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 /* max amount of low RAM to map in */ 86 unsigned long __max_low_memory = MAX_LOW_MEM; 87 88 /* 89 * address of the limit of what is accessible with initial MMU setup - 90 * 256MB usually, but only 16MB on 601. 91 */ 92 phys_addr_t __initial_memory_limit_addr = (phys_addr_t)0x10000000; 93 94 /* 95 * Check for command-line options that affect what MMU_init will do. 96 */ 97 void MMU_setup(void) 98 { 99 /* Check for nobats option (used in mapin_ram). */ 100 if (strstr(cmd_line, "nobats")) { 101 __map_without_bats = 1; 102 } 103 104 if (strstr(cmd_line, "noltlbs")) { 105 __map_without_ltlbs = 1; 106 } 107 #ifdef CONFIG_DEBUG_PAGEALLOC 108 __map_without_bats = 1; 109 __map_without_ltlbs = 1; 110 #endif 111 } 112 113 /* 114 * MMU_init sets up the basic memory mappings for the kernel, 115 * including both RAM and possibly some I/O regions, 116 * and sets up the page tables and the MMU hardware ready to go. 117 */ 118 void __init MMU_init(void) 119 { 120 if (ppc_md.progress) 121 ppc_md.progress("MMU:enter", 0x111); 122 123 /* 601 can only access 16MB at the moment */ 124 if (PVR_VER(mfspr(SPRN_PVR)) == 1) 125 __initial_memory_limit_addr = 0x01000000; 126 /* 8xx can only access 8MB at the moment */ 127 if (PVR_VER(mfspr(SPRN_PVR)) == 0x50) 128 __initial_memory_limit_addr = 0x00800000; 129 130 /* parse args from command line */ 131 MMU_setup(); 132 133 if (lmb.memory.cnt > 1) { 134 lmb.memory.cnt = 1; 135 lmb_analyze(); 136 printk(KERN_WARNING "Only using first contiguous memory region"); 137 } 138 139 total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr; 140 lowmem_end_addr = memstart_addr + total_lowmem; 141 142 #ifdef CONFIG_FSL_BOOKE 143 /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB 144 * entries, so we need to adjust lowmem to match the amount we can map 145 * in the fixed entries */ 146 adjust_total_lowmem(); 147 #endif /* CONFIG_FSL_BOOKE */ 148 149 if (total_lowmem > __max_low_memory) { 150 total_lowmem = __max_low_memory; 151 lowmem_end_addr = memstart_addr + total_lowmem; 152 #ifndef CONFIG_HIGHMEM 153 total_memory = total_lowmem; 154 lmb_enforce_memory_limit(lowmem_end_addr); 155 lmb_analyze(); 156 #endif /* CONFIG_HIGHMEM */ 157 } 158 159 /* Initialize the MMU hardware */ 160 if (ppc_md.progress) 161 ppc_md.progress("MMU:hw init", 0x300); 162 MMU_init_hw(); 163 164 /* Map in all of RAM starting at KERNELBASE */ 165 if (ppc_md.progress) 166 ppc_md.progress("MMU:mapin", 0x301); 167 mapin_ram(); 168 169 /* Initialize early top-down ioremap allocator */ 170 ioremap_bot = IOREMAP_TOP; 171 172 /* Map in I/O resources */ 173 if (ppc_md.progress) 174 ppc_md.progress("MMU:setio", 0x302); 175 176 if (ppc_md.progress) 177 ppc_md.progress("MMU:exit", 0x211); 178 179 /* From now on, btext is no longer BAT mapped if it was at all */ 180 #ifdef CONFIG_BOOTX_TEXT 181 btext_unmap(); 182 #endif 183 } 184 185 /* This is only called until mem_init is done. */ 186 void __init *early_get_page(void) 187 { 188 void *p; 189 190 if (init_bootmem_done) { 191 p = alloc_bootmem_pages(PAGE_SIZE); 192 } else { 193 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE, 194 __initial_memory_limit_addr)); 195 } 196 return p; 197 } 198 199 /* Free up now-unused memory */ 200 static void free_sec(unsigned long start, unsigned long end, const char *name) 201 { 202 unsigned long cnt = 0; 203 204 while (start < end) { 205 ClearPageReserved(virt_to_page(start)); 206 init_page_count(virt_to_page(start)); 207 free_page(start); 208 cnt++; 209 start += PAGE_SIZE; 210 } 211 if (cnt) { 212 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name); 213 totalram_pages += cnt; 214 } 215 } 216 217 void free_initmem(void) 218 { 219 #define FREESEC(TYPE) \ 220 free_sec((unsigned long)(&__ ## TYPE ## _begin), \ 221 (unsigned long)(&__ ## TYPE ## _end), \ 222 #TYPE); 223 224 printk ("Freeing unused kernel memory:"); 225 FREESEC(init); 226 printk("\n"); 227 ppc_md.progress = NULL; 228 #undef FREESEC 229 } 230 231 #ifdef CONFIG_BLK_DEV_INITRD 232 void free_initrd_mem(unsigned long start, unsigned long end) 233 { 234 if (start < end) 235 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 236 for (; start < end; start += PAGE_SIZE) { 237 ClearPageReserved(virt_to_page(start)); 238 init_page_count(virt_to_page(start)); 239 free_page(start); 240 totalram_pages++; 241 } 242 } 243 #endif 244 245 #ifdef CONFIG_PROC_KCORE 246 static struct kcore_list kcore_vmem; 247 248 static int __init setup_kcore(void) 249 { 250 int i; 251 252 for (i = 0; i < lmb.memory.cnt; i++) { 253 unsigned long base; 254 unsigned long size; 255 struct kcore_list *kcore_mem; 256 257 base = lmb.memory.region[i].base; 258 size = lmb.memory.region[i].size; 259 260 kcore_mem = kmalloc(sizeof(struct kcore_list), GFP_ATOMIC); 261 if (!kcore_mem) 262 panic("%s: kmalloc failed\n", __func__); 263 264 /* must stay under 32 bits */ 265 if ( 0xfffffffful - (unsigned long)__va(base) < size) { 266 size = 0xfffffffful - (unsigned long)(__va(base)); 267 printk(KERN_DEBUG "setup_kcore: restrict size=%lx\n", 268 size); 269 } 270 271 kclist_add(kcore_mem, __va(base), size); 272 } 273 274 kclist_add(&kcore_vmem, (void *)VMALLOC_START, 275 VMALLOC_END-VMALLOC_START); 276 277 return 0; 278 } 279 module_init(setup_kcore); 280 #endif 281