1 #include <linux/initrd.h> 2 #include <linux/ioport.h> 3 #include <linux/swap.h> 4 5 #include <asm/cacheflush.h> 6 #include <asm/e820.h> 7 #include <asm/init.h> 8 #include <asm/page.h> 9 #include <asm/page_types.h> 10 #include <asm/sections.h> 11 #include <asm/setup.h> 12 #include <asm/system.h> 13 #include <asm/tlbflush.h> 14 #include <asm/tlb.h> 15 #include <asm/proto.h> 16 17 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 18 19 unsigned long __initdata e820_table_start; 20 unsigned long __meminitdata e820_table_end; 21 unsigned long __meminitdata e820_table_top; 22 23 int after_bootmem; 24 25 int direct_gbpages 26 #ifdef CONFIG_DIRECT_GBPAGES 27 = 1 28 #endif 29 ; 30 31 static void __init find_early_table_space(unsigned long end, int use_pse, 32 int use_gbpages) 33 { 34 unsigned long puds, pmds, ptes, tables, start; 35 36 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT; 37 tables = roundup(puds * sizeof(pud_t), PAGE_SIZE); 38 39 if (use_gbpages) { 40 unsigned long extra; 41 42 extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT); 43 pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT; 44 } else 45 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT; 46 47 tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE); 48 49 if (use_pse) { 50 unsigned long extra; 51 52 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT); 53 #ifdef CONFIG_X86_32 54 extra += PMD_SIZE; 55 #endif 56 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT; 57 } else 58 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT; 59 60 tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE); 61 62 #ifdef CONFIG_X86_32 63 /* for fixmap */ 64 tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE); 65 #endif 66 67 /* 68 * RED-PEN putting page tables only on node 0 could 69 * cause a hotspot and fill up ZONE_DMA. The page tables 70 * need roughly 0.5KB per GB. 71 */ 72 #ifdef CONFIG_X86_32 73 start = 0x7000; 74 #else 75 start = 0x8000; 76 #endif 77 e820_table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT, 78 tables, PAGE_SIZE); 79 if (e820_table_start == -1UL) 80 panic("Cannot find space for the kernel page tables"); 81 82 e820_table_start >>= PAGE_SHIFT; 83 e820_table_end = e820_table_start; 84 e820_table_top = e820_table_start + (tables >> PAGE_SHIFT); 85 86 printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n", 87 end, e820_table_start << PAGE_SHIFT, e820_table_top << PAGE_SHIFT); 88 } 89 90 struct map_range { 91 unsigned long start; 92 unsigned long end; 93 unsigned page_size_mask; 94 }; 95 96 #ifdef CONFIG_X86_32 97 #define NR_RANGE_MR 3 98 #else /* CONFIG_X86_64 */ 99 #define NR_RANGE_MR 5 100 #endif 101 102 static int __meminit save_mr(struct map_range *mr, int nr_range, 103 unsigned long start_pfn, unsigned long end_pfn, 104 unsigned long page_size_mask) 105 { 106 if (start_pfn < end_pfn) { 107 if (nr_range >= NR_RANGE_MR) 108 panic("run out of range for init_memory_mapping\n"); 109 mr[nr_range].start = start_pfn<<PAGE_SHIFT; 110 mr[nr_range].end = end_pfn<<PAGE_SHIFT; 111 mr[nr_range].page_size_mask = page_size_mask; 112 nr_range++; 113 } 114 115 return nr_range; 116 } 117 118 /* 119 * Setup the direct mapping of the physical memory at PAGE_OFFSET. 120 * This runs before bootmem is initialized and gets pages directly from 121 * the physical memory. To access them they are temporarily mapped. 122 */ 123 unsigned long __init_refok init_memory_mapping(unsigned long start, 124 unsigned long end) 125 { 126 unsigned long page_size_mask = 0; 127 unsigned long start_pfn, end_pfn; 128 unsigned long ret = 0; 129 unsigned long pos; 130 131 struct map_range mr[NR_RANGE_MR]; 132 int nr_range, i; 133 int use_pse, use_gbpages; 134 135 printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end); 136 137 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK) 138 /* 139 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. 140 * This will simplify cpa(), which otherwise needs to support splitting 141 * large pages into small in interrupt context, etc. 142 */ 143 use_pse = use_gbpages = 0; 144 #else 145 use_pse = cpu_has_pse; 146 use_gbpages = direct_gbpages; 147 #endif 148 149 /* Enable PSE if available */ 150 if (cpu_has_pse) 151 set_in_cr4(X86_CR4_PSE); 152 153 /* Enable PGE if available */ 154 if (cpu_has_pge) { 155 set_in_cr4(X86_CR4_PGE); 156 __supported_pte_mask |= _PAGE_GLOBAL; 157 } 158 159 if (use_gbpages) 160 page_size_mask |= 1 << PG_LEVEL_1G; 161 if (use_pse) 162 page_size_mask |= 1 << PG_LEVEL_2M; 163 164 memset(mr, 0, sizeof(mr)); 165 nr_range = 0; 166 167 /* head if not big page alignment ? */ 168 start_pfn = start >> PAGE_SHIFT; 169 pos = start_pfn << PAGE_SHIFT; 170 #ifdef CONFIG_X86_32 171 /* 172 * Don't use a large page for the first 2/4MB of memory 173 * because there are often fixed size MTRRs in there 174 * and overlapping MTRRs into large pages can cause 175 * slowdowns. 176 */ 177 if (pos == 0) 178 end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT); 179 else 180 end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT) 181 << (PMD_SHIFT - PAGE_SHIFT); 182 #else /* CONFIG_X86_64 */ 183 end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT) 184 << (PMD_SHIFT - PAGE_SHIFT); 185 #endif 186 if (end_pfn > (end >> PAGE_SHIFT)) 187 end_pfn = end >> PAGE_SHIFT; 188 if (start_pfn < end_pfn) { 189 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 190 pos = end_pfn << PAGE_SHIFT; 191 } 192 193 /* big page (2M) range */ 194 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT) 195 << (PMD_SHIFT - PAGE_SHIFT); 196 #ifdef CONFIG_X86_32 197 end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT); 198 #else /* CONFIG_X86_64 */ 199 end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT) 200 << (PUD_SHIFT - PAGE_SHIFT); 201 if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT))) 202 end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)); 203 #endif 204 205 if (start_pfn < end_pfn) { 206 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 207 page_size_mask & (1<<PG_LEVEL_2M)); 208 pos = end_pfn << PAGE_SHIFT; 209 } 210 211 #ifdef CONFIG_X86_64 212 /* big page (1G) range */ 213 start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT) 214 << (PUD_SHIFT - PAGE_SHIFT); 215 end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT); 216 if (start_pfn < end_pfn) { 217 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 218 page_size_mask & 219 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G))); 220 pos = end_pfn << PAGE_SHIFT; 221 } 222 223 /* tail is not big page (1G) alignment */ 224 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT) 225 << (PMD_SHIFT - PAGE_SHIFT); 226 end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT); 227 if (start_pfn < end_pfn) { 228 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 229 page_size_mask & (1<<PG_LEVEL_2M)); 230 pos = end_pfn << PAGE_SHIFT; 231 } 232 #endif 233 234 /* tail is not big page (2M) alignment */ 235 start_pfn = pos>>PAGE_SHIFT; 236 end_pfn = end>>PAGE_SHIFT; 237 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 238 239 /* try to merge same page size and continuous */ 240 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) { 241 unsigned long old_start; 242 if (mr[i].end != mr[i+1].start || 243 mr[i].page_size_mask != mr[i+1].page_size_mask) 244 continue; 245 /* move it */ 246 old_start = mr[i].start; 247 memmove(&mr[i], &mr[i+1], 248 (nr_range - 1 - i) * sizeof(struct map_range)); 249 mr[i--].start = old_start; 250 nr_range--; 251 } 252 253 for (i = 0; i < nr_range; i++) 254 printk(KERN_DEBUG " %010lx - %010lx page %s\n", 255 mr[i].start, mr[i].end, 256 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":( 257 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k")); 258 259 /* 260 * Find space for the kernel direct mapping tables. 261 * 262 * Later we should allocate these tables in the local node of the 263 * memory mapped. Unfortunately this is done currently before the 264 * nodes are discovered. 265 */ 266 if (!after_bootmem) 267 find_early_table_space(end, use_pse, use_gbpages); 268 269 #ifdef CONFIG_X86_32 270 for (i = 0; i < nr_range; i++) 271 kernel_physical_mapping_init(mr[i].start, mr[i].end, 272 mr[i].page_size_mask); 273 ret = end; 274 #else /* CONFIG_X86_64 */ 275 for (i = 0; i < nr_range; i++) 276 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end, 277 mr[i].page_size_mask); 278 #endif 279 280 #ifdef CONFIG_X86_32 281 early_ioremap_page_table_range_init(); 282 283 load_cr3(swapper_pg_dir); 284 #endif 285 286 #ifdef CONFIG_X86_64 287 if (!after_bootmem && !start) { 288 pud_t *pud; 289 pmd_t *pmd; 290 291 mmu_cr4_features = read_cr4(); 292 293 /* 294 * _brk_end cannot change anymore, but it and _end may be 295 * located on different 2M pages. cleanup_highmap(), however, 296 * can only consider _end when it runs, so destroy any 297 * mappings beyond _brk_end here. 298 */ 299 pud = pud_offset(pgd_offset_k(_brk_end), _brk_end); 300 pmd = pmd_offset(pud, _brk_end - 1); 301 while (++pmd <= pmd_offset(pud, (unsigned long)_end - 1)) 302 pmd_clear(pmd); 303 } 304 #endif 305 __flush_tlb_all(); 306 307 if (!after_bootmem && e820_table_end > e820_table_start) 308 reserve_early(e820_table_start << PAGE_SHIFT, 309 e820_table_end << PAGE_SHIFT, "PGTABLE"); 310 311 if (!after_bootmem) 312 early_memtest(start, end); 313 314 return ret >> PAGE_SHIFT; 315 } 316 317 318 /* 319 * devmem_is_allowed() checks to see if /dev/mem access to a certain address 320 * is valid. The argument is a physical page number. 321 * 322 * 323 * On x86, access has to be given to the first megabyte of ram because that area 324 * contains bios code and data regions used by X and dosemu and similar apps. 325 * Access has to be given to non-kernel-ram areas as well, these contain the PCI 326 * mmio resources as well as potential bios/acpi data regions. 327 */ 328 int devmem_is_allowed(unsigned long pagenr) 329 { 330 if (pagenr <= 256) 331 return 1; 332 if (iomem_is_exclusive(pagenr << PAGE_SHIFT)) 333 return 0; 334 if (!page_is_ram(pagenr)) 335 return 1; 336 return 0; 337 } 338 339 void free_init_pages(char *what, unsigned long begin, unsigned long end) 340 { 341 unsigned long addr = begin; 342 343 if (addr >= end) 344 return; 345 346 /* 347 * If debugging page accesses then do not free this memory but 348 * mark them not present - any buggy init-section access will 349 * create a kernel page fault: 350 */ 351 #ifdef CONFIG_DEBUG_PAGEALLOC 352 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n", 353 begin, PAGE_ALIGN(end)); 354 set_memory_np(begin, (end - begin) >> PAGE_SHIFT); 355 #else 356 /* 357 * We just marked the kernel text read only above, now that 358 * we are going to free part of that, we need to make that 359 * writeable first. 360 */ 361 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); 362 363 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); 364 365 for (; addr < end; addr += PAGE_SIZE) { 366 ClearPageReserved(virt_to_page(addr)); 367 init_page_count(virt_to_page(addr)); 368 memset((void *)(addr & ~(PAGE_SIZE-1)), 369 POISON_FREE_INITMEM, PAGE_SIZE); 370 free_page(addr); 371 totalram_pages++; 372 } 373 #endif 374 } 375 376 void free_initmem(void) 377 { 378 free_init_pages("unused kernel memory", 379 (unsigned long)(&__init_begin), 380 (unsigned long)(&__init_end)); 381 } 382 383 #ifdef CONFIG_BLK_DEV_INITRD 384 void free_initrd_mem(unsigned long start, unsigned long end) 385 { 386 free_init_pages("initrd memory", start, end); 387 } 388 #endif 389