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 pgd_t *pgd = pgd_offset_k(vaddr); 57 p4d_t *p4d = p4d_offset(pgd, vaddr); 58 pud_t *pud = pud_offset(p4d, vaddr); 59 60 return pte_offset_kernel(pmd_offset(pud, vaddr), vaddr); 61 } 62 63 static void __init highmem_init(void) 64 { 65 pr_debug("%x\n", (u32)PKMAP_BASE); 66 map_page(PKMAP_BASE, 0, 0); /* XXX gross */ 67 pkmap_page_table = virt_to_kpte(PKMAP_BASE); 68 69 kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN)); 70 kmap_prot = PAGE_KERNEL; 71 } 72 73 static void highmem_setup(void) 74 { 75 unsigned long pfn; 76 77 for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) { 78 struct page *page = pfn_to_page(pfn); 79 80 /* FIXME not sure about */ 81 if (!memblock_is_reserved(pfn << PAGE_SHIFT)) 82 free_highmem_page(page); 83 } 84 } 85 #endif /* CONFIG_HIGHMEM */ 86 87 /* 88 * paging_init() sets up the page tables - in fact we've already done this. 89 */ 90 static void __init paging_init(void) 91 { 92 unsigned long zones_size[MAX_NR_ZONES]; 93 #ifdef CONFIG_MMU 94 int idx; 95 96 /* Setup fixmaps */ 97 for (idx = 0; idx < __end_of_fixed_addresses; idx++) 98 clear_fixmap(idx); 99 #endif 100 101 /* Clean every zones */ 102 memset(zones_size, 0, sizeof(zones_size)); 103 104 #ifdef CONFIG_HIGHMEM 105 highmem_init(); 106 107 zones_size[ZONE_DMA] = max_low_pfn; 108 zones_size[ZONE_HIGHMEM] = max_pfn; 109 #else 110 zones_size[ZONE_DMA] = max_pfn; 111 #endif 112 113 /* We don't have holes in memory map */ 114 free_area_init_nodes(zones_size); 115 } 116 117 void __init setup_memory(void) 118 { 119 struct memblock_region *reg; 120 121 #ifndef CONFIG_MMU 122 u32 kernel_align_start, kernel_align_size; 123 124 /* Find main memory where is the kernel */ 125 for_each_memblock(memory, reg) { 126 memory_start = (u32)reg->base; 127 lowmem_size = reg->size; 128 if ((memory_start <= (u32)_text) && 129 ((u32)_text <= (memory_start + lowmem_size - 1))) { 130 memory_size = lowmem_size; 131 PAGE_OFFSET = memory_start; 132 pr_info("%s: Main mem: 0x%x, size 0x%08x\n", 133 __func__, (u32) memory_start, 134 (u32) memory_size); 135 break; 136 } 137 } 138 139 if (!memory_start || !memory_size) { 140 panic("%s: Missing memory setting 0x%08x, size=0x%08x\n", 141 __func__, (u32) memory_start, (u32) memory_size); 142 } 143 144 /* reservation of region where is the kernel */ 145 kernel_align_start = PAGE_DOWN((u32)_text); 146 /* ALIGN can be remove because _end in vmlinux.lds.S is align */ 147 kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start; 148 pr_info("%s: kernel addr:0x%08x-0x%08x size=0x%08x\n", 149 __func__, kernel_align_start, kernel_align_start 150 + kernel_align_size, kernel_align_size); 151 memblock_reserve(kernel_align_start, kernel_align_size); 152 #endif 153 /* 154 * Kernel: 155 * start: base phys address of kernel - page align 156 * end: base phys address of kernel - page align 157 * 158 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start) 159 * max_low_pfn 160 * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn) 161 */ 162 163 /* memory start is from the kernel end (aligned) to higher addr */ 164 min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */ 165 /* RAM is assumed contiguous */ 166 max_mapnr = memory_size >> PAGE_SHIFT; 167 max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT; 168 max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT; 169 170 pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr); 171 pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn); 172 pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn); 173 pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn); 174 175 /* Add active regions with valid PFNs */ 176 for_each_memblock(memory, reg) { 177 unsigned long start_pfn, end_pfn; 178 179 start_pfn = memblock_region_memory_base_pfn(reg); 180 end_pfn = memblock_region_memory_end_pfn(reg); 181 memblock_set_node(start_pfn << PAGE_SHIFT, 182 (end_pfn - start_pfn) << PAGE_SHIFT, 183 &memblock.memory, 0); 184 } 185 186 /* XXX need to clip this if using highmem? */ 187 sparse_memory_present_with_active_regions(0); 188 189 paging_init(); 190 } 191 192 void __init mem_init(void) 193 { 194 high_memory = (void *)__va(memory_start + lowmem_size - 1); 195 196 /* this will put all memory onto the freelists */ 197 memblock_free_all(); 198 #ifdef CONFIG_HIGHMEM 199 highmem_setup(); 200 #endif 201 202 mem_init_print_info(NULL); 203 #ifdef CONFIG_MMU 204 pr_info("Kernel virtual memory layout:\n"); 205 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP); 206 #ifdef CONFIG_HIGHMEM 207 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n", 208 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP)); 209 #endif /* CONFIG_HIGHMEM */ 210 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n", 211 ioremap_bot, ioremap_base); 212 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n", 213 (unsigned long)VMALLOC_START, VMALLOC_END); 214 #endif 215 mem_init_done = 1; 216 } 217 218 #ifndef CONFIG_MMU 219 int page_is_ram(unsigned long pfn) 220 { 221 return __range_ok(pfn, 0); 222 } 223 #else 224 int page_is_ram(unsigned long pfn) 225 { 226 return pfn < max_low_pfn; 227 } 228 229 /* 230 * Check for command-line options that affect what MMU_init will do. 231 */ 232 static void mm_cmdline_setup(void) 233 { 234 unsigned long maxmem = 0; 235 char *p = cmd_line; 236 237 /* Look for mem= option on command line */ 238 p = strstr(cmd_line, "mem="); 239 if (p) { 240 p += 4; 241 maxmem = memparse(p, &p); 242 if (maxmem && memory_size > maxmem) { 243 memory_size = maxmem; 244 memblock.memory.regions[0].size = memory_size; 245 } 246 } 247 } 248 249 /* 250 * MMU_init_hw does the chip-specific initialization of the MMU hardware. 251 */ 252 static void __init mmu_init_hw(void) 253 { 254 /* 255 * The Zone Protection Register (ZPR) defines how protection will 256 * be applied to every page which is a member of a given zone. At 257 * present, we utilize only two of the zones. 258 * The zone index bits (of ZSEL) in the PTE are used for software 259 * indicators, except the LSB. For user access, zone 1 is used, 260 * for kernel access, zone 0 is used. We set all but zone 1 261 * to zero, allowing only kernel access as indicated in the PTE. 262 * For zone 1, we set a 01 binary (a value of 10 will not work) 263 * to allow user access as indicated in the PTE. This also allows 264 * kernel access as indicated in the PTE. 265 */ 266 __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \ 267 "mts rzpr, r11;" 268 : : : "r11"); 269 } 270 271 /* 272 * MMU_init sets up the basic memory mappings for the kernel, 273 * including both RAM and possibly some I/O regions, 274 * and sets up the page tables and the MMU hardware ready to go. 275 */ 276 277 /* called from head.S */ 278 asmlinkage void __init mmu_init(void) 279 { 280 unsigned int kstart, ksize; 281 282 if (!memblock.reserved.cnt) { 283 pr_emerg("Error memory count\n"); 284 machine_restart(NULL); 285 } 286 287 if ((u32) memblock.memory.regions[0].size < 0x400000) { 288 pr_emerg("Memory must be greater than 4MB\n"); 289 machine_restart(NULL); 290 } 291 292 if ((u32) memblock.memory.regions[0].size < kernel_tlb) { 293 pr_emerg("Kernel size is greater than memory node\n"); 294 machine_restart(NULL); 295 } 296 297 /* Find main memory where the kernel is */ 298 memory_start = (u32) memblock.memory.regions[0].base; 299 lowmem_size = memory_size = (u32) memblock.memory.regions[0].size; 300 301 if (lowmem_size > CONFIG_LOWMEM_SIZE) { 302 lowmem_size = CONFIG_LOWMEM_SIZE; 303 #ifndef CONFIG_HIGHMEM 304 memory_size = lowmem_size; 305 #endif 306 } 307 308 mm_cmdline_setup(); /* FIXME parse args from command line - not used */ 309 310 /* 311 * Map out the kernel text/data/bss from the available physical 312 * memory. 313 */ 314 kstart = __pa(CONFIG_KERNEL_START); /* kernel start */ 315 /* kernel size */ 316 ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START)); 317 memblock_reserve(kstart, ksize); 318 319 #if defined(CONFIG_BLK_DEV_INITRD) 320 /* Remove the init RAM disk from the available memory. */ 321 if (initrd_start) { 322 unsigned long size; 323 size = initrd_end - initrd_start; 324 memblock_reserve(__virt_to_phys(initrd_start), size); 325 } 326 #endif /* CONFIG_BLK_DEV_INITRD */ 327 328 /* Initialize the MMU hardware */ 329 mmu_init_hw(); 330 331 /* Map in all of RAM starting at CONFIG_KERNEL_START */ 332 mapin_ram(); 333 334 /* Extend vmalloc and ioremap area as big as possible */ 335 #ifdef CONFIG_HIGHMEM 336 ioremap_base = ioremap_bot = PKMAP_BASE; 337 #else 338 ioremap_base = ioremap_bot = FIXADDR_START; 339 #endif 340 341 /* Initialize the context management stuff */ 342 mmu_context_init(); 343 344 /* Shortly after that, the entire linear mapping will be available */ 345 /* This will also cause that unflatten device tree will be allocated 346 * inside 768MB limit */ 347 memblock_set_current_limit(memory_start + lowmem_size - 1); 348 } 349 350 /* This is only called until mem_init is done. */ 351 void __init *early_get_page(void) 352 { 353 /* 354 * Mem start + kernel_tlb -> here is limit 355 * because of mem mapping from head.S 356 */ 357 return memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE, 358 MEMBLOCK_LOW_LIMIT, memory_start + kernel_tlb, 359 NUMA_NO_NODE); 360 } 361 362 #endif /* CONFIG_MMU */ 363 364 void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask) 365 { 366 void *p; 367 368 if (mem_init_done) { 369 p = kzalloc(size, mask); 370 } else { 371 p = memblock_alloc(size, SMP_CACHE_BYTES); 372 if (!p) 373 panic("%s: Failed to allocate %zu bytes\n", 374 __func__, size); 375 } 376 377 return p; 378 } 379