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 pgt_buf_start; 22 unsigned long __meminitdata pgt_buf_end; 23 unsigned long __meminitdata pgt_buf_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 = 0, good_end = end; 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 69 good_end = max_pfn_mapped << PAGE_SHIFT; 70 #endif 71 72 base = memblock_find_in_range(start, good_end, tables, PAGE_SIZE); 73 if (base == MEMBLOCK_ERROR) 74 panic("Cannot find space for the kernel page tables"); 75 76 pgt_buf_start = base >> PAGE_SHIFT; 77 pgt_buf_end = pgt_buf_start; 78 pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT); 79 80 printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n", 81 end, pgt_buf_start << PAGE_SHIFT, pgt_buf_top << PAGE_SHIFT); 82 } 83 84 void __init native_pagetable_reserve(u64 start, u64 end) 85 { 86 memblock_x86_reserve_range(start, end, "PGTABLE"); 87 } 88 89 struct map_range { 90 unsigned long start; 91 unsigned long end; 92 unsigned page_size_mask; 93 }; 94 95 #ifdef CONFIG_X86_32 96 #define NR_RANGE_MR 3 97 #else /* CONFIG_X86_64 */ 98 #define NR_RANGE_MR 5 99 #endif 100 101 static int __meminit save_mr(struct map_range *mr, int nr_range, 102 unsigned long start_pfn, unsigned long end_pfn, 103 unsigned long page_size_mask) 104 { 105 if (start_pfn < end_pfn) { 106 if (nr_range >= NR_RANGE_MR) 107 panic("run out of range for init_memory_mapping\n"); 108 mr[nr_range].start = start_pfn<<PAGE_SHIFT; 109 mr[nr_range].end = end_pfn<<PAGE_SHIFT; 110 mr[nr_range].page_size_mask = page_size_mask; 111 nr_range++; 112 } 113 114 return nr_range; 115 } 116 117 /* 118 * Setup the direct mapping of the physical memory at PAGE_OFFSET. 119 * This runs before bootmem is initialized and gets pages directly from 120 * the physical memory. To access them they are temporarily mapped. 121 */ 122 unsigned long __init_refok init_memory_mapping(unsigned long start, 123 unsigned long end) 124 { 125 unsigned long page_size_mask = 0; 126 unsigned long start_pfn, end_pfn; 127 unsigned long ret = 0; 128 unsigned long pos; 129 130 struct map_range mr[NR_RANGE_MR]; 131 int nr_range, i; 132 int use_pse, use_gbpages; 133 134 printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end); 135 136 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK) 137 /* 138 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. 139 * This will simplify cpa(), which otherwise needs to support splitting 140 * large pages into small in interrupt context, etc. 141 */ 142 use_pse = use_gbpages = 0; 143 #else 144 use_pse = cpu_has_pse; 145 use_gbpages = direct_gbpages; 146 #endif 147 148 /* Enable PSE if available */ 149 if (cpu_has_pse) 150 set_in_cr4(X86_CR4_PSE); 151 152 /* Enable PGE if available */ 153 if (cpu_has_pge) { 154 set_in_cr4(X86_CR4_PGE); 155 __supported_pte_mask |= _PAGE_GLOBAL; 156 } 157 158 if (use_gbpages) 159 page_size_mask |= 1 << PG_LEVEL_1G; 160 if (use_pse) 161 page_size_mask |= 1 << PG_LEVEL_2M; 162 163 memset(mr, 0, sizeof(mr)); 164 nr_range = 0; 165 166 /* head if not big page alignment ? */ 167 start_pfn = start >> PAGE_SHIFT; 168 pos = start_pfn << PAGE_SHIFT; 169 #ifdef CONFIG_X86_32 170 /* 171 * Don't use a large page for the first 2/4MB of memory 172 * because there are often fixed size MTRRs in there 173 * and overlapping MTRRs into large pages can cause 174 * slowdowns. 175 */ 176 if (pos == 0) 177 end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT); 178 else 179 end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT) 180 << (PMD_SHIFT - PAGE_SHIFT); 181 #else /* CONFIG_X86_64 */ 182 end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT) 183 << (PMD_SHIFT - PAGE_SHIFT); 184 #endif 185 if (end_pfn > (end >> PAGE_SHIFT)) 186 end_pfn = end >> PAGE_SHIFT; 187 if (start_pfn < end_pfn) { 188 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 189 pos = end_pfn << PAGE_SHIFT; 190 } 191 192 /* big page (2M) range */ 193 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT) 194 << (PMD_SHIFT - PAGE_SHIFT); 195 #ifdef CONFIG_X86_32 196 end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT); 197 #else /* CONFIG_X86_64 */ 198 end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT) 199 << (PUD_SHIFT - PAGE_SHIFT); 200 if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT))) 201 end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)); 202 #endif 203 204 if (start_pfn < end_pfn) { 205 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 206 page_size_mask & (1<<PG_LEVEL_2M)); 207 pos = end_pfn << PAGE_SHIFT; 208 } 209 210 #ifdef CONFIG_X86_64 211 /* big page (1G) range */ 212 start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT) 213 << (PUD_SHIFT - PAGE_SHIFT); 214 end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT); 215 if (start_pfn < end_pfn) { 216 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 217 page_size_mask & 218 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G))); 219 pos = end_pfn << PAGE_SHIFT; 220 } 221 222 /* tail is not big page (1G) alignment */ 223 start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT) 224 << (PMD_SHIFT - PAGE_SHIFT); 225 end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT); 226 if (start_pfn < end_pfn) { 227 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 228 page_size_mask & (1<<PG_LEVEL_2M)); 229 pos = end_pfn << PAGE_SHIFT; 230 } 231 #endif 232 233 /* tail is not big page (2M) alignment */ 234 start_pfn = pos>>PAGE_SHIFT; 235 end_pfn = end>>PAGE_SHIFT; 236 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 237 238 /* try to merge same page size and continuous */ 239 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) { 240 unsigned long old_start; 241 if (mr[i].end != mr[i+1].start || 242 mr[i].page_size_mask != mr[i+1].page_size_mask) 243 continue; 244 /* move it */ 245 old_start = mr[i].start; 246 memmove(&mr[i], &mr[i+1], 247 (nr_range - 1 - i) * sizeof(struct map_range)); 248 mr[i--].start = old_start; 249 nr_range--; 250 } 251 252 for (i = 0; i < nr_range; i++) 253 printk(KERN_DEBUG " %010lx - %010lx page %s\n", 254 mr[i].start, mr[i].end, 255 (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":( 256 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k")); 257 258 /* 259 * Find space for the kernel direct mapping tables. 260 * 261 * Later we should allocate these tables in the local node of the 262 * memory mapped. Unfortunately this is done currently before the 263 * nodes are discovered. 264 */ 265 if (!after_bootmem) 266 find_early_table_space(end, use_pse, use_gbpages); 267 268 for (i = 0; i < nr_range; i++) 269 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end, 270 mr[i].page_size_mask); 271 272 #ifdef CONFIG_X86_32 273 early_ioremap_page_table_range_init(); 274 275 load_cr3(swapper_pg_dir); 276 #endif 277 278 __flush_tlb_all(); 279 280 /* 281 * Reserve the kernel pagetable pages we used (pgt_buf_start - 282 * pgt_buf_end) and free the other ones (pgt_buf_end - pgt_buf_top) 283 * so that they can be reused for other purposes. 284 * 285 * On native it just means calling memblock_x86_reserve_range, on Xen it 286 * also means marking RW the pagetable pages that we allocated before 287 * but that haven't been used. 288 * 289 * In fact on xen we mark RO the whole range pgt_buf_start - 290 * pgt_buf_top, because we have to make sure that when 291 * init_memory_mapping reaches the pagetable pages area, it maps 292 * RO all the pagetable pages, including the ones that are beyond 293 * pgt_buf_end at that time. 294 */ 295 if (!after_bootmem && pgt_buf_end > pgt_buf_start) 296 x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start), 297 PFN_PHYS(pgt_buf_end)); 298 299 if (!after_bootmem) 300 early_memtest(start, end); 301 302 return ret >> PAGE_SHIFT; 303 } 304 305 306 /* 307 * devmem_is_allowed() checks to see if /dev/mem access to a certain address 308 * is valid. The argument is a physical page number. 309 * 310 * 311 * On x86, access has to be given to the first megabyte of ram because that area 312 * contains bios code and data regions used by X and dosemu and similar apps. 313 * Access has to be given to non-kernel-ram areas as well, these contain the PCI 314 * mmio resources as well as potential bios/acpi data regions. 315 */ 316 int devmem_is_allowed(unsigned long pagenr) 317 { 318 if (pagenr <= 256) 319 return 1; 320 if (iomem_is_exclusive(pagenr << PAGE_SHIFT)) 321 return 0; 322 if (!page_is_ram(pagenr)) 323 return 1; 324 return 0; 325 } 326 327 void free_init_pages(char *what, unsigned long begin, unsigned long end) 328 { 329 unsigned long addr; 330 unsigned long begin_aligned, end_aligned; 331 332 /* Make sure boundaries are page aligned */ 333 begin_aligned = PAGE_ALIGN(begin); 334 end_aligned = end & PAGE_MASK; 335 336 if (WARN_ON(begin_aligned != begin || end_aligned != end)) { 337 begin = begin_aligned; 338 end = end_aligned; 339 } 340 341 if (begin >= end) 342 return; 343 344 addr = begin; 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, 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 and non-executable first. 360 */ 361 set_memory_nx(begin, (end - begin) >> PAGE_SHIFT); 362 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); 363 364 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); 365 366 for (; addr < end; addr += PAGE_SIZE) { 367 ClearPageReserved(virt_to_page(addr)); 368 init_page_count(virt_to_page(addr)); 369 memset((void *)addr, 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 /* 387 * end could be not aligned, and We can not align that, 388 * decompresser could be confused by aligned initrd_end 389 * We already reserve the end partial page before in 390 * - i386_start_kernel() 391 * - x86_64_start_kernel() 392 * - relocate_initrd() 393 * So here We can do PAGE_ALIGN() safely to get partial page to be freed 394 */ 395 free_init_pages("initrd memory", start, PAGE_ALIGN(end)); 396 } 397 #endif 398