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