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