1 /* 2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Licensed under the GPL 4 */ 5 6 #include <linux/stddef.h> 7 #include <linux/module.h> 8 #include <linux/bootmem.h> 9 #include <linux/highmem.h> 10 #include <linux/mm.h> 11 #include <linux/swap.h> 12 #include <linux/slab.h> 13 #include <asm/fixmap.h> 14 #include <asm/page.h> 15 #include <as-layout.h> 16 #include <init.h> 17 #include <kern.h> 18 #include <kern_util.h> 19 #include <mem_user.h> 20 #include <os.h> 21 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); 25 26 /* 27 * Initialized during boot, and readonly for initializing page tables 28 * afterwards 29 */ 30 pgd_t swapper_pg_dir[PTRS_PER_PGD]; 31 32 /* Initialized at boot time, and readonly after that */ 33 unsigned long long highmem; 34 int kmalloc_ok = 0; 35 36 /* Used during early boot */ 37 static unsigned long brk_end; 38 39 void __init mem_init(void) 40 { 41 /* clear the zero-page */ 42 memset(empty_zero_page, 0, PAGE_SIZE); 43 44 /* Map in the area just after the brk now that kmalloc is about 45 * to be turned on. 46 */ 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; 51 52 /* this will put all low memory onto the freelists */ 53 free_all_bootmem(); 54 max_low_pfn = totalram_pages; 55 max_pfn = totalram_pages; 56 mem_init_print_info(NULL); 57 kmalloc_ok = 1; 58 } 59 60 /* 61 * Create a page table and place a pointer to it in a middle page 62 * directory entry. 63 */ 64 static void __init one_page_table_init(pmd_t *pmd) 65 { 66 if (pmd_none(*pmd)) { 67 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); 68 set_pmd(pmd, __pmd(_KERNPG_TABLE + 69 (unsigned long) __pa(pte))); 70 if (pte != pte_offset_kernel(pmd, 0)) 71 BUG(); 72 } 73 } 74 75 static void __init one_md_table_init(pud_t *pud) 76 { 77 #ifdef CONFIG_3_LEVEL_PGTABLES 78 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); 79 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table))); 80 if (pmd_table != pmd_offset(pud, 0)) 81 BUG(); 82 #endif 83 } 84 85 static void __init fixrange_init(unsigned long start, unsigned long end, 86 pgd_t *pgd_base) 87 { 88 pgd_t *pgd; 89 pud_t *pud; 90 pmd_t *pmd; 91 int i, j; 92 unsigned long vaddr; 93 94 vaddr = start; 95 i = pgd_index(vaddr); 96 j = pmd_index(vaddr); 97 pgd = pgd_base + i; 98 99 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) { 100 pud = pud_offset(pgd, vaddr); 101 if (pud_none(*pud)) 102 one_md_table_init(pud); 103 pmd = pmd_offset(pud, vaddr); 104 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) { 105 one_page_table_init(pmd); 106 vaddr += PMD_SIZE; 107 } 108 j = 0; 109 } 110 } 111 112 static void __init fixaddr_user_init( void) 113 { 114 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA 115 long size = FIXADDR_USER_END - FIXADDR_USER_START; 116 pgd_t *pgd; 117 pud_t *pud; 118 pmd_t *pmd; 119 pte_t *pte; 120 phys_t p; 121 unsigned long v, vaddr = FIXADDR_USER_START; 122 123 if (!size) 124 return; 125 126 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir); 127 v = (unsigned long) alloc_bootmem_low_pages(size); 128 memcpy((void *) v , (void *) FIXADDR_USER_START, size); 129 p = __pa(v); 130 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE, 131 p += PAGE_SIZE) { 132 pgd = swapper_pg_dir + pgd_index(vaddr); 133 pud = pud_offset(pgd, vaddr); 134 pmd = pmd_offset(pud, vaddr); 135 pte = pte_offset_kernel(pmd, vaddr); 136 pte_set_val(*pte, p, PAGE_READONLY); 137 } 138 #endif 139 } 140 141 void __init paging_init(void) 142 { 143 unsigned long zones_size[MAX_NR_ZONES], vaddr; 144 int i; 145 146 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 147 for (i = 0; i < ARRAY_SIZE(zones_size); i++) 148 zones_size[i] = 0; 149 150 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) - 151 (uml_physmem >> PAGE_SHIFT); 152 free_area_init(zones_size); 153 154 /* 155 * Fixed mappings, only the page table structure has to be 156 * created - mappings will be set by set_fixmap(): 157 */ 158 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 159 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir); 160 161 fixaddr_user_init(); 162 } 163 164 /* 165 * This can't do anything because nothing in the kernel image can be freed 166 * since it's not in kernel physical memory. 167 */ 168 169 void free_initmem(void) 170 { 171 } 172 173 #ifdef CONFIG_BLK_DEV_INITRD 174 void free_initrd_mem(unsigned long start, unsigned long end) 175 { 176 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 177 } 178 #endif 179 180 /* Allocate and free page tables. */ 181 182 pgd_t *pgd_alloc(struct mm_struct *mm) 183 { 184 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL); 185 186 if (pgd) { 187 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); 188 memcpy(pgd + USER_PTRS_PER_PGD, 189 swapper_pg_dir + USER_PTRS_PER_PGD, 190 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); 191 } 192 return pgd; 193 } 194 195 void pgd_free(struct mm_struct *mm, pgd_t *pgd) 196 { 197 free_page((unsigned long) pgd); 198 } 199 200 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 201 { 202 pte_t *pte; 203 204 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO); 205 return pte; 206 } 207 208 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) 209 { 210 struct page *pte; 211 212 pte = alloc_page(GFP_KERNEL|__GFP_ZERO); 213 if (!pte) 214 return NULL; 215 if (!pgtable_page_ctor(pte)) { 216 __free_page(pte); 217 return NULL; 218 } 219 return pte; 220 } 221 222 #ifdef CONFIG_3_LEVEL_PGTABLES 223 pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) 224 { 225 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL); 226 227 if (pmd) 228 memset(pmd, 0, PAGE_SIZE); 229 230 return pmd; 231 } 232 #endif 233 234 void *uml_kmalloc(int size, int flags) 235 { 236 return kmalloc(size, flags); 237 } 238