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/pfn.h>
25 #include <linux/poison.h>
26 #include <linux/bootmem.h>
27 #include <linux/slab.h>
28 #include <linux/proc_fs.h>
29 #include <linux/memory_hotplug.h>
30 #include <linux/initrd.h>
31 #include <linux/cpumask.h>
34 #include <asm/processor.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/pgtable.h>
39 #include <asm/fixmap.h>
44 #include <asm/tlbflush.h>
45 #include <asm/pgalloc.h>
46 #include <asm/sections.h>
47 #include <asm/paravirt.h>
48 #include <asm/setup.h>
49 #include <asm/cacheflush.h>
52 unsigned int __VMALLOC_RESERVE
= 128 << 20;
54 unsigned long max_low_pfn_mapped
;
55 unsigned long max_pfn_mapped
;
57 DEFINE_PER_CPU(struct mmu_gather
, mmu_gathers
);
58 unsigned long highstart_pfn
, highend_pfn
;
60 static noinline
int do_test_wp_bit(void);
63 static unsigned long __initdata table_start
;
64 static unsigned long __meminitdata table_end
;
65 static unsigned long __meminitdata table_top
;
67 static int __initdata after_init_bootmem
;
69 static __init
void *alloc_low_page(unsigned long *phys
)
71 unsigned long pfn
= table_end
++;
75 panic("alloc_low_page: ran out of memory");
77 adr
= __va(pfn
* PAGE_SIZE
);
78 memset(adr
, 0, PAGE_SIZE
);
79 *phys
= pfn
* PAGE_SIZE
;
84 * Creates a middle page table and puts a pointer to it in the
85 * given global directory entry. This only returns the gd entry
86 * in non-PAE compilation mode, since the middle layer is folded.
88 static pmd_t
* __init
one_md_table_init(pgd_t
*pgd
)
95 if (!(pgd_val(*pgd
) & _PAGE_PRESENT
)) {
96 if (after_init_bootmem
)
97 pmd_table
= (pmd_t
*)alloc_bootmem_low_pages(PAGE_SIZE
);
99 pmd_table
= (pmd_t
*)alloc_low_page(&phys
);
100 paravirt_alloc_pmd(&init_mm
, __pa(pmd_table
) >> PAGE_SHIFT
);
101 set_pgd(pgd
, __pgd(__pa(pmd_table
) | _PAGE_PRESENT
));
102 pud
= pud_offset(pgd
, 0);
103 BUG_ON(pmd_table
!= pmd_offset(pud
, 0));
106 pud
= pud_offset(pgd
, 0);
107 pmd_table
= pmd_offset(pud
, 0);
113 * Create a page table and place a pointer to it in a middle page
116 static pte_t
* __init
one_page_table_init(pmd_t
*pmd
)
118 if (!(pmd_val(*pmd
) & _PAGE_PRESENT
)) {
119 pte_t
*page_table
= NULL
;
121 if (after_init_bootmem
) {
122 #ifdef CONFIG_DEBUG_PAGEALLOC
123 page_table
= (pte_t
*) alloc_bootmem_pages(PAGE_SIZE
);
127 (pte_t
*)alloc_bootmem_low_pages(PAGE_SIZE
);
130 page_table
= (pte_t
*)alloc_low_page(&phys
);
133 paravirt_alloc_pte(&init_mm
, __pa(page_table
) >> PAGE_SHIFT
);
134 set_pmd(pmd
, __pmd(__pa(page_table
) | _PAGE_TABLE
));
135 BUG_ON(page_table
!= pte_offset_kernel(pmd
, 0));
138 return pte_offset_kernel(pmd
, 0);
142 * This function initializes a certain range of kernel virtual memory
143 * with new bootmem page tables, everywhere page tables are missing in
146 * NOTE: The pagetables are allocated contiguous on the physical space
147 * so we can cache the place of the first one and move around without
148 * checking the pgd every time.
151 page_table_range_init(unsigned long start
, unsigned long end
, pgd_t
*pgd_base
)
153 int pgd_idx
, pmd_idx
;
159 pgd_idx
= pgd_index(vaddr
);
160 pmd_idx
= pmd_index(vaddr
);
161 pgd
= pgd_base
+ pgd_idx
;
163 for ( ; (pgd_idx
< PTRS_PER_PGD
) && (vaddr
!= end
); pgd
++, pgd_idx
++) {
164 pmd
= one_md_table_init(pgd
);
165 pmd
= pmd
+ pmd_index(vaddr
);
166 for (; (pmd_idx
< PTRS_PER_PMD
) && (vaddr
!= end
);
168 one_page_table_init(pmd
);
176 static inline int is_kernel_text(unsigned long addr
)
178 if (addr
>= PAGE_OFFSET
&& addr
<= (unsigned long)__init_end
)
184 * This maps the physical memory to kernel virtual address space, a total
185 * of max_low_pfn pages, by creating page tables starting from address
188 static void __init
kernel_physical_mapping_init(pgd_t
*pgd_base
,
189 unsigned long start_pfn
,
190 unsigned long end_pfn
,
193 int pgd_idx
, pmd_idx
, pte_ofs
;
198 unsigned pages_2m
= 0, pages_4k
= 0;
204 pgd_idx
= pgd_index((pfn
<<PAGE_SHIFT
) + PAGE_OFFSET
);
205 pgd
= pgd_base
+ pgd_idx
;
206 for (; pgd_idx
< PTRS_PER_PGD
; pgd
++, pgd_idx
++) {
207 pmd
= one_md_table_init(pgd
);
211 #ifdef CONFIG_X86_PAE
212 pmd_idx
= pmd_index((pfn
<<PAGE_SHIFT
) + PAGE_OFFSET
);
217 for (; pmd_idx
< PTRS_PER_PMD
&& pfn
< end_pfn
;
219 unsigned int addr
= pfn
* PAGE_SIZE
+ PAGE_OFFSET
;
222 * Map with big pages if possible, otherwise
223 * create normal page tables:
227 pgprot_t prot
= PAGE_KERNEL_LARGE
;
229 addr2
= (pfn
+ PTRS_PER_PTE
-1) * PAGE_SIZE
+
230 PAGE_OFFSET
+ PAGE_SIZE
-1;
232 if (is_kernel_text(addr
) ||
233 is_kernel_text(addr2
))
234 prot
= PAGE_KERNEL_LARGE_EXEC
;
237 set_pmd(pmd
, pfn_pmd(pfn
, prot
));
242 pte
= one_page_table_init(pmd
);
244 pte_ofs
= pte_index((pfn
<<PAGE_SHIFT
) + PAGE_OFFSET
);
246 for (; pte_ofs
< PTRS_PER_PTE
&& pfn
< end_pfn
;
247 pte
++, pfn
++, pte_ofs
++, addr
+= PAGE_SIZE
) {
248 pgprot_t prot
= PAGE_KERNEL
;
250 if (is_kernel_text(addr
))
251 prot
= PAGE_KERNEL_EXEC
;
254 set_pte(pte
, pfn_pte(pfn
, prot
));
258 update_page_count(PG_LEVEL_2M
, pages_2m
);
259 update_page_count(PG_LEVEL_4K
, pages_4k
);
263 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
264 * is valid. The argument is a physical page number.
267 * On x86, access has to be given to the first megabyte of ram because that area
268 * contains bios code and data regions used by X and dosemu and similar apps.
269 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
270 * mmio resources as well as potential bios/acpi data regions.
272 int devmem_is_allowed(unsigned long pagenr
)
276 if (!page_is_ram(pagenr
))
281 #ifdef CONFIG_HIGHMEM
285 static inline pte_t
*kmap_get_fixmap_pte(unsigned long vaddr
)
287 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr
),
288 vaddr
), vaddr
), vaddr
);
291 static void __init
kmap_init(void)
293 unsigned long kmap_vstart
;
296 * Cache the first kmap pte:
298 kmap_vstart
= __fix_to_virt(FIX_KMAP_BEGIN
);
299 kmap_pte
= kmap_get_fixmap_pte(kmap_vstart
);
301 kmap_prot
= PAGE_KERNEL
;
304 static void __init
permanent_kmaps_init(pgd_t
*pgd_base
)
313 page_table_range_init(vaddr
, vaddr
+ PAGE_SIZE
*LAST_PKMAP
, pgd_base
);
315 pgd
= swapper_pg_dir
+ pgd_index(vaddr
);
316 pud
= pud_offset(pgd
, vaddr
);
317 pmd
= pmd_offset(pud
, vaddr
);
318 pte
= pte_offset_kernel(pmd
, vaddr
);
319 pkmap_page_table
= pte
;
322 static void __init
add_one_highpage_init(struct page
*page
, int pfn
)
324 ClearPageReserved(page
);
325 init_page_count(page
);
330 struct add_highpages_data
{
331 unsigned long start_pfn
;
332 unsigned long end_pfn
;
335 static int __init
add_highpages_work_fn(unsigned long start_pfn
,
336 unsigned long end_pfn
, void *datax
)
340 unsigned long final_start_pfn
, final_end_pfn
;
341 struct add_highpages_data
*data
;
343 data
= (struct add_highpages_data
*)datax
;
345 final_start_pfn
= max(start_pfn
, data
->start_pfn
);
346 final_end_pfn
= min(end_pfn
, data
->end_pfn
);
347 if (final_start_pfn
>= final_end_pfn
)
350 for (node_pfn
= final_start_pfn
; node_pfn
< final_end_pfn
;
352 if (!pfn_valid(node_pfn
))
354 page
= pfn_to_page(node_pfn
);
355 add_one_highpage_init(page
, node_pfn
);
362 void __init
add_highpages_with_active_regions(int nid
, unsigned long start_pfn
,
363 unsigned long end_pfn
)
365 struct add_highpages_data data
;
367 data
.start_pfn
= start_pfn
;
368 data
.end_pfn
= end_pfn
;
370 work_with_active_regions(nid
, add_highpages_work_fn
, &data
);
374 static void __init
set_highmem_pages_init(void)
376 add_highpages_with_active_regions(0, highstart_pfn
, highend_pfn
);
378 totalram_pages
+= totalhigh_pages
;
380 #endif /* !CONFIG_NUMA */
383 # define kmap_init() do { } while (0)
384 # define permanent_kmaps_init(pgd_base) do { } while (0)
385 # define set_highmem_pages_init() do { } while (0)
386 #endif /* CONFIG_HIGHMEM */
388 void __init
native_pagetable_setup_start(pgd_t
*base
)
390 unsigned long pfn
, va
;
397 * Remove any mappings which extend past the end of physical
398 * memory from the boot time page table:
400 for (pfn
= max_low_pfn
+ 1; pfn
< 1<<(32-PAGE_SHIFT
); pfn
++) {
401 va
= PAGE_OFFSET
+ (pfn
<<PAGE_SHIFT
);
402 pgd
= base
+ pgd_index(va
);
403 if (!pgd_present(*pgd
))
406 pud
= pud_offset(pgd
, va
);
407 pmd
= pmd_offset(pud
, va
);
408 if (!pmd_present(*pmd
))
411 pte
= pte_offset_kernel(pmd
, va
);
412 if (!pte_present(*pte
))
415 pte_clear(NULL
, va
, pte
);
417 paravirt_alloc_pmd(&init_mm
, __pa(base
) >> PAGE_SHIFT
);
420 void __init
native_pagetable_setup_done(pgd_t
*base
)
425 * Build a proper pagetable for the kernel mappings. Up until this
426 * point, we've been running on some set of pagetables constructed by
429 * If we're booting on native hardware, this will be a pagetable
430 * constructed in arch/x86/kernel/head_32.S. The root of the
431 * pagetable will be swapper_pg_dir.
433 * If we're booting paravirtualized under a hypervisor, then there are
434 * more options: we may already be running PAE, and the pagetable may
435 * or may not be based in swapper_pg_dir. In any case,
436 * paravirt_pagetable_setup_start() will set up swapper_pg_dir
437 * appropriately for the rest of the initialization to work.
439 * In general, pagetable_init() assumes that the pagetable may already
440 * be partially populated, and so it avoids stomping on any existing
443 static void __init
early_ioremap_page_table_range_init(pgd_t
*pgd_base
)
445 unsigned long vaddr
, end
;
448 * Fixed mappings, only the page table structure has to be
449 * created - mappings will be set by set_fixmap():
451 early_ioremap_clear();
452 vaddr
= __fix_to_virt(__end_of_fixed_addresses
- 1) & PMD_MASK
;
453 end
= (FIXADDR_TOP
+ PMD_SIZE
- 1) & PMD_MASK
;
454 page_table_range_init(vaddr
, end
, pgd_base
);
455 early_ioremap_reset();
458 static void __init
pagetable_init(void)
460 pgd_t
*pgd_base
= swapper_pg_dir
;
462 permanent_kmaps_init(pgd_base
);
465 #ifdef CONFIG_ACPI_SLEEP
467 * ACPI suspend needs this for resume, because things like the intel-agp
468 * driver might have split up a kernel 4MB mapping.
470 char swsusp_pg_dir
[PAGE_SIZE
]
471 __attribute__ ((aligned(PAGE_SIZE
)));
473 static inline void save_pg_dir(void)
475 memcpy(swsusp_pg_dir
, swapper_pg_dir
, PAGE_SIZE
);
477 #else /* !CONFIG_ACPI_SLEEP */
478 static inline void save_pg_dir(void)
481 #endif /* !CONFIG_ACPI_SLEEP */
483 void zap_low_mappings(void)
488 * Zap initial low-memory mappings.
490 * Note that "pgd_clear()" doesn't do it for
491 * us, because pgd_clear() is a no-op on i386.
493 for (i
= 0; i
< KERNEL_PGD_BOUNDARY
; i
++) {
494 #ifdef CONFIG_X86_PAE
495 set_pgd(swapper_pg_dir
+i
, __pgd(1 + __pa(empty_zero_page
)));
497 set_pgd(swapper_pg_dir
+i
, __pgd(0));
505 pteval_t __supported_pte_mask __read_mostly
= ~(_PAGE_NX
| _PAGE_GLOBAL
);
506 EXPORT_SYMBOL_GPL(__supported_pte_mask
);
508 #ifdef CONFIG_X86_PAE
510 static int disable_nx __initdata
;
515 * Control non executable mappings.
520 static int __init
noexec_setup(char *str
)
522 if (!str
|| !strcmp(str
, "on")) {
524 __supported_pte_mask
|= _PAGE_NX
;
528 if (!strcmp(str
, "off")) {
530 __supported_pte_mask
&= ~_PAGE_NX
;
538 early_param("noexec", noexec_setup
);
540 static void __init
set_nx(void)
542 unsigned int v
[4], l
, h
;
544 if (cpu_has_pae
&& (cpuid_eax(0x80000000) > 0x80000001)) {
545 cpuid(0x80000001, &v
[0], &v
[1], &v
[2], &v
[3]);
547 if ((v
[3] & (1 << 20)) && !disable_nx
) {
548 rdmsr(MSR_EFER
, l
, h
);
550 wrmsr(MSR_EFER
, l
, h
);
552 __supported_pte_mask
|= _PAGE_NX
;
558 /* user-defined highmem size */
559 static unsigned int highmem_pages
= -1;
562 * highmem=size forces highmem to be exactly 'size' bytes.
563 * This works even on boxes that have no highmem otherwise.
564 * This also works to reduce highmem size on bigger boxes.
566 static int __init
parse_highmem(char *arg
)
571 highmem_pages
= memparse(arg
, &arg
) >> PAGE_SHIFT
;
574 early_param("highmem", parse_highmem
);
577 * Determine low and high memory ranges:
579 void __init
find_low_pfn_range(void)
581 /* it could update max_pfn */
583 /* max_low_pfn is 0, we already have early_res support */
585 max_low_pfn
= max_pfn
;
586 if (max_low_pfn
> MAXMEM_PFN
) {
587 if (highmem_pages
== -1)
588 highmem_pages
= max_pfn
- MAXMEM_PFN
;
589 if (highmem_pages
+ MAXMEM_PFN
< max_pfn
)
590 max_pfn
= MAXMEM_PFN
+ highmem_pages
;
591 if (highmem_pages
+ MAXMEM_PFN
> max_pfn
) {
592 printk(KERN_WARNING
"only %luMB highmem pages "
593 "available, ignoring highmem size of %uMB.\n",
594 pages_to_mb(max_pfn
- MAXMEM_PFN
),
595 pages_to_mb(highmem_pages
));
598 max_low_pfn
= MAXMEM_PFN
;
599 #ifndef CONFIG_HIGHMEM
600 /* Maximum memory usable is what is directly addressable */
601 printk(KERN_WARNING
"Warning only %ldMB will be used.\n",
603 if (max_pfn
> MAX_NONPAE_PFN
)
605 "Use a HIGHMEM64G enabled kernel.\n");
607 printk(KERN_WARNING
"Use a HIGHMEM enabled kernel.\n");
608 max_pfn
= MAXMEM_PFN
;
609 #else /* !CONFIG_HIGHMEM */
610 #ifndef CONFIG_HIGHMEM64G
611 if (max_pfn
> MAX_NONPAE_PFN
) {
612 max_pfn
= MAX_NONPAE_PFN
;
613 printk(KERN_WARNING
"Warning only 4GB will be used."
614 "Use a HIGHMEM64G enabled kernel.\n");
616 #endif /* !CONFIG_HIGHMEM64G */
617 #endif /* !CONFIG_HIGHMEM */
619 if (highmem_pages
== -1)
621 #ifdef CONFIG_HIGHMEM
622 if (highmem_pages
>= max_pfn
) {
623 printk(KERN_ERR
"highmem size specified (%uMB) is "
624 "bigger than pages available (%luMB)!.\n",
625 pages_to_mb(highmem_pages
),
626 pages_to_mb(max_pfn
));
630 if (max_low_pfn
- highmem_pages
<
631 64*1024*1024/PAGE_SIZE
){
632 printk(KERN_ERR
"highmem size %uMB results in "
633 "smaller than 64MB lowmem, ignoring it.\n"
634 , pages_to_mb(highmem_pages
));
637 max_low_pfn
-= highmem_pages
;
641 printk(KERN_ERR
"ignoring highmem size on non-highmem"
647 #ifndef CONFIG_NEED_MULTIPLE_NODES
648 void __init
initmem_init(unsigned long start_pfn
,
649 unsigned long end_pfn
)
651 #ifdef CONFIG_HIGHMEM
652 highstart_pfn
= highend_pfn
= max_pfn
;
653 if (max_pfn
> max_low_pfn
)
654 highstart_pfn
= max_low_pfn
;
655 memory_present(0, 0, highend_pfn
);
656 e820_register_active_regions(0, 0, highend_pfn
);
657 printk(KERN_NOTICE
"%ldMB HIGHMEM available.\n",
658 pages_to_mb(highend_pfn
- highstart_pfn
));
659 num_physpages
= highend_pfn
;
660 high_memory
= (void *) __va(highstart_pfn
* PAGE_SIZE
- 1) + 1;
662 memory_present(0, 0, max_low_pfn
);
663 e820_register_active_regions(0, 0, max_low_pfn
);
664 num_physpages
= max_low_pfn
;
665 high_memory
= (void *) __va(max_low_pfn
* PAGE_SIZE
- 1) + 1;
667 #ifdef CONFIG_FLATMEM
668 max_mapnr
= num_physpages
;
670 printk(KERN_NOTICE
"%ldMB LOWMEM available.\n",
671 pages_to_mb(max_low_pfn
));
673 setup_bootmem_allocator();
675 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
677 static void __init
zone_sizes_init(void)
679 unsigned long max_zone_pfns
[MAX_NR_ZONES
];
680 memset(max_zone_pfns
, 0, sizeof(max_zone_pfns
));
681 max_zone_pfns
[ZONE_DMA
] =
682 virt_to_phys((char *)MAX_DMA_ADDRESS
) >> PAGE_SHIFT
;
683 max_zone_pfns
[ZONE_NORMAL
] = max_low_pfn
;
684 #ifdef CONFIG_HIGHMEM
685 max_zone_pfns
[ZONE_HIGHMEM
] = highend_pfn
;
688 free_area_init_nodes(max_zone_pfns
);
691 void __init
setup_bootmem_allocator(void)
694 unsigned long bootmap_size
, bootmap
;
696 * Initialize the boot-time allocator (with low memory only):
698 bootmap_size
= bootmem_bootmap_pages(max_low_pfn
)<<PAGE_SHIFT
;
699 bootmap
= find_e820_area(min_low_pfn
<<PAGE_SHIFT
,
700 max_pfn_mapped
<<PAGE_SHIFT
, bootmap_size
,
703 panic("Cannot find bootmem map of size %ld\n", bootmap_size
);
704 reserve_early(bootmap
, bootmap
+ bootmap_size
, "BOOTMAP");
706 /* don't touch min_low_pfn */
707 bootmap_size
= init_bootmem_node(NODE_DATA(0), bootmap
>> PAGE_SHIFT
,
708 min_low_pfn
, max_low_pfn
);
709 printk(KERN_INFO
" mapped low ram: 0 - %08lx\n",
710 max_pfn_mapped
<<PAGE_SHIFT
);
711 printk(KERN_INFO
" low ram: %08lx - %08lx\n",
712 min_low_pfn
<<PAGE_SHIFT
, max_low_pfn
<<PAGE_SHIFT
);
713 printk(KERN_INFO
" bootmap %08lx - %08lx\n",
714 bootmap
, bootmap
+ bootmap_size
);
715 for_each_online_node(i
)
716 free_bootmem_with_active_regions(i
, max_low_pfn
);
717 early_res_to_bootmem(0, max_low_pfn
<<PAGE_SHIFT
);
719 after_init_bootmem
= 1;
722 static void __init
find_early_table_space(unsigned long end
)
724 unsigned long puds
, pmds
, ptes
, tables
, start
;
726 puds
= (end
+ PUD_SIZE
- 1) >> PUD_SHIFT
;
727 tables
= PAGE_ALIGN(puds
* sizeof(pud_t
));
729 pmds
= (end
+ PMD_SIZE
- 1) >> PMD_SHIFT
;
730 tables
+= PAGE_ALIGN(pmds
* sizeof(pmd_t
));
735 extra
= end
- ((end
>>PMD_SHIFT
) << PMD_SHIFT
);
737 ptes
= (extra
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
739 ptes
= (end
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
741 tables
+= PAGE_ALIGN(ptes
* sizeof(pte_t
));
744 tables
+= PAGE_SIZE
* 2;
747 * RED-PEN putting page tables only on node 0 could
748 * cause a hotspot and fill up ZONE_DMA. The page tables
749 * need roughly 0.5KB per GB.
752 table_start
= find_e820_area(start
, max_pfn_mapped
<<PAGE_SHIFT
,
754 if (table_start
== -1UL)
755 panic("Cannot find space for the kernel page tables");
757 table_start
>>= PAGE_SHIFT
;
758 table_end
= table_start
;
759 table_top
= table_start
+ (tables
>>PAGE_SHIFT
);
761 printk(KERN_DEBUG
"kernel direct mapping tables up to %lx @ %lx-%lx\n",
762 end
, table_start
<< PAGE_SHIFT
,
763 (table_start
<< PAGE_SHIFT
) + tables
);
766 unsigned long __init_refok
init_memory_mapping(unsigned long start
,
769 pgd_t
*pgd_base
= swapper_pg_dir
;
770 unsigned long start_pfn
, end_pfn
;
771 unsigned long big_page_start
;
774 * Find space for the kernel direct mapping tables.
776 if (!after_init_bootmem
)
777 find_early_table_space(end
);
779 #ifdef CONFIG_X86_PAE
782 printk(KERN_INFO
"NX (Execute Disable) protection: active\n");
785 /* Enable PSE if available */
787 set_in_cr4(X86_CR4_PSE
);
789 /* Enable PGE if available */
791 set_in_cr4(X86_CR4_PGE
);
792 __supported_pte_mask
|= _PAGE_GLOBAL
;
796 * Don't use a large page for the first 2/4MB of memory
797 * because there are often fixed size MTRRs in there
798 * and overlapping MTRRs into large pages can cause
801 big_page_start
= PMD_SIZE
;
803 if (start
< big_page_start
) {
804 start_pfn
= start
>> PAGE_SHIFT
;
805 end_pfn
= min(big_page_start
>>PAGE_SHIFT
, end
>>PAGE_SHIFT
);
807 /* head is not big page alignment ? */
808 start_pfn
= start
>> PAGE_SHIFT
;
809 end_pfn
= ((start
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
810 << (PMD_SHIFT
- PAGE_SHIFT
);
812 if (start_pfn
< end_pfn
)
813 kernel_physical_mapping_init(pgd_base
, start_pfn
, end_pfn
, 0);
816 start_pfn
= ((start
+ (PMD_SIZE
- 1))>>PMD_SHIFT
)
817 << (PMD_SHIFT
- PAGE_SHIFT
);
818 if (start_pfn
< (big_page_start
>> PAGE_SHIFT
))
819 start_pfn
= big_page_start
>> PAGE_SHIFT
;
820 end_pfn
= (end
>>PMD_SHIFT
) << (PMD_SHIFT
- PAGE_SHIFT
);
821 if (start_pfn
< end_pfn
)
822 kernel_physical_mapping_init(pgd_base
, start_pfn
, end_pfn
,
825 /* tail is not big page alignment ? */
827 if (start_pfn
> (big_page_start
>>PAGE_SHIFT
)) {
828 end_pfn
= end
>> PAGE_SHIFT
;
829 if (start_pfn
< end_pfn
)
830 kernel_physical_mapping_init(pgd_base
, start_pfn
,
834 early_ioremap_page_table_range_init(pgd_base
);
836 load_cr3(swapper_pg_dir
);
840 if (!after_init_bootmem
)
841 reserve_early(table_start
<< PAGE_SHIFT
,
842 table_end
<< PAGE_SHIFT
, "PGTABLE");
844 if (!after_init_bootmem
)
845 early_memtest(start
, end
);
847 return end
>> PAGE_SHIFT
;
852 * paging_init() sets up the page tables - note that the first 8MB are
853 * already mapped by head.S.
855 * This routines also unmaps the page at virtual kernel address 0, so
856 * that we can trap those pesky NULL-reference errors in the kernel.
858 void __init
paging_init(void)
867 * NOTE: at this point the bootmem allocator is fully available.
874 * Test if the WP bit works in supervisor mode. It isn't supported on 386's
875 * and also on some strange 486's. All 586+'s are OK. This used to involve
876 * black magic jumps to work around some nasty CPU bugs, but fortunately the
877 * switch to using exceptions got rid of all that.
879 static void __init
test_wp_bit(void)
882 "Checking if this processor honours the WP bit even in supervisor mode...");
884 /* Any page-aligned address will do, the test is non-destructive */
885 __set_fixmap(FIX_WP_TEST
, __pa(&swapper_pg_dir
), PAGE_READONLY
);
886 boot_cpu_data
.wp_works_ok
= do_test_wp_bit();
887 clear_fixmap(FIX_WP_TEST
);
889 if (!boot_cpu_data
.wp_works_ok
) {
890 printk(KERN_CONT
"No.\n");
891 #ifdef CONFIG_X86_WP_WORKS_OK
893 "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
896 printk(KERN_CONT
"Ok.\n");
900 static struct kcore_list kcore_mem
, kcore_vmalloc
;
902 void __init
mem_init(void)
904 int codesize
, reservedpages
, datasize
, initsize
;
907 #ifdef CONFIG_FLATMEM
910 /* this will put all low memory onto the freelists */
911 totalram_pages
+= free_all_bootmem();
914 for (tmp
= 0; tmp
< max_low_pfn
; tmp
++)
916 * Only count reserved RAM pages:
918 if (page_is_ram(tmp
) && PageReserved(pfn_to_page(tmp
)))
921 set_highmem_pages_init();
923 codesize
= (unsigned long) &_etext
- (unsigned long) &_text
;
924 datasize
= (unsigned long) &_edata
- (unsigned long) &_etext
;
925 initsize
= (unsigned long) &__init_end
- (unsigned long) &__init_begin
;
927 kclist_add(&kcore_mem
, __va(0), max_low_pfn
<< PAGE_SHIFT
);
928 kclist_add(&kcore_vmalloc
, (void *)VMALLOC_START
,
929 VMALLOC_END
-VMALLOC_START
);
931 printk(KERN_INFO
"Memory: %luk/%luk available (%dk kernel code, "
932 "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
933 (unsigned long) nr_free_pages() << (PAGE_SHIFT
-10),
934 num_physpages
<< (PAGE_SHIFT
-10),
936 reservedpages
<< (PAGE_SHIFT
-10),
939 (unsigned long) (totalhigh_pages
<< (PAGE_SHIFT
-10))
942 printk(KERN_INFO
"virtual kernel memory layout:\n"
943 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
944 #ifdef CONFIG_HIGHMEM
945 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
947 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
948 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
949 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
950 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
951 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
952 FIXADDR_START
, FIXADDR_TOP
,
953 (FIXADDR_TOP
- FIXADDR_START
) >> 10,
955 #ifdef CONFIG_HIGHMEM
956 PKMAP_BASE
, PKMAP_BASE
+LAST_PKMAP
*PAGE_SIZE
,
957 (LAST_PKMAP
*PAGE_SIZE
) >> 10,
960 VMALLOC_START
, VMALLOC_END
,
961 (VMALLOC_END
- VMALLOC_START
) >> 20,
963 (unsigned long)__va(0), (unsigned long)high_memory
,
964 ((unsigned long)high_memory
- (unsigned long)__va(0)) >> 20,
966 (unsigned long)&__init_begin
, (unsigned long)&__init_end
,
967 ((unsigned long)&__init_end
-
968 (unsigned long)&__init_begin
) >> 10,
970 (unsigned long)&_etext
, (unsigned long)&_edata
,
971 ((unsigned long)&_edata
- (unsigned long)&_etext
) >> 10,
973 (unsigned long)&_text
, (unsigned long)&_etext
,
974 ((unsigned long)&_etext
- (unsigned long)&_text
) >> 10);
976 #ifdef CONFIG_HIGHMEM
977 BUG_ON(PKMAP_BASE
+ LAST_PKMAP
*PAGE_SIZE
> FIXADDR_START
);
978 BUG_ON(VMALLOC_END
> PKMAP_BASE
);
980 BUG_ON(VMALLOC_START
> VMALLOC_END
);
981 BUG_ON((unsigned long)high_memory
> VMALLOC_START
);
983 if (boot_cpu_data
.wp_works_ok
< 0)
991 #ifdef CONFIG_MEMORY_HOTPLUG
992 int arch_add_memory(int nid
, u64 start
, u64 size
)
994 struct pglist_data
*pgdata
= NODE_DATA(nid
);
995 struct zone
*zone
= pgdata
->node_zones
+ ZONE_HIGHMEM
;
996 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
997 unsigned long nr_pages
= size
>> PAGE_SHIFT
;
999 return __add_pages(zone
, start_pfn
, nr_pages
);
1004 * This function cannot be __init, since exceptions don't work in that
1005 * section. Put this after the callers, so that it cannot be inlined.
1007 static noinline
int do_test_wp_bit(void)
1012 __asm__
__volatile__(
1018 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST
)),
1027 #ifdef CONFIG_DEBUG_RODATA
1028 const int rodata_test_data
= 0xC3;
1029 EXPORT_SYMBOL_GPL(rodata_test_data
);
1031 void mark_rodata_ro(void)
1033 unsigned long start
= PFN_ALIGN(_text
);
1034 unsigned long size
= PFN_ALIGN(_etext
) - start
;
1036 #ifndef CONFIG_DYNAMIC_FTRACE
1037 /* Dynamic tracing modifies the kernel text section */
1038 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);
1039 printk(KERN_INFO
"Write protecting the kernel text: %luk\n",
1042 #ifdef CONFIG_CPA_DEBUG
1043 printk(KERN_INFO
"Testing CPA: Reverting %lx-%lx\n",
1045 set_pages_rw(virt_to_page(start
), size
>>PAGE_SHIFT
);
1047 printk(KERN_INFO
"Testing CPA: write protecting again\n");
1048 set_pages_ro(virt_to_page(start
), size
>>PAGE_SHIFT
);
1050 #endif /* CONFIG_DYNAMIC_FTRACE */
1053 size
= (unsigned long)__end_rodata
- start
;
1054 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);
1055 printk(KERN_INFO
"Write protecting the kernel read-only data: %luk\n",
1059 #ifdef CONFIG_CPA_DEBUG
1060 printk(KERN_INFO
"Testing CPA: undo %lx-%lx\n", start
, start
+ size
);
1061 set_pages_rw(virt_to_page(start
), size
>> PAGE_SHIFT
);
1063 printk(KERN_INFO
"Testing CPA: write protecting again\n");
1064 set_pages_ro(virt_to_page(start
), size
>> PAGE_SHIFT
);
1069 void free_init_pages(char *what
, unsigned long begin
, unsigned long end
)
1071 #ifdef CONFIG_DEBUG_PAGEALLOC
1073 * If debugging page accesses then do not free this memory but
1074 * mark them not present - any buggy init-section access will
1075 * create a kernel page fault:
1077 printk(KERN_INFO
"debug: unmapping init memory %08lx..%08lx\n",
1078 begin
, PAGE_ALIGN(end
));
1079 set_memory_np(begin
, (end
- begin
) >> PAGE_SHIFT
);
1084 * We just marked the kernel text read only above, now that
1085 * we are going to free part of that, we need to make that
1088 set_memory_rw(begin
, (end
- begin
) >> PAGE_SHIFT
);
1090 for (addr
= begin
; addr
< end
; addr
+= PAGE_SIZE
) {
1091 ClearPageReserved(virt_to_page(addr
));
1092 init_page_count(virt_to_page(addr
));
1093 memset((void *)addr
, POISON_FREE_INITMEM
, PAGE_SIZE
);
1097 printk(KERN_INFO
"Freeing %s: %luk freed\n", what
, (end
- begin
) >> 10);
1101 void free_initmem(void)
1103 free_init_pages("unused kernel memory",
1104 (unsigned long)(&__init_begin
),
1105 (unsigned long)(&__init_end
));
1108 #ifdef CONFIG_BLK_DEV_INITRD
1109 void free_initrd_mem(unsigned long start
, unsigned long end
)
1111 free_init_pages("initrd memory", start
, end
);
1115 int __init
reserve_bootmem_generic(unsigned long phys
, unsigned long len
,
1118 return reserve_bootmem(phys
, len
, flags
);