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/bootmem.h> 8#include <linux/highmem.h> 9#include <linux/mm.h> 10#include <linux/swap.h> 11#include <linux/slab.h> 12#include <asm/fixmap.h> 13#include <asm/page.h> 14#include "as-layout.h" 15#include "init.h" 16#include "kern.h" 17#include "kern_util.h" 18#include "mem_user.h" 19#include "os.h" 20 21/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */ 22unsigned long *empty_zero_page = NULL; 23/* allocated in paging_init and unchanged thereafter */ 24static unsigned long *empty_bad_page = NULL; 25 26/* 27 * Initialized during boot, and readonly for initializing page tables 28 * afterwards 29 */ 30pgd_t swapper_pg_dir[PTRS_PER_PGD]; 31 32/* Initialized at boot time, and readonly after that */ 33unsigned long long highmem; 34int kmalloc_ok = 0; 35 36/* Used during early boot */ 37static unsigned long brk_end; 38 39#ifdef CONFIG_HIGHMEM 40static void setup_highmem(unsigned long highmem_start, 41 unsigned long highmem_len) 42{ 43 struct page *page; 44 unsigned long highmem_pfn; 45 int i; 46 47 highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT; 48 for (i = 0; i < highmem_len >> PAGE_SHIFT; i++) { 49 page = &mem_map[highmem_pfn + i]; 50 ClearPageReserved(page); 51 init_page_count(page); 52 __free_page(page); 53 } 54} 55#endif 56 57void __init mem_init(void) 58{ 59 /* clear the zero-page */ 60 memset(empty_zero_page, 0, PAGE_SIZE); 61 62 /* Map in the area just after the brk now that kmalloc is about 63 * to be turned on. 64 */ 65 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0)); 66 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0); 67 free_bootmem(__pa(brk_end), uml_reserved - brk_end); 68 uml_reserved = brk_end; 69 70 /* this will put all low memory onto the freelists */ 71 totalram_pages = free_all_bootmem(); 72 max_low_pfn = totalram_pages; 73#ifdef CONFIG_HIGHMEM 74 totalhigh_pages = highmem >> PAGE_SHIFT; 75 totalram_pages += totalhigh_pages; 76#endif 77 num_physpages = totalram_pages; 78 max_pfn = totalram_pages; 79 printk(KERN_INFO "Memory: %luk available\n", 80 nr_free_pages() << (PAGE_SHIFT-10)); 81 kmalloc_ok = 1; 82 83#ifdef CONFIG_HIGHMEM 84 setup_highmem(end_iomem, highmem); 85#endif 86} 87 88/* 89 * Create a page table and place a pointer to it in a middle page 90 * directory entry. 91 */ 92static void __init one_page_table_init(pmd_t *pmd) 93{ 94 if (pmd_none(*pmd)) { 95 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); 96 set_pmd(pmd, __pmd(_KERNPG_TABLE + 97 (unsigned long) __pa(pte))); 98 if (pte != pte_offset_kernel(pmd, 0)) 99 BUG(); 100 } 101} 102 103static void __init one_md_table_init(pud_t *pud) 104{ 105#ifdef CONFIG_3_LEVEL_PGTABLES 106 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); 107 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table))); 108 if (pmd_table != pmd_offset(pud, 0)) 109 BUG(); 110#endif 111} 112 113static void __init fixrange_init(unsigned long start, unsigned long end, 114 pgd_t *pgd_base) 115{ 116 pgd_t *pgd; 117 pud_t *pud; 118 pmd_t *pmd; 119 int i, j; 120 unsigned long vaddr; 121 122 vaddr = start; 123 i = pgd_index(vaddr); 124 j = pmd_index(vaddr); 125 pgd = pgd_base + i; 126 127 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) { 128 pud = pud_offset(pgd, vaddr); 129 if (pud_none(*pud)) 130 one_md_table_init(pud); 131 pmd = pmd_offset(pud, vaddr); 132 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) { 133 one_page_table_init(pmd); 134 vaddr += PMD_SIZE; 135 } 136 j = 0; 137 } 138} 139 140#ifdef CONFIG_HIGHMEM 141pte_t *kmap_pte; 142pgprot_t kmap_prot; 143 144#define kmap_get_fixmap_pte(vaddr) \ 145 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\ 146 (vaddr)), (vaddr)) 147 148static void __init kmap_init(void) 149{ 150 unsigned long kmap_vstart; 151 152 /* cache the first kmap pte */ 153 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 154 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 155 156 kmap_prot = PAGE_KERNEL; 157} 158 159static void __init init_highmem(void) 160{ 161 pgd_t *pgd; 162 pud_t *pud; 163 pmd_t *pmd; 164 pte_t *pte; 165 unsigned long vaddr; 166 167 /* 168 * Permanent kmaps: 169 */ 170 vaddr = PKMAP_BASE; 171 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir); 172 173 pgd = swapper_pg_dir + pgd_index(vaddr); 174 pud = pud_offset(pgd, vaddr); 175 pmd = pmd_offset(pud, vaddr); 176 pte = pte_offset_kernel(pmd, vaddr); 177 pkmap_page_table = pte; 178 179 kmap_init(); 180} 181#endif /* CONFIG_HIGHMEM */ 182 183static void __init fixaddr_user_init( void) 184{ 185#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA 186 long size = FIXADDR_USER_END - FIXADDR_USER_START; 187 pgd_t *pgd; 188 pud_t *pud; 189 pmd_t *pmd; 190 pte_t *pte; 191 phys_t p; 192 unsigned long v, vaddr = FIXADDR_USER_START; 193 194 if (!size) 195 return; 196 197 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir); 198 v = (unsigned long) alloc_bootmem_low_pages(size); 199 memcpy((void *) v , (void *) FIXADDR_USER_START, size); 200 p = __pa(v); 201 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE, 202 p += PAGE_SIZE) { 203 pgd = swapper_pg_dir + pgd_index(vaddr); 204 pud = pud_offset(pgd, vaddr); 205 pmd = pmd_offset(pud, vaddr); 206 pte = pte_offset_kernel(pmd, vaddr); 207 pte_set_val(*pte, p, PAGE_READONLY); 208 } 209#endif 210} 211 212void __init paging_init(void) 213{ 214 unsigned long zones_size[MAX_NR_ZONES], vaddr; 215 int i; 216 217 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 218 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 219 for (i = 0; i < ARRAY_SIZE(zones_size); i++) 220 zones_size[i] = 0; 221 222 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) - 223 (uml_physmem >> PAGE_SHIFT); 224#ifdef CONFIG_HIGHMEM 225 zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT; 226#endif 227 free_area_init(zones_size); 228 229 /* 230 * Fixed mappings, only the page table structure has to be 231 * created - mappings will be set by set_fixmap(): 232 */ 233 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 234 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir); 235 236 fixaddr_user_init(); 237 238#ifdef CONFIG_HIGHMEM 239 init_highmem(); 240#endif 241} 242 243/* 244 * This can't do anything because nothing in the kernel image can be freed 245 * since it's not in kernel physical memory. 246 */ 247 248void free_initmem(void) 249{ 250} 251 252#ifdef CONFIG_BLK_DEV_INITRD 253void free_initrd_mem(unsigned long start, unsigned long end) 254{ 255 if (start < end) 256 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n", 257 (end - start) >> 10); 258 for (; start < end; start += PAGE_SIZE) { 259 ClearPageReserved(virt_to_page(start)); 260 init_page_count(virt_to_page(start)); 261 free_page(start); 262 totalram_pages++; 263 } 264} 265#endif 266 267/* Allocate and free page tables. */ 268 269pgd_t *pgd_alloc(struct mm_struct *mm) 270{ 271 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL); 272 273 if (pgd) { 274 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); 275 memcpy(pgd + USER_PTRS_PER_PGD, 276 swapper_pg_dir + USER_PTRS_PER_PGD, 277 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); 278 } 279 return pgd; 280} 281 282void pgd_free(struct mm_struct *mm, pgd_t *pgd) 283{ 284 free_page((unsigned long) pgd); 285} 286 287pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 288{ 289 pte_t *pte; 290 291 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 292 return pte; 293} 294 295pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) 296{ 297 struct page *pte; 298 299 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 300 if (pte) 301 pgtable_page_ctor(pte); 302 return pte; 303} 304 305#ifdef CONFIG_3_LEVEL_PGTABLES 306pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) 307{ 308 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL); 309 310 if (pmd) 311 memset(pmd, 0, PAGE_SIZE); 312 313 return pmd; 314} 315#endif 316 317void *uml_kmalloc(int size, int flags) 318{ 319 return kmalloc(size, flags); 320} 321