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/dma-map-ops.h> 11 #include <linux/memblock.h> 12 #include <linux/init.h> 13 #include <linux/kernel.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 char *klimit = _end; 33 34 /* 35 * Initialize the bootmem system and give it all the memory we 36 * have available. 37 */ 38 unsigned long memory_start; 39 EXPORT_SYMBOL(memory_start); 40 unsigned long memory_size; 41 EXPORT_SYMBOL(memory_size); 42 unsigned long lowmem_size; 43 44 EXPORT_SYMBOL(min_low_pfn); 45 EXPORT_SYMBOL(max_low_pfn); 46 47 #ifdef CONFIG_HIGHMEM 48 pte_t *kmap_pte; 49 EXPORT_SYMBOL(kmap_pte); 50 51 static void __init highmem_init(void) 52 { 53 pr_debug("%x\n", (u32)PKMAP_BASE); 54 map_page(PKMAP_BASE, 0, 0); /* XXX gross */ 55 pkmap_page_table = virt_to_kpte(PKMAP_BASE); 56 57 kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN)); 58 } 59 60 static void highmem_setup(void) 61 { 62 unsigned long pfn; 63 64 for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) { 65 struct page *page = pfn_to_page(pfn); 66 67 /* FIXME not sure about */ 68 if (!memblock_is_reserved(pfn << PAGE_SHIFT)) 69 free_highmem_page(page); 70 } 71 } 72 #endif /* CONFIG_HIGHMEM */ 73 74 /* 75 * paging_init() sets up the page tables - in fact we've already done this. 76 */ 77 static void __init paging_init(void) 78 { 79 unsigned long zones_size[MAX_NR_ZONES]; 80 int idx; 81 82 /* Setup fixmaps */ 83 for (idx = 0; idx < __end_of_fixed_addresses; idx++) 84 clear_fixmap(idx); 85 86 /* Clean every zones */ 87 memset(zones_size, 0, sizeof(zones_size)); 88 89 #ifdef CONFIG_HIGHMEM 90 highmem_init(); 91 92 zones_size[ZONE_DMA] = max_low_pfn; 93 zones_size[ZONE_HIGHMEM] = max_pfn; 94 #else 95 zones_size[ZONE_DMA] = max_pfn; 96 #endif 97 98 /* We don't have holes in memory map */ 99 free_area_init(zones_size); 100 } 101 102 void __init setup_memory(void) 103 { 104 /* 105 * Kernel: 106 * start: base phys address of kernel - page align 107 * end: base phys address of kernel - page align 108 * 109 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start) 110 * max_low_pfn 111 * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn) 112 */ 113 114 /* memory start is from the kernel end (aligned) to higher addr */ 115 min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */ 116 /* RAM is assumed contiguous */ 117 max_mapnr = memory_size >> PAGE_SHIFT; 118 max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT; 119 max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT; 120 121 pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr); 122 pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn); 123 pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn); 124 pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn); 125 126 paging_init(); 127 } 128 129 void __init mem_init(void) 130 { 131 high_memory = (void *)__va(memory_start + lowmem_size - 1); 132 133 /* this will put all memory onto the freelists */ 134 memblock_free_all(); 135 #ifdef CONFIG_HIGHMEM 136 highmem_setup(); 137 #endif 138 139 mem_init_print_info(NULL); 140 mem_init_done = 1; 141 } 142 143 int page_is_ram(unsigned long pfn) 144 { 145 return pfn < max_low_pfn; 146 } 147 148 /* 149 * Check for command-line options that affect what MMU_init will do. 150 */ 151 static void mm_cmdline_setup(void) 152 { 153 unsigned long maxmem = 0; 154 char *p = cmd_line; 155 156 /* Look for mem= option on command line */ 157 p = strstr(cmd_line, "mem="); 158 if (p) { 159 p += 4; 160 maxmem = memparse(p, &p); 161 if (maxmem && memory_size > maxmem) { 162 memory_size = maxmem; 163 memblock.memory.regions[0].size = memory_size; 164 } 165 } 166 } 167 168 /* 169 * MMU_init_hw does the chip-specific initialization of the MMU hardware. 170 */ 171 static void __init mmu_init_hw(void) 172 { 173 /* 174 * The Zone Protection Register (ZPR) defines how protection will 175 * be applied to every page which is a member of a given zone. At 176 * present, we utilize only two of the zones. 177 * The zone index bits (of ZSEL) in the PTE are used for software 178 * indicators, except the LSB. For user access, zone 1 is used, 179 * for kernel access, zone 0 is used. We set all but zone 1 180 * to zero, allowing only kernel access as indicated in the PTE. 181 * For zone 1, we set a 01 binary (a value of 10 will not work) 182 * to allow user access as indicated in the PTE. This also allows 183 * kernel access as indicated in the PTE. 184 */ 185 __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \ 186 "mts rzpr, r11;" 187 : : : "r11"); 188 } 189 190 /* 191 * MMU_init sets up the basic memory mappings for the kernel, 192 * including both RAM and possibly some I/O regions, 193 * and sets up the page tables and the MMU hardware ready to go. 194 */ 195 196 /* called from head.S */ 197 asmlinkage void __init mmu_init(void) 198 { 199 unsigned int kstart, ksize; 200 201 if (!memblock.reserved.cnt) { 202 pr_emerg("Error memory count\n"); 203 machine_restart(NULL); 204 } 205 206 if ((u32) memblock.memory.regions[0].size < 0x400000) { 207 pr_emerg("Memory must be greater than 4MB\n"); 208 machine_restart(NULL); 209 } 210 211 if ((u32) memblock.memory.regions[0].size < kernel_tlb) { 212 pr_emerg("Kernel size is greater than memory node\n"); 213 machine_restart(NULL); 214 } 215 216 /* Find main memory where the kernel is */ 217 memory_start = (u32) memblock.memory.regions[0].base; 218 lowmem_size = memory_size = (u32) memblock.memory.regions[0].size; 219 220 if (lowmem_size > CONFIG_LOWMEM_SIZE) { 221 lowmem_size = CONFIG_LOWMEM_SIZE; 222 #ifndef CONFIG_HIGHMEM 223 memory_size = lowmem_size; 224 #endif 225 } 226 227 mm_cmdline_setup(); /* FIXME parse args from command line - not used */ 228 229 /* 230 * Map out the kernel text/data/bss from the available physical 231 * memory. 232 */ 233 kstart = __pa(CONFIG_KERNEL_START); /* kernel start */ 234 /* kernel size */ 235 ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START)); 236 memblock_reserve(kstart, ksize); 237 238 #if defined(CONFIG_BLK_DEV_INITRD) 239 /* Remove the init RAM disk from the available memory. */ 240 if (initrd_start) { 241 unsigned long size; 242 size = initrd_end - initrd_start; 243 memblock_reserve(__virt_to_phys(initrd_start), size); 244 } 245 #endif /* CONFIG_BLK_DEV_INITRD */ 246 247 /* Initialize the MMU hardware */ 248 mmu_init_hw(); 249 250 /* Map in all of RAM starting at CONFIG_KERNEL_START */ 251 mapin_ram(); 252 253 /* Extend vmalloc and ioremap area as big as possible */ 254 #ifdef CONFIG_HIGHMEM 255 ioremap_base = ioremap_bot = PKMAP_BASE; 256 #else 257 ioremap_base = ioremap_bot = FIXADDR_START; 258 #endif 259 260 /* Initialize the context management stuff */ 261 mmu_context_init(); 262 263 /* Shortly after that, the entire linear mapping will be available */ 264 /* This will also cause that unflatten device tree will be allocated 265 * inside 768MB limit */ 266 memblock_set_current_limit(memory_start + lowmem_size - 1); 267 268 parse_early_param(); 269 270 /* CMA initialization */ 271 dma_contiguous_reserve(memory_start + lowmem_size - 1); 272 } 273 274 /* This is only called until mem_init is done. */ 275 void __init *early_get_page(void) 276 { 277 /* 278 * Mem start + kernel_tlb -> here is limit 279 * because of mem mapping from head.S 280 */ 281 return memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE, 282 MEMBLOCK_LOW_LIMIT, memory_start + kernel_tlb, 283 NUMA_NO_NODE); 284 } 285 286 void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask) 287 { 288 void *p; 289 290 if (mem_init_done) { 291 p = kzalloc(size, mask); 292 } else { 293 p = memblock_alloc(size, SMP_CACHE_BYTES); 294 if (!p) 295 panic("%s: Failed to allocate %zu bytes\n", 296 __func__, size); 297 } 298 299 return p; 300 } 301