1 #include <linux/gfp.h> 2 #include <linux/initrd.h> 3 #include <linux/ioport.h> 4 #include <linux/swap.h> 5 #include <linux/memblock.h> 6 7 #include <asm/cacheflush.h> 8 #include <asm/e820.h> 9 #include <asm/init.h> 10 #include <asm/page.h> 11 #include <asm/page_types.h> 12 #include <asm/sections.h> 13 #include <asm/setup.h> 14 #include <asm/system.h> 15 #include <asm/tlbflush.h> 16 #include <asm/tlb.h> 17 #include <asm/proto.h> 18 19 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 20 21 unsigned long __initdata e820_table_start; 22 unsigned long __meminitdata e820_table_end; 23 unsigned long __meminitdata e820_table_top; 24 25 int after_bootmem; 26 27 int direct_gbpages 28 #ifdef CONFIG_DIRECT_GBPAGES 29 = 1 30 #endif 31 ; 32 33 static void __init find_early_table_space(unsigned long end, int use_pse, 34 int use_gbpages) 35 { 36 unsigned long puds, pmds, ptes, tables, start; 37 phys_addr_t base; 38 39 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT; 40 tables = roundup(puds * sizeof(pud_t), PAGE_SIZE); 41 42 if (use_gbpages) { 43 unsigned long extra; 44 45 extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT); 46 pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT; 47 } else 48 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT; 49 50 tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE); 51 52 if (use_pse) { 53 unsigned long extra; 54 55 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT); 56 #ifdef CONFIG_X86_32 57 extra += PMD_SIZE; 58 #endif 59 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT; 60 } else 61 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT; 62 63 tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE); 64 65 #ifdef CONFIG_X86_32 66 /* for fixmap */ 67 tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE); 68 #endif 69 70 /* 71 * RED-PEN putting page tables only on node 0 could 72 * cause a hotspot and fill up ZONE_DMA. The page tables 73 * need roughly 0.5KB per GB. 74 */ 75 #ifdef CONFIG_X86_32 76 start = 0x7000; 77 #else 78 start = 0x8000; 79 #endif 80 base = memblock_find_in_range(start, max_pfn_mapped<<PAGE_SHIFT, 81 tables, PAGE_SIZE); 82 if (base == MEMBLOCK_ERROR) 83 panic("Cannot find space for the kernel page tables"); 84 85 e820_table_start = base >> PAGE_SHIFT; 86 e820_table_end = e820_table_start; 87 e820_table_top = e820_table_start + (tables >> PAGE_SHIFT); 88 89 printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n", 90 end, e820_table_start << PAGE_SHIFT, e820_table_top << PAGE_SHIFT); 91 } 92 93 struct map_range { 94 unsigned long start; 95 unsigned long end; 96 unsigned page_size_mask; 97 }; 98 99 #ifdef CONFIG_X86_32 100 #define NR_RANGE_MR 3 101 #else /* CONFIG_X86_64 */ 102 #define NR_RANGE_MR 5 103 #endif 104 105 static int __meminit save_mr(struct map_range *mr, int nr_range, 106 unsigned long start_pfn, unsigned long end_pfn, 107 unsigned long page_size_mask) 108 { 109 if (start_pfn < end_pfn) { 110 if (nr_range >= NR_RANGE_MR) 111 panic("run out of range for init_memory_mapping\n"); 112 mr[nr_range].start = start_pfn<<PAGE_SHIFT; 113 mr[nr_range].end = end_pfn<<PAGE_SHIFT; 114 mr[nr_range].page_size_mask = page_size_mask; 115 nr_range++; 116 } 117 118 return nr_range; 119 } 120 121 /* 122 * Setup the direct mapping of the physical memory at PAGE_OFFSET. 123 * This runs before bootmem is initialized and gets pages directly from 124 * the physical memory. To access them they are temporarily mapped. 125 */ 126 unsigned long __init_refok init_memory_mapping(unsigned long start, 127 unsigned long end) 128 { 129 unsigned long page_size_mask = 0; 130 unsigned long start_pfn, end_pfn; 131 unsigned long ret = 0; 132 unsigned long pos; 133 134 struct map_range mr[NR_RANGE_MR]; 135 int nr_range, i; 136 int use_pse, use_gbpages; 137 138 printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end); 139 140 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK) 141 /* 142 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. 143 * This will simplify cpa(), which otherwise needs to support splitting 144 * large pages into small in interrupt context, etc. 145 */ 146 use_pse = use_gbpages = 0; 147 #else 148 use_pse = cpu_has_pse; 149 use_gbpages = direct_gbpages; 150 #endif 151 152 /* Enable PSE if available */ 153 if (cpu_has_pse) 154 set_in_cr4(X86_CR4_PSE); 155 156 /* Enable PGE if available */ 157 if (cpu_has_pge) { 158 set_in_cr4(X86_CR4_PGE); 159 __supported_pte_mask |= _PAGE_GLOBAL; 160 } 161 162 if (use_gbpages) 163 page_size_mask |= 1 << PG_LEVEL_1G; 164 if (use_pse) 165 page_size_mask |= 1 << PG_LEVEL_2M; 166 167 memset(mr, 0, sizeof(mr)); 168 nr_range = 0; 169 170 /* head if not big page alignment ? */ 171 start_pfn = start >> PAGE_SHIFT; 172 pos = start_pfn << PAGE_SHIFT; 173 #ifdef CONFIG_X86_32 174 /* 175 * Don't use a large page for the first 2/4MB of memory 176 * because there are often fixed size MTRRs in there 177 * and overlapping MTRRs into large pages can cause 178 * slowdowns. 179 */ 180 if (pos == 0) 181 end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT); 182 else 183 end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT) 184 << (PMD_SHIFT - PAGE_SHIFT); 185 #else /* CONFIG_X86_64 */ 186 end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT) 187 << (PMD_SHIFT - PAGE_SHIFT); 188 #endif 189 if (end_pfn > (end >> PAGE_SHIFT)) 190 end_pfn = end >> PAGE_SHIFT; 191 if (start_pfn < end_pfn) { 192 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 193 pos = end_pfn << PAGE_SHIFT; 194 } 195 196 /* big page (2M) range */ 197 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT) 198 << (PMD_SHIFT - PAGE_SHIFT); 199 #ifdef CONFIG_X86_32 200 end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT); 201 #else /* CONFIG_X86_64 */ 202 end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT) 203 << (PUD_SHIFT - PAGE_SHIFT); 204 if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT))) 205 end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)); 206 #endif 207 208 if (start_pfn < end_pfn) { 209 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 210 page_size_mask & (1<<PG_LEVEL_2M)); 211 pos = end_pfn << PAGE_SHIFT; 212 } 213 214 #ifdef CONFIG_X86_64 215 /* big page (1G) range */ 216 start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT) 217 << (PUD_SHIFT - PAGE_SHIFT); 218 end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT); 219 if (start_pfn < end_pfn) { 220 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 221 page_size_mask & 222 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G))); 223 pos = end_pfn << PAGE_SHIFT; 224 } 225 226 /* tail is not big page (1G) alignment */ 227 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT) 228 << (PMD_SHIFT - PAGE_SHIFT); 229 end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT); 230 if (start_pfn < end_pfn) { 231 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 232 page_size_mask & (1<<PG_LEVEL_2M)); 233 pos = end_pfn << PAGE_SHIFT; 234 } 235 #endif 236 237 /* tail is not big page (2M) alignment */ 238 start_pfn = pos>>PAGE_SHIFT; 239 end_pfn = end>>PAGE_SHIFT; 240 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 241 242 /* try to merge same page size and continuous */ 243 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) { 244 unsigned long old_start; 245 if (mr[i].end != mr[i+1].start || 246 mr[i].page_size_mask != mr[i+1].page_size_mask) 247 continue; 248 /* move it */ 249 old_start = mr[i].start; 250 memmove(&mr[i], &mr[i+1], 251 (nr_range - 1 - i) * sizeof(struct map_range)); 252 mr[i--].start = old_start; 253 nr_range--; 254 } 255 256 for (i = 0; i < nr_range; i++) 257 printk(KERN_DEBUG " %010lx - %010lx page %s\n", 258 mr[i].start, mr[i].end, 259 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":( 260 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k")); 261 262 /* 263 * Find space for the kernel direct mapping tables. 264 * 265 * Later we should allocate these tables in the local node of the 266 * memory mapped. Unfortunately this is done currently before the 267 * nodes are discovered. 268 */ 269 if (!after_bootmem) 270 find_early_table_space(end, use_pse, use_gbpages); 271 272 for (i = 0; i < nr_range; i++) 273 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end, 274 mr[i].page_size_mask); 275 276 #ifdef CONFIG_X86_32 277 early_ioremap_page_table_range_init(); 278 279 load_cr3(swapper_pg_dir); 280 #endif 281 282 #ifdef CONFIG_X86_64 283 if (!after_bootmem && !start) { 284 pud_t *pud; 285 pmd_t *pmd; 286 287 mmu_cr4_features = read_cr4(); 288 289 /* 290 * _brk_end cannot change anymore, but it and _end may be 291 * located on different 2M pages. cleanup_highmap(), however, 292 * can only consider _end when it runs, so destroy any 293 * mappings beyond _brk_end here. 294 */ 295 pud = pud_offset(pgd_offset_k(_brk_end), _brk_end); 296 pmd = pmd_offset(pud, _brk_end - 1); 297 while (++pmd <= pmd_offset(pud, (unsigned long)_end - 1)) 298 pmd_clear(pmd); 299 } 300 #endif 301 __flush_tlb_all(); 302 303 if (!after_bootmem && e820_table_end > e820_table_start) 304 memblock_x86_reserve_range(e820_table_start << PAGE_SHIFT, 305 e820_table_end << PAGE_SHIFT, "PGTABLE"); 306 307 if (!after_bootmem) 308 early_memtest(start, end); 309 310 return ret >> PAGE_SHIFT; 311 } 312 313 314 /* 315 * devmem_is_allowed() checks to see if /dev/mem access to a certain address 316 * is valid. The argument is a physical page number. 317 * 318 * 319 * On x86, access has to be given to the first megabyte of ram because that area 320 * contains bios code and data regions used by X and dosemu and similar apps. 321 * Access has to be given to non-kernel-ram areas as well, these contain the PCI 322 * mmio resources as well as potential bios/acpi data regions. 323 */ 324 int devmem_is_allowed(unsigned long pagenr) 325 { 326 if (pagenr <= 256) 327 return 1; 328 if (iomem_is_exclusive(pagenr << PAGE_SHIFT)) 329 return 0; 330 if (!page_is_ram(pagenr)) 331 return 1; 332 return 0; 333 } 334 335 void free_init_pages(char *what, unsigned long begin, unsigned long end) 336 { 337 unsigned long addr; 338 unsigned long begin_aligned, end_aligned; 339 340 /* Make sure boundaries are page aligned */ 341 begin_aligned = PAGE_ALIGN(begin); 342 end_aligned = end & PAGE_MASK; 343 344 if (WARN_ON(begin_aligned != begin || end_aligned != end)) { 345 begin = begin_aligned; 346 end = end_aligned; 347 } 348 349 if (begin >= end) 350 return; 351 352 addr = begin; 353 354 /* 355 * If debugging page accesses then do not free this memory but 356 * mark them not present - any buggy init-section access will 357 * create a kernel page fault: 358 */ 359 #ifdef CONFIG_DEBUG_PAGEALLOC 360 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n", 361 begin, end); 362 set_memory_np(begin, (end - begin) >> PAGE_SHIFT); 363 #else 364 /* 365 * We just marked the kernel text read only above, now that 366 * we are going to free part of that, we need to make that 367 * writeable and non-executable first. 368 */ 369 set_memory_nx(begin, (end - begin) >> PAGE_SHIFT); 370 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); 371 372 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); 373 374 for (; addr < end; addr += PAGE_SIZE) { 375 ClearPageReserved(virt_to_page(addr)); 376 init_page_count(virt_to_page(addr)); 377 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); 378 free_page(addr); 379 totalram_pages++; 380 } 381 #endif 382 } 383 384 void free_initmem(void) 385 { 386 free_init_pages("unused kernel memory", 387 (unsigned long)(&__init_begin), 388 (unsigned long)(&__init_end)); 389 } 390 391 #ifdef CONFIG_BLK_DEV_INITRD 392 void free_initrd_mem(unsigned long start, unsigned long end) 393 { 394 /* 395 * end could be not aligned, and We can not align that, 396 * decompresser could be confused by aligned initrd_end 397 * We already reserve the end partial page before in 398 * - i386_start_kernel() 399 * - x86_64_start_kernel() 400 * - relocate_initrd() 401 * So here We can do PAGE_ALIGN() safely to get partial page to be freed 402 */ 403 free_init_pages("initrd memory", start, PAGE_ALIGN(end)); 404 } 405 #endif 406