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 /* allocated in paging_init and unchanged thereafter */ 26 static unsigned long *empty_bad_page = NULL; 27 28 /* 29 * Initialized during boot, and readonly for initializing page tables 30 * afterwards 31 */ 32 pgd_t swapper_pg_dir[PTRS_PER_PGD]; 33 34 /* Initialized at boot time, and readonly after that */ 35 unsigned long long highmem; 36 int kmalloc_ok = 0; 37 38 /* Used during early boot */ 39 static unsigned long brk_end; 40 41 #ifdef CONFIG_HIGHMEM 42 static void setup_highmem(unsigned long highmem_start, 43 unsigned long highmem_len) 44 { 45 unsigned long highmem_pfn; 46 int i; 47 48 highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT; 49 for (i = 0; i < highmem_len >> PAGE_SHIFT; i++) 50 free_highmem_page(&mem_map[highmem_pfn + i]); 51 } 52 #endif 53 54 void __init mem_init(void) 55 { 56 /* clear the zero-page */ 57 memset(empty_zero_page, 0, PAGE_SIZE); 58 59 /* Map in the area just after the brk now that kmalloc is about 60 * to be turned on. 61 */ 62 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0)); 63 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0); 64 free_bootmem(__pa(brk_end), uml_reserved - brk_end); 65 uml_reserved = brk_end; 66 67 /* this will put all low memory onto the freelists */ 68 totalram_pages = free_all_bootmem(); 69 max_low_pfn = totalram_pages; 70 #ifdef CONFIG_HIGHMEM 71 setup_highmem(end_iomem, highmem); 72 #endif 73 num_physpages = totalram_pages; 74 max_pfn = totalram_pages; 75 printk(KERN_INFO "Memory: %luk available\n", 76 nr_free_pages() << (PAGE_SHIFT-10)); 77 kmalloc_ok = 1; 78 } 79 80 /* 81 * Create a page table and place a pointer to it in a middle page 82 * directory entry. 83 */ 84 static void __init one_page_table_init(pmd_t *pmd) 85 { 86 if (pmd_none(*pmd)) { 87 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); 88 set_pmd(pmd, __pmd(_KERNPG_TABLE + 89 (unsigned long) __pa(pte))); 90 if (pte != pte_offset_kernel(pmd, 0)) 91 BUG(); 92 } 93 } 94 95 static void __init one_md_table_init(pud_t *pud) 96 { 97 #ifdef CONFIG_3_LEVEL_PGTABLES 98 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); 99 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table))); 100 if (pmd_table != pmd_offset(pud, 0)) 101 BUG(); 102 #endif 103 } 104 105 static void __init fixrange_init(unsigned long start, unsigned long end, 106 pgd_t *pgd_base) 107 { 108 pgd_t *pgd; 109 pud_t *pud; 110 pmd_t *pmd; 111 int i, j; 112 unsigned long vaddr; 113 114 vaddr = start; 115 i = pgd_index(vaddr); 116 j = pmd_index(vaddr); 117 pgd = pgd_base + i; 118 119 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) { 120 pud = pud_offset(pgd, vaddr); 121 if (pud_none(*pud)) 122 one_md_table_init(pud); 123 pmd = pmd_offset(pud, vaddr); 124 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) { 125 one_page_table_init(pmd); 126 vaddr += PMD_SIZE; 127 } 128 j = 0; 129 } 130 } 131 132 #ifdef CONFIG_HIGHMEM 133 pte_t *kmap_pte; 134 pgprot_t kmap_prot; 135 136 #define kmap_get_fixmap_pte(vaddr) \ 137 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\ 138 (vaddr)), (vaddr)) 139 140 static void __init kmap_init(void) 141 { 142 unsigned long kmap_vstart; 143 144 /* cache the first kmap pte */ 145 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 146 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 147 148 kmap_prot = PAGE_KERNEL; 149 } 150 151 static void __init init_highmem(void) 152 { 153 pgd_t *pgd; 154 pud_t *pud; 155 pmd_t *pmd; 156 pte_t *pte; 157 unsigned long vaddr; 158 159 /* 160 * Permanent kmaps: 161 */ 162 vaddr = PKMAP_BASE; 163 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir); 164 165 pgd = swapper_pg_dir + pgd_index(vaddr); 166 pud = pud_offset(pgd, vaddr); 167 pmd = pmd_offset(pud, vaddr); 168 pte = pte_offset_kernel(pmd, vaddr); 169 pkmap_page_table = pte; 170 171 kmap_init(); 172 } 173 #endif /* CONFIG_HIGHMEM */ 174 175 static void __init fixaddr_user_init( void) 176 { 177 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA 178 long size = FIXADDR_USER_END - FIXADDR_USER_START; 179 pgd_t *pgd; 180 pud_t *pud; 181 pmd_t *pmd; 182 pte_t *pte; 183 phys_t p; 184 unsigned long v, vaddr = FIXADDR_USER_START; 185 186 if (!size) 187 return; 188 189 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir); 190 v = (unsigned long) alloc_bootmem_low_pages(size); 191 memcpy((void *) v , (void *) FIXADDR_USER_START, size); 192 p = __pa(v); 193 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE, 194 p += PAGE_SIZE) { 195 pgd = swapper_pg_dir + pgd_index(vaddr); 196 pud = pud_offset(pgd, vaddr); 197 pmd = pmd_offset(pud, vaddr); 198 pte = pte_offset_kernel(pmd, vaddr); 199 pte_set_val(*pte, p, PAGE_READONLY); 200 } 201 #endif 202 } 203 204 void __init paging_init(void) 205 { 206 unsigned long zones_size[MAX_NR_ZONES], vaddr; 207 int i; 208 209 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 210 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 211 for (i = 0; i < ARRAY_SIZE(zones_size); i++) 212 zones_size[i] = 0; 213 214 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) - 215 (uml_physmem >> PAGE_SHIFT); 216 #ifdef CONFIG_HIGHMEM 217 zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT; 218 #endif 219 free_area_init(zones_size); 220 221 /* 222 * Fixed mappings, only the page table structure has to be 223 * created - mappings will be set by set_fixmap(): 224 */ 225 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 226 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir); 227 228 fixaddr_user_init(); 229 230 #ifdef CONFIG_HIGHMEM 231 init_highmem(); 232 #endif 233 } 234 235 /* 236 * This can't do anything because nothing in the kernel image can be freed 237 * since it's not in kernel physical memory. 238 */ 239 240 void free_initmem(void) 241 { 242 } 243 244 #ifdef CONFIG_BLK_DEV_INITRD 245 void free_initrd_mem(unsigned long start, unsigned long end) 246 { 247 free_reserved_area(start, end, 0, "initrd"); 248 } 249 #endif 250 251 /* Allocate and free page tables. */ 252 253 pgd_t *pgd_alloc(struct mm_struct *mm) 254 { 255 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL); 256 257 if (pgd) { 258 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); 259 memcpy(pgd + USER_PTRS_PER_PGD, 260 swapper_pg_dir + USER_PTRS_PER_PGD, 261 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); 262 } 263 return pgd; 264 } 265 266 void pgd_free(struct mm_struct *mm, pgd_t *pgd) 267 { 268 free_page((unsigned long) pgd); 269 } 270 271 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 272 { 273 pte_t *pte; 274 275 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 276 return pte; 277 } 278 279 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) 280 { 281 struct page *pte; 282 283 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 284 if (pte) 285 pgtable_page_ctor(pte); 286 return pte; 287 } 288 289 #ifdef CONFIG_3_LEVEL_PGTABLES 290 pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) 291 { 292 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL); 293 294 if (pmd) 295 memset(pmd, 0, PAGE_SIZE); 296 297 return pmd; 298 } 299 #endif 300 301 void *uml_kmalloc(int size, int flags) 302 { 303 return kmalloc(size, flags); 304 } 305