371 строка
8.4 KiB
C
371 строка
8.4 KiB
C
/*
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* Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
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* Licensed under the GPL
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*/
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#include "linux/stddef.h"
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#include "linux/kernel.h"
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#include "linux/mm.h"
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#include "linux/bootmem.h"
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#include "linux/swap.h"
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#include "linux/highmem.h"
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#include "linux/gfp.h"
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#include "asm/page.h"
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#include "asm/fixmap.h"
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#include "asm/pgalloc.h"
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#include "kern_util.h"
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#include "as-layout.h"
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#include "kern.h"
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#include "mem_user.h"
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#include "um_uaccess.h"
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#include "os.h"
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#include "linux/types.h"
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#include "linux/string.h"
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#include "init.h"
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#include "kern_constants.h"
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/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
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unsigned long *empty_zero_page = NULL;
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/* allocated in paging_init and unchanged thereafter */
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unsigned long *empty_bad_page = NULL;
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pgd_t swapper_pg_dir[PTRS_PER_PGD];
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unsigned long long highmem;
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int kmalloc_ok = 0;
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static unsigned long brk_end;
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void unmap_physmem(void)
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{
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os_unmap_memory((void *) brk_end, uml_reserved - brk_end);
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}
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static void map_cb(void *unused)
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{
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map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
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}
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#ifdef CONFIG_HIGHMEM
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static void setup_highmem(unsigned long highmem_start,
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unsigned long highmem_len)
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{
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struct page *page;
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unsigned long highmem_pfn;
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int i;
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highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT;
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for(i = 0; i < highmem_len >> PAGE_SHIFT; i++){
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page = &mem_map[highmem_pfn + i];
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ClearPageReserved(page);
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init_page_count(page);
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__free_page(page);
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}
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}
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#endif
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void __init mem_init(void)
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{
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/* clear the zero-page */
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memset((void *) empty_zero_page, 0, PAGE_SIZE);
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/* Map in the area just after the brk now that kmalloc is about
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* to be turned on.
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*/
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brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
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map_cb(NULL);
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initial_thread_cb(map_cb, NULL);
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free_bootmem(__pa(brk_end), uml_reserved - brk_end);
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uml_reserved = brk_end;
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/* this will put all low memory onto the freelists */
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totalram_pages = free_all_bootmem();
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max_low_pfn = totalram_pages;
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#ifdef CONFIG_HIGHMEM
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totalhigh_pages = highmem >> PAGE_SHIFT;
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totalram_pages += totalhigh_pages;
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#endif
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num_physpages = totalram_pages;
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max_pfn = totalram_pages;
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printk(KERN_INFO "Memory: %luk available\n",
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(unsigned long) nr_free_pages() << (PAGE_SHIFT-10));
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kmalloc_ok = 1;
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#ifdef CONFIG_HIGHMEM
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setup_highmem(end_iomem, highmem);
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#endif
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}
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/*
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* Create a page table and place a pointer to it in a middle page
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* directory entry.
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*/
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static void __init one_page_table_init(pmd_t *pmd)
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{
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if (pmd_none(*pmd)) {
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pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
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set_pmd(pmd, __pmd(_KERNPG_TABLE +
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(unsigned long) __pa(pte)));
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if (pte != pte_offset_kernel(pmd, 0))
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BUG();
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}
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}
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static void __init one_md_table_init(pud_t *pud)
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{
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#ifdef CONFIG_3_LEVEL_PGTABLES
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pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
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set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
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if (pmd_table != pmd_offset(pud, 0))
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BUG();
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#endif
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}
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static void __init fixrange_init(unsigned long start, unsigned long end,
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pgd_t *pgd_base)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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int i, j;
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unsigned long vaddr;
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vaddr = start;
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i = pgd_index(vaddr);
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j = pmd_index(vaddr);
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pgd = pgd_base + i;
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for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
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pud = pud_offset(pgd, vaddr);
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if (pud_none(*pud))
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one_md_table_init(pud);
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pmd = pmd_offset(pud, vaddr);
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for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
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one_page_table_init(pmd);
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vaddr += PMD_SIZE;
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}
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j = 0;
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}
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}
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#ifdef CONFIG_HIGHMEM
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pte_t *kmap_pte;
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pgprot_t kmap_prot;
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#define kmap_get_fixmap_pte(vaddr) \
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pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
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(vaddr)), (vaddr))
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static void __init kmap_init(void)
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{
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unsigned long kmap_vstart;
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/* cache the first kmap pte */
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kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
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kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
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kmap_prot = PAGE_KERNEL;
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}
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static void __init init_highmem(void)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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unsigned long vaddr;
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/*
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* Permanent kmaps:
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*/
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vaddr = PKMAP_BASE;
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fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
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pgd = swapper_pg_dir + pgd_index(vaddr);
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pud = pud_offset(pgd, vaddr);
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pmd = pmd_offset(pud, vaddr);
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pte = pte_offset_kernel(pmd, vaddr);
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pkmap_page_table = pte;
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kmap_init();
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}
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#endif /* CONFIG_HIGHMEM */
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static void __init fixaddr_user_init( void)
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{
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#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
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long size = FIXADDR_USER_END - FIXADDR_USER_START;
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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unsigned long paddr, vaddr = FIXADDR_USER_START;
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if ( ! size )
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return;
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fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
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paddr = (unsigned long)alloc_bootmem_low_pages( size);
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memcpy( (void *)paddr, (void *)FIXADDR_USER_START, size);
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paddr = __pa(paddr);
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for ( ; size > 0; size-=PAGE_SIZE, vaddr+=PAGE_SIZE, paddr+=PAGE_SIZE){
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pgd = swapper_pg_dir + pgd_index(vaddr);
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pud = pud_offset(pgd, vaddr);
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pmd = pmd_offset(pud, vaddr);
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pte = pte_offset_kernel(pmd, vaddr);
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pte_set_val( (*pte), paddr, PAGE_READONLY);
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}
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#endif
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}
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void __init paging_init(void)
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{
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unsigned long zones_size[MAX_NR_ZONES], vaddr;
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int i;
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empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
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empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
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for(i = 0; i < ARRAY_SIZE(zones_size); i++)
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zones_size[i] = 0;
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zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
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(uml_physmem >> PAGE_SHIFT);
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#ifdef CONFIG_HIGHMEM
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zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT;
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#endif
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free_area_init(zones_size);
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/*
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* Fixed mappings, only the page table structure has to be
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* created - mappings will be set by set_fixmap():
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*/
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vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
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fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
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fixaddr_user_init();
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#ifdef CONFIG_HIGHMEM
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init_highmem();
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#endif
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}
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struct page *arch_validate(struct page *page, gfp_t mask, int order)
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{
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unsigned long addr, zero = 0;
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int i;
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again:
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if(page == NULL)
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return page;
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if(PageHighMem(page))
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return page;
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addr = (unsigned long) page_address(page);
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for(i = 0; i < (1 << order); i++){
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current->thread.fault_addr = (void *) addr;
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if(__do_copy_to_user((void __user *) addr, &zero,
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sizeof(zero),
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¤t->thread.fault_addr,
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¤t->thread.fault_catcher)){
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if(!(mask & __GFP_WAIT))
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return NULL;
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else break;
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}
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addr += PAGE_SIZE;
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}
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if(i == (1 << order))
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return page;
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page = alloc_pages(mask, order);
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goto again;
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}
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/* This can't do anything because nothing in the kernel image can be freed
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* since it's not in kernel physical memory.
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*/
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void free_initmem(void)
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{
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}
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#ifdef CONFIG_BLK_DEV_INITRD
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void free_initrd_mem(unsigned long start, unsigned long end)
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{
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if (start < end)
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printk ("Freeing initrd memory: %ldk freed\n",
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(end - start) >> 10);
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for (; start < end; start += PAGE_SIZE) {
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ClearPageReserved(virt_to_page(start));
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init_page_count(virt_to_page(start));
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free_page(start);
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totalram_pages++;
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}
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}
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#endif
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void show_mem(void)
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{
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int pfn, total = 0, reserved = 0;
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int shared = 0, cached = 0;
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int highmem = 0;
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struct page *page;
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printk("Mem-info:\n");
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show_free_areas();
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printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
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pfn = max_mapnr;
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while(pfn-- > 0) {
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page = pfn_to_page(pfn);
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total++;
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if(PageHighMem(page))
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highmem++;
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if(PageReserved(page))
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reserved++;
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else if(PageSwapCache(page))
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cached++;
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else if(page_count(page))
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shared += page_count(page) - 1;
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}
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printk("%d pages of RAM\n", total);
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printk("%d pages of HIGHMEM\n", highmem);
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printk("%d reserved pages\n", reserved);
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printk("%d pages shared\n", shared);
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printk("%d pages swap cached\n", cached);
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}
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/*
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* Allocate and free page tables.
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*/
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pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
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if (pgd) {
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memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
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memcpy(pgd + USER_PTRS_PER_PGD,
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swapper_pg_dir + USER_PTRS_PER_PGD,
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
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}
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return pgd;
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}
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void pgd_free(pgd_t *pgd)
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{
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free_page((unsigned long) pgd);
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}
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pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
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{
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pte_t *pte;
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pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
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return pte;
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}
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struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
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{
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struct page *pte;
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pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
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return pte;
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}
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