1 /* 2 * Copyright (C) 2007-2008 Michal Simek <[email protected]> 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/of_fdt.h> 17 #include <linux/pagemap.h> 18 #include <linux/pfn.h> 19 #include <linux/slab.h> 20 #include <linux/swap.h> 21 #include <linux/export.h> 22 23 #include <asm/page.h> 24 #include <asm/mmu_context.h> 25 #include <asm/pgalloc.h> 26 #include <asm/sections.h> 27 #include <asm/tlb.h> 28 #include <asm/fixmap.h> 29 30 /* Use for MMU and noMMU because of PCI generic code */ 31 int mem_init_done; 32 33 char *klimit = _end; 34 35 /* 36 * Initialize the bootmem system and give it all the memory we 37 * have available. 38 */ 39 unsigned long memory_start; 40 EXPORT_SYMBOL(memory_start); 41 unsigned long memory_size; 42 EXPORT_SYMBOL(memory_size); 43 unsigned long lowmem_size; 44 45 EXPORT_SYMBOL(min_low_pfn); 46 EXPORT_SYMBOL(max_low_pfn); 47 48 #ifdef CONFIG_HIGHMEM 49 static void __init highmem_init(void) 50 { 51 pr_debug("%x\n", (u32)PKMAP_BASE); 52 map_page(PKMAP_BASE, 0, 0); /* XXX gross */ 53 pkmap_page_table = virt_to_kpte(PKMAP_BASE); 54 } 55 #endif /* CONFIG_HIGHMEM */ 56 57 /* 58 * paging_init() sets up the page tables - in fact we've already done this. 59 */ 60 static void __init paging_init(void) 61 { 62 unsigned long zones_size[MAX_NR_ZONES]; 63 int idx; 64 65 /* Setup fixmaps */ 66 for (idx = 0; idx < __end_of_fixed_addresses; idx++) 67 clear_fixmap(idx); 68 69 /* Clean every zones */ 70 memset(zones_size, 0, sizeof(zones_size)); 71 72 #ifdef CONFIG_HIGHMEM 73 highmem_init(); 74 75 zones_size[ZONE_DMA] = max_low_pfn; 76 zones_size[ZONE_HIGHMEM] = max_pfn; 77 #else 78 zones_size[ZONE_DMA] = max_pfn; 79 #endif 80 81 /* We don't have holes in memory map */ 82 free_area_init(zones_size); 83 } 84 85 void __init setup_memory(void) 86 { 87 /* 88 * Kernel: 89 * start: base phys address of kernel - page align 90 * end: base phys address of kernel - page align 91 * 92 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start) 93 * max_low_pfn 94 */ 95 96 /* memory start is from the kernel end (aligned) to higher addr */ 97 min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */ 98 max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT; 99 max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT; 100 101 pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn); 102 pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn); 103 pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn); 104 105 paging_init(); 106 } 107 108 void __init mem_init(void) 109 { 110 /* this will put all memory onto the freelists */ 111 memblock_free_all(); 112 113 mem_init_done = 1; 114 } 115 116 int page_is_ram(unsigned long pfn) 117 { 118 return pfn < max_low_pfn; 119 } 120 121 /* 122 * Check for command-line options that affect what MMU_init will do. 123 */ 124 static void mm_cmdline_setup(void) 125 { 126 unsigned long maxmem = 0; 127 char *p = cmd_line; 128 129 /* Look for mem= option on command line */ 130 p = strstr(cmd_line, "mem="); 131 if (p) { 132 p += 4; 133 maxmem = memparse(p, &p); 134 if (maxmem && memory_size > maxmem) { 135 memory_size = maxmem; 136 memblock.memory.regions[0].size = memory_size; 137 } 138 } 139 } 140 141 /* 142 * MMU_init_hw does the chip-specific initialization of the MMU hardware. 143 */ 144 static void __init mmu_init_hw(void) 145 { 146 /* 147 * The Zone Protection Register (ZPR) defines how protection will 148 * be applied to every page which is a member of a given zone. At 149 * present, we utilize only two of the zones. 150 * The zone index bits (of ZSEL) in the PTE are used for software 151 * indicators, except the LSB. For user access, zone 1 is used, 152 * for kernel access, zone 0 is used. We set all but zone 1 153 * to zero, allowing only kernel access as indicated in the PTE. 154 * For zone 1, we set a 01 binary (a value of 10 will not work) 155 * to allow user access as indicated in the PTE. This also allows 156 * kernel access as indicated in the PTE. 157 */ 158 __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \ 159 "mts rzpr, r11;" 160 : : : "r11"); 161 } 162 163 /* 164 * MMU_init sets up the basic memory mappings for the kernel, 165 * including both RAM and possibly some I/O regions, 166 * and sets up the page tables and the MMU hardware ready to go. 167 */ 168 169 /* called from head.S */ 170 asmlinkage void __init mmu_init(void) 171 { 172 unsigned int kstart, ksize; 173 174 if ((u32) memblock.memory.regions[0].size < 0x400000) { 175 pr_emerg("Memory must be greater than 4MB\n"); 176 machine_restart(NULL); 177 } 178 179 if ((u32) memblock.memory.regions[0].size < kernel_tlb) { 180 pr_emerg("Kernel size is greater than memory node\n"); 181 machine_restart(NULL); 182 } 183 184 /* Find main memory where the kernel is */ 185 memory_start = (u32) memblock.memory.regions[0].base; 186 lowmem_size = memory_size = (u32) memblock.memory.regions[0].size; 187 188 if (lowmem_size > CONFIG_LOWMEM_SIZE) { 189 lowmem_size = CONFIG_LOWMEM_SIZE; 190 #ifndef CONFIG_HIGHMEM 191 memory_size = lowmem_size; 192 #endif 193 } 194 195 mm_cmdline_setup(); /* FIXME parse args from command line - not used */ 196 197 /* 198 * Map out the kernel text/data/bss from the available physical 199 * memory. 200 */ 201 kstart = __pa(CONFIG_KERNEL_START); /* kernel start */ 202 /* kernel size */ 203 ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START)); 204 memblock_reserve(kstart, ksize); 205 206 #if defined(CONFIG_BLK_DEV_INITRD) 207 /* Remove the init RAM disk from the available memory. */ 208 if (initrd_start) { 209 unsigned long size; 210 size = initrd_end - initrd_start; 211 memblock_reserve(__virt_to_phys(initrd_start), size); 212 } 213 #endif /* CONFIG_BLK_DEV_INITRD */ 214 215 /* Initialize the MMU hardware */ 216 mmu_init_hw(); 217 218 /* Map in all of RAM starting at CONFIG_KERNEL_START */ 219 mapin_ram(); 220 221 /* Extend vmalloc and ioremap area as big as possible */ 222 #ifdef CONFIG_HIGHMEM 223 ioremap_base = ioremap_bot = PKMAP_BASE; 224 #else 225 ioremap_base = ioremap_bot = FIXADDR_START; 226 #endif 227 228 /* Initialize the context management stuff */ 229 mmu_context_init(); 230 231 /* Shortly after that, the entire linear mapping will be available */ 232 /* This will also cause that unflatten device tree will be allocated 233 * inside 768MB limit */ 234 memblock_set_current_limit(memory_start + lowmem_size - 1); 235 236 parse_early_param(); 237 238 early_init_fdt_scan_reserved_mem(); 239 240 /* CMA initialization */ 241 dma_contiguous_reserve(memory_start + lowmem_size - 1); 242 243 memblock_dump_all(); 244 } 245 246 static const pgprot_t protection_map[16] = { 247 [VM_NONE] = PAGE_NONE, 248 [VM_READ] = PAGE_READONLY_X, 249 [VM_WRITE] = PAGE_COPY, 250 [VM_WRITE | VM_READ] = PAGE_COPY_X, 251 [VM_EXEC] = PAGE_READONLY, 252 [VM_EXEC | VM_READ] = PAGE_READONLY_X, 253 [VM_EXEC | VM_WRITE] = PAGE_COPY, 254 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_X, 255 [VM_SHARED] = PAGE_NONE, 256 [VM_SHARED | VM_READ] = PAGE_READONLY_X, 257 [VM_SHARED | VM_WRITE] = PAGE_SHARED, 258 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED_X, 259 [VM_SHARED | VM_EXEC] = PAGE_READONLY, 260 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_X, 261 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED, 262 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_X 263 }; 264 DECLARE_VM_GET_PAGE_PROT 265