explain why we shift by 5 and why we don't have to worry about
413 * 'step_size << 5' overflowing:
415 * initial mapped size is PMD_SIZE (2M).
416 * We can not set step_size to be PUD_SIZE (1G) yet.
417 * In worse case, when we cross the 1G boundary, and
418 * PG_LEVEL_2M is not set, we will need 1+1+512 pages (2M + 8k)
419 * to map 1G range with PTE. Use 5 as shift for now.
421 * Don't need to worry about overflow, on 32bit, when step_size
422 * is 0, round_down() returns 0 for start, and that turns it
423 * into 0x100000000ULL.
425 return step_size << 5;
429 * memory_map_top_down - Map [map_start, map_end) top down
430 * @map_start: start address of the target memory range
431 * @map_end: end address of the target memory range
433 * This function will setup direct mapping for memory range
434 * [map_start, map_end) in top-down. That said, the page tables
435 * will be allocated at the end of the memory, and we map the
436 * memory in top-down.
438 static void __init memory_map_top_down(unsigned long map_start,
439 unsigned long map_end)
441 unsigned long real_end, start, last_start;
442 unsigned long step_size;
444 unsigned long mapped_ram_size = 0;
445 unsigned long new_mapped_ram_size;
447 /* xen has big range in reserved near end of ram, skip it at first.*/
448 addr = memblock_find_in_range(map_start, map_end, PMD_SIZE, PMD_SIZE);
449 real_end = addr + PMD_SIZE;
451 /* step_size need to be small so pgt_buf from BRK could cover it */
452 step_size = PMD_SIZE;
453 max_pfn_mapped = 0; /* will get exact value next */
454 min_pfn_mapped = real_end >> PAGE_SHIFT;
455 last_start = start = real_end;
458 * We start from the top (end of memory) and go to the bottom.
459 * The memblock_find_in_range() gets us a block of RAM from the
460 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages
463 while (last_start > map_start) {
464 if (last_start > step_size) {
465 start = round_down(last_start - 1, step_size);
466 if (start < map_start)
470 new_mapped_ram_size = init_range_memory_mapping(start,
473 min_pfn_mapped = last_start >> PAGE_SHIFT;
474 /* only increase step_size after big range get mapped */
475 if (new_mapped_ram_size > mapped_ram_size)
476 step_size = get_new_step_size(step_size);
477 mapped_ram_size += new_mapped_ram_size;
480 if (real_end < map_end)
481 init_range_memory_mapping(real_end, map_end);
485 * memory_map_bottom_up - Map [map_start, map_end) bottom up
486 * @map_start: start address of the target memory range
487 * @map_end: end address of the target memory range
489 * This function will setup direct mapping for memory range
490 * [map_start, map_end) in bottom-up. Since we have limited the
491 * bottom-up allocation above the kernel, the page tables will
492 * be allocated just above the kernel and we map the memory
493 * in [map_start, map_end) in bottom-up.
495 static void __init memory_map_bottom_up(unsigned long map_start,
496 unsigned long map_end)
498 unsigned long next, new_mapped_ram_size, start;
499 unsigned long mapped_ram_size = 0;
500 /* step_size need to be small so pgt_buf from BRK could cover it */
501 unsigned long step_size = PMD_SIZE;
504 min_pfn_mapped = start >> PAGE_SHIFT;
507 * We start from the bottom (@map_start) and go to the top (@map_end).
508 * The memblock_find_in_range() gets us a block of RAM from the
509 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages
512 while (start < map_end) {
513 if (map_end - start > step_size) {
514 next = round_up(start + 1, step_size);
520 new_mapped_ram_size = init_range_memory_mapping(start, next);
523 if (new_mapped_ram_size > mapped_ram_size)
524 step_size = get_new_step_size(step_size);
525 mapped_ram_size += new_mapped_ram_size;
529 void __init init_mem_mapping(void)
533 probe_page_size_mask();
536 end = max_pfn << PAGE_SHIFT;
538 end = max_low_pfn << PAGE_SHIFT;
541 /* the ISA range is always mapped regardless of memory holes */
542 init_memory_mapping(0, ISA_END_ADDRESS);
545 * If the allocation is in bottom-up direction, we setup direct mapping
546 * in bottom-up, otherwise we setup direct mapping in top-down.
548 if (memblock_bottom_up()) {
549 unsigned long kernel_end = __pa_symbol(_end);
552 * we need two separate calls here. This is because we want to
553 * allocate page tables above the kernel. So we first map
554 * [kernel_end, end) to make memory above the kernel be mapped
555 * as soon as possible. And then use page tables allocated above
556 * the kernel to map [ISA_END_ADDRESS, kernel_end).
558 memory_map_bottom_up(kernel_end, end);
559 memory_map_bottom_up(ISA_END_ADDRESS, kernel_end);
561 memory_map_top_down(ISA_END_ADDRESS, end);
565 if (max_pfn > max_low_pfn) {
566 /* can we preseve max_low_pfn ?*/
567 max_low_pfn = max_pfn;
570 early_ioremap_page_table_range_init();
573 load_cr3(swapper_pg_dir);
576 early_memtest(0, max_pfn_mapped << PAGE_SHIFT);
580 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
581 * is valid. The argument is a physical page number.
584 * On x86, access has to be given to the first megabyte of ram because that area
585 * contains bios code and data regions used by X and dosemu and similar apps.
586 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
587 * mmio resources as well as potential bios/acpi data regions.
589 int devmem_is_allowed(unsigned long pagenr)
593 if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
595 if (!page_is_ram(pagenr))
600 void free_init_pages(char *what, unsigned long begin, unsigned long end)
602 unsigned long begin_aligned, end_aligned;
604 /* Make sure boundaries are page aligned */
605 begin_aligned = PAGE_ALIGN(begin);
606 end_aligned = end & PAGE_MASK;
608 if (WARN_ON(begin_aligned != begin || end_aligned != end)) {
609 begin = begin_aligned;
617 * If debugging page accesses then do not free this memory but
618 * mark them not present - any buggy init-section access will
619 * create a kernel page fault:
621 #ifdef CONFIG_DEBUG_PAGEALLOC
622 printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n",
624 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
627 * We just marked the kernel text read only above, now that
628 * we are going to free part of that, we need to make that
629 * writeable and non-executable first.
631 set_memory_nx(begin, (end - begin) >> PAGE_SHIFT);
632 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
634 free_reserved_area((void *)begin, (void *)end, POISON_FREE_INITMEM, what);
638 void free_initmem(void)
640 free_init_pages("unused kernel",
641 (unsigned long)(&__init_begin),
642 (unsigned long)(&__init_end));
645 #ifdef CONFIG_BLK_DEV_INITRD
646 void __init free_initrd_mem(unsigned long start, unsigned long end)
648 #ifdef CONFIG_MICROCODE_EARLY
650 * Remember, initrd memory may contain microcode or other useful things.
651 * Before we lose initrd mem, we need to find a place to hold them
652 * now that normal virtual memory is enabled.
654 save_microcode_in_initrd();
658 * end could be not aligned, and We can not align that,
659 * decompresser could be confused by aligned initrd_end
660 * We already reserve the end partial page before in
661 * - i386_start_kernel()
662 * - x86_64_start_kernel()
663 * - relocate_initrd()
664 * So here We can do PAGE_ALIGN() safely to get partial page to be freed
666 free_init_pages("initrd", start, PAGE_ALIGN(end));
670 void __init zone_sizes_init(void)
672 unsigned long max_zone_pfns[MAX_NR_ZONES];
674 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
676 #ifdef CONFIG_ZONE_DMA
677 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
679 #ifdef CONFIG_ZONE_DMA32
680 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
682 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
683 #ifdef CONFIG_HIGHMEM
684 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
687 free_area_init_nodes(max_zone_pfns);