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 static void __init fixrange_init(unsigned long start, unsigned long end, 104 pgd_t *pgd_base) 105 { 106 pgd_t *pgd; 107 pmd_t *pmd; 108 pte_t *pte; 109 int i, j; 110 unsigned long vaddr; 111 112 vaddr = start; 113 i = pgd_index(vaddr); 114 j = pmd_index(vaddr); 115 pgd = pgd_base + i; 116 117 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) { 118 pmd = (pmd_t *)pgd; 119 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) { 120 if (pmd_none(*pmd)) { 121 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); 122 set_pmd(pmd, __pmd(_KERNPG_TABLE + 123 (unsigned long) __pa(pte))); 124 if (pte != pte_offset_kernel(pmd, 0)) 125 BUG(); 126 } 127 vaddr += PMD_SIZE; 128 } 129 j = 0; 130 } 131 } 132 133 #ifdef CONFIG_HIGHMEM 134 pte_t *kmap_pte; 135 pgprot_t kmap_prot; 136 137 #define kmap_get_fixmap_pte(vaddr) \ 138 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\ 139 (vaddr)), (vaddr)) 140 141 static void __init kmap_init(void) 142 { 143 unsigned long kmap_vstart; 144 145 /* cache the first kmap pte */ 146 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 147 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 148 149 kmap_prot = PAGE_KERNEL; 150 } 151 152 static void init_highmem(void) 153 { 154 pgd_t *pgd; 155 pud_t *pud; 156 pmd_t *pmd; 157 pte_t *pte; 158 unsigned long vaddr; 159 160 /* 161 * Permanent kmaps: 162 */ 163 vaddr = PKMAP_BASE; 164 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir); 165 166 pgd = swapper_pg_dir + pgd_index(vaddr); 167 pud = pud_offset(pgd, vaddr); 168 pmd = pmd_offset(pud, vaddr); 169 pte = pte_offset_kernel(pmd, vaddr); 170 pkmap_page_table = pte; 171 172 kmap_init(); 173 } 174 #endif /* CONFIG_HIGHMEM */ 175 176 static void __init fixaddr_user_init( void) 177 { 178 #if CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA 179 long size = FIXADDR_USER_END - FIXADDR_USER_START; 180 pgd_t *pgd; 181 pud_t *pud; 182 pmd_t *pmd; 183 pte_t *pte; 184 unsigned long paddr, vaddr = FIXADDR_USER_START; 185 186 if ( ! size ) 187 return; 188 189 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir); 190 paddr = (unsigned long)alloc_bootmem_low_pages( size); 191 memcpy( (void *)paddr, (void *)FIXADDR_USER_START, size); 192 paddr = __pa(paddr); 193 for ( ; size > 0; size-=PAGE_SIZE, vaddr+=PAGE_SIZE, paddr+=PAGE_SIZE){ 194 pgd = swapper_pg_dir + pgd_index(vaddr); 195 pud = pud_offset(pgd, vaddr); 196 pmd = pmd_offset(pud, vaddr); 197 pte = pte_offset_kernel(pmd, vaddr); 198 pte_set_val( (*pte), paddr, PAGE_READONLY); 199 } 200 #endif 201 } 202 203 void paging_init(void) 204 { 205 unsigned long zones_size[MAX_NR_ZONES], vaddr; 206 int i; 207 208 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 209 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); 210 for(i=0;i<sizeof(zones_size)/sizeof(zones_size[0]);i++) 211 zones_size[i] = 0; 212 zones_size[0] = (end_iomem >> PAGE_SHIFT) - (uml_physmem >> PAGE_SHIFT); 213 zones_size[2] = highmem >> PAGE_SHIFT; 214 free_area_init(zones_size); 215 216 /* 217 * Fixed mappings, only the page table structure has to be 218 * created - mappings will be set by set_fixmap(): 219 */ 220 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 221 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir); 222 223 fixaddr_user_init(); 224 225 #ifdef CONFIG_HIGHMEM 226 init_highmem(); 227 #endif 228 } 229 230 struct page *arch_validate(struct page *page, int mask, int order) 231 { 232 unsigned long addr, zero = 0; 233 int i; 234 235 again: 236 if(page == NULL) return(page); 237 if(PageHighMem(page)) return(page); 238 239 addr = (unsigned long) page_address(page); 240 for(i = 0; i < (1 << order); i++){ 241 current->thread.fault_addr = (void *) addr; 242 if(__do_copy_to_user((void __user *) addr, &zero, 243 sizeof(zero), 244 ¤t->thread.fault_addr, 245 ¤t->thread.fault_catcher)){ 246 if(!(mask & __GFP_WAIT)) return(NULL); 247 else break; 248 } 249 addr += PAGE_SIZE; 250 } 251 252 if(i == (1 << order)) return(page); 253 page = alloc_pages(mask, order); 254 goto again; 255 } 256 257 /* This can't do anything because nothing in the kernel image can be freed 258 * since it's not in kernel physical memory. 259 */ 260 261 void free_initmem(void) 262 { 263 } 264 265 #ifdef CONFIG_BLK_DEV_INITRD 266 267 void free_initrd_mem(unsigned long start, unsigned long end) 268 { 269 if (start < end) 270 printk ("Freeing initrd memory: %ldk freed\n", 271 (end - start) >> 10); 272 for (; start < end; start += PAGE_SIZE) { 273 ClearPageReserved(virt_to_page(start)); 274 set_page_count(virt_to_page(start), 1); 275 free_page(start); 276 totalram_pages++; 277 } 278 } 279 280 #endif 281 282 void show_mem(void) 283 { 284 int pfn, total = 0, reserved = 0; 285 int shared = 0, cached = 0; 286 int highmem = 0; 287 struct page *page; 288 289 printk("Mem-info:\n"); 290 show_free_areas(); 291 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); 292 pfn = max_mapnr; 293 while(pfn-- > 0) { 294 page = pfn_to_page(pfn); 295 total++; 296 if(PageHighMem(page)) 297 highmem++; 298 if(PageReserved(page)) 299 reserved++; 300 else if(PageSwapCache(page)) 301 cached++; 302 else if(page_count(page)) 303 shared += page_count(page) - 1; 304 } 305 printk("%d pages of RAM\n", total); 306 printk("%d pages of HIGHMEM\n", highmem); 307 printk("%d reserved pages\n", reserved); 308 printk("%d pages shared\n", shared); 309 printk("%d pages swap cached\n", cached); 310 } 311 312 /* 313 * Allocate and free page tables. 314 */ 315 316 pgd_t *pgd_alloc(struct mm_struct *mm) 317 { 318 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL); 319 320 if (pgd) { 321 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); 322 memcpy(pgd + USER_PTRS_PER_PGD, 323 swapper_pg_dir + USER_PTRS_PER_PGD, 324 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); 325 } 326 return pgd; 327 } 328 329 void pgd_free(pgd_t *pgd) 330 { 331 free_page((unsigned long) pgd); 332 } 333 334 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 335 { 336 pte_t *pte; 337 338 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 339 return pte; 340 } 341 342 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) 343 { 344 struct page *pte; 345 346 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 347 return pte; 348 } 349 350 /* 351 * Overrides for Emacs so that we follow Linus's tabbing style. 352 * Emacs will notice this stuff at the end of the file and automatically 353 * adjust the settings for this buffer only. This must remain at the end 354 * of the file. 355 * --------------------------------------------------------------------------- 356 * Local variables: 357 * c-file-style: "linux" 358 * End: 359 */ 360