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