1 /* 2 * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com) 3 * Licensed under the GPL 4 */ 5 6 #include "linux/stddef.h" 7 #include "linux/kernel.h" 8 #include "linux/mm.h" 9 #include "linux/bootmem.h" 10 #include "linux/swap.h" 11 #include "linux/highmem.h" 12 #include "linux/gfp.h" 13 #include "asm/page.h" 14 #include "asm/fixmap.h" 15 #include "asm/pgalloc.h" 16 #include "user_util.h" 17 #include "kern_util.h" 18 #include "kern.h" 19 #include "mem_user.h" 20 #include "uml_uaccess.h" 21 #include "os.h" 22 #include "linux/types.h" 23 #include "linux/string.h" 24 #include "init.h" 25 #include "kern_constants.h" 26 27 /* Changed during early boot */ 28 unsigned long *empty_zero_page = NULL; 29 unsigned long *empty_bad_page = NULL; 30 pgd_t swapper_pg_dir[PTRS_PER_PGD]; 31 unsigned long long highmem; 32 int kmalloc_ok = 0; 33 34 static unsigned long brk_end; 35 36 void unmap_physmem(void) 37 { 38 os_unmap_memory((void *) brk_end, uml_reserved - brk_end); 39 } 40 41 static void map_cb(void *unused) 42 { 43 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0); 44 } 45 46 #ifdef CONFIG_HIGHMEM 47 static void setup_highmem(unsigned long highmem_start, 48 unsigned long highmem_len) 49 { 50 struct page *page; 51 unsigned long highmem_pfn; 52 int i; 53 54 highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT; 55 for(i = 0; i < highmem_len >> PAGE_SHIFT; i++){ 56 page = &mem_map[highmem_pfn + i]; 57 ClearPageReserved(page); 58 init_page_count(page); 59 __free_page(page); 60 } 61 } 62 #endif 63 64 void mem_init(void) 65 { 66 max_low_pfn = (high_physmem - uml_physmem) >> PAGE_SHIFT; 67 68 /* clear the zero-page */ 69 memset((void *) empty_zero_page, 0, PAGE_SIZE); 70 71 /* Map in the area just after the brk now that kmalloc is about 72 * to be turned on. 73 */ 74 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0)); 75 map_cb(NULL); 76 initial_thread_cb(map_cb, NULL); 77 free_bootmem(__pa(brk_end), uml_reserved - brk_end); 78 uml_reserved = brk_end; 79 80 /* this will put all low memory onto the freelists */ 81 totalram_pages = free_all_bootmem(); 82 #ifdef CONFIG_HIGHMEM 83 totalhigh_pages = highmem >> PAGE_SHIFT; 84 totalram_pages += totalhigh_pages; 85 #endif 86 num_physpages = totalram_pages; 87 max_pfn = totalram_pages; 88 printk(KERN_INFO "Memory: %luk available\n", 89 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10)); 90 kmalloc_ok = 1; 91 92 #ifdef CONFIG_HIGHMEM 93 setup_highmem(end_iomem, highmem); 94 #endif 95 } 96 97 /* 98 * Create a page table and place a pointer to it in a middle page 99 * directory entry. 100 */ 101 static void __init one_page_table_init(pmd_t *pmd) 102 { 103 if (pmd_none(*pmd)) { 104 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); 105 set_pmd(pmd, __pmd(_KERNPG_TABLE + 106 (unsigned long) __pa(pte))); 107 if (pte != pte_offset_kernel(pmd, 0)) 108 BUG(); 109 } 110 } 111 112 static void __init one_md_table_init(pud_t *pud) 113 { 114 #ifdef CONFIG_3_LEVEL_PGTABLES 115 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); 116 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table))); 117 if (pmd_table != pmd_offset(pud, 0)) 118 BUG(); 119 #endif 120 } 121 122 static void __init fixrange_init(unsigned long start, unsigned long end, 123 pgd_t *pgd_base) 124 { 125 pgd_t *pgd; 126 pud_t *pud; 127 pmd_t *pmd; 128 int i, j; 129 unsigned long vaddr; 130 131 vaddr = start; 132 i = pgd_index(vaddr); 133 j = pmd_index(vaddr); 134 pgd = pgd_base + i; 135 136 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) { 137 pud = pud_offset(pgd, vaddr); 138 if (pud_none(*pud)) 139 one_md_table_init(pud); 140 pmd = pmd_offset(pud, vaddr); 141 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) { 142 one_page_table_init(pmd); 143 vaddr += PMD_SIZE; 144 } 145 j = 0; 146 } 147 } 148 149 #ifdef CONFIG_HIGHMEM 150 pte_t *kmap_pte; 151 pgprot_t kmap_prot; 152 153 #define kmap_get_fixmap_pte(vaddr) \ 154 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\ 155 (vaddr)), (vaddr)) 156 157 static void __init kmap_init(void) 158 { 159 unsigned long kmap_vstart; 160 161 /* cache the first kmap pte */ 162 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 163 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 164 165 kmap_prot = PAGE_KERNEL; 166 } 167 168 static void init_highmem(void) 169 { 170 pgd_t *pgd; 171 pud_t *pud; 172 pmd_t *pmd; 173 pte_t *pte; 174 unsigned long vaddr; 175 176 /* 177 * Permanent kmaps: 178 */ 179 vaddr = PKMAP_BASE; 180 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir); 181 182 pgd = swapper_pg_dir + pgd_index(vaddr); 183 pud = pud_offset(pgd, vaddr); 184 pmd = pmd_offset(pud, vaddr); 185 pte = pte_offset_kernel(pmd, vaddr); 186 pkmap_page_table = pte; 187 188 kmap_init(); 189 } 190 #endif /* CONFIG_HIGHMEM */ 191 192 static void __init fixaddr_user_init( void) 193 { 194 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA 195 long size = FIXADDR_USER_END - FIXADDR_USER_START; 196 pgd_t *pgd; 197 pud_t *pud; 198 pmd_t *pmd; 199 pte_t *pte; 200 unsigned long paddr, vaddr = FIXADDR_USER_START; 201 202 if ( ! size ) 203 return; 204 205 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir); 206 paddr = (unsigned long)alloc_bootmem_low_pages( size); 207 memcpy( (void *)paddr, (void *)FIXADDR_USER_START, size); 208 paddr = __pa(paddr); 209 for ( ; size > 0; size-=PAGE_SIZE, vaddr+=PAGE_SIZE, paddr+=PAGE_SIZE){ 210 pgd = swapper_pg_dir + pgd_index(vaddr); 211 pud = pud_offset(pgd, vaddr); 212 pmd = pmd_offset(pud, vaddr); 213 pte = pte_offset_kernel(pmd, vaddr); 214 pte_set_val( (*pte), paddr, PAGE_READONLY); 215 } 216 #endif 217 } 218 219 void paging_init(void) 220 { 221 unsigned long zones_size[MAX_NR_ZONES], vaddr; 222 int i; 223 224 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 225 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 226 for(i = 0; i < ARRAY_SIZE(zones_size); i++) 227 zones_size[i] = 0; 228 229 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) - 230 (uml_physmem >> PAGE_SHIFT); 231 #ifdef CONFIG_HIGHMEM 232 zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT; 233 #endif 234 free_area_init(zones_size); 235 236 /* 237 * Fixed mappings, only the page table structure has to be 238 * created - mappings will be set by set_fixmap(): 239 */ 240 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 241 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir); 242 243 fixaddr_user_init(); 244 245 #ifdef CONFIG_HIGHMEM 246 init_highmem(); 247 #endif 248 } 249 250 struct page *arch_validate(struct page *page, gfp_t mask, int order) 251 { 252 unsigned long addr, zero = 0; 253 int i; 254 255 again: 256 if(page == NULL) return(page); 257 if(PageHighMem(page)) return(page); 258 259 addr = (unsigned long) page_address(page); 260 for(i = 0; i < (1 << order); i++){ 261 current->thread.fault_addr = (void *) addr; 262 if(__do_copy_to_user((void __user *) addr, &zero, 263 sizeof(zero), 264 ¤t->thread.fault_addr, 265 ¤t->thread.fault_catcher)){ 266 if(!(mask & __GFP_WAIT)) return(NULL); 267 else break; 268 } 269 addr += PAGE_SIZE; 270 } 271 272 if(i == (1 << order)) return(page); 273 page = alloc_pages(mask, order); 274 goto again; 275 } 276 277 /* This can't do anything because nothing in the kernel image can be freed 278 * since it's not in kernel physical memory. 279 */ 280 281 void free_initmem(void) 282 { 283 } 284 285 #ifdef CONFIG_BLK_DEV_INITRD 286 287 void free_initrd_mem(unsigned long start, unsigned long end) 288 { 289 if (start < end) 290 printk ("Freeing initrd memory: %ldk freed\n", 291 (end - start) >> 10); 292 for (; start < end; start += PAGE_SIZE) { 293 ClearPageReserved(virt_to_page(start)); 294 init_page_count(virt_to_page(start)); 295 free_page(start); 296 totalram_pages++; 297 } 298 } 299 300 #endif 301 302 void show_mem(void) 303 { 304 int pfn, total = 0, reserved = 0; 305 int shared = 0, cached = 0; 306 int highmem = 0; 307 struct page *page; 308 309 printk("Mem-info:\n"); 310 show_free_areas(); 311 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); 312 pfn = max_mapnr; 313 while(pfn-- > 0) { 314 page = pfn_to_page(pfn); 315 total++; 316 if(PageHighMem(page)) 317 highmem++; 318 if(PageReserved(page)) 319 reserved++; 320 else if(PageSwapCache(page)) 321 cached++; 322 else if(page_count(page)) 323 shared += page_count(page) - 1; 324 } 325 printk("%d pages of RAM\n", total); 326 printk("%d pages of HIGHMEM\n", highmem); 327 printk("%d reserved pages\n", reserved); 328 printk("%d pages shared\n", shared); 329 printk("%d pages swap cached\n", cached); 330 } 331 332 /* 333 * Allocate and free page tables. 334 */ 335 336 pgd_t *pgd_alloc(struct mm_struct *mm) 337 { 338 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL); 339 340 if (pgd) { 341 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); 342 memcpy(pgd + USER_PTRS_PER_PGD, 343 swapper_pg_dir + USER_PTRS_PER_PGD, 344 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); 345 } 346 return pgd; 347 } 348 349 void pgd_free(pgd_t *pgd) 350 { 351 free_page((unsigned long) pgd); 352 } 353 354 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 355 { 356 pte_t *pte; 357 358 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 359 return pte; 360 } 361 362 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) 363 { 364 struct page *pte; 365 366 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 367 return pte; 368 } 369 370 struct iomem_region *iomem_regions = NULL; 371 int iomem_size = 0; 372 373 extern int parse_iomem(char *str, int *add) __init; 374 375 __uml_setup("iomem=", parse_iomem, 376 "iomem=<name>,<file>\n" 377 " Configure <file> as an IO memory region named <name>.\n\n" 378 ); 379 380 /* 381 * Overrides for Emacs so that we follow Linus's tabbing style. 382 * Emacs will notice this stuff at the end of the file and automatically 383 * adjust the settings for this buffer only. This must remain at the end 384 * of the file. 385 * --------------------------------------------------------------------------- 386 * Local variables: 387 * c-file-style: "linux" 388 * End: 389 */ 390