2 * linux/arch/x86_64/mm/init.c
4 * Copyright (C) 1995 Linus Torvalds
5 * Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
6 * Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
9 #include <linux/signal.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/ptrace.h>
16 #include <linux/mman.h>
18 #include <linux/swap.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/initrd.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/proc_fs.h>
25 #include <linux/pci.h>
26 #include <linux/pfn.h>
27 #include <linux/poison.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/module.h>
30 #include <linux/memory_hotplug.h>
31 #include <linux/nmi.h>
33 #include <asm/processor.h>
34 #include <asm/system.h>
35 #include <asm/uaccess.h>
36 #include <asm/pgtable.h>
37 #include <asm/pgalloc.h>
39 #include <asm/fixmap.h>
43 #include <asm/mmu_context.h>
44 #include <asm/proto.h>
46 #include <asm/sections.h>
47 #include <asm/kdebug.h>
49 #include <asm/cacheflush.h>
52 * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
53 * The direct mapping extends to max_pfn_mapped, so that we can directly access
54 * apertures, ACPI and other tables without having to play with fixmaps.
56 unsigned long max_low_pfn_mapped;
57 unsigned long max_pfn_mapped;
59 static unsigned long dma_reserve __initdata;
61 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
64 #ifdef CONFIG_DIRECT_GBPAGES
69 static int __init parse_direct_gbpages_off(char *arg)
74 early_param("nogbpages", parse_direct_gbpages_off);
76 static int __init parse_direct_gbpages_on(char *arg)
81 early_param("gbpages", parse_direct_gbpages_on);
84 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
85 * physical space so we can cache the place of the first one and move
86 * around without checking the pgd every time.
92 * NOTE: This function is marked __ref because it calls __init function
93 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
95 static __ref void *spp_getpage(void)
100 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
102 ptr = alloc_bootmem_pages(PAGE_SIZE);
104 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
105 panic("set_pte_phys: cannot allocate page data %s\n",
106 after_bootmem ? "after bootmem" : "");
109 pr_debug("spp_getpage %p\n", ptr);
115 set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
121 pud = pud_page + pud_index(vaddr);
122 if (pud_none(*pud)) {
123 pmd = (pmd_t *) spp_getpage();
124 pud_populate(&init_mm, pud, pmd);
125 if (pmd != pmd_offset(pud, 0)) {
126 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
127 pmd, pmd_offset(pud, 0));
131 pmd = pmd_offset(pud, vaddr);
132 if (pmd_none(*pmd)) {
133 pte = (pte_t *) spp_getpage();
134 pmd_populate_kernel(&init_mm, pmd, pte);
135 if (pte != pte_offset_kernel(pmd, 0)) {
136 printk(KERN_ERR "PAGETABLE BUG #02!\n");
141 pte = pte_offset_kernel(pmd, vaddr);
142 if (!pte_none(*pte) && pte_val(new_pte) &&
143 pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
145 set_pte(pte, new_pte);
148 * It's enough to flush this one mapping.
149 * (PGE mappings get flushed as well)
151 __flush_tlb_one(vaddr);
155 set_pte_vaddr(unsigned long vaddr, pte_t pteval)
160 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
162 pgd = pgd_offset_k(vaddr);
163 if (pgd_none(*pgd)) {
165 "PGD FIXMAP MISSING, it should be setup in head.S!\n");
168 pud_page = (pud_t*)pgd_page_vaddr(*pgd);
169 set_pte_vaddr_pud(pud_page, vaddr, pteval);
173 * Create large page table mappings for a range of physical addresses.
175 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
182 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
183 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
184 pgd = pgd_offset_k((unsigned long)__va(phys));
185 if (pgd_none(*pgd)) {
186 pud = (pud_t *) spp_getpage();
187 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
190 pud = pud_offset(pgd, (unsigned long)__va(phys));
191 if (pud_none(*pud)) {
192 pmd = (pmd_t *) spp_getpage();
193 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
196 pmd = pmd_offset(pud, phys);
197 BUG_ON(!pmd_none(*pmd));
198 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
202 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
204 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
207 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
209 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
213 * The head.S code sets up the kernel high mapping:
215 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
217 * phys_addr holds the negative offset to the kernel, which is added
218 * to the compile time generated pmds. This results in invalid pmds up
219 * to the point where we hit the physaddr 0 mapping.
221 * We limit the mappings to the region from _text to _end. _end is
222 * rounded up to the 2MB boundary. This catches the invalid pmds as
223 * well, as they are located before _text:
225 void __init cleanup_highmap(void)
227 unsigned long vaddr = __START_KERNEL_map;
228 unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1;
229 pmd_t *pmd = level2_kernel_pgt;
230 pmd_t *last_pmd = pmd + PTRS_PER_PMD;
232 for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
235 if (vaddr < (unsigned long) _text || vaddr > end)
236 set_pmd(pmd, __pmd(0));
240 static unsigned long __initdata table_start;
241 static unsigned long __meminitdata table_end;
242 static unsigned long __meminitdata table_top;
244 static __ref void *alloc_low_page(unsigned long *phys)
246 unsigned long pfn = table_end++;
250 adr = (void *)get_zeroed_page(GFP_ATOMIC);
256 if (pfn >= table_top)
257 panic("alloc_low_page: ran out of memory");
259 adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
260 memset(adr, 0, PAGE_SIZE);
261 *phys = pfn * PAGE_SIZE;
265 static __ref void unmap_low_page(void *adr)
270 early_iounmap(adr, PAGE_SIZE);
273 static unsigned long __meminit
274 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
278 unsigned long last_map_addr = end;
281 pte_t *pte = pte_page + pte_index(addr);
283 for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
286 if (!after_bootmem) {
287 for(; i < PTRS_PER_PTE; i++, pte++)
288 set_pte(pte, __pte(0));
294 * We will re-use the existing mapping.
295 * Xen for example has some special requirements, like mapping
296 * pagetable pages as RO. So assume someone who pre-setup
297 * these mappings are more intelligent.
303 printk(" pte=%p addr=%lx pte=%016lx\n",
304 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
306 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
307 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
310 update_page_count(PG_LEVEL_4K, pages);
312 return last_map_addr;
315 static unsigned long __meminit
316 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
319 pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
321 return phys_pte_init(pte, address, end, prot);
324 static unsigned long __meminit
325 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
326 unsigned long page_size_mask, pgprot_t prot)
328 unsigned long pages = 0;
329 unsigned long last_map_addr = end;
331 int i = pmd_index(address);
333 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
334 unsigned long pte_phys;
335 pmd_t *pmd = pmd_page + pmd_index(address);
337 pgprot_t new_prot = prot;
339 if (address >= end) {
340 if (!after_bootmem) {
341 for (; i < PTRS_PER_PMD; i++, pmd++)
342 set_pmd(pmd, __pmd(0));
348 if (!pmd_large(*pmd)) {
349 spin_lock(&init_mm.page_table_lock);
350 last_map_addr = phys_pte_update(pmd, address,
352 spin_unlock(&init_mm.page_table_lock);
356 * If we are ok with PG_LEVEL_2M mapping, then we will
357 * use the existing mapping,
359 * Otherwise, we will split the large page mapping but
360 * use the same existing protection bits except for
361 * large page, so that we don't violate Intel's TLB
362 * Application note (317080) which says, while changing
363 * the page sizes, new and old translations should
364 * not differ with respect to page frame and
367 if (page_size_mask & (1 << PG_LEVEL_2M))
369 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
372 if (page_size_mask & (1<<PG_LEVEL_2M)) {
374 spin_lock(&init_mm.page_table_lock);
375 set_pte((pte_t *)pmd,
376 pfn_pte(address >> PAGE_SHIFT,
377 __pgprot(pgprot_val(prot) | _PAGE_PSE)));
378 spin_unlock(&init_mm.page_table_lock);
379 last_map_addr = (address & PMD_MASK) + PMD_SIZE;
383 pte = alloc_low_page(&pte_phys);
384 last_map_addr = phys_pte_init(pte, address, end, new_prot);
387 spin_lock(&init_mm.page_table_lock);
388 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
389 spin_unlock(&init_mm.page_table_lock);
391 update_page_count(PG_LEVEL_2M, pages);
392 return last_map_addr;
395 static unsigned long __meminit
396 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
397 unsigned long page_size_mask, pgprot_t prot)
399 pmd_t *pmd = pmd_offset(pud, 0);
400 unsigned long last_map_addr;
402 last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
404 return last_map_addr;
407 static unsigned long __meminit
408 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
409 unsigned long page_size_mask)
411 unsigned long pages = 0;
412 unsigned long last_map_addr = end;
413 int i = pud_index(addr);
415 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
416 unsigned long pmd_phys;
417 pud_t *pud = pud_page + pud_index(addr);
419 pgprot_t prot = PAGE_KERNEL;
424 if (!after_bootmem &&
425 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
426 set_pud(pud, __pud(0));
431 if (!pud_large(*pud)) {
432 last_map_addr = phys_pmd_update(pud, addr, end,
433 page_size_mask, prot);
437 * If we are ok with PG_LEVEL_1G mapping, then we will
438 * use the existing mapping.
440 * Otherwise, we will split the gbpage mapping but use
441 * the same existing protection bits except for large
442 * page, so that we don't violate Intel's TLB
443 * Application note (317080) which says, while changing
444 * the page sizes, new and old translations should
445 * not differ with respect to page frame and
448 if (page_size_mask & (1 << PG_LEVEL_1G))
450 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
453 if (page_size_mask & (1<<PG_LEVEL_1G)) {
455 spin_lock(&init_mm.page_table_lock);
456 set_pte((pte_t *)pud,
457 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
458 spin_unlock(&init_mm.page_table_lock);
459 last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
463 pmd = alloc_low_page(&pmd_phys);
464 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
468 spin_lock(&init_mm.page_table_lock);
469 pud_populate(&init_mm, pud, __va(pmd_phys));
470 spin_unlock(&init_mm.page_table_lock);
474 update_page_count(PG_LEVEL_1G, pages);
476 return last_map_addr;
479 static unsigned long __meminit
480 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
481 unsigned long page_size_mask)
485 pud = (pud_t *)pgd_page_vaddr(*pgd);
487 return phys_pud_init(pud, addr, end, page_size_mask);
490 static void __init find_early_table_space(unsigned long end, int use_pse,
493 unsigned long puds, pmds, ptes, tables, start;
495 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
496 tables = round_up(puds * sizeof(pud_t), PAGE_SIZE);
499 extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
500 pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
502 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
503 tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
507 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
508 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
510 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
511 tables += round_up(ptes * sizeof(pte_t), PAGE_SIZE);
514 * RED-PEN putting page tables only on node 0 could
515 * cause a hotspot and fill up ZONE_DMA. The page tables
516 * need roughly 0.5KB per GB.
519 table_start = find_e820_area(start, end, tables, PAGE_SIZE);
520 if (table_start == -1UL)
521 panic("Cannot find space for the kernel page tables");
523 table_start >>= PAGE_SHIFT;
524 table_end = table_start;
525 table_top = table_start + (tables >> PAGE_SHIFT);
527 printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
528 end, table_start << PAGE_SHIFT, table_top << PAGE_SHIFT);
531 static void __init init_gbpages(void)
533 if (direct_gbpages && cpu_has_gbpages)
534 printk(KERN_INFO "Using GB pages for direct mapping\n");
539 static unsigned long __init kernel_physical_mapping_init(unsigned long start,
541 unsigned long page_size_mask)
544 unsigned long next, last_map_addr = end;
546 start = (unsigned long)__va(start);
547 end = (unsigned long)__va(end);
549 for (; start < end; start = next) {
550 pgd_t *pgd = pgd_offset_k(start);
551 unsigned long pud_phys;
554 next = (start + PGDIR_SIZE) & PGDIR_MASK;
559 last_map_addr = phys_pud_update(pgd, __pa(start),
560 __pa(end), page_size_mask);
564 pud = alloc_low_page(&pud_phys);
565 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
569 spin_lock(&init_mm.page_table_lock);
570 pgd_populate(&init_mm, pgd, __va(pud_phys));
571 spin_unlock(&init_mm.page_table_lock);
575 return last_map_addr;
581 unsigned page_size_mask;
584 #define NR_RANGE_MR 5
586 static int save_mr(struct map_range *mr, int nr_range,
587 unsigned long start_pfn, unsigned long end_pfn,
588 unsigned long page_size_mask)
591 if (start_pfn < end_pfn) {
592 if (nr_range >= NR_RANGE_MR)
593 panic("run out of range for init_memory_mapping\n");
594 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
595 mr[nr_range].end = end_pfn<<PAGE_SHIFT;
596 mr[nr_range].page_size_mask = page_size_mask;
604 * Setup the direct mapping of the physical memory at PAGE_OFFSET.
605 * This runs before bootmem is initialized and gets pages directly from
606 * the physical memory. To access them they are temporarily mapped.
608 unsigned long __init_refok init_memory_mapping(unsigned long start,
611 unsigned long last_map_addr = 0;
612 unsigned long page_size_mask = 0;
613 unsigned long start_pfn, end_pfn;
615 struct map_range mr[NR_RANGE_MR];
617 int use_pse, use_gbpages;
619 printk(KERN_INFO "init_memory_mapping\n");
622 * Find space for the kernel direct mapping tables.
624 * Later we should allocate these tables in the local node of the
625 * memory mapped. Unfortunately this is done currently before the
626 * nodes are discovered.
631 #ifdef CONFIG_DEBUG_PAGEALLOC
633 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
634 * This will simplify cpa(), which otherwise needs to support splitting
635 * large pages into small in interrupt context, etc.
637 use_pse = use_gbpages = 0;
639 use_pse = cpu_has_pse;
640 use_gbpages = direct_gbpages;
644 page_size_mask |= 1 << PG_LEVEL_1G;
646 page_size_mask |= 1 << PG_LEVEL_2M;
648 memset(mr, 0, sizeof(mr));
651 /* head if not big page alignment ?*/
652 start_pfn = start >> PAGE_SHIFT;
653 end_pfn = ((start + (PMD_SIZE - 1)) >> PMD_SHIFT)
654 << (PMD_SHIFT - PAGE_SHIFT);
655 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
657 /* big page (2M) range*/
658 start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
659 << (PMD_SHIFT - PAGE_SHIFT);
660 end_pfn = ((start + (PUD_SIZE - 1))>>PUD_SHIFT)
661 << (PUD_SHIFT - PAGE_SHIFT);
662 if (end_pfn > ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT)))
663 end_pfn = ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT));
664 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
665 page_size_mask & (1<<PG_LEVEL_2M));
667 /* big page (1G) range */
669 end_pfn = (end>>PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
670 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
672 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
674 /* tail is not big page (1G) alignment */
676 end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
677 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
678 page_size_mask & (1<<PG_LEVEL_2M));
680 /* tail is not big page (2M) alignment */
682 end_pfn = end>>PAGE_SHIFT;
683 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
685 /* try to merge same page size and continuous */
686 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
687 unsigned long old_start;
688 if (mr[i].end != mr[i+1].start ||
689 mr[i].page_size_mask != mr[i+1].page_size_mask)
692 old_start = mr[i].start;
693 memmove(&mr[i], &mr[i+1],
694 (nr_range - 1 - i) * sizeof (struct map_range));
695 mr[i].start = old_start;
699 for (i = 0; i < nr_range; i++)
700 printk(KERN_DEBUG " %010lx - %010lx page %s\n",
701 mr[i].start, mr[i].end,
702 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
703 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
706 find_early_table_space(end, use_pse, use_gbpages);
708 for (i = 0; i < nr_range; i++)
709 last_map_addr = kernel_physical_mapping_init(
710 mr[i].start, mr[i].end,
711 mr[i].page_size_mask);
714 mmu_cr4_features = read_cr4();
717 if (!after_bootmem && table_end > table_start)
718 reserve_early(table_start << PAGE_SHIFT,
719 table_end << PAGE_SHIFT, "PGTABLE");
721 printk(KERN_INFO "last_map_addr: %lx end: %lx\n",
725 early_memtest(start, end);
727 return last_map_addr >> PAGE_SHIFT;
731 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn)
733 unsigned long bootmap_size, bootmap;
735 bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
736 bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
739 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
740 /* don't touch min_low_pfn */
741 bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
743 e820_register_active_regions(0, start_pfn, end_pfn);
744 free_bootmem_with_active_regions(0, end_pfn);
745 early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
746 reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
749 void __init paging_init(void)
751 unsigned long max_zone_pfns[MAX_NR_ZONES];
753 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
754 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
755 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
756 max_zone_pfns[ZONE_NORMAL] = max_pfn;
758 memory_present(0, 0, max_pfn);
760 free_area_init_nodes(max_zone_pfns);
765 * Memory hotplug specific functions
767 #ifdef CONFIG_MEMORY_HOTPLUG
769 * Memory is added always to NORMAL zone. This means you will never get
770 * additional DMA/DMA32 memory.
772 int arch_add_memory(int nid, u64 start, u64 size)
774 struct pglist_data *pgdat = NODE_DATA(nid);
775 struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
776 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
777 unsigned long nr_pages = size >> PAGE_SHIFT;
780 last_mapped_pfn = init_memory_mapping(start, start + size-1);
781 if (last_mapped_pfn > max_pfn_mapped)
782 max_pfn_mapped = last_mapped_pfn;
784 ret = __add_pages(zone, start_pfn, nr_pages);
789 EXPORT_SYMBOL_GPL(arch_add_memory);
791 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
792 int memory_add_physaddr_to_nid(u64 start)
796 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
799 #endif /* CONFIG_MEMORY_HOTPLUG */
802 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
803 * is valid. The argument is a physical page number.
806 * On x86, access has to be given to the first megabyte of ram because that area
807 * contains bios code and data regions used by X and dosemu and similar apps.
808 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
809 * mmio resources as well as potential bios/acpi data regions.
811 int devmem_is_allowed(unsigned long pagenr)
815 if (!page_is_ram(pagenr))
821 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
822 kcore_modules, kcore_vsyscall;
824 void __init mem_init(void)
826 long codesize, reservedpages, datasize, initsize;
830 /* clear_bss() already clear the empty_zero_page */
834 /* this will put all low memory onto the freelists */
836 totalram_pages = numa_free_all_bootmem();
838 totalram_pages = free_all_bootmem();
840 reservedpages = max_pfn - totalram_pages -
841 absent_pages_in_range(0, max_pfn);
844 codesize = (unsigned long) &_etext - (unsigned long) &_text;
845 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
846 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
848 /* Register memory areas for /proc/kcore */
849 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
850 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
851 VMALLOC_END-VMALLOC_START);
852 kclist_add(&kcore_kernel, &_stext, _end - _stext);
853 kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
854 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
855 VSYSCALL_END - VSYSCALL_START);
857 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
858 "%ldk reserved, %ldk data, %ldk init)\n",
859 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
860 max_pfn << (PAGE_SHIFT-10),
862 reservedpages << (PAGE_SHIFT-10),
867 void free_init_pages(char *what, unsigned long begin, unsigned long end)
869 unsigned long addr = begin;
875 * If debugging page accesses then do not free this memory but
876 * mark them not present - any buggy init-section access will
877 * create a kernel page fault:
879 #ifdef CONFIG_DEBUG_PAGEALLOC
880 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
881 begin, PAGE_ALIGN(end));
882 set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
884 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
886 for (; addr < end; addr += PAGE_SIZE) {
887 ClearPageReserved(virt_to_page(addr));
888 init_page_count(virt_to_page(addr));
889 memset((void *)(addr & ~(PAGE_SIZE-1)),
890 POISON_FREE_INITMEM, PAGE_SIZE);
897 void free_initmem(void)
899 free_init_pages("unused kernel memory",
900 (unsigned long)(&__init_begin),
901 (unsigned long)(&__init_end));
904 #ifdef CONFIG_DEBUG_RODATA
905 const int rodata_test_data = 0xC3;
906 EXPORT_SYMBOL_GPL(rodata_test_data);
908 void mark_rodata_ro(void)
910 unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
911 unsigned long rodata_start =
912 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
914 #ifdef CONFIG_DYNAMIC_FTRACE
915 /* Dynamic tracing modifies the kernel text section */
916 start = rodata_start;
919 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
920 (end - start) >> 10);
921 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
924 * The rodata section (but not the kernel text!) should also be
927 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
931 #ifdef CONFIG_CPA_DEBUG
932 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
933 set_memory_rw(start, (end-start) >> PAGE_SHIFT);
935 printk(KERN_INFO "Testing CPA: again\n");
936 set_memory_ro(start, (end-start) >> PAGE_SHIFT);
942 #ifdef CONFIG_BLK_DEV_INITRD
943 void free_initrd_mem(unsigned long start, unsigned long end)
945 free_init_pages("initrd memory", start, end);
949 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
956 unsigned long pfn = phys >> PAGE_SHIFT;
958 if (pfn >= max_pfn) {
960 * This can happen with kdump kernels when accessing
963 if (pfn < max_pfn_mapped)
966 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
971 /* Should check here against the e820 map to avoid double free */
973 nid = phys_to_nid(phys);
974 next_nid = phys_to_nid(phys + len - 1);
976 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
978 ret = reserve_bootmem(phys, len, flags);
984 reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
987 if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
988 dma_reserve += len / PAGE_SIZE;
989 set_dma_reserve(dma_reserve);
995 int kern_addr_valid(unsigned long addr)
997 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1003 if (above != 0 && above != -1UL)
1006 pgd = pgd_offset_k(addr);
1010 pud = pud_offset(pgd, addr);
1014 pmd = pmd_offset(pud, addr);
1018 if (pmd_large(*pmd))
1019 return pfn_valid(pmd_pfn(*pmd));
1021 pte = pte_offset_kernel(pmd, addr);
1025 return pfn_valid(pte_pfn(*pte));
1029 * A pseudo VMA to allow ptrace access for the vsyscall page. This only
1030 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
1031 * not need special handling anymore:
1033 static struct vm_area_struct gate_vma = {
1034 .vm_start = VSYSCALL_START,
1035 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
1036 .vm_page_prot = PAGE_READONLY_EXEC,
1037 .vm_flags = VM_READ | VM_EXEC
1040 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
1042 #ifdef CONFIG_IA32_EMULATION
1043 if (test_tsk_thread_flag(tsk, TIF_IA32))
1049 int in_gate_area(struct task_struct *task, unsigned long addr)
1051 struct vm_area_struct *vma = get_gate_vma(task);
1056 return (addr >= vma->vm_start) && (addr < vma->vm_end);
1060 * Use this when you have no reliable task/vma, typically from interrupt
1061 * context. It is less reliable than using the task's vma and may give
1064 int in_gate_area_no_task(unsigned long addr)
1066 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
1069 const char *arch_vma_name(struct vm_area_struct *vma)
1071 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
1073 if (vma == &gate_vma)
1074 return "[vsyscall]";
1078 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1080 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1082 static long __meminitdata addr_start, addr_end;
1083 static void __meminitdata *p_start, *p_end;
1084 static int __meminitdata node_start;
1087 vmemmap_populate(struct page *start_page, unsigned long size, int node)
1089 unsigned long addr = (unsigned long)start_page;
1090 unsigned long end = (unsigned long)(start_page + size);
1096 for (; addr < end; addr = next) {
1099 pgd = vmemmap_pgd_populate(addr, node);
1103 pud = vmemmap_pud_populate(pgd, addr, node);
1108 next = (addr + PAGE_SIZE) & PAGE_MASK;
1109 pmd = vmemmap_pmd_populate(pud, addr, node);
1114 p = vmemmap_pte_populate(pmd, addr, node);
1119 addr_end = addr + PAGE_SIZE;
1120 p_end = p + PAGE_SIZE;
1122 next = pmd_addr_end(addr, end);
1124 pmd = pmd_offset(pud, addr);
1125 if (pmd_none(*pmd)) {
1128 p = vmemmap_alloc_block(PMD_SIZE, node);
1132 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1134 set_pmd(pmd, __pmd(pte_val(entry)));
1136 /* check to see if we have contiguous blocks */
1137 if (p_end != p || node_start != node) {
1139 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1140 addr_start, addr_end-1, p_start, p_end-1, node_start);
1146 addr_end = addr + PMD_SIZE;
1147 p_end = p + PMD_SIZE;
1149 vmemmap_verify((pte_t *)pmd, node, addr, next);
1156 void __meminit vmemmap_populate_print_last(void)
1159 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1160 addr_start, addr_end-1, p_start, p_end-1, node_start);