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