1 /* 2 * Copyright (C) 2007-2008 Michal Simek <monstr@monstr.eu> 3 * Copyright (C) 2006 Atmark Techno, Inc. 4 * 5 * This file is subject to the terms and conditions of the GNU General Public 6 * License. See the file "COPYING" in the main directory of this archive 7 * for more details. 8 */ 9 10 #include <linux/bootmem.h> 11 #include <linux/init.h> 12 #include <linux/kernel.h> 13 #include <linux/memblock.h> 14 #include <linux/mm.h> /* mem_init */ 15 #include <linux/initrd.h> 16 #include <linux/pagemap.h> 17 #include <linux/pfn.h> 18 #include <linux/slab.h> 19 #include <linux/swap.h> 20 #include <linux/export.h> 21 22 #include <asm/page.h> 23 #include <asm/mmu_context.h> 24 #include <asm/pgalloc.h> 25 #include <asm/sections.h> 26 #include <asm/tlb.h> 27 #include <asm/fixmap.h> 28 29 /* Use for MMU and noMMU because of PCI generic code */ 30 int mem_init_done; 31 32 #ifndef CONFIG_MMU 33 unsigned int __page_offset; 34 EXPORT_SYMBOL(__page_offset); 35 36 #else 37 static int init_bootmem_done; 38 #endif /* CONFIG_MMU */ 39 40 char *klimit = _end; 41 42 /* 43 * Initialize the bootmem system and give it all the memory we 44 * have available. 45 */ 46 unsigned long memory_start; 47 EXPORT_SYMBOL(memory_start); 48 unsigned long memory_size; 49 EXPORT_SYMBOL(memory_size); 50 unsigned long lowmem_size; 51 52 #ifdef CONFIG_HIGHMEM 53 pte_t *kmap_pte; 54 EXPORT_SYMBOL(kmap_pte); 55 pgprot_t kmap_prot; 56 EXPORT_SYMBOL(kmap_prot); 57 58 static inline pte_t *virt_to_kpte(unsigned long vaddr) 59 { 60 return pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), 61 vaddr), vaddr); 62 } 63 64 static void __init highmem_init(void) 65 { 66 pr_debug("%x\n", (u32)PKMAP_BASE); 67 map_page(PKMAP_BASE, 0, 0); /* XXX gross */ 68 pkmap_page_table = virt_to_kpte(PKMAP_BASE); 69 70 kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN)); 71 kmap_prot = PAGE_KERNEL; 72 } 73 74 static void highmem_setup(void) 75 { 76 unsigned long pfn; 77 78 for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) { 79 struct page *page = pfn_to_page(pfn); 80 81 /* FIXME not sure about */ 82 if (!memblock_is_reserved(pfn << PAGE_SHIFT)) 83 free_highmem_page(page); 84 } 85 } 86 #endif /* CONFIG_HIGHMEM */ 87 88 /* 89 * paging_init() sets up the page tables - in fact we've already done this. 90 */ 91 static void __init paging_init(void) 92 { 93 unsigned long zones_size[MAX_NR_ZONES]; 94 #ifdef CONFIG_MMU 95 int idx; 96 97 /* Setup fixmaps */ 98 for (idx = 0; idx < __end_of_fixed_addresses; idx++) 99 clear_fixmap(idx); 100 #endif 101 102 /* Clean every zones */ 103 memset(zones_size, 0, sizeof(zones_size)); 104 105 #ifdef CONFIG_HIGHMEM 106 highmem_init(); 107 108 zones_size[ZONE_DMA] = max_low_pfn; 109 zones_size[ZONE_HIGHMEM] = max_pfn; 110 #else 111 zones_size[ZONE_DMA] = max_pfn; 112 #endif 113 114 /* We don't have holes in memory map */ 115 free_area_init_nodes(zones_size); 116 } 117 118 void __init setup_memory(void) 119 { 120 unsigned long map_size; 121 struct memblock_region *reg; 122 123 #ifndef CONFIG_MMU 124 u32 kernel_align_start, kernel_align_size; 125 126 /* Find main memory where is the kernel */ 127 for_each_memblock(memory, reg) { 128 memory_start = (u32)reg->base; 129 lowmem_size = reg->size; 130 if ((memory_start <= (u32)_text) && 131 ((u32)_text <= (memory_start + lowmem_size - 1))) { 132 memory_size = lowmem_size; 133 PAGE_OFFSET = memory_start; 134 pr_info("%s: Main mem: 0x%x, size 0x%08x\n", 135 __func__, (u32) memory_start, 136 (u32) memory_size); 137 break; 138 } 139 } 140 141 if (!memory_start || !memory_size) { 142 panic("%s: Missing memory setting 0x%08x, size=0x%08x\n", 143 __func__, (u32) memory_start, (u32) memory_size); 144 } 145 146 /* reservation of region where is the kernel */ 147 kernel_align_start = PAGE_DOWN((u32)_text); 148 /* ALIGN can be remove because _end in vmlinux.lds.S is align */ 149 kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start; 150 pr_info("%s: kernel addr:0x%08x-0x%08x size=0x%08x\n", 151 __func__, kernel_align_start, kernel_align_start 152 + kernel_align_size, kernel_align_size); 153 memblock_reserve(kernel_align_start, kernel_align_size); 154 #endif 155 /* 156 * Kernel: 157 * start: base phys address of kernel - page align 158 * end: base phys address of kernel - page align 159 * 160 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start) 161 * max_low_pfn 162 * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn) 163 */ 164 165 /* memory start is from the kernel end (aligned) to higher addr */ 166 min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */ 167 /* RAM is assumed contiguous */ 168 max_mapnr = memory_size >> PAGE_SHIFT; 169 max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT; 170 max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT; 171 172 pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr); 173 pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn); 174 pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn); 175 pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn); 176 177 /* 178 * Find an area to use for the bootmem bitmap. 179 * We look for the first area which is at least 180 * 128kB in length (128kB is enough for a bitmap 181 * for 4GB of memory, using 4kB pages), plus 1 page 182 * (in case the address isn't page-aligned). 183 */ 184 map_size = init_bootmem_node(NODE_DATA(0), 185 PFN_UP(TOPHYS((u32)klimit)), min_low_pfn, max_low_pfn); 186 memblock_reserve(PFN_UP(TOPHYS((u32)klimit)) << PAGE_SHIFT, map_size); 187 188 /* Add active regions with valid PFNs */ 189 for_each_memblock(memory, reg) { 190 unsigned long start_pfn, end_pfn; 191 192 start_pfn = memblock_region_memory_base_pfn(reg); 193 end_pfn = memblock_region_memory_end_pfn(reg); 194 memblock_set_node(start_pfn << PAGE_SHIFT, 195 (end_pfn - start_pfn) << PAGE_SHIFT, 196 &memblock.memory, 0); 197 } 198 199 /* free bootmem is whole main memory */ 200 free_bootmem_with_active_regions(0, max_low_pfn); 201 202 /* reserve allocate blocks */ 203 for_each_memblock(reserved, reg) { 204 unsigned long top = reg->base + reg->size - 1; 205 206 pr_debug("reserved - 0x%08x-0x%08x, %lx, %lx\n", 207 (u32) reg->base, (u32) reg->size, top, 208 memory_start + lowmem_size - 1); 209 210 if (top <= (memory_start + lowmem_size - 1)) { 211 reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT); 212 } else if (reg->base < (memory_start + lowmem_size - 1)) { 213 unsigned long trunc_size = memory_start + lowmem_size - 214 reg->base; 215 reserve_bootmem(reg->base, trunc_size, BOOTMEM_DEFAULT); 216 } 217 } 218 219 /* XXX need to clip this if using highmem? */ 220 sparse_memory_present_with_active_regions(0); 221 222 #ifdef CONFIG_MMU 223 init_bootmem_done = 1; 224 #endif 225 paging_init(); 226 } 227 228 #ifdef CONFIG_BLK_DEV_INITRD 229 void free_initrd_mem(unsigned long start, unsigned long end) 230 { 231 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 232 } 233 #endif 234 235 void free_initmem(void) 236 { 237 free_initmem_default(-1); 238 } 239 240 void __init mem_init(void) 241 { 242 high_memory = (void *)__va(memory_start + lowmem_size - 1); 243 244 /* this will put all memory onto the freelists */ 245 free_all_bootmem(); 246 #ifdef CONFIG_HIGHMEM 247 highmem_setup(); 248 #endif 249 250 mem_init_print_info(NULL); 251 #ifdef CONFIG_MMU 252 pr_info("Kernel virtual memory layout:\n"); 253 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP); 254 #ifdef CONFIG_HIGHMEM 255 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n", 256 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP)); 257 #endif /* CONFIG_HIGHMEM */ 258 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n", 259 ioremap_bot, ioremap_base); 260 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n", 261 (unsigned long)VMALLOC_START, VMALLOC_END); 262 #endif 263 mem_init_done = 1; 264 } 265 266 #ifndef CONFIG_MMU 267 int page_is_ram(unsigned long pfn) 268 { 269 return __range_ok(pfn, 0); 270 } 271 #else 272 int page_is_ram(unsigned long pfn) 273 { 274 return pfn < max_low_pfn; 275 } 276 277 /* 278 * Check for command-line options that affect what MMU_init will do. 279 */ 280 static void mm_cmdline_setup(void) 281 { 282 unsigned long maxmem = 0; 283 char *p = cmd_line; 284 285 /* Look for mem= option on command line */ 286 p = strstr(cmd_line, "mem="); 287 if (p) { 288 p += 4; 289 maxmem = memparse(p, &p); 290 if (maxmem && memory_size > maxmem) { 291 memory_size = maxmem; 292 memblock.memory.regions[0].size = memory_size; 293 } 294 } 295 } 296 297 /* 298 * MMU_init_hw does the chip-specific initialization of the MMU hardware. 299 */ 300 static void __init mmu_init_hw(void) 301 { 302 /* 303 * The Zone Protection Register (ZPR) defines how protection will 304 * be applied to every page which is a member of a given zone. At 305 * present, we utilize only two of the zones. 306 * The zone index bits (of ZSEL) in the PTE are used for software 307 * indicators, except the LSB. For user access, zone 1 is used, 308 * for kernel access, zone 0 is used. We set all but zone 1 309 * to zero, allowing only kernel access as indicated in the PTE. 310 * For zone 1, we set a 01 binary (a value of 10 will not work) 311 * to allow user access as indicated in the PTE. This also allows 312 * kernel access as indicated in the PTE. 313 */ 314 __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \ 315 "mts rzpr, r11;" 316 : : : "r11"); 317 } 318 319 /* 320 * MMU_init sets up the basic memory mappings for the kernel, 321 * including both RAM and possibly some I/O regions, 322 * and sets up the page tables and the MMU hardware ready to go. 323 */ 324 325 /* called from head.S */ 326 asmlinkage void __init mmu_init(void) 327 { 328 unsigned int kstart, ksize; 329 330 if (!memblock.reserved.cnt) { 331 pr_emerg("Error memory count\n"); 332 machine_restart(NULL); 333 } 334 335 if ((u32) memblock.memory.regions[0].size < 0x400000) { 336 pr_emerg("Memory must be greater than 4MB\n"); 337 machine_restart(NULL); 338 } 339 340 if ((u32) memblock.memory.regions[0].size < kernel_tlb) { 341 pr_emerg("Kernel size is greater than memory node\n"); 342 machine_restart(NULL); 343 } 344 345 /* Find main memory where the kernel is */ 346 memory_start = (u32) memblock.memory.regions[0].base; 347 lowmem_size = memory_size = (u32) memblock.memory.regions[0].size; 348 349 if (lowmem_size > CONFIG_LOWMEM_SIZE) { 350 lowmem_size = CONFIG_LOWMEM_SIZE; 351 #ifndef CONFIG_HIGHMEM 352 memory_size = lowmem_size; 353 #endif 354 } 355 356 mm_cmdline_setup(); /* FIXME parse args from command line - not used */ 357 358 /* 359 * Map out the kernel text/data/bss from the available physical 360 * memory. 361 */ 362 kstart = __pa(CONFIG_KERNEL_START); /* kernel start */ 363 /* kernel size */ 364 ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START)); 365 memblock_reserve(kstart, ksize); 366 367 #if defined(CONFIG_BLK_DEV_INITRD) 368 /* Remove the init RAM disk from the available memory. */ 369 if (initrd_start) { 370 unsigned long size; 371 size = initrd_end - initrd_start; 372 memblock_reserve(__virt_to_phys(initrd_start), size); 373 } 374 #endif /* CONFIG_BLK_DEV_INITRD */ 375 376 /* Initialize the MMU hardware */ 377 mmu_init_hw(); 378 379 /* Map in all of RAM starting at CONFIG_KERNEL_START */ 380 mapin_ram(); 381 382 /* Extend vmalloc and ioremap area as big as possible */ 383 #ifdef CONFIG_HIGHMEM 384 ioremap_base = ioremap_bot = PKMAP_BASE; 385 #else 386 ioremap_base = ioremap_bot = FIXADDR_START; 387 #endif 388 389 /* Initialize the context management stuff */ 390 mmu_context_init(); 391 392 /* Shortly after that, the entire linear mapping will be available */ 393 /* This will also cause that unflatten device tree will be allocated 394 * inside 768MB limit */ 395 memblock_set_current_limit(memory_start + lowmem_size - 1); 396 } 397 398 /* This is only called until mem_init is done. */ 399 void __init *early_get_page(void) 400 { 401 void *p; 402 if (init_bootmem_done) { 403 p = alloc_bootmem_pages(PAGE_SIZE); 404 } else { 405 /* 406 * Mem start + kernel_tlb -> here is limit 407 * because of mem mapping from head.S 408 */ 409 p = __va(memblock_alloc_base(PAGE_SIZE, PAGE_SIZE, 410 memory_start + kernel_tlb)); 411 } 412 return p; 413 } 414 415 #endif /* CONFIG_MMU */ 416 417 void * __ref alloc_maybe_bootmem(size_t size, gfp_t mask) 418 { 419 if (mem_init_done) 420 return kmalloc(size, mask); 421 else 422 return alloc_bootmem(size); 423 } 424 425 void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask) 426 { 427 void *p; 428 429 if (mem_init_done) 430 p = kzalloc(size, mask); 431 else { 432 p = alloc_bootmem(size); 433 if (p) 434 memset(p, 0, size); 435 } 436 return p; 437 } 438