1 /* 2 * PowerPC version 3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 4 * 5 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) 6 * and Cort Dougan (PReP) (cort@cs.nmt.edu) 7 * Copyright (C) 1996 Paul Mackerras 8 * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com) 9 * 10 * Derived from "arch/i386/mm/init.c" 11 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License 15 * as published by the Free Software Foundation; either version 16 * 2 of the License, or (at your option) any later version. 17 * 18 */ 19 20 #include <linux/module.h> 21 #include <linux/sched.h> 22 #include <linux/kernel.h> 23 #include <linux/errno.h> 24 #include <linux/string.h> 25 #include <linux/types.h> 26 #include <linux/mm.h> 27 #include <linux/stddef.h> 28 #include <linux/init.h> 29 #include <linux/bootmem.h> 30 #include <linux/highmem.h> 31 #include <linux/initrd.h> 32 #include <linux/pagemap.h> 33 #include <linux/lmb.h> 34 35 #include <asm/pgalloc.h> 36 #include <asm/prom.h> 37 #include <asm/io.h> 38 #include <asm/pgtable.h> 39 #include <asm/mmu.h> 40 #include <asm/smp.h> 41 #include <asm/machdep.h> 42 #include <asm/btext.h> 43 #include <asm/tlb.h> 44 #include <asm/sections.h> 45 #include <asm/system.h> 46 47 #include "mmu_decl.h" 48 49 #if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL) 50 /* The ammount of lowmem must be within 0xF0000000 - KERNELBASE. */ 51 #if (CONFIG_LOWMEM_SIZE > (0xF0000000 - PAGE_OFFSET)) 52 #error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL" 53 #endif 54 #endif 55 #define MAX_LOW_MEM CONFIG_LOWMEM_SIZE 56 57 phys_addr_t total_memory; 58 phys_addr_t total_lowmem; 59 60 phys_addr_t memstart_addr = (phys_addr_t)~0ull; 61 EXPORT_SYMBOL(memstart_addr); 62 phys_addr_t kernstart_addr; 63 EXPORT_SYMBOL(kernstart_addr); 64 phys_addr_t lowmem_end_addr; 65 66 int boot_mapsize; 67 #ifdef CONFIG_PPC_PMAC 68 unsigned long agp_special_page; 69 EXPORT_SYMBOL(agp_special_page); 70 #endif 71 72 void MMU_init(void); 73 74 /* XXX should be in current.h -- paulus */ 75 extern struct task_struct *current_set[NR_CPUS]; 76 77 /* 78 * this tells the system to map all of ram with the segregs 79 * (i.e. page tables) instead of the bats. 80 * -- Cort 81 */ 82 int __map_without_bats; 83 int __map_without_ltlbs; 84 85 /* 86 * This tells the system to allow ioremapping memory marked as reserved. 87 */ 88 int __allow_ioremap_reserved; 89 90 /* max amount of low RAM to map in */ 91 unsigned long __max_low_memory = MAX_LOW_MEM; 92 93 /* 94 * address of the limit of what is accessible with initial MMU setup - 95 * 256MB usually, but only 16MB on 601. 96 */ 97 phys_addr_t __initial_memory_limit_addr = (phys_addr_t)0x10000000; 98 99 /* 100 * Check for command-line options that affect what MMU_init will do. 101 */ 102 void MMU_setup(void) 103 { 104 /* Check for nobats option (used in mapin_ram). */ 105 if (strstr(cmd_line, "nobats")) { 106 __map_without_bats = 1; 107 } 108 109 if (strstr(cmd_line, "noltlbs")) { 110 __map_without_ltlbs = 1; 111 } 112 #ifdef CONFIG_DEBUG_PAGEALLOC 113 __map_without_bats = 1; 114 __map_without_ltlbs = 1; 115 #endif 116 } 117 118 /* 119 * MMU_init sets up the basic memory mappings for the kernel, 120 * including both RAM and possibly some I/O regions, 121 * and sets up the page tables and the MMU hardware ready to go. 122 */ 123 void __init MMU_init(void) 124 { 125 if (ppc_md.progress) 126 ppc_md.progress("MMU:enter", 0x111); 127 128 /* 601 can only access 16MB at the moment */ 129 if (PVR_VER(mfspr(SPRN_PVR)) == 1) 130 __initial_memory_limit_addr = 0x01000000; 131 /* 8xx can only access 8MB at the moment */ 132 if (PVR_VER(mfspr(SPRN_PVR)) == 0x50) 133 __initial_memory_limit_addr = 0x00800000; 134 135 /* parse args from command line */ 136 MMU_setup(); 137 138 if (lmb.memory.cnt > 1) { 139 #ifndef CONFIG_WII 140 lmb.memory.cnt = 1; 141 lmb_analyze(); 142 printk(KERN_WARNING "Only using first contiguous memory region"); 143 #else 144 wii_memory_fixups(); 145 #endif 146 } 147 148 total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr; 149 lowmem_end_addr = memstart_addr + total_lowmem; 150 151 #ifdef CONFIG_FSL_BOOKE 152 /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB 153 * entries, so we need to adjust lowmem to match the amount we can map 154 * in the fixed entries */ 155 adjust_total_lowmem(); 156 #endif /* CONFIG_FSL_BOOKE */ 157 158 if (total_lowmem > __max_low_memory) { 159 total_lowmem = __max_low_memory; 160 lowmem_end_addr = memstart_addr + total_lowmem; 161 #ifndef CONFIG_HIGHMEM 162 total_memory = total_lowmem; 163 lmb_enforce_memory_limit(lowmem_end_addr); 164 lmb_analyze(); 165 #endif /* CONFIG_HIGHMEM */ 166 } 167 168 /* Initialize the MMU hardware */ 169 if (ppc_md.progress) 170 ppc_md.progress("MMU:hw init", 0x300); 171 MMU_init_hw(); 172 173 /* Map in all of RAM starting at KERNELBASE */ 174 if (ppc_md.progress) 175 ppc_md.progress("MMU:mapin", 0x301); 176 mapin_ram(); 177 178 /* Initialize early top-down ioremap allocator */ 179 ioremap_bot = IOREMAP_TOP; 180 181 /* Map in I/O resources */ 182 if (ppc_md.progress) 183 ppc_md.progress("MMU:setio", 0x302); 184 185 if (ppc_md.progress) 186 ppc_md.progress("MMU:exit", 0x211); 187 188 /* From now on, btext is no longer BAT mapped if it was at all */ 189 #ifdef CONFIG_BOOTX_TEXT 190 btext_unmap(); 191 #endif 192 } 193 194 /* This is only called until mem_init is done. */ 195 void __init *early_get_page(void) 196 { 197 void *p; 198 199 if (init_bootmem_done) { 200 p = alloc_bootmem_pages(PAGE_SIZE); 201 } else { 202 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE, 203 __initial_memory_limit_addr)); 204 } 205 return p; 206 } 207 208 /* Free up now-unused memory */ 209 static void free_sec(unsigned long start, unsigned long end, const char *name) 210 { 211 unsigned long cnt = 0; 212 213 while (start < end) { 214 ClearPageReserved(virt_to_page(start)); 215 init_page_count(virt_to_page(start)); 216 free_page(start); 217 cnt++; 218 start += PAGE_SIZE; 219 } 220 if (cnt) { 221 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name); 222 totalram_pages += cnt; 223 } 224 } 225 226 void free_initmem(void) 227 { 228 #define FREESEC(TYPE) \ 229 free_sec((unsigned long)(&__ ## TYPE ## _begin), \ 230 (unsigned long)(&__ ## TYPE ## _end), \ 231 #TYPE); 232 233 printk ("Freeing unused kernel memory:"); 234 FREESEC(init); 235 printk("\n"); 236 ppc_md.progress = NULL; 237 #undef FREESEC 238 } 239 240 #ifdef CONFIG_BLK_DEV_INITRD 241 void free_initrd_mem(unsigned long start, unsigned long end) 242 { 243 if (start < end) 244 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 245 for (; start < end; start += PAGE_SIZE) { 246 ClearPageReserved(virt_to_page(start)); 247 init_page_count(virt_to_page(start)); 248 free_page(start); 249 totalram_pages++; 250 } 251 } 252 #endif 253 254