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