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 totalhigh_pages = highmem >> PAGE_SHIFT; 83 totalram_pages += totalhigh_pages; 84 num_physpages = totalram_pages; 85 max_pfn = totalram_pages; 86 printk(KERN_INFO "Memory: %luk available\n", 87 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10)); 88 kmalloc_ok = 1; 89 90 #ifdef CONFIG_HIGHMEM 91 setup_highmem(end_iomem, highmem); 92 #endif 93 } 94 95 /* 96 * Create a page table and place a pointer to it in a middle page 97 * directory entry. 98 */ 99 static void __init one_page_table_init(pmd_t *pmd) 100 { 101 if (pmd_none(*pmd)) { 102 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); 103 set_pmd(pmd, __pmd(_KERNPG_TABLE + 104 (unsigned long) __pa(pte))); 105 if (pte != pte_offset_kernel(pmd, 0)) 106 BUG(); 107 } 108 } 109 110 static void __init one_md_table_init(pud_t *pud) 111 { 112 #ifdef CONFIG_3_LEVEL_PGTABLES 113 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); 114 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table))); 115 if (pmd_table != pmd_offset(pud, 0)) 116 BUG(); 117 #endif 118 } 119 120 static void __init fixrange_init(unsigned long start, unsigned long end, 121 pgd_t *pgd_base) 122 { 123 pgd_t *pgd; 124 pud_t *pud; 125 pmd_t *pmd; 126 int i, j; 127 unsigned long vaddr; 128 129 vaddr = start; 130 i = pgd_index(vaddr); 131 j = pmd_index(vaddr); 132 pgd = pgd_base + i; 133 134 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) { 135 pud = pud_offset(pgd, vaddr); 136 if (pud_none(*pud)) 137 one_md_table_init(pud); 138 pmd = pmd_offset(pud, vaddr); 139 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) { 140 one_page_table_init(pmd); 141 vaddr += PMD_SIZE; 142 } 143 j = 0; 144 } 145 } 146 147 #ifdef CONFIG_HIGHMEM 148 pte_t *kmap_pte; 149 pgprot_t kmap_prot; 150 151 #define kmap_get_fixmap_pte(vaddr) \ 152 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\ 153 (vaddr)), (vaddr)) 154 155 static void __init kmap_init(void) 156 { 157 unsigned long kmap_vstart; 158 159 /* cache the first kmap pte */ 160 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 161 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 162 163 kmap_prot = PAGE_KERNEL; 164 } 165 166 static void init_highmem(void) 167 { 168 pgd_t *pgd; 169 pud_t *pud; 170 pmd_t *pmd; 171 pte_t *pte; 172 unsigned long vaddr; 173 174 /* 175 * Permanent kmaps: 176 */ 177 vaddr = PKMAP_BASE; 178 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir); 179 180 pgd = swapper_pg_dir + pgd_index(vaddr); 181 pud = pud_offset(pgd, vaddr); 182 pmd = pmd_offset(pud, vaddr); 183 pte = pte_offset_kernel(pmd, vaddr); 184 pkmap_page_table = pte; 185 186 kmap_init(); 187 } 188 #endif /* CONFIG_HIGHMEM */ 189 190 static void __init fixaddr_user_init( void) 191 { 192 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA 193 long size = FIXADDR_USER_END - FIXADDR_USER_START; 194 pgd_t *pgd; 195 pud_t *pud; 196 pmd_t *pmd; 197 pte_t *pte; 198 unsigned long paddr, vaddr = FIXADDR_USER_START; 199 200 if ( ! size ) 201 return; 202 203 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir); 204 paddr = (unsigned long)alloc_bootmem_low_pages( size); 205 memcpy( (void *)paddr, (void *)FIXADDR_USER_START, size); 206 paddr = __pa(paddr); 207 for ( ; size > 0; size-=PAGE_SIZE, vaddr+=PAGE_SIZE, paddr+=PAGE_SIZE){ 208 pgd = swapper_pg_dir + pgd_index(vaddr); 209 pud = pud_offset(pgd, vaddr); 210 pmd = pmd_offset(pud, vaddr); 211 pte = pte_offset_kernel(pmd, vaddr); 212 pte_set_val( (*pte), paddr, PAGE_READONLY); 213 } 214 #endif 215 } 216 217 void paging_init(void) 218 { 219 unsigned long zones_size[MAX_NR_ZONES], vaddr; 220 int i; 221 222 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 223 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 224 for(i=0;i<sizeof(zones_size)/sizeof(zones_size[0]);i++) 225 zones_size[i] = 0; 226 zones_size[ZONE_DMA] = (end_iomem >> PAGE_SHIFT) - (uml_physmem >> PAGE_SHIFT); 227 zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT; 228 free_area_init(zones_size); 229 230 /* 231 * Fixed mappings, only the page table structure has to be 232 * created - mappings will be set by set_fixmap(): 233 */ 234 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 235 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir); 236 237 fixaddr_user_init(); 238 239 #ifdef CONFIG_HIGHMEM 240 init_highmem(); 241 #endif 242 } 243 244 struct page *arch_validate(struct page *page, gfp_t mask, int order) 245 { 246 unsigned long addr, zero = 0; 247 int i; 248 249 again: 250 if(page == NULL) return(page); 251 if(PageHighMem(page)) return(page); 252 253 addr = (unsigned long) page_address(page); 254 for(i = 0; i < (1 << order); i++){ 255 current->thread.fault_addr = (void *) addr; 256 if(__do_copy_to_user((void __user *) addr, &zero, 257 sizeof(zero), 258 ¤t->thread.fault_addr, 259 ¤t->thread.fault_catcher)){ 260 if(!(mask & __GFP_WAIT)) return(NULL); 261 else break; 262 } 263 addr += PAGE_SIZE; 264 } 265 266 if(i == (1 << order)) return(page); 267 page = alloc_pages(mask, order); 268 goto again; 269 } 270 271 /* This can't do anything because nothing in the kernel image can be freed 272 * since it's not in kernel physical memory. 273 */ 274 275 void free_initmem(void) 276 { 277 } 278 279 #ifdef CONFIG_BLK_DEV_INITRD 280 281 void free_initrd_mem(unsigned long start, unsigned long end) 282 { 283 if (start < end) 284 printk ("Freeing initrd memory: %ldk freed\n", 285 (end - start) >> 10); 286 for (; start < end; start += PAGE_SIZE) { 287 ClearPageReserved(virt_to_page(start)); 288 init_page_count(virt_to_page(start)); 289 free_page(start); 290 totalram_pages++; 291 } 292 } 293 294 #endif 295 296 void show_mem(void) 297 { 298 int pfn, total = 0, reserved = 0; 299 int shared = 0, cached = 0; 300 int highmem = 0; 301 struct page *page; 302 303 printk("Mem-info:\n"); 304 show_free_areas(); 305 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); 306 pfn = max_mapnr; 307 while(pfn-- > 0) { 308 page = pfn_to_page(pfn); 309 total++; 310 if(PageHighMem(page)) 311 highmem++; 312 if(PageReserved(page)) 313 reserved++; 314 else if(PageSwapCache(page)) 315 cached++; 316 else if(page_count(page)) 317 shared += page_count(page) - 1; 318 } 319 printk("%d pages of RAM\n", total); 320 printk("%d pages of HIGHMEM\n", highmem); 321 printk("%d reserved pages\n", reserved); 322 printk("%d pages shared\n", shared); 323 printk("%d pages swap cached\n", cached); 324 } 325 326 /* 327 * Allocate and free page tables. 328 */ 329 330 pgd_t *pgd_alloc(struct mm_struct *mm) 331 { 332 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL); 333 334 if (pgd) { 335 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); 336 memcpy(pgd + USER_PTRS_PER_PGD, 337 swapper_pg_dir + USER_PTRS_PER_PGD, 338 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); 339 } 340 return pgd; 341 } 342 343 void pgd_free(pgd_t *pgd) 344 { 345 free_page((unsigned long) pgd); 346 } 347 348 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 349 { 350 pte_t *pte; 351 352 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 353 return pte; 354 } 355 356 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) 357 { 358 struct page *pte; 359 360 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 361 return pte; 362 } 363 364 struct iomem_region *iomem_regions = NULL; 365 int iomem_size = 0; 366 367 extern int parse_iomem(char *str, int *add) __init; 368 369 __uml_setup("iomem=", parse_iomem, 370 "iomem=<name>,<file>\n" 371 " Configure <file> as an IO memory region named <name>.\n\n" 372 ); 373 374 /* 375 * Overrides for Emacs so that we follow Linus's tabbing style. 376 * Emacs will notice this stuff at the end of the file and automatically 377 * adjust the settings for this buffer only. This must remain at the end 378 * of the file. 379 * --------------------------------------------------------------------------- 380 * Local variables: 381 * c-file-style: "linux" 382 * End: 383 */ 384