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/memblock.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 memblock_free(__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 = max_low_pfn;
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,
70 panic("%s: Failed to allocate %lu bytes align=%lx\n",
71 __func__, PAGE_SIZE, PAGE_SIZE);
73 set_pmd(pmd, __pmd(_KERNPG_TABLE +
74 (unsigned long) __pa(pte)));
75 if (pte != pte_offset_kernel(pmd, 0))
80 static void __init one_md_table_init(pud_t *pud)
82 #ifdef CONFIG_3_LEVEL_PGTABLES
83 pmd_t *pmd_table = (pmd_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
85 panic("%s: Failed to allocate %lu bytes align=%lx\n",
86 __func__, PAGE_SIZE, PAGE_SIZE);
88 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
89 if (pmd_table != pmd_offset(pud, 0))
94 static void __init fixrange_init(unsigned long start, unsigned long end,
104 i = pgd_index(vaddr);
105 j = pmd_index(vaddr);
108 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
109 pud = pud_offset(pgd, vaddr);
111 one_md_table_init(pud);
112 pmd = pmd_offset(pud, vaddr);
113 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
114 one_page_table_init(pmd);
121 static void __init fixaddr_user_init( void)
123 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
124 long size = FIXADDR_USER_END - FIXADDR_USER_START;
130 unsigned long v, vaddr = FIXADDR_USER_START;
135 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
136 v = (unsigned long) memblock_alloc_low(size, PAGE_SIZE);
138 panic("%s: Failed to allocate %lu bytes align=%lx\n",
139 __func__, size, PAGE_SIZE);
141 memcpy((void *) v , (void *) FIXADDR_USER_START, size);
143 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
145 pgd = swapper_pg_dir + pgd_index(vaddr);
146 pud = pud_offset(pgd, vaddr);
147 pmd = pmd_offset(pud, vaddr);
148 pte = pte_offset_kernel(pmd, vaddr);
149 pte_set_val(*pte, p, PAGE_READONLY);
154 void __init paging_init(void)
156 unsigned long zones_size[MAX_NR_ZONES], vaddr;
159 empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
161 if (!empty_zero_page)
162 panic("%s: Failed to allocate %lu bytes align=%lx\n",
163 __func__, PAGE_SIZE, PAGE_SIZE);
165 for (i = 0; i < ARRAY_SIZE(zones_size); i++)
168 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
169 (uml_physmem >> PAGE_SHIFT);
170 free_area_init(zones_size);
173 * Fixed mappings, only the page table structure has to be
174 * created - mappings will be set by set_fixmap():
176 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
177 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
183 * This can't do anything because nothing in the kernel image can be freed
184 * since it's not in kernel physical memory.
187 void free_initmem(void)
191 /* Allocate and free page tables. */
193 pgd_t *pgd_alloc(struct mm_struct *mm)
195 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
198 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
199 memcpy(pgd + USER_PTRS_PER_PGD,
200 swapper_pg_dir + USER_PTRS_PER_PGD,
201 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
206 void pgd_free(struct mm_struct *mm, pgd_t *pgd)
208 free_page((unsigned long) pgd);
211 #ifdef CONFIG_3_LEVEL_PGTABLES
212 pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
214 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
217 memset(pmd, 0, PAGE_SIZE);
223 void *uml_kmalloc(int size, int flags)
225 return kmalloc(size, flags);