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/slab.h>
29 #include <linux/proc_fs.h>
30 #include <linux/memory_hotplug.h>
31 #include <linux/initrd.h>
32 #include <linux/cpumask.h>
35 #include <asm/bios_ebda.h>
36 #include <asm/processor.h>
37 #include <asm/system.h>
38 #include <asm/uaccess.h>
39 #include <asm/pgtable.h>
41 #include <asm/fixmap.h>
46 #include <asm/tlbflush.h>
47 #include <asm/pgalloc.h>
48 #include <asm/sections.h>
49 #include <asm/paravirt.h>
50 #include <asm/setup.h>
51 #include <asm/cacheflush.h>
53 unsigned long max_low_pfn_mapped
;
54 unsigned long max_pfn_mapped
;
56 DEFINE_PER_CPU(struct mmu_gather
, mmu_gathers
);
57 unsigned long highstart_pfn
, highend_pfn
;
59 static noinline
int do_test_wp_bit(void);
62 static unsigned long __initdata table_start
;
63 static unsigned long __meminitdata table_end
;
64 static unsigned long __meminitdata table_top
;
66 static int __initdata after_init_bootmem
;
68 static __init
void *alloc_low_page(void)
70 unsigned long pfn
= table_end
++;
74 panic("alloc_low_page: ran out of memory");
76 adr
= __va(pfn
* PAGE_SIZE
);
77 memset(adr
, 0, PAGE_SIZE
);
82 * Creates a middle page table and puts a pointer to it in the
83 * given global directory entry. This only returns the gd entry
84 * in non-PAE compilation mode, since the middle layer is folded.
86 static pmd_t
* __init
one_md_table_init(pgd_t
*pgd
)
92 if (!(pgd_val(*pgd
) & _PAGE_PRESENT
)) {
93 if (after_init_bootmem
)
94 pmd_table
= (pmd_t
*)alloc_bootmem_low_pages(PAGE_SIZE
);
96 pmd_table
= (pmd_t
*)alloc_low_page();
97 paravirt_alloc_pmd(&init_mm
, __pa(pmd_table
) >> PAGE_SHIFT
);
98 set_pgd(pgd
, __pgd(__pa(pmd_table
) | _PAGE_PRESENT
));
99 pud
= pud_offset(pgd
, 0);
100 BUG_ON(pmd_table
!= pmd_offset(pud
, 0));
105 pud
= pud_offset(pgd
, 0);
106 pmd_table
= pmd_offset(pud
, 0);
112 * Create a page table and place a pointer to it in a middle page
115 static pte_t
* __init
one_page_table_init(pmd_t
*pmd
)
117 if (!(pmd_val(*pmd
) & _PAGE_PRESENT
)) {
118 pte_t
*page_table
= NULL
;
120 if (after_init_bootmem
) {
121 #ifdef CONFIG_DEBUG_PAGEALLOC
122 page_table
= (pte_t
*) alloc_bootmem_pages(PAGE_SIZE
);
126 (pte_t
*)alloc_bootmem_low_pages(PAGE_SIZE
);
128 page_table
= (pte_t
*)alloc_low_page();
130 paravirt_alloc_pte(&init_mm
, __pa(page_table
) >> PAGE_SHIFT
);
131 set_pmd(pmd
, __pmd(__pa(page_table
) | _PAGE_TABLE
));
132 BUG_ON(page_table
!= pte_offset_kernel(pmd
, 0));
135 return pte_offset_kernel(pmd
, 0);
138 static pte_t
*__init
page_table_kmap_check(pte_t
*pte
, pmd_t
*pmd
,
139 unsigned long vaddr
, pte_t
*lastpte
)
141 #ifdef CONFIG_HIGHMEM
143 * Something (early fixmap) may already have put a pte
144 * page here, which causes the page table allocation
145 * to become nonlinear. Attempt to fix it, and if it
146 * is still nonlinear then we have to bug.
148 int pmd_idx_kmap_begin
= fix_to_virt(FIX_KMAP_END
) >> PMD_SHIFT
;
149 int pmd_idx_kmap_end
= fix_to_virt(FIX_KMAP_BEGIN
) >> PMD_SHIFT
;
151 if (pmd_idx_kmap_begin
!= pmd_idx_kmap_end
152 && (vaddr
>> PMD_SHIFT
) >= pmd_idx_kmap_begin
153 && (vaddr
>> PMD_SHIFT
) <= pmd_idx_kmap_end
154 && ((__pa(pte
) >> PAGE_SHIFT
) < table_start
155 || (__pa(pte
) >> PAGE_SHIFT
) >= table_end
)) {
159 BUG_ON(after_init_bootmem
);
160 newpte
= alloc_low_page();
161 for (i
= 0; i
< PTRS_PER_PTE
; i
++)
162 set_pte(newpte
+ i
, pte
[i
]);
164 paravirt_alloc_pte(&init_mm
, __pa(newpte
) >> PAGE_SHIFT
);
165 set_pmd(pmd
, __pmd(__pa(newpte
)|_PAGE_TABLE
));
166 BUG_ON(newpte
!= pte_offset_kernel(pmd
, 0));
169 paravirt_release_pte(__pa(pte
) >> PAGE_SHIFT
);
172 BUG_ON(vaddr
< fix_to_virt(FIX_KMAP_BEGIN
- 1)
173 && vaddr
> fix_to_virt(FIX_KMAP_END
)
174 && lastpte
&& lastpte
+ PTRS_PER_PTE
!= pte
);
180 * This function initializes a certain range of kernel virtual memory
181 * with new bootmem page tables, everywhere page tables are missing in
184 * NOTE: The pagetables are allocated contiguous on the physical space
185 * so we can cache the place of the first one and move around without
186 * checking the pgd every time.
189 page_table_range_init(unsigned long start
, unsigned long end
, pgd_t
*pgd_base
)
191 int pgd_idx
, pmd_idx
;
198 pgd_idx
= pgd_index(vaddr
);
199 pmd_idx
= pmd_index(vaddr
);
200 pgd
= pgd_base
+ pgd_idx
;
202 for ( ; (pgd_idx
< PTRS_PER_PGD
) && (vaddr
!= end
); pgd
++, pgd_idx
++) {
203 pmd
= one_md_table_init(pgd
);
204 pmd
= pmd
+ pmd_index(vaddr
);
205 for (; (pmd_idx
< PTRS_PER_PMD
) && (vaddr
!= end
);
207 pte
= page_table_kmap_check(one_page_table_init(pmd
),
216 static inline int is_kernel_text(unsigned long addr
)
218 if (addr
>= PAGE_OFFSET
&& addr
<= (unsigned long)__init_end
)
224 * This maps the physical memory to kernel virtual address space, a total
225 * of max_low_pfn pages, by creating page tables starting from address
228 static void __init
kernel_physical_mapping_init(pgd_t
*pgd_base
,
229 unsigned long start_pfn
,
230 unsigned long end_pfn
,
233 int pgd_idx
, pmd_idx
, pte_ofs
;
238 unsigned pages_2m
, pages_4k
;
242 * First iteration will setup identity mapping using large/small pages
243 * based on use_pse, with other attributes same as set by
244 * the early code in head_32.S
246 * Second iteration will setup the appropriate attributes (NX, GLOBAL..)
247 * as desired for the kernel identity mapping.
249 * This two pass mechanism conforms to the TLB app note which says:
251 * "Software should not write to a paging-structure entry in a way
252 * that would change, for any linear address, both the page size
253 * and either the page frame or attributes."
261 pages_2m
= pages_4k
= 0;
263 pgd_idx
= pgd_index((pfn
<<PAGE_SHIFT
) + PAGE_OFFSET
);
264 pgd
= pgd_base
+ pgd_idx
;
265 for (; pgd_idx
< PTRS_PER_PGD
; pgd
++, pgd_idx
++) {
266 pmd
= one_md_table_init(pgd
);
270 #ifdef CONFIG_X86_PAE
271 pmd_idx
= pmd_index((pfn
<<PAGE_SHIFT
) + PAGE_OFFSET
);
276 for (; pmd_idx
< PTRS_PER_PMD
&& pfn
< end_pfn
;
278 unsigned int addr
= pfn
* PAGE_SIZE
+ PAGE_OFFSET
;
281 * Map with big pages if possible, otherwise
282 * create normal page tables:
286 pgprot_t prot
= PAGE_KERNEL_LARGE
;
288 * first pass will use the same initial
289 * identity mapping attribute + _PAGE_PSE.
292 __pgprot(PTE_IDENT_ATTR
|
295 addr2
= (pfn
+ PTRS_PER_PTE
-1) * PAGE_SIZE
+
296 PAGE_OFFSET
+ PAGE_SIZE
-1;
298 if (is_kernel_text(addr
) ||
299 is_kernel_text(addr2
))
300 prot
= PAGE_KERNEL_LARGE_EXEC
;
303 if (mapping_iter
== 1)
304 set_pmd(pmd
, pfn_pmd(pfn
, init_prot
));
306 set_pmd(pmd
, pfn_pmd(pfn
, prot
));
311 pte
= one_page_table_init(pmd
);
313 pte_ofs
= pte_index((pfn
<<PAGE_SHIFT
) + PAGE_OFFSET
);
315 for (; pte_ofs
< PTRS_PER_PTE
&& pfn
< end_pfn
;
316 pte
++, pfn
++, pte_ofs
++, addr
+= PAGE_SIZE
) {
317 pgprot_t prot
= PAGE_KERNEL
;
319 * first pass will use the same initial
320 * identity mapping attribute.
322 pgprot_t init_prot
= __pgprot(PTE_IDENT_ATTR
);
324 if (is_kernel_text(addr
))
325 prot
= PAGE_KERNEL_EXEC
;
328 if (mapping_iter
== 1)
329 set_pte(pte
, pfn_pte(pfn
, init_prot
));
331 set_pte(pte
, pfn_pte(pfn
, prot
));
335 if (mapping_iter
== 1) {
337 * update direct mapping page count only in the first
340 update_page_count(PG_LEVEL_2M
, pages_2m
);
341 update_page_count(PG_LEVEL_4K
, pages_4k
);
344 * local global flush tlb, which will flush the previous
345 * mappings present in both small and large page TLB's.
350 * Second iteration will set the actual desired PTE attributes.
358 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
359 * is valid. The argument is a physical page number.
362 * On x86, access has to be given to the first megabyte of ram because that area
363 * contains bios code and data regions used by X and dosemu and similar apps.
364 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
365 * mmio resources as well as potential bios/acpi data regions.
367 int devmem_is_allowed(unsigned long pagenr
)
371 if (iomem_is_exclusive(pagenr
<< PAGE_SHIFT
))
373 if (!page_is_ram(pagenr
))
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
, int pfn
)
421 ClearPageReserved(page
);
422 init_page_count(page
);
427 struct add_highpages_data
{
428 unsigned long start_pfn
;
429 unsigned long end_pfn
;
432 static int __init
add_highpages_work_fn(unsigned long start_pfn
,
433 unsigned long end_pfn
, void *datax
)
437 unsigned long final_start_pfn
, final_end_pfn
;
438 struct add_highpages_data
*data
;
440 data
= (struct add_highpages_data
*)datax
;
442 final_start_pfn
= max(start_pfn
, data
->start_pfn
);
443 final_end_pfn
= min(end_pfn
, data
->end_pfn
);
444 if (final_start_pfn
>= final_end_pfn
)
447 for (node_pfn
= final_start_pfn
; node_pfn
< final_end_pfn
;
449 if (!pfn_valid(node_pfn
))
451 page
= pfn_to_page(node_pfn
);
452 add_one_highpage_init(page
, node_pfn
);
459 void __init
add_highpages_with_active_regions(int nid
, unsigned long start_pfn
,
460 unsigned long end_pfn
)
462 struct add_highpages_data data
;
464 data
.start_pfn
= start_pfn
;
465 data
.end_pfn
= end_pfn
;
467 work_with_active_regions(nid
, add_highpages_work_fn
, &data
);
471 static inline void permanent_kmaps_init(pgd_t
*pgd_base
)
474 #endif /* CONFIG_HIGHMEM */
476 void __init
native_pagetable_setup_start(pgd_t
*base
)
478 unsigned long pfn
, va
;
485 * Remove any mappings which extend past the end of physical
486 * memory from the boot time page table:
488 for (pfn
= max_low_pfn
+ 1; pfn
< 1<<(32-PAGE_SHIFT
); pfn
++) {
489 va
= PAGE_OFFSET
+ (pfn
<<PAGE_SHIFT
);
490 pgd
= base
+ pgd_index(va
);
491 if (!pgd_present(*pgd
))
494 pud
= pud_offset(pgd
, va
);
495 pmd
= pmd_offset(pud
, va
);
496 if (!pmd_present(*pmd
))
499 pte
= pte_offset_kernel(pmd
, va
);
500 if (!pte_present(*pte
))
503 pte_clear(NULL
, va
, pte
);
505 paravirt_alloc_pmd(&init_mm
, __pa(base
) >> PAGE_SHIFT
);
508 void __init
native_pagetable_setup_done(pgd_t
*base
)
513 * Build a proper pagetable for the kernel mappings. Up until this
514 * point, we've been running on some set of pagetables constructed by
517 * If we're booting on native hardware, this will be a pagetable
518 * constructed in arch/x86/kernel/head_32.S. The root of the
519 * pagetable will be swapper_pg_dir.
521 * If we're booting paravirtualized under a hypervisor, then there are
522 * more options: we may already be running PAE, and the pagetable may
523 * or may not be based in swapper_pg_dir. In any case,
524 * paravirt_pagetable_setup_start() will set up swapper_pg_dir
525 * appropriately for the rest of the initialization to work.
527 * In general, pagetable_init() assumes that the pagetable may already
528 * be partially populated, and so it avoids stomping on any existing
531 static void __init
early_ioremap_page_table_range_init(pgd_t
*pgd_base
)
533 unsigned long vaddr
, end
;
536 * Fixed mappings, only the page table structure has to be
537 * created - mappings will be set by set_fixmap():
539 vaddr
= __fix_to_virt(__end_of_fixed_addresses
- 1) & PMD_MASK
;
540 end
= (FIXADDR_TOP
+ PMD_SIZE
- 1) & PMD_MASK
;
541 page_table_range_init(vaddr
, end
, pgd_base
);
542 early_ioremap_reset();
545 static void __init
pagetable_init(void)
547 pgd_t
*pgd_base
= swapper_pg_dir
;
549 permanent_kmaps_init(pgd_base
);
552 #ifdef CONFIG_ACPI_SLEEP
554 * ACPI suspend needs this for resume, because things like the intel-agp
555 * driver might have split up a kernel 4MB mapping.
557 char swsusp_pg_dir
[PAGE_SIZE
]
558 __attribute__ ((aligned(PAGE_SIZE
)));
560 static inline void save_pg_dir(void)
562 memcpy(swsusp_pg_dir
, swapper_pg_dir
, PAGE_SIZE
);
564 #else /* !CONFIG_ACPI_SLEEP */
565 static inline void save_pg_dir(void)
568 #endif /* !CONFIG_ACPI_SLEEP */
570 void zap_low_mappings(void)
575 * Zap initial low-memory mappings.
577 * Note that "pgd_clear()" doesn't do it for
578 * us, because pgd_clear() is a no-op on i386.
580 for (i
= 0; i
< KERNEL_PGD_BOUNDARY
; i
++) {
581 #ifdef CONFIG_X86_PAE
582 set_pgd(swapper_pg_dir
+i
, __pgd(1 + __pa(empty_zero_page
)));
584 set_pgd(swapper_pg_dir
+i
, __pgd(0));
592 pteval_t __supported_pte_mask __read_mostly
= ~(_PAGE_NX
| _PAGE_GLOBAL
| _PAGE_IOMAP
);
593 EXPORT_SYMBOL_GPL(__supported_pte_mask
);
595 #ifdef CONFIG_X86_PAE
597 static int disable_nx __initdata
;
602 * Control non executable mappings.
607 static int __init
noexec_setup(char *str
)
609 if (!str
|| !strcmp(str
, "on")) {
611 __supported_pte_mask
|= _PAGE_NX
;
615 if (!strcmp(str
, "off")) {
617 __supported_pte_mask
&= ~_PAGE_NX
;
625 early_param("noexec", noexec_setup
);
627 static void __init
set_nx(void)
629 unsigned int v
[4], l
, h
;
631 if (cpu_has_pae
&& (cpuid_eax(0x80000000) > 0x80000001)) {
632 cpuid(0x80000001, &v
[0], &v
[1], &v
[2], &v
[3]);
634 if ((v
[3] & (1 << 20)) && !disable_nx
) {
635 rdmsr(MSR_EFER
, l
, h
);
637 wrmsr(MSR_EFER
, l
, h
);
639 __supported_pte_mask
|= _PAGE_NX
;
645 /* user-defined highmem size */
646 static unsigned int highmem_pages
= -1;
649 * highmem=size forces highmem to be exactly 'size' bytes.
650 * This works even on boxes that have no highmem otherwise.
651 * This also works to reduce highmem size on bigger boxes.
653 static int __init
parse_highmem(char *arg
)
658 highmem_pages
= memparse(arg
, &arg
) >> PAGE_SHIFT
;
661 early_param("highmem", parse_highmem
);
663 #define MSG_HIGHMEM_TOO_BIG \
664 "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
666 #define MSG_LOWMEM_TOO_SMALL \
667 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
669 * All of RAM fits into lowmem - but if user wants highmem
670 * artificially via the highmem=x boot parameter then create
673 void __init
lowmem_pfn_init(void)
675 /* max_low_pfn is 0, we already have early_res support */
676 max_low_pfn
= max_pfn
;
678 if (highmem_pages
== -1)
680 #ifdef CONFIG_HIGHMEM
681 if (highmem_pages
>= max_pfn
) {
682 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG
,
683 pages_to_mb(highmem_pages
), pages_to_mb(max_pfn
));
687 if (max_low_pfn
- highmem_pages
< 64*1024*1024/PAGE_SIZE
) {
688 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL
,
689 pages_to_mb(highmem_pages
));
692 max_low_pfn
-= highmem_pages
;
696 printk(KERN_ERR
"ignoring highmem size on non-highmem kernel!\n");
700 #define MSG_HIGHMEM_TOO_SMALL \
701 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
703 #define MSG_HIGHMEM_TRIMMED \
704 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
706 * We have more RAM than fits into lowmem - we try to put it into
707 * highmem, also taking the highmem=x boot parameter into account:
709 void __init
highmem_pfn_init(void)
711 max_low_pfn
= MAXMEM_PFN
;
713 if (highmem_pages
== -1)
714 highmem_pages
= max_pfn
- MAXMEM_PFN
;
716 if (highmem_pages
+ MAXMEM_PFN
< max_pfn
)
717 max_pfn
= MAXMEM_PFN
+ highmem_pages
;
719 if (highmem_pages
+ MAXMEM_PFN
> max_pfn
) {
720 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL
,
721 pages_to_mb(max_pfn
- MAXMEM_PFN
),
722 pages_to_mb(highmem_pages
));
725 #ifndef CONFIG_HIGHMEM
726 /* Maximum memory usable is what is directly addressable */
727 printk(KERN_WARNING
"Warning only %ldMB will be used.\n", MAXMEM
>>20);
728 if (max_pfn
> MAX_NONPAE_PFN
)
729 printk(KERN_WARNING
"Use a HIGHMEM64G enabled kernel.\n");
731 printk(KERN_WARNING
"Use a HIGHMEM enabled kernel.\n");
732 max_pfn
= MAXMEM_PFN
;
733 #else /* !CONFIG_HIGHMEM */
734 #ifndef CONFIG_HIGHMEM64G
735 if (max_pfn
> MAX_NONPAE_PFN
) {
736 max_pfn
= MAX_NONPAE_PFN
;
737 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED
);
739 #endif /* !CONFIG_HIGHMEM64G */
740 #endif /* !CONFIG_HIGHMEM */
744 * Determine low and high memory ranges:
746 void __init
find_low_pfn_range(void)
748 /* it could update max_pfn */
750 if (max_pfn
<= MAXMEM_PFN
)
756 #ifndef CONFIG_NEED_MULTIPLE_NODES
757 void __init
initmem_init(unsigned long start_pfn
,
758 unsigned long end_pfn
)
760 #ifdef CONFIG_HIGHMEM
761 highstart_pfn
= highend_pfn
= max_pfn
;
762 if (max_pfn
> max_low_pfn
)
763 highstart_pfn
= max_low_pfn
;
764 memory_present(0, 0, highend_pfn
);
765 e820_register_active_regions(0, 0, highend_pfn
);
766 printk(KERN_NOTICE
"%ldMB HIGHMEM available.\n",
767 pages_to_mb(highend_pfn
- highstart_pfn
));
768 num_physpages
= highend_pfn
;
769 high_memory
= (void *) __va(highstart_pfn
* PAGE_SIZE
- 1) + 1;
771 memory_present(0, 0, max_low_pfn
);
772 e820_register_active_regions(0, 0, max_low_pfn
);
773 num_physpages
= max_low_pfn
;
774 high_memory
= (void *) __va(max_low_pfn
* PAGE_SIZE
- 1) + 1;
776 #ifdef CONFIG_FLATMEM
777 max_mapnr
= num_physpages
;
779 printk(KERN_NOTICE
"%ldMB LOWMEM available.\n",
780 pages_to_mb(max_low_pfn
));
782 setup_bootmem_allocator();
784 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
786 static void __init
zone_sizes_init(void)
788 unsigned long max_zone_pfns
[MAX_NR_ZONES
];
789 memset(max_zone_pfns
, 0, sizeof(max_zone_pfns
));
790 max_zone_pfns
[ZONE_DMA
] =
791 virt_to_phys((char *)MAX_DMA_ADDRESS
) >> PAGE_SHIFT
;
792 max_zone_pfns
[ZONE_NORMAL
] = max_low_pfn
;
793 #ifdef CONFIG_HIGHMEM
794 max_zone_pfns
[ZONE_HIGHMEM
] = highend_pfn
;
797 free_area_init_nodes(max_zone_pfns
);
800 void __init
setup_bootmem_allocator(void)
803 unsigned long bootmap_size
, bootmap
;
805 * Initialize the boot-time allocator (with low memory only):
807 bootmap_size
= bootmem_bootmap_pages(max_low_pfn
)<<PAGE_SHIFT
;
808 bootmap
= find_e820_area(min_low_pfn
<<PAGE_SHIFT
,
809 max_pfn_mapped
<<PAGE_SHIFT
, bootmap_size
,
812 panic("Cannot find bootmem map of size %ld\n", bootmap_size
);
813 reserve_early(bootmap
, bootmap
+ bootmap_size
, "BOOTMAP");
815 /* don't touch min_low_pfn */
816 bootmap_size
= init_bootmem_node(NODE_DATA(0), bootmap
>> PAGE_SHIFT
,
817 min_low_pfn
, max_low_pfn
);
818 printk(KERN_INFO
" mapped low ram: 0 - %08lx\n",
819 max_pfn_mapped
<<PAGE_SHIFT
);
820 printk(KERN_INFO
" low ram: %08lx - %08lx\n",
821 min_low_pfn
<<PAGE_SHIFT
, max_low_pfn
<<PAGE_SHIFT
);
822 printk(KERN_INFO
" bootmap %08lx - %08lx\n",
823 bootmap
, bootmap
+ bootmap_size
);
824 for_each_online_node(i
)
825 free_bootmem_with_active_regions(i
, max_low_pfn
);
826 early_res_to_bootmem(0, max_low_pfn
<<PAGE_SHIFT
);
828 after_init_bootmem
= 1;
831 static void __init
find_early_table_space(unsigned long end
, int use_pse
)
833 unsigned long puds
, pmds
, ptes
, tables
, start
;
835 puds
= (end
+ PUD_SIZE
- 1) >> PUD_SHIFT
;
836 tables
= roundup(puds
* sizeof(pud_t
), PAGE_SIZE
);
838 pmds
= (end
+ PMD_SIZE
- 1) >> PMD_SHIFT
;
839 tables
+= roundup(pmds
* sizeof(pmd_t
), PAGE_SIZE
);
844 extra
= end
- ((end
>>PMD_SHIFT
) << PMD_SHIFT
);
846 ptes
= (extra
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
848 ptes
= (end
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
850 tables
+= roundup(ptes
* sizeof(pte_t
), PAGE_SIZE
);
853 tables
+= roundup(__end_of_fixed_addresses
* sizeof(pte_t
), PAGE_SIZE
);
856 * RED-PEN putting page tables only on node 0 could
857 * cause a hotspot and fill up ZONE_DMA. The page tables
858 * need roughly 0.5KB per GB.
861 table_start
= find_e820_area(start
, max_pfn_mapped
<<PAGE_SHIFT
,
863 if (table_start
== -1UL)
864 panic("Cannot find space for the kernel page tables");
866 table_start
>>= PAGE_SHIFT
;
867 table_end
= table_start
;
868 table_top
= table_start
+ (tables
>>PAGE_SHIFT
);
870 printk(KERN_DEBUG
"kernel direct mapping tables up to %lx @ %lx-%lx\n",
871 end
, table_start
<< PAGE_SHIFT
,
872 (table_start
<< PAGE_SHIFT
) + tables
);
875 unsigned long __init_refok
init_memory_mapping(unsigned long start
,
878 pgd_t
*pgd_base
= swapper_pg_dir
;
879 unsigned long start_pfn
, end_pfn
;
880 unsigned long big_page_start
;
881 #ifdef CONFIG_DEBUG_PAGEALLOC
883 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
884 * This will simplify cpa(), which otherwise needs to support splitting
885 * large pages into small in interrupt context, etc.
889 int use_pse
= cpu_has_pse
;
893 * Find space for the kernel direct mapping tables.
895 if (!after_init_bootmem
)
896 find_early_table_space(end
, use_pse
);
898 #ifdef CONFIG_X86_PAE
901 printk(KERN_INFO
"NX (Execute Disable) protection: active\n");
904 /* Enable PSE if available */
906 set_in_cr4(X86_CR4_PSE
);
908 /* Enable PGE if available */
910 set_in_cr4(X86_CR4_PGE
);
911 __supported_pte_mask
|= _PAGE_GLOBAL
;
915 * Don't use a large page for the first 2/4MB of memory
916 * because there are often fixed size MTRRs in there
917 * and overlapping MTRRs into large pages can cause
920 big_page_start
= PMD_SIZE
;
922 if (start
< big_page_start
) {
923 start_pfn
= start
>> PAGE_SHIFT
;
924 end_pfn
= min(big_page_start
>>PAGE_SHIFT
, end
>>PAGE_SHIFT
);
926 /* head is not big page alignment ? */
927 start_pfn
= start
>> PAGE_SHIFT
;
928 end_pfn
= ((start
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
929 << (PMD_SHIFT
- PAGE_SHIFT
);
931 if (start_pfn
< end_pfn
)
932 kernel_physical_mapping_init(pgd_base
, start_pfn
, end_pfn
, 0);
935 start_pfn
= ((start
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
936 << (PMD_SHIFT
- PAGE_SHIFT
);
937 if (start_pfn
< (big_page_start
>> PAGE_SHIFT
))
938 start_pfn
= big_page_start
>> PAGE_SHIFT
;
939 end_pfn
= (end
>>PMD_SHIFT
) << (PMD_SHIFT
- PAGE_SHIFT
);
940 if (start_pfn
< end_pfn
)
941 kernel_physical_mapping_init(pgd_base
, start_pfn
, end_pfn
,
944 /* tail is not big page alignment ? */
946 if (start_pfn
> (big_page_start
>>PAGE_SHIFT
)) {
947 end_pfn
= end
>> PAGE_SHIFT
;
948 if (start_pfn
< end_pfn
)
949 kernel_physical_mapping_init(pgd_base
, start_pfn
,
953 early_ioremap_page_table_range_init(pgd_base
);
955 load_cr3(swapper_pg_dir
);
959 if (!after_init_bootmem
)
960 reserve_early(table_start
<< PAGE_SHIFT
,
961 table_end
<< PAGE_SHIFT
, "PGTABLE");
963 if (!after_init_bootmem
)
964 early_memtest(start
, end
);
966 return end
>> PAGE_SHIFT
;
971 * paging_init() sets up the page tables - note that the first 8MB are
972 * already mapped by head.S.
974 * This routines also unmaps the page at virtual kernel address 0, so
975 * that we can trap those pesky NULL-reference errors in the kernel.
977 void __init
paging_init(void)
986 * NOTE: at this point the bootmem allocator is fully available.
993 * Test if the WP bit works in supervisor mode. It isn't supported on 386's
994 * and also on some strange 486's. All 586+'s are OK. This used to involve
995 * black magic jumps to work around some nasty CPU bugs, but fortunately the
996 * switch to using exceptions got rid of all that.
998 static void __init
test_wp_bit(void)
1001 "Checking if this processor honours the WP bit even in supervisor mode...");
1003 /* Any page-aligned address will do, the test is non-destructive */
1004 __set_fixmap(FIX_WP_TEST
, __pa(&swapper_pg_dir
), PAGE_READONLY
);
1005 boot_cpu_data
.wp_works_ok
= do_test_wp_bit();
1006 clear_fixmap(FIX_WP_TEST
);
1008 if (!boot_cpu_data
.wp_works_ok
) {
1009 printk(KERN_CONT
"No.\n");
1010 #ifdef CONFIG_X86_WP_WORKS_OK
1012 "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
1015 printk(KERN_CONT
"Ok.\n");
1019 static struct kcore_list kcore_mem
, kcore_vmalloc
;
1021 void __init
mem_init(void)
1023 int codesize
, reservedpages
, datasize
, initsize
;
1028 #ifdef CONFIG_FLATMEM
1031 /* this will put all low memory onto the freelists */
1032 totalram_pages
+= free_all_bootmem();
1035 for (tmp
= 0; tmp
< max_low_pfn
; tmp
++)
1037 * Only count reserved RAM pages:
1039 if (page_is_ram(tmp
) && PageReserved(pfn_to_page(tmp
)))
1042 set_highmem_pages_init();
1044 codesize
= (unsigned long) &_etext
- (unsigned long) &_text
;
1045 datasize
= (unsigned long) &_edata
- (unsigned long) &_etext
;
1046 initsize
= (unsigned long) &__init_end
- (unsigned long) &__init_begin
;
1048 kclist_add(&kcore_mem
, __va(0), max_low_pfn
<< PAGE_SHIFT
);
1049 kclist_add(&kcore_vmalloc
, (void *)VMALLOC_START
,
1050 VMALLOC_END
-VMALLOC_START
);
1052 printk(KERN_INFO
"Memory: %luk/%luk available (%dk kernel code, "
1053 "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
1054 (unsigned long) nr_free_pages() << (PAGE_SHIFT
-10),
1055 num_physpages
<< (PAGE_SHIFT
-10),
1057 reservedpages
<< (PAGE_SHIFT
-10),
1060 (unsigned long) (totalhigh_pages
<< (PAGE_SHIFT
-10))
1063 printk(KERN_INFO
"virtual kernel memory layout:\n"
1064 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
1065 #ifdef CONFIG_HIGHMEM
1066 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
1068 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
1069 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
1070 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
1071 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
1072 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
1073 FIXADDR_START
, FIXADDR_TOP
,
1074 (FIXADDR_TOP
- FIXADDR_START
) >> 10,
1076 #ifdef CONFIG_HIGHMEM
1077 PKMAP_BASE
, PKMAP_BASE
+LAST_PKMAP
*PAGE_SIZE
,
1078 (LAST_PKMAP
*PAGE_SIZE
) >> 10,
1081 VMALLOC_START
, VMALLOC_END
,
1082 (VMALLOC_END
- VMALLOC_START
) >> 20,
1084 (unsigned long)__va(0), (unsigned long)high_memory
,
1085 ((unsigned long)high_memory
- (unsigned long)__va(0)) >> 20,
1087 (unsigned long)&__init_begin
, (unsigned long)&__init_end
,
1088 ((unsigned long)&__init_end
-
1089 (unsigned long)&__init_begin
) >> 10,
1091 (unsigned long)&_etext
, (unsigned long)&_edata
,
1092 ((unsigned long)&_edata
- (unsigned long)&_etext
) >> 10,
1094 (unsigned long)&_text
, (unsigned long)&_etext
,
1095 ((unsigned long)&_etext
- (unsigned long)&_text
) >> 10);
1098 * Check boundaries twice: Some fundamental inconsistencies can
1099 * be detected at build time already.
1101 #define __FIXADDR_TOP (-PAGE_SIZE)
1102 #ifdef CONFIG_HIGHMEM
1103 BUILD_BUG_ON(PKMAP_BASE
+ LAST_PKMAP
*PAGE_SIZE
> FIXADDR_START
);
1104 BUILD_BUG_ON(VMALLOC_END
> PKMAP_BASE
);
1106 #define high_memory (-128UL << 20)
1107 BUILD_BUG_ON(VMALLOC_START
>= VMALLOC_END
);
1109 #undef __FIXADDR_TOP
1111 #ifdef CONFIG_HIGHMEM
1112 BUG_ON(PKMAP_BASE
+ LAST_PKMAP
*PAGE_SIZE
> FIXADDR_START
);
1113 BUG_ON(VMALLOC_END
> PKMAP_BASE
);
1115 BUG_ON(VMALLOC_START
>= VMALLOC_END
);
1116 BUG_ON((unsigned long)high_memory
> VMALLOC_START
);
1118 if (boot_cpu_data
.wp_works_ok
< 0)
1125 #ifdef CONFIG_MEMORY_HOTPLUG
1126 int arch_add_memory(int nid
, u64 start
, u64 size
)
1128 struct pglist_data
*pgdata
= NODE_DATA(nid
);
1129 struct zone
*zone
= pgdata
->node_zones
+ ZONE_HIGHMEM
;
1130 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
1131 unsigned long nr_pages
= size
>> PAGE_SHIFT
;
1133 return __add_pages(nid
, zone
, start_pfn
, nr_pages
);
1138 * This function cannot be __init, since exceptions don't work in that
1139 * section. Put this after the callers, so that it cannot be inlined.
1141 static noinline
int do_test_wp_bit(void)
1146 __asm__
__volatile__(
1152 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST
)),
1161 #ifdef CONFIG_DEBUG_RODATA
1162 const int rodata_test_data
= 0xC3;
1163 EXPORT_SYMBOL_GPL(rodata_test_data
);
1165 void mark_rodata_ro(void)
1167 unsigned long start
= PFN_ALIGN(_text
);
1168 unsigned long size
= PFN_ALIGN(_etext
) - start
;
1170 #ifndef CONFIG_DYNAMIC_FTRACE
1171 /* Dynamic tracing modifies the kernel text section */
1172 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);
1173 printk(KERN_INFO
"Write protecting the kernel text: %luk\n",
1176 #ifdef CONFIG_CPA_DEBUG
1177 printk(KERN_INFO
"Testing CPA: Reverting %lx-%lx\n",
1179 set_pages_rw(virt_to_page(start
), size
>>PAGE_SHIFT
);
1181 printk(KERN_INFO
"Testing CPA: write protecting again\n");
1182 set_pages_ro(virt_to_page(start
), size
>>PAGE_SHIFT
);
1184 #endif /* CONFIG_DYNAMIC_FTRACE */
1187 size
= (unsigned long)__end_rodata
- start
;
1188 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);
1189 printk(KERN_INFO
"Write protecting the kernel read-only data: %luk\n",
1193 #ifdef CONFIG_CPA_DEBUG
1194 printk(KERN_INFO
"Testing CPA: undo %lx-%lx\n", start
, start
+ size
);
1195 set_pages_rw(virt_to_page(start
), size
>> PAGE_SHIFT
);
1197 printk(KERN_INFO
"Testing CPA: write protecting again\n");
1198 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);
1203 #ifdef CONFIG_BLK_DEV_INITRD
1204 void free_initrd_mem(unsigned long start
, unsigned long end
)
1206 free_init_pages("initrd memory", start
, end
);
1210 int __init
reserve_bootmem_generic(unsigned long phys
, unsigned long len
,
1213 return reserve_bootmem(phys
, len
, flags
);