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 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 58 59 phys_addr_t total_memory; 60 phys_addr_t total_lowmem; 61 62 phys_addr_t memstart_addr = (phys_addr_t)~0ull; 63 EXPORT_SYMBOL(memstart_addr); 64 phys_addr_t kernstart_addr; 65 EXPORT_SYMBOL(kernstart_addr); 66 phys_addr_t lowmem_end_addr; 67 68 int boot_mapsize; 69 #ifdef CONFIG_PPC_PMAC 70 unsigned long agp_special_page; 71 EXPORT_SYMBOL(agp_special_page); 72 #endif 73 74 void MMU_init(void); 75 76 /* XXX should be in current.h -- paulus */ 77 extern struct task_struct *current_set[NR_CPUS]; 78 79 /* 80 * this tells the system to map all of ram with the segregs 81 * (i.e. page tables) instead of the bats. 82 * -- Cort 83 */ 84 int __map_without_bats; 85 int __map_without_ltlbs; 86 87 /* max amount of low RAM to map in */ 88 unsigned long __max_low_memory = MAX_LOW_MEM; 89 90 /* 91 * address of the limit of what is accessible with initial MMU setup - 92 * 256MB usually, but only 16MB on 601. 93 */ 94 phys_addr_t __initial_memory_limit_addr = (phys_addr_t)0x10000000; 95 96 /* 97 * Check for command-line options that affect what MMU_init will do. 98 */ 99 void MMU_setup(void) 100 { 101 /* Check for nobats option (used in mapin_ram). */ 102 if (strstr(cmd_line, "nobats")) { 103 __map_without_bats = 1; 104 } 105 106 if (strstr(cmd_line, "noltlbs")) { 107 __map_without_ltlbs = 1; 108 } 109 #ifdef CONFIG_DEBUG_PAGEALLOC 110 __map_without_bats = 1; 111 __map_without_ltlbs = 1; 112 #endif 113 } 114 115 /* 116 * MMU_init sets up the basic memory mappings for the kernel, 117 * including both RAM and possibly some I/O regions, 118 * and sets up the page tables and the MMU hardware ready to go. 119 */ 120 void __init MMU_init(void) 121 { 122 if (ppc_md.progress) 123 ppc_md.progress("MMU:enter", 0x111); 124 125 /* 601 can only access 16MB at the moment */ 126 if (PVR_VER(mfspr(SPRN_PVR)) == 1) 127 __initial_memory_limit_addr = 0x01000000; 128 /* 8xx can only access 8MB at the moment */ 129 if (PVR_VER(mfspr(SPRN_PVR)) == 0x50) 130 __initial_memory_limit_addr = 0x00800000; 131 132 /* parse args from command line */ 133 MMU_setup(); 134 135 if (lmb.memory.cnt > 1) { 136 lmb.memory.cnt = 1; 137 lmb_analyze(); 138 printk(KERN_WARNING "Only using first contiguous memory region"); 139 } 140 141 total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr; 142 lowmem_end_addr = memstart_addr + total_lowmem; 143 144 #ifdef CONFIG_FSL_BOOKE 145 /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB 146 * entries, so we need to adjust lowmem to match the amount we can map 147 * in the fixed entries */ 148 adjust_total_lowmem(); 149 #endif /* CONFIG_FSL_BOOKE */ 150 151 if (total_lowmem > __max_low_memory) { 152 total_lowmem = __max_low_memory; 153 lowmem_end_addr = memstart_addr + total_lowmem; 154 #ifndef CONFIG_HIGHMEM 155 total_memory = total_lowmem; 156 lmb_enforce_memory_limit(lowmem_end_addr); 157 lmb_analyze(); 158 #endif /* CONFIG_HIGHMEM */ 159 } 160 161 /* Initialize the MMU hardware */ 162 if (ppc_md.progress) 163 ppc_md.progress("MMU:hw init", 0x300); 164 MMU_init_hw(); 165 166 /* Map in all of RAM starting at KERNELBASE */ 167 if (ppc_md.progress) 168 ppc_md.progress("MMU:mapin", 0x301); 169 mapin_ram(); 170 171 /* Initialize early top-down ioremap allocator */ 172 ioremap_bot = IOREMAP_TOP; 173 174 /* Map in I/O resources */ 175 if (ppc_md.progress) 176 ppc_md.progress("MMU:setio", 0x302); 177 178 if (ppc_md.progress) 179 ppc_md.progress("MMU:exit", 0x211); 180 181 /* From now on, btext is no longer BAT mapped if it was at all */ 182 #ifdef CONFIG_BOOTX_TEXT 183 btext_unmap(); 184 #endif 185 } 186 187 /* This is only called until mem_init is done. */ 188 void __init *early_get_page(void) 189 { 190 void *p; 191 192 if (init_bootmem_done) { 193 p = alloc_bootmem_pages(PAGE_SIZE); 194 } else { 195 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE, 196 __initial_memory_limit_addr)); 197 } 198 return p; 199 } 200 201 /* Free up now-unused memory */ 202 static void free_sec(unsigned long start, unsigned long end, const char *name) 203 { 204 unsigned long cnt = 0; 205 206 while (start < end) { 207 ClearPageReserved(virt_to_page(start)); 208 init_page_count(virt_to_page(start)); 209 free_page(start); 210 cnt++; 211 start += PAGE_SIZE; 212 } 213 if (cnt) { 214 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name); 215 totalram_pages += cnt; 216 } 217 } 218 219 void free_initmem(void) 220 { 221 #define FREESEC(TYPE) \ 222 free_sec((unsigned long)(&__ ## TYPE ## _begin), \ 223 (unsigned long)(&__ ## TYPE ## _end), \ 224 #TYPE); 225 226 printk ("Freeing unused kernel memory:"); 227 FREESEC(init); 228 printk("\n"); 229 ppc_md.progress = NULL; 230 #undef FREESEC 231 } 232 233 #ifdef CONFIG_BLK_DEV_INITRD 234 void free_initrd_mem(unsigned long start, unsigned long end) 235 { 236 if (start < end) 237 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 238 for (; start < end; start += PAGE_SIZE) { 239 ClearPageReserved(virt_to_page(start)); 240 init_page_count(virt_to_page(start)); 241 free_page(start); 242 totalram_pages++; 243 } 244 } 245 #endif 246 247 #ifdef CONFIG_PROC_KCORE 248 static struct kcore_list kcore_vmem; 249 250 static int __init setup_kcore(void) 251 { 252 int i; 253 254 for (i = 0; i < lmb.memory.cnt; i++) { 255 unsigned long base; 256 unsigned long size; 257 struct kcore_list *kcore_mem; 258 259 base = lmb.memory.region[i].base; 260 size = lmb.memory.region[i].size; 261 262 kcore_mem = kmalloc(sizeof(struct kcore_list), GFP_ATOMIC); 263 if (!kcore_mem) 264 panic("%s: kmalloc failed\n", __func__); 265 266 /* must stay under 32 bits */ 267 if ( 0xfffffffful - (unsigned long)__va(base) < size) { 268 size = 0xfffffffful - (unsigned long)(__va(base)); 269 printk(KERN_DEBUG "setup_kcore: restrict size=%lx\n", 270 size); 271 } 272 273 kclist_add(kcore_mem, __va(base), size); 274 } 275 276 kclist_add(&kcore_vmem, (void *)VMALLOC_START, 277 VMALLOC_END-VMALLOC_START); 278 279 return 0; 280 } 281 module_init(setup_kcore); 282 #endif 283