3 * Copyright (C) 1995 Linus Torvalds
5 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
8 #include <linux/module.h>
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/hugetlb.h>
19 #include <linux/swap.h>
20 #include <linux/smp.h>
21 #include <linux/init.h>
22 #include <linux/highmem.h>
23 #include <linux/pagemap.h>
24 #include <linux/pci.h>
25 #include <linux/pfn.h>
26 #include <linux/poison.h>
27 #include <linux/bootmem.h>
28 #include <linux/memblock.h>
29 #include <linux/proc_fs.h>
30 #include <linux/memory_hotplug.h>
31 #include <linux/initrd.h>
32 #include <linux/cpumask.h>
33 #include <linux/gfp.h>
36 #include <asm/bios_ebda.h>
37 #include <asm/processor.h>
38 #include <asm/system.h>
39 #include <asm/uaccess.h>
40 #include <asm/pgtable.h>
42 #include <asm/fixmap.h>
47 #include <asm/tlbflush.h>
48 #include <asm/olpc_ofw.h>
49 #include <asm/pgalloc.h>
50 #include <asm/sections.h>
51 #include <asm/paravirt.h>
52 #include <asm/setup.h>
53 #include <asm/cacheflush.h>
54 #include <asm/page_types.h>
57 unsigned long highstart_pfn, highend_pfn;
59 static noinline int do_test_wp_bit(void);
61 bool __read_mostly __vmalloc_start_set = false;
63 static __init void *alloc_low_page(void)
65 unsigned long pfn = pgt_buf_end++;
68 if (pfn >= pgt_buf_top)
69 panic("alloc_low_page: ran out of memory");
71 adr = __va(pfn * PAGE_SIZE);
77 * Creates a middle page table and puts a pointer to it in the
78 * given global directory entry. This only returns the gd entry
79 * in non-PAE compilation mode, since the middle layer is folded.
81 static pmd_t * __init one_md_table_init(pgd_t *pgd)
87 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
89 pmd_table = (pmd_t *)alloc_bootmem_pages(PAGE_SIZE);
91 pmd_table = (pmd_t *)alloc_low_page();
92 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
93 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
94 pud = pud_offset(pgd, 0);
95 BUG_ON(pmd_table != pmd_offset(pud, 0));
100 pud = pud_offset(pgd, 0);
101 pmd_table = pmd_offset(pud, 0);
107 * Create a page table and place a pointer to it in a middle page
110 static pte_t * __init one_page_table_init(pmd_t *pmd)
112 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
113 pte_t *page_table = NULL;
116 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
117 page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
121 (pte_t *)alloc_bootmem_pages(PAGE_SIZE);
123 page_table = (pte_t *)alloc_low_page();
125 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
126 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
127 BUG_ON(page_table != pte_offset_kernel(pmd, 0));
130 return pte_offset_kernel(pmd, 0);
133 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
135 int pgd_idx = pgd_index(vaddr);
136 int pmd_idx = pmd_index(vaddr);
138 return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx;
141 pte_t * __init populate_extra_pte(unsigned long vaddr)
143 int pte_idx = pte_index(vaddr);
146 pmd = populate_extra_pmd(vaddr);
147 return one_page_table_init(pmd) + pte_idx;
150 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
151 unsigned long vaddr, pte_t *lastpte)
153 #ifdef CONFIG_HIGHMEM
155 * Something (early fixmap) may already have put a pte
156 * page here, which causes the page table allocation
157 * to become nonlinear. Attempt to fix it, and if it
158 * is still nonlinear then we have to bug.
160 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
161 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
163 if (pmd_idx_kmap_begin != pmd_idx_kmap_end
164 && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
165 && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end
166 && ((__pa(pte) >> PAGE_SHIFT) < pgt_buf_start
167 || (__pa(pte) >> PAGE_SHIFT) >= pgt_buf_end)) {
171 BUG_ON(after_bootmem);
172 newpte = alloc_low_page();
173 for (i = 0; i < PTRS_PER_PTE; i++)
174 set_pte(newpte + i, pte[i]);
176 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
177 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
178 BUG_ON(newpte != pte_offset_kernel(pmd, 0));
181 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
184 BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
185 && vaddr > fix_to_virt(FIX_KMAP_END)
186 && lastpte && lastpte + PTRS_PER_PTE != pte);
192 * This function initializes a certain range of kernel virtual memory
193 * with new bootmem page tables, everywhere page tables are missing in
196 * NOTE: The pagetables are allocated contiguous on the physical space
197 * so we can cache the place of the first one and move around without
198 * checking the pgd every time.
201 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
203 int pgd_idx, pmd_idx;
210 pgd_idx = pgd_index(vaddr);
211 pmd_idx = pmd_index(vaddr);
212 pgd = pgd_base + pgd_idx;
214 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
215 pmd = one_md_table_init(pgd);
216 pmd = pmd + pmd_index(vaddr);
217 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
219 pte = page_table_kmap_check(one_page_table_init(pmd),
228 static inline int is_kernel_text(unsigned long addr)
230 if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end)
236 * This maps the physical memory to kernel virtual address space, a total
237 * of max_low_pfn pages, by creating page tables starting from address
241 kernel_physical_mapping_init(unsigned long start,
243 unsigned long page_size_mask)
245 int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
246 unsigned long last_map_addr = end;
247 unsigned long start_pfn, end_pfn;
248 pgd_t *pgd_base = swapper_pg_dir;
249 int pgd_idx, pmd_idx, pte_ofs;
254 unsigned pages_2m, pages_4k;
257 start_pfn = start >> PAGE_SHIFT;
258 end_pfn = end >> PAGE_SHIFT;
261 * First iteration will setup identity mapping using large/small pages
262 * based on use_pse, with other attributes same as set by
263 * the early code in head_32.S
265 * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
266 * as desired for the kernel identity mapping.
268 * This two pass mechanism conforms to the TLB app note which says:
270 * "Software should not write to a paging-structure entry in a way
271 * that would change, for any linear address, both the page size
272 * and either the page frame or attributes."
280 pages_2m = pages_4k = 0;
282 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
283 pgd = pgd_base + pgd_idx;
284 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
285 pmd = one_md_table_init(pgd);
289 #ifdef CONFIG_X86_PAE
290 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
295 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
297 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
300 * Map with big pages if possible, otherwise
301 * create normal page tables:
305 pgprot_t prot = PAGE_KERNEL_LARGE;
307 * first pass will use the same initial
308 * identity mapping attribute + _PAGE_PSE.
311 __pgprot(PTE_IDENT_ATTR |
314 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
315 PAGE_OFFSET + PAGE_SIZE-1;
317 if (is_kernel_text(addr) ||
318 is_kernel_text(addr2))
319 prot = PAGE_KERNEL_LARGE_EXEC;
322 if (mapping_iter == 1)
323 set_pmd(pmd, pfn_pmd(pfn, init_prot));
325 set_pmd(pmd, pfn_pmd(pfn, prot));
330 pte = one_page_table_init(pmd);
332 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
334 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
335 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
336 pgprot_t prot = PAGE_KERNEL;
338 * first pass will use the same initial
339 * identity mapping attribute.
341 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
343 if (is_kernel_text(addr))
344 prot = PAGE_KERNEL_EXEC;
347 if (mapping_iter == 1) {
348 set_pte(pte, pfn_pte(pfn, init_prot));
349 last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
351 set_pte(pte, pfn_pte(pfn, prot));
355 if (mapping_iter == 1) {
357 * update direct mapping page count only in the first
360 update_page_count(PG_LEVEL_2M, pages_2m);
361 update_page_count(PG_LEVEL_4K, pages_4k);
364 * local global flush tlb, which will flush the previous
365 * mappings present in both small and large page TLB's.
370 * Second iteration will set the actual desired PTE attributes.
375 return last_map_addr;
381 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
383 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
384 vaddr), vaddr), vaddr);
387 static void __init kmap_init(void)
389 unsigned long kmap_vstart;
392 * Cache the first kmap pte:
394 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
395 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
397 kmap_prot = PAGE_KERNEL;
400 #ifdef CONFIG_HIGHMEM
401 static void __init permanent_kmaps_init(pgd_t *pgd_base)
410 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
412 pgd = swapper_pg_dir + pgd_index(vaddr);
413 pud = pud_offset(pgd, vaddr);
414 pmd = pmd_offset(pud, vaddr);
415 pte = pte_offset_kernel(pmd, vaddr);
416 pkmap_page_table = pte;
419 static void __init add_one_highpage_init(struct page *page)
421 ClearPageReserved(page);
422 init_page_count(page);
427 void __init add_highpages_with_active_regions(int nid,
428 unsigned long start_pfn, unsigned long end_pfn)
430 phys_addr_t start, end;
433 for_each_free_mem_range(i, nid, &start, &end, NULL) {
434 unsigned long pfn = clamp_t(unsigned long, PFN_UP(start),
436 unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end),
438 for ( ; pfn < e_pfn; pfn++)
440 add_one_highpage_init(pfn_to_page(pfn));
444 static inline void permanent_kmaps_init(pgd_t *pgd_base)
447 #endif /* CONFIG_HIGHMEM */
449 void __init native_pagetable_setup_start(pgd_t *base)
451 unsigned long pfn, va;
458 * Remove any mappings which extend past the end of physical
459 * memory from the boot time page table:
461 for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
462 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
463 pgd = base + pgd_index(va);
464 if (!pgd_present(*pgd))
467 pud = pud_offset(pgd, va);
468 pmd = pmd_offset(pud, va);
469 if (!pmd_present(*pmd))
472 pte = pte_offset_kernel(pmd, va);
473 if (!pte_present(*pte))
476 pte_clear(NULL, va, pte);
478 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
481 void __init native_pagetable_setup_done(pgd_t *base)
486 * Build a proper pagetable for the kernel mappings. Up until this
487 * point, we've been running on some set of pagetables constructed by
490 * If we're booting on native hardware, this will be a pagetable
491 * constructed in arch/x86/kernel/head_32.S. The root of the
492 * pagetable will be swapper_pg_dir.
494 * If we're booting paravirtualized under a hypervisor, then there are
495 * more options: we may already be running PAE, and the pagetable may
496 * or may not be based in swapper_pg_dir. In any case,
497 * paravirt_pagetable_setup_start() will set up swapper_pg_dir
498 * appropriately for the rest of the initialization to work.
500 * In general, pagetable_init() assumes that the pagetable may already
501 * be partially populated, and so it avoids stomping on any existing
504 void __init early_ioremap_page_table_range_init(void)
506 pgd_t *pgd_base = swapper_pg_dir;
507 unsigned long vaddr, end;
510 * Fixed mappings, only the page table structure has to be
511 * created - mappings will be set by set_fixmap():
513 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
514 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
515 page_table_range_init(vaddr, end, pgd_base);
516 early_ioremap_reset();
519 static void __init pagetable_init(void)
521 pgd_t *pgd_base = swapper_pg_dir;
523 permanent_kmaps_init(pgd_base);
526 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
527 EXPORT_SYMBOL_GPL(__supported_pte_mask);
529 /* user-defined highmem size */
530 static unsigned int highmem_pages = -1;
533 * highmem=size forces highmem to be exactly 'size' bytes.
534 * This works even on boxes that have no highmem otherwise.
535 * This also works to reduce highmem size on bigger boxes.
537 static int __init parse_highmem(char *arg)
542 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
545 early_param("highmem", parse_highmem);
547 #define MSG_HIGHMEM_TOO_BIG \
548 "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
550 #define MSG_LOWMEM_TOO_SMALL \
551 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
553 * All of RAM fits into lowmem - but if user wants highmem
554 * artificially via the highmem=x boot parameter then create
557 void __init lowmem_pfn_init(void)
559 /* max_low_pfn is 0, we already have early_res support */
560 max_low_pfn = max_pfn;
562 if (highmem_pages == -1)
564 #ifdef CONFIG_HIGHMEM
565 if (highmem_pages >= max_pfn) {
566 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
567 pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
571 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
572 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
573 pages_to_mb(highmem_pages));
576 max_low_pfn -= highmem_pages;
580 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
584 #define MSG_HIGHMEM_TOO_SMALL \
585 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
587 #define MSG_HIGHMEM_TRIMMED \
588 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
590 * We have more RAM than fits into lowmem - we try to put it into
591 * highmem, also taking the highmem=x boot parameter into account:
593 void __init highmem_pfn_init(void)
595 max_low_pfn = MAXMEM_PFN;
597 if (highmem_pages == -1)
598 highmem_pages = max_pfn - MAXMEM_PFN;
600 if (highmem_pages + MAXMEM_PFN < max_pfn)
601 max_pfn = MAXMEM_PFN + highmem_pages;
603 if (highmem_pages + MAXMEM_PFN > max_pfn) {
604 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
605 pages_to_mb(max_pfn - MAXMEM_PFN),
606 pages_to_mb(highmem_pages));
609 #ifndef CONFIG_HIGHMEM
610 /* Maximum memory usable is what is directly addressable */
611 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
612 if (max_pfn > MAX_NONPAE_PFN)
613 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
615 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
616 max_pfn = MAXMEM_PFN;
617 #else /* !CONFIG_HIGHMEM */
618 #ifndef CONFIG_HIGHMEM64G
619 if (max_pfn > MAX_NONPAE_PFN) {
620 max_pfn = MAX_NONPAE_PFN;
621 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
623 #endif /* !CONFIG_HIGHMEM64G */
624 #endif /* !CONFIG_HIGHMEM */
628 * Determine low and high memory ranges:
630 void __init find_low_pfn_range(void)
632 /* it could update max_pfn */
634 if (max_pfn <= MAXMEM_PFN)
640 #ifndef CONFIG_NEED_MULTIPLE_NODES
641 void __init initmem_init(void)
643 #ifdef CONFIG_HIGHMEM
644 highstart_pfn = highend_pfn = max_pfn;
645 if (max_pfn > max_low_pfn)
646 highstart_pfn = max_low_pfn;
647 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
648 pages_to_mb(highend_pfn - highstart_pfn));
649 num_physpages = highend_pfn;
650 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
652 num_physpages = max_low_pfn;
653 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
656 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0);
657 sparse_memory_present_with_active_regions(0);
659 #ifdef CONFIG_FLATMEM
660 max_mapnr = num_physpages;
662 __vmalloc_start_set = true;
664 printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
665 pages_to_mb(max_low_pfn));
667 setup_bootmem_allocator();
669 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
671 static void __init zone_sizes_init(void)
673 unsigned long max_zone_pfns[MAX_NR_ZONES];
674 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
675 #ifdef CONFIG_ZONE_DMA
676 max_zone_pfns[ZONE_DMA] =
677 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
679 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
680 #ifdef CONFIG_HIGHMEM
681 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
684 free_area_init_nodes(max_zone_pfns);
687 void __init setup_bootmem_allocator(void)
689 printk(KERN_INFO " mapped low ram: 0 - %08lx\n",
690 max_pfn_mapped<<PAGE_SHIFT);
691 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
697 * paging_init() sets up the page tables - note that the first 8MB are
698 * already mapped by head.S.
700 * This routines also unmaps the page at virtual kernel address 0, so
701 * that we can trap those pesky NULL-reference errors in the kernel.
703 void __init paging_init(void)
712 * NOTE: at this point the bootmem allocator is fully available.
714 olpc_dt_build_devicetree();
715 sparse_memory_present_with_active_regions(MAX_NUMNODES);
721 * Test if the WP bit works in supervisor mode. It isn't supported on 386's
722 * and also on some strange 486's. All 586+'s are OK. This used to involve
723 * black magic jumps to work around some nasty CPU bugs, but fortunately the
724 * switch to using exceptions got rid of all that.
726 static void __init test_wp_bit(void)
729 "Checking if this processor honours the WP bit even in supervisor mode...");
731 /* Any page-aligned address will do, the test is non-destructive */
732 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
733 boot_cpu_data.wp_works_ok = do_test_wp_bit();
734 clear_fixmap(FIX_WP_TEST);
736 if (!boot_cpu_data.wp_works_ok) {
737 printk(KERN_CONT "No.\n");
738 #ifdef CONFIG_X86_WP_WORKS_OK
740 "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
743 printk(KERN_CONT "Ok.\n");
747 void __init mem_init(void)
749 int codesize, reservedpages, datasize, initsize;
754 #ifdef CONFIG_FLATMEM
757 /* this will put all low memory onto the freelists */
758 totalram_pages += free_all_bootmem();
761 for (tmp = 0; tmp < max_low_pfn; tmp++)
763 * Only count reserved RAM pages:
765 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp)))
768 set_highmem_pages_init();
770 codesize = (unsigned long) &_etext - (unsigned long) &_text;
771 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
772 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
774 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
775 "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
776 nr_free_pages() << (PAGE_SHIFT-10),
777 num_physpages << (PAGE_SHIFT-10),
779 reservedpages << (PAGE_SHIFT-10),
782 totalhigh_pages << (PAGE_SHIFT-10));
784 printk(KERN_INFO "virtual kernel memory layout:\n"
785 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
786 #ifdef CONFIG_HIGHMEM
787 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
789 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
790 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
791 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
792 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
793 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
794 FIXADDR_START, FIXADDR_TOP,
795 (FIXADDR_TOP - FIXADDR_START) >> 10,
797 #ifdef CONFIG_HIGHMEM
798 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
799 (LAST_PKMAP*PAGE_SIZE) >> 10,
802 VMALLOC_START, VMALLOC_END,
803 (VMALLOC_END - VMALLOC_START) >> 20,
805 (unsigned long)__va(0), (unsigned long)high_memory,
806 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
808 (unsigned long)&__init_begin, (unsigned long)&__init_end,
809 ((unsigned long)&__init_end -
810 (unsigned long)&__init_begin) >> 10,
812 (unsigned long)&_etext, (unsigned long)&_edata,
813 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
815 (unsigned long)&_text, (unsigned long)&_etext,
816 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
819 * Check boundaries twice: Some fundamental inconsistencies can
820 * be detected at build time already.
822 #define __FIXADDR_TOP (-PAGE_SIZE)
823 #ifdef CONFIG_HIGHMEM
824 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
825 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE);
827 #define high_memory (-128UL << 20)
828 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
832 #ifdef CONFIG_HIGHMEM
833 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
834 BUG_ON(VMALLOC_END > PKMAP_BASE);
836 BUG_ON(VMALLOC_START >= VMALLOC_END);
837 BUG_ON((unsigned long)high_memory > VMALLOC_START);
839 if (boot_cpu_data.wp_works_ok < 0)
843 #ifdef CONFIG_MEMORY_HOTPLUG
844 int arch_add_memory(int nid, u64 start, u64 size)
846 struct pglist_data *pgdata = NODE_DATA(nid);
847 struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM;
848 unsigned long start_pfn = start >> PAGE_SHIFT;
849 unsigned long nr_pages = size >> PAGE_SHIFT;
851 return __add_pages(nid, zone, start_pfn, nr_pages);
856 * This function cannot be __init, since exceptions don't work in that
857 * section. Put this after the callers, so that it cannot be inlined.
859 static noinline int do_test_wp_bit(void)
864 __asm__ __volatile__(
870 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)),
879 #ifdef CONFIG_DEBUG_RODATA
880 const int rodata_test_data = 0xC3;
881 EXPORT_SYMBOL_GPL(rodata_test_data);
883 int kernel_set_to_readonly __read_mostly;
885 void set_kernel_text_rw(void)
887 unsigned long start = PFN_ALIGN(_text);
888 unsigned long size = PFN_ALIGN(_etext) - start;
890 if (!kernel_set_to_readonly)
893 pr_debug("Set kernel text: %lx - %lx for read write\n",
896 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
899 void set_kernel_text_ro(void)
901 unsigned long start = PFN_ALIGN(_text);
902 unsigned long size = PFN_ALIGN(_etext) - start;
904 if (!kernel_set_to_readonly)
907 pr_debug("Set kernel text: %lx - %lx for read only\n",
910 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
913 static void mark_nxdata_nx(void)
916 * When this called, init has already been executed and released,
917 * so everything past _etext should be NX.
919 unsigned long start = PFN_ALIGN(_etext);
921 * This comes from is_kernel_text upper limit. Also HPAGE where used:
923 unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start;
925 if (__supported_pte_mask & _PAGE_NX)
926 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10);
927 set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT);
930 void mark_rodata_ro(void)
932 unsigned long start = PFN_ALIGN(_text);
933 unsigned long size = PFN_ALIGN(_etext) - start;
935 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
936 printk(KERN_INFO "Write protecting the kernel text: %luk\n",
939 kernel_set_to_readonly = 1;
941 #ifdef CONFIG_CPA_DEBUG
942 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
944 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
946 printk(KERN_INFO "Testing CPA: write protecting again\n");
947 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
951 size = (unsigned long)__end_rodata - start;
952 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
953 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
957 #ifdef CONFIG_CPA_DEBUG
958 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
959 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
961 printk(KERN_INFO "Testing CPA: write protecting again\n");
962 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);