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/uaccess.h>
39 #include <asm/pgtable.h>
41 #include <asm/fixmap.h>
46 #include <asm/tlbflush.h>
47 #include <asm/olpc_ofw.h>
48 #include <asm/pgalloc.h>
49 #include <asm/sections.h>
50 #include <asm/paravirt.h>
51 #include <asm/setup.h>
52 #include <asm/cacheflush.h>
53 #include <asm/page_types.h>
56 #include "mm_internal.h"
58 unsigned long highstart_pfn
, highend_pfn
;
60 static noinline
int do_test_wp_bit(void);
62 bool __read_mostly __vmalloc_start_set
= false;
65 * Creates a middle page table and puts a pointer to it in the
66 * given global directory entry. This only returns the gd entry
67 * in non-PAE compilation mode, since the middle layer is folded.
69 static pmd_t
* __init
one_md_table_init(pgd_t
*pgd
)
75 if (!(pgd_val(*pgd
) & _PAGE_PRESENT
)) {
76 pmd_table
= (pmd_t
*)alloc_low_page();
77 paravirt_alloc_pmd(&init_mm
, __pa(pmd_table
) >> PAGE_SHIFT
);
78 set_pgd(pgd
, __pgd(__pa(pmd_table
) | _PAGE_PRESENT
));
79 pud
= pud_offset(pgd
, 0);
80 BUG_ON(pmd_table
!= pmd_offset(pud
, 0));
85 pud
= pud_offset(pgd
, 0);
86 pmd_table
= pmd_offset(pud
, 0);
92 * Create a page table and place a pointer to it in a middle page
95 static pte_t
* __init
one_page_table_init(pmd_t
*pmd
)
97 if (!(pmd_val(*pmd
) & _PAGE_PRESENT
)) {
98 pte_t
*page_table
= (pte_t
*)alloc_low_page();
100 paravirt_alloc_pte(&init_mm
, __pa(page_table
) >> PAGE_SHIFT
);
101 set_pmd(pmd
, __pmd(__pa(page_table
) | _PAGE_TABLE
));
102 BUG_ON(page_table
!= pte_offset_kernel(pmd
, 0));
105 return pte_offset_kernel(pmd
, 0);
108 pmd_t
* __init
populate_extra_pmd(unsigned long vaddr
)
110 int pgd_idx
= pgd_index(vaddr
);
111 int pmd_idx
= pmd_index(vaddr
);
113 return one_md_table_init(swapper_pg_dir
+ pgd_idx
) + pmd_idx
;
116 pte_t
* __init
populate_extra_pte(unsigned long vaddr
)
118 int pte_idx
= pte_index(vaddr
);
121 pmd
= populate_extra_pmd(vaddr
);
122 return one_page_table_init(pmd
) + pte_idx
;
125 static unsigned long __init
126 page_table_range_init_count(unsigned long start
, unsigned long end
)
128 unsigned long count
= 0;
129 #ifdef CONFIG_HIGHMEM
130 int pmd_idx_kmap_begin
= fix_to_virt(FIX_KMAP_END
) >> PMD_SHIFT
;
131 int pmd_idx_kmap_end
= fix_to_virt(FIX_KMAP_BEGIN
) >> PMD_SHIFT
;
132 int pgd_idx
, pmd_idx
;
135 if (pmd_idx_kmap_begin
== pmd_idx_kmap_end
)
139 pgd_idx
= pgd_index(vaddr
);
141 for ( ; (pgd_idx
< PTRS_PER_PGD
) && (vaddr
!= end
); pgd_idx
++) {
142 for (; (pmd_idx
< PTRS_PER_PMD
) && (vaddr
!= end
);
144 if ((vaddr
>> PMD_SHIFT
) >= pmd_idx_kmap_begin
&&
145 (vaddr
>> PMD_SHIFT
) <= pmd_idx_kmap_end
)
155 static pte_t
*__init
page_table_kmap_check(pte_t
*pte
, pmd_t
*pmd
,
156 unsigned long vaddr
, pte_t
*lastpte
,
159 #ifdef CONFIG_HIGHMEM
161 * Something (early fixmap) may already have put a pte
162 * page here, which causes the page table allocation
163 * to become nonlinear. Attempt to fix it, and if it
164 * is still nonlinear then we have to bug.
166 int pmd_idx_kmap_begin
= fix_to_virt(FIX_KMAP_END
) >> PMD_SHIFT
;
167 int pmd_idx_kmap_end
= fix_to_virt(FIX_KMAP_BEGIN
) >> PMD_SHIFT
;
169 if (pmd_idx_kmap_begin
!= pmd_idx_kmap_end
170 && (vaddr
>> PMD_SHIFT
) >= pmd_idx_kmap_begin
171 && (vaddr
>> PMD_SHIFT
) <= pmd_idx_kmap_end
) {
175 BUG_ON(after_bootmem
);
177 for (i
= 0; i
< PTRS_PER_PTE
; i
++)
178 set_pte(newpte
+ i
, pte
[i
]);
179 *adr
= (void *)(((unsigned long)(*adr
)) + PAGE_SIZE
);
181 paravirt_alloc_pte(&init_mm
, __pa(newpte
) >> PAGE_SHIFT
);
182 set_pmd(pmd
, __pmd(__pa(newpte
)|_PAGE_TABLE
));
183 BUG_ON(newpte
!= pte_offset_kernel(pmd
, 0));
186 paravirt_release_pte(__pa(pte
) >> PAGE_SHIFT
);
189 BUG_ON(vaddr
< fix_to_virt(FIX_KMAP_BEGIN
- 1)
190 && vaddr
> fix_to_virt(FIX_KMAP_END
)
191 && lastpte
&& lastpte
+ PTRS_PER_PTE
!= pte
);
197 * This function initializes a certain range of kernel virtual memory
198 * with new bootmem page tables, everywhere page tables are missing in
201 * NOTE: The pagetables are allocated contiguous on the physical space
202 * so we can cache the place of the first one and move around without
203 * checking the pgd every time.
206 page_table_range_init(unsigned long start
, unsigned long end
, pgd_t
*pgd_base
)
208 int pgd_idx
, pmd_idx
;
213 unsigned long count
= page_table_range_init_count(start
, end
);
217 adr
= alloc_low_pages(count
);
220 pgd_idx
= pgd_index(vaddr
);
221 pmd_idx
= pmd_index(vaddr
);
222 pgd
= pgd_base
+ pgd_idx
;
224 for ( ; (pgd_idx
< PTRS_PER_PGD
) && (vaddr
!= end
); pgd
++, pgd_idx
++) {
225 pmd
= one_md_table_init(pgd
);
226 pmd
= pmd
+ pmd_index(vaddr
);
227 for (; (pmd_idx
< PTRS_PER_PMD
) && (vaddr
!= end
);
229 pte
= page_table_kmap_check(one_page_table_init(pmd
),
230 pmd
, vaddr
, pte
, &adr
);
238 static inline int is_kernel_text(unsigned long addr
)
240 if (addr
>= (unsigned long)_text
&& addr
<= (unsigned long)__init_end
)
246 * This maps the physical memory to kernel virtual address space, a total
247 * of max_low_pfn pages, by creating page tables starting from address
251 kernel_physical_mapping_init(unsigned long start
,
253 unsigned long page_size_mask
)
255 int use_pse
= page_size_mask
== (1<<PG_LEVEL_2M
);
256 unsigned long last_map_addr
= end
;
257 unsigned long start_pfn
, end_pfn
;
258 pgd_t
*pgd_base
= swapper_pg_dir
;
259 int pgd_idx
, pmd_idx
, pte_ofs
;
264 unsigned pages_2m
, pages_4k
;
267 start_pfn
= start
>> PAGE_SHIFT
;
268 end_pfn
= end
>> PAGE_SHIFT
;
271 * First iteration will setup identity mapping using large/small pages
272 * based on use_pse, with other attributes same as set by
273 * the early code in head_32.S
275 * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
276 * as desired for the kernel identity mapping.
278 * This two pass mechanism conforms to the TLB app note which says:
280 * "Software should not write to a paging-structure entry in a way
281 * that would change, for any linear address, both the page size
282 * and either the page frame or attributes."
290 pages_2m
= pages_4k
= 0;
292 pgd_idx
= pgd_index((pfn
<<PAGE_SHIFT
) + PAGE_OFFSET
);
293 pgd
= pgd_base
+ pgd_idx
;
294 for (; pgd_idx
< PTRS_PER_PGD
; pgd
++, pgd_idx
++) {
295 pmd
= one_md_table_init(pgd
);
299 #ifdef CONFIG_X86_PAE
300 pmd_idx
= pmd_index((pfn
<<PAGE_SHIFT
) + PAGE_OFFSET
);
305 for (; pmd_idx
< PTRS_PER_PMD
&& pfn
< end_pfn
;
307 unsigned int addr
= pfn
* PAGE_SIZE
+ PAGE_OFFSET
;
310 * Map with big pages if possible, otherwise
311 * create normal page tables:
315 pgprot_t prot
= PAGE_KERNEL_LARGE
;
317 * first pass will use the same initial
318 * identity mapping attribute + _PAGE_PSE.
321 __pgprot(PTE_IDENT_ATTR
|
324 pfn
&= PMD_MASK
>> PAGE_SHIFT
;
325 addr2
= (pfn
+ PTRS_PER_PTE
-1) * PAGE_SIZE
+
326 PAGE_OFFSET
+ PAGE_SIZE
-1;
328 if (is_kernel_text(addr
) ||
329 is_kernel_text(addr2
))
330 prot
= PAGE_KERNEL_LARGE_EXEC
;
333 if (mapping_iter
== 1)
334 set_pmd(pmd
, pfn_pmd(pfn
, init_prot
));
336 set_pmd(pmd
, pfn_pmd(pfn
, prot
));
341 pte
= one_page_table_init(pmd
);
343 pte_ofs
= pte_index((pfn
<<PAGE_SHIFT
) + PAGE_OFFSET
);
345 for (; pte_ofs
< PTRS_PER_PTE
&& pfn
< end_pfn
;
346 pte
++, pfn
++, pte_ofs
++, addr
+= PAGE_SIZE
) {
347 pgprot_t prot
= PAGE_KERNEL
;
349 * first pass will use the same initial
350 * identity mapping attribute.
352 pgprot_t init_prot
= __pgprot(PTE_IDENT_ATTR
);
354 if (is_kernel_text(addr
))
355 prot
= PAGE_KERNEL_EXEC
;
358 if (mapping_iter
== 1) {
359 set_pte(pte
, pfn_pte(pfn
, init_prot
));
360 last_map_addr
= (pfn
<< PAGE_SHIFT
) + PAGE_SIZE
;
362 set_pte(pte
, pfn_pte(pfn
, prot
));
366 if (mapping_iter
== 1) {
368 * update direct mapping page count only in the first
371 update_page_count(PG_LEVEL_2M
, pages_2m
);
372 update_page_count(PG_LEVEL_4K
, pages_4k
);
375 * local global flush tlb, which will flush the previous
376 * mappings present in both small and large page TLB's.
381 * Second iteration will set the actual desired PTE attributes.
386 return last_map_addr
;
392 static inline pte_t
*kmap_get_fixmap_pte(unsigned long vaddr
)
394 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr
),
395 vaddr
), vaddr
), vaddr
);
398 static void __init
kmap_init(void)
400 unsigned long kmap_vstart
;
403 * Cache the first kmap pte:
405 kmap_vstart
= __fix_to_virt(FIX_KMAP_BEGIN
);
406 kmap_pte
= kmap_get_fixmap_pte(kmap_vstart
);
408 kmap_prot
= PAGE_KERNEL
;
411 #ifdef CONFIG_HIGHMEM
412 static void __init
permanent_kmaps_init(pgd_t
*pgd_base
)
421 page_table_range_init(vaddr
, vaddr
+ PAGE_SIZE
*LAST_PKMAP
, pgd_base
);
423 pgd
= swapper_pg_dir
+ pgd_index(vaddr
);
424 pud
= pud_offset(pgd
, vaddr
);
425 pmd
= pmd_offset(pud
, vaddr
);
426 pte
= pte_offset_kernel(pmd
, vaddr
);
427 pkmap_page_table
= pte
;
430 static void __init
add_one_highpage_init(struct page
*page
)
432 ClearPageReserved(page
);
433 init_page_count(page
);
438 void __init
add_highpages_with_active_regions(int nid
,
439 unsigned long start_pfn
, unsigned long end_pfn
)
441 phys_addr_t start
, end
;
444 for_each_free_mem_range(i
, nid
, &start
, &end
, NULL
) {
445 unsigned long pfn
= clamp_t(unsigned long, PFN_UP(start
),
447 unsigned long e_pfn
= clamp_t(unsigned long, PFN_DOWN(end
),
449 for ( ; pfn
< e_pfn
; pfn
++)
451 add_one_highpage_init(pfn_to_page(pfn
));
455 static inline void permanent_kmaps_init(pgd_t
*pgd_base
)
458 #endif /* CONFIG_HIGHMEM */
460 void __init
native_pagetable_init(void)
462 unsigned long pfn
, va
;
463 pgd_t
*pgd
, *base
= swapper_pg_dir
;
469 * Remove any mappings which extend past the end of physical
470 * memory from the boot time page table.
471 * In virtual address space, we should have at least two pages
472 * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END
473 * definition. And max_low_pfn is set to VMALLOC_END physical
474 * address. If initial memory mapping is doing right job, we
475 * should have pte used near max_low_pfn or one pmd is not present.
477 for (pfn
= max_low_pfn
; pfn
< 1<<(32-PAGE_SHIFT
); pfn
++) {
478 va
= PAGE_OFFSET
+ (pfn
<<PAGE_SHIFT
);
479 pgd
= base
+ pgd_index(va
);
480 if (!pgd_present(*pgd
))
483 pud
= pud_offset(pgd
, va
);
484 pmd
= pmd_offset(pud
, va
);
485 if (!pmd_present(*pmd
))
488 /* should not be large page here */
489 if (pmd_large(*pmd
)) {
490 pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n",
491 pfn
, pmd
, __pa(pmd
));
495 pte
= pte_offset_kernel(pmd
, va
);
496 if (!pte_present(*pte
))
499 printk(KERN_DEBUG
"clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n",
500 pfn
, pmd
, __pa(pmd
), pte
, __pa(pte
));
501 pte_clear(NULL
, va
, pte
);
503 paravirt_alloc_pmd(&init_mm
, __pa(base
) >> PAGE_SHIFT
);
508 * Build a proper pagetable for the kernel mappings. Up until this
509 * point, we've been running on some set of pagetables constructed by
512 * If we're booting on native hardware, this will be a pagetable
513 * constructed in arch/x86/kernel/head_32.S. The root of the
514 * pagetable will be swapper_pg_dir.
516 * If we're booting paravirtualized under a hypervisor, then there are
517 * more options: we may already be running PAE, and the pagetable may
518 * or may not be based in swapper_pg_dir. In any case,
519 * paravirt_pagetable_init() will set up swapper_pg_dir
520 * appropriately for the rest of the initialization to work.
522 * In general, pagetable_init() assumes that the pagetable may already
523 * be partially populated, and so it avoids stomping on any existing
526 void __init
early_ioremap_page_table_range_init(void)
528 pgd_t
*pgd_base
= swapper_pg_dir
;
529 unsigned long vaddr
, end
;
532 * Fixed mappings, only the page table structure has to be
533 * created - mappings will be set by set_fixmap():
535 vaddr
= __fix_to_virt(__end_of_fixed_addresses
- 1) & PMD_MASK
;
536 end
= (FIXADDR_TOP
+ PMD_SIZE
- 1) & PMD_MASK
;
537 page_table_range_init(vaddr
, end
, pgd_base
);
538 early_ioremap_reset();
541 static void __init
pagetable_init(void)
543 pgd_t
*pgd_base
= swapper_pg_dir
;
545 permanent_kmaps_init(pgd_base
);
548 pteval_t __supported_pte_mask __read_mostly
= ~(_PAGE_NX
| _PAGE_GLOBAL
| _PAGE_IOMAP
);
549 EXPORT_SYMBOL_GPL(__supported_pte_mask
);
551 /* user-defined highmem size */
552 static unsigned int highmem_pages
= -1;
555 * highmem=size forces highmem to be exactly 'size' bytes.
556 * This works even on boxes that have no highmem otherwise.
557 * This also works to reduce highmem size on bigger boxes.
559 static int __init
parse_highmem(char *arg
)
564 highmem_pages
= memparse(arg
, &arg
) >> PAGE_SHIFT
;
567 early_param("highmem", parse_highmem
);
569 #define MSG_HIGHMEM_TOO_BIG \
570 "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
572 #define MSG_LOWMEM_TOO_SMALL \
573 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
575 * All of RAM fits into lowmem - but if user wants highmem
576 * artificially via the highmem=x boot parameter then create
579 static void __init
lowmem_pfn_init(void)
581 /* max_low_pfn is 0, we already have early_res support */
582 max_low_pfn
= max_pfn
;
584 if (highmem_pages
== -1)
586 #ifdef CONFIG_HIGHMEM
587 if (highmem_pages
>= max_pfn
) {
588 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG
,
589 pages_to_mb(highmem_pages
), pages_to_mb(max_pfn
));
593 if (max_low_pfn
- highmem_pages
< 64*1024*1024/PAGE_SIZE
) {
594 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL
,
595 pages_to_mb(highmem_pages
));
598 max_low_pfn
-= highmem_pages
;
602 printk(KERN_ERR
"ignoring highmem size on non-highmem kernel!\n");
606 #define MSG_HIGHMEM_TOO_SMALL \
607 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
609 #define MSG_HIGHMEM_TRIMMED \
610 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
612 * We have more RAM than fits into lowmem - we try to put it into
613 * highmem, also taking the highmem=x boot parameter into account:
615 static void __init
highmem_pfn_init(void)
617 max_low_pfn
= MAXMEM_PFN
;
619 if (highmem_pages
== -1)
620 highmem_pages
= max_pfn
- MAXMEM_PFN
;
622 if (highmem_pages
+ MAXMEM_PFN
< max_pfn
)
623 max_pfn
= MAXMEM_PFN
+ highmem_pages
;
625 if (highmem_pages
+ MAXMEM_PFN
> max_pfn
) {
626 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL
,
627 pages_to_mb(max_pfn
- MAXMEM_PFN
),
628 pages_to_mb(highmem_pages
));
631 #ifndef CONFIG_HIGHMEM
632 /* Maximum memory usable is what is directly addressable */
633 printk(KERN_WARNING
"Warning only %ldMB will be used.\n", MAXMEM
>>20);
634 if (max_pfn
> MAX_NONPAE_PFN
)
635 printk(KERN_WARNING
"Use a HIGHMEM64G enabled kernel.\n");
637 printk(KERN_WARNING
"Use a HIGHMEM enabled kernel.\n");
638 max_pfn
= MAXMEM_PFN
;
639 #else /* !CONFIG_HIGHMEM */
640 #ifndef CONFIG_HIGHMEM64G
641 if (max_pfn
> MAX_NONPAE_PFN
) {
642 max_pfn
= MAX_NONPAE_PFN
;
643 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED
);
645 #endif /* !CONFIG_HIGHMEM64G */
646 #endif /* !CONFIG_HIGHMEM */
650 * Determine low and high memory ranges:
652 void __init
find_low_pfn_range(void)
654 /* it could update max_pfn */
656 if (max_pfn
<= MAXMEM_PFN
)
662 #ifndef CONFIG_NEED_MULTIPLE_NODES
663 void __init
initmem_init(void)
665 #ifdef CONFIG_HIGHMEM
666 highstart_pfn
= highend_pfn
= max_pfn
;
667 if (max_pfn
> max_low_pfn
)
668 highstart_pfn
= max_low_pfn
;
669 printk(KERN_NOTICE
"%ldMB HIGHMEM available.\n",
670 pages_to_mb(highend_pfn
- highstart_pfn
));
671 num_physpages
= highend_pfn
;
672 high_memory
= (void *) __va(highstart_pfn
* PAGE_SIZE
- 1) + 1;
674 num_physpages
= max_low_pfn
;
675 high_memory
= (void *) __va(max_low_pfn
* PAGE_SIZE
- 1) + 1;
678 memblock_set_node(0, (phys_addr_t
)ULLONG_MAX
, 0);
679 sparse_memory_present_with_active_regions(0);
681 #ifdef CONFIG_FLATMEM
682 max_mapnr
= num_physpages
;
684 __vmalloc_start_set
= true;
686 printk(KERN_NOTICE
"%ldMB LOWMEM available.\n",
687 pages_to_mb(max_low_pfn
));
689 setup_bootmem_allocator();
691 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
693 void __init
setup_bootmem_allocator(void)
695 printk(KERN_INFO
" mapped low ram: 0 - %08lx\n",
696 max_pfn_mapped
<<PAGE_SHIFT
);
697 printk(KERN_INFO
" low ram: 0 - %08lx\n", max_low_pfn
<<PAGE_SHIFT
);
701 * paging_init() sets up the page tables - note that the first 8MB are
702 * already mapped by head.S.
704 * This routines also unmaps the page at virtual kernel address 0, so
705 * that we can trap those pesky NULL-reference errors in the kernel.
707 void __init
paging_init(void)
716 * NOTE: at this point the bootmem allocator is fully available.
718 olpc_dt_build_devicetree();
719 sparse_memory_present_with_active_regions(MAX_NUMNODES
);
725 * Test if the WP bit works in supervisor mode. It isn't supported on 386's
726 * and also on some strange 486's. All 586+'s are OK. This used to involve
727 * black magic jumps to work around some nasty CPU bugs, but fortunately the
728 * switch to using exceptions got rid of all that.
730 static void __init
test_wp_bit(void)
733 "Checking if this processor honours the WP bit even in supervisor mode...");
735 /* Any page-aligned address will do, the test is non-destructive */
736 __set_fixmap(FIX_WP_TEST
, __pa(&swapper_pg_dir
), PAGE_KERNEL_RO
);
737 boot_cpu_data
.wp_works_ok
= do_test_wp_bit();
738 clear_fixmap(FIX_WP_TEST
);
740 if (!boot_cpu_data
.wp_works_ok
) {
741 printk(KERN_CONT
"No.\n");
742 panic("Linux doesn't support CPUs with broken WP.");
744 printk(KERN_CONT
"Ok.\n");
748 void __init
mem_init(void)
750 int codesize
, reservedpages
, datasize
, initsize
;
755 #ifdef CONFIG_FLATMEM
759 * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to
760 * be done before free_all_bootmem(). Memblock use free low memory for
761 * temporary data (see find_range_array()) and for this purpose can use
762 * pages that was already passed to the buddy allocator, hence marked as
763 * not accessible in the page tables when compiled with
764 * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not
767 set_highmem_pages_init();
769 /* this will put all low memory onto the freelists */
770 totalram_pages
+= free_all_bootmem();
773 for (tmp
= 0; tmp
< max_low_pfn
; tmp
++)
775 * Only count reserved RAM pages:
777 if (page_is_ram(tmp
) && PageReserved(pfn_to_page(tmp
)))
782 codesize
= (unsigned long) &_etext
- (unsigned long) &_text
;
783 datasize
= (unsigned long) &_edata
- (unsigned long) &_etext
;
784 initsize
= (unsigned long) &__init_end
- (unsigned long) &__init_begin
;
786 printk(KERN_INFO
"Memory: %luk/%luk available (%dk kernel code, "
787 "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
788 nr_free_pages() << (PAGE_SHIFT
-10),
789 num_physpages
<< (PAGE_SHIFT
-10),
791 reservedpages
<< (PAGE_SHIFT
-10),
794 totalhigh_pages
<< (PAGE_SHIFT
-10));
796 printk(KERN_INFO
"virtual kernel memory layout:\n"
797 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
798 #ifdef CONFIG_HIGHMEM
799 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
801 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
802 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
803 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
804 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
805 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
806 FIXADDR_START
, FIXADDR_TOP
,
807 (FIXADDR_TOP
- FIXADDR_START
) >> 10,
809 #ifdef CONFIG_HIGHMEM
810 PKMAP_BASE
, PKMAP_BASE
+LAST_PKMAP
*PAGE_SIZE
,
811 (LAST_PKMAP
*PAGE_SIZE
) >> 10,
814 VMALLOC_START
, VMALLOC_END
,
815 (VMALLOC_END
- VMALLOC_START
) >> 20,
817 (unsigned long)__va(0), (unsigned long)high_memory
,
818 ((unsigned long)high_memory
- (unsigned long)__va(0)) >> 20,
820 (unsigned long)&__init_begin
, (unsigned long)&__init_end
,
821 ((unsigned long)&__init_end
-
822 (unsigned long)&__init_begin
) >> 10,
824 (unsigned long)&_etext
, (unsigned long)&_edata
,
825 ((unsigned long)&_edata
- (unsigned long)&_etext
) >> 10,
827 (unsigned long)&_text
, (unsigned long)&_etext
,
828 ((unsigned long)&_etext
- (unsigned long)&_text
) >> 10);
831 * Check boundaries twice: Some fundamental inconsistencies can
832 * be detected at build time already.
834 #define __FIXADDR_TOP (-PAGE_SIZE)
835 #ifdef CONFIG_HIGHMEM
836 BUILD_BUG_ON(PKMAP_BASE
+ LAST_PKMAP
*PAGE_SIZE
> FIXADDR_START
);
837 BUILD_BUG_ON(VMALLOC_END
> PKMAP_BASE
);
839 #define high_memory (-128UL << 20)
840 BUILD_BUG_ON(VMALLOC_START
>= VMALLOC_END
);
844 #ifdef CONFIG_HIGHMEM
845 BUG_ON(PKMAP_BASE
+ LAST_PKMAP
*PAGE_SIZE
> FIXADDR_START
);
846 BUG_ON(VMALLOC_END
> PKMAP_BASE
);
848 BUG_ON(VMALLOC_START
>= VMALLOC_END
);
849 BUG_ON((unsigned long)high_memory
> VMALLOC_START
);
851 if (boot_cpu_data
.wp_works_ok
< 0)
855 #ifdef CONFIG_MEMORY_HOTPLUG
856 int arch_add_memory(int nid
, u64 start
, u64 size
)
858 struct pglist_data
*pgdata
= NODE_DATA(nid
);
859 struct zone
*zone
= pgdata
->node_zones
+ ZONE_HIGHMEM
;
860 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
861 unsigned long nr_pages
= size
>> PAGE_SHIFT
;
863 return __add_pages(nid
, zone
, start_pfn
, nr_pages
);
866 #ifdef CONFIG_MEMORY_HOTREMOVE
867 int arch_remove_memory(u64 start
, u64 size
)
869 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
870 unsigned long nr_pages
= size
>> PAGE_SHIFT
;
873 zone
= page_zone(pfn_to_page(start_pfn
));
874 return __remove_pages(zone
, start_pfn
, nr_pages
);
880 * This function cannot be __init, since exceptions don't work in that
881 * section. Put this after the callers, so that it cannot be inlined.
883 static noinline
int do_test_wp_bit(void)
888 __asm__
__volatile__(
894 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST
)),
903 #ifdef CONFIG_DEBUG_RODATA
904 const int rodata_test_data
= 0xC3;
905 EXPORT_SYMBOL_GPL(rodata_test_data
);
907 int kernel_set_to_readonly __read_mostly
;
909 void set_kernel_text_rw(void)
911 unsigned long start
= PFN_ALIGN(_text
);
912 unsigned long size
= PFN_ALIGN(_etext
) - start
;
914 if (!kernel_set_to_readonly
)
917 pr_debug("Set kernel text: %lx - %lx for read write\n",
920 set_pages_rw(virt_to_page(start
), size
>> PAGE_SHIFT
);
923 void set_kernel_text_ro(void)
925 unsigned long start
= PFN_ALIGN(_text
);
926 unsigned long size
= PFN_ALIGN(_etext
) - start
;
928 if (!kernel_set_to_readonly
)
931 pr_debug("Set kernel text: %lx - %lx for read only\n",
934 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);
937 static void mark_nxdata_nx(void)
940 * When this called, init has already been executed and released,
941 * so everything past _etext should be NX.
943 unsigned long start
= PFN_ALIGN(_etext
);
945 * This comes from is_kernel_text upper limit. Also HPAGE where used:
947 unsigned long size
= (((unsigned long)__init_end
+ HPAGE_SIZE
) & HPAGE_MASK
) - start
;
949 if (__supported_pte_mask
& _PAGE_NX
)
950 printk(KERN_INFO
"NX-protecting the kernel data: %luk\n", size
>> 10);
951 set_pages_nx(virt_to_page(start
), size
>> PAGE_SHIFT
);
954 void mark_rodata_ro(void)
956 unsigned long start
= PFN_ALIGN(_text
);
957 unsigned long size
= PFN_ALIGN(_etext
) - start
;
959 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);
960 printk(KERN_INFO
"Write protecting the kernel text: %luk\n",
963 kernel_set_to_readonly
= 1;
965 #ifdef CONFIG_CPA_DEBUG
966 printk(KERN_INFO
"Testing CPA: Reverting %lx-%lx\n",
968 set_pages_rw(virt_to_page(start
), size
>>PAGE_SHIFT
);
970 printk(KERN_INFO
"Testing CPA: write protecting again\n");
971 set_pages_ro(virt_to_page(start
), size
>>PAGE_SHIFT
);
975 size
= (unsigned long)__end_rodata
- start
;
976 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);
977 printk(KERN_INFO
"Write protecting the kernel read-only data: %luk\n",
981 #ifdef CONFIG_CPA_DEBUG
982 printk(KERN_INFO
"Testing CPA: undo %lx-%lx\n", start
, start
+ size
);
983 set_pages_rw(virt_to_page(start
), size
>> PAGE_SHIFT
);
985 printk(KERN_INFO
"Testing CPA: write protecting again\n");
986 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);