2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
6 #include <linux/stddef.h>
7 #include <linux/module.h>
8 #include <linux/bootmem.h>
9 #include <linux/highmem.h>
11 #include <linux/swap.h>
12 #include <linux/slab.h>
13 #include <asm/fixmap.h>
15 #include <as-layout.h>
18 #include <kern_util.h>
22 /* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
23 unsigned long *empty_zero_page = NULL;
24 EXPORT_SYMBOL(empty_zero_page);
27 * Initialized during boot, and readonly for initializing page tables
30 pgd_t swapper_pg_dir[PTRS_PER_PGD];
32 /* Initialized at boot time, and readonly after that */
33 unsigned long long highmem;
36 /* Used during early boot */
37 static unsigned long brk_end;
39 void __init mem_init(void)
41 /* clear the zero-page */
42 memset(empty_zero_page, 0, PAGE_SIZE);
44 /* Map in the area just after the brk now that kmalloc is about
47 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
48 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
49 free_bootmem(__pa(brk_end), uml_reserved - brk_end);
50 uml_reserved = brk_end;
52 /* this will put all low memory onto the freelists */
54 max_low_pfn = totalram_pages;
55 max_pfn = totalram_pages;
56 mem_init_print_info(NULL);
61 * Create a page table and place a pointer to it in a middle page
64 static void __init one_page_table_init(pmd_t *pmd)
67 pte_t *pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
69 set_pmd(pmd, __pmd(_KERNPG_TABLE +
70 (unsigned long) __pa(pte)));
71 if (pte != pte_offset_kernel(pmd, 0))
76 static void __init one_md_table_init(pud_t *pud)
78 #ifdef CONFIG_3_LEVEL_PGTABLES
79 pmd_t *pmd_table = (pmd_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
80 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
81 if (pmd_table != pmd_offset(pud, 0))
86 static void __init fixrange_init(unsigned long start, unsigned long end,
100 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
101 pud = pud_offset(pgd, vaddr);
103 one_md_table_init(pud);
104 pmd = pmd_offset(pud, vaddr);
105 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
106 one_page_table_init(pmd);
113 static void __init fixaddr_user_init( void)
115 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
116 long size = FIXADDR_USER_END - FIXADDR_USER_START;
122 unsigned long v, vaddr = FIXADDR_USER_START;
127 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
128 v = (unsigned long) memblock_alloc_low(size, PAGE_SIZE);
129 memcpy((void *) v , (void *) FIXADDR_USER_START, size);
131 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
133 pgd = swapper_pg_dir + pgd_index(vaddr);
134 pud = pud_offset(pgd, vaddr);
135 pmd = pmd_offset(pud, vaddr);
136 pte = pte_offset_kernel(pmd, vaddr);
137 pte_set_val(*pte, p, PAGE_READONLY);
142 void __init paging_init(void)
144 unsigned long zones_size[MAX_NR_ZONES], vaddr;
147 empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
149 for (i = 0; i < ARRAY_SIZE(zones_size); i++)
152 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
153 (uml_physmem >> PAGE_SHIFT);
154 free_area_init(zones_size);
157 * Fixed mappings, only the page table structure has to be
158 * created - mappings will be set by set_fixmap():
160 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
161 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
167 * This can't do anything because nothing in the kernel image can be freed
168 * since it's not in kernel physical memory.
171 void free_initmem(void)
175 #ifdef CONFIG_BLK_DEV_INITRD
176 void free_initrd_mem(unsigned long start, unsigned long end)
178 free_reserved_area((void *)start, (void *)end, -1, "initrd");
182 /* Allocate and free page tables. */
184 pgd_t *pgd_alloc(struct mm_struct *mm)
186 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
189 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
190 memcpy(pgd + USER_PTRS_PER_PGD,
191 swapper_pg_dir + USER_PTRS_PER_PGD,
192 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
197 void pgd_free(struct mm_struct *mm, pgd_t *pgd)
199 free_page((unsigned long) pgd);
202 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
206 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
210 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
214 pte = alloc_page(GFP_KERNEL|__GFP_ZERO);
217 if (!pgtable_page_ctor(pte)) {
224 #ifdef CONFIG_3_LEVEL_PGTABLES
225 pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
227 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
230 memset(pmd, 0, PAGE_SIZE);
236 void *uml_kmalloc(int size, int flags)
238 return kmalloc(size, flags);