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 34 #include <asm/pgalloc.h> 35 #include <asm/prom.h> 36 #include <asm/io.h> 37 #include <asm/mmu_context.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/lmb.h> 45 #include <asm/sections.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 - KERNELBASE)) 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 unsigned long total_memory; 60 unsigned long total_lowmem; 61 62 unsigned long ppc_memstart; 63 unsigned long ppc_memoffset = PAGE_OFFSET; 64 65 int boot_mapsize; 66 #ifdef CONFIG_PPC_PMAC 67 unsigned long agp_special_page; 68 EXPORT_SYMBOL(agp_special_page); 69 #endif 70 71 #ifdef CONFIG_HIGHMEM 72 pte_t *kmap_pte; 73 pgprot_t kmap_prot; 74 75 EXPORT_SYMBOL(kmap_prot); 76 EXPORT_SYMBOL(kmap_pte); 77 #endif 78 79 void MMU_init(void); 80 81 /* XXX should be in current.h -- paulus */ 82 extern struct task_struct *current_set[NR_CPUS]; 83 84 extern int init_bootmem_done; 85 86 /* 87 * this tells the system to map all of ram with the segregs 88 * (i.e. page tables) instead of the bats. 89 * -- Cort 90 */ 91 int __map_without_bats; 92 int __map_without_ltlbs; 93 94 /* max amount of low RAM to map in */ 95 unsigned long __max_low_memory = MAX_LOW_MEM; 96 97 /* 98 * limit of what is accessible with initial MMU setup - 99 * 256MB usually, but only 16MB on 601. 100 */ 101 unsigned long __initial_memory_limit = 0x10000000; 102 103 /* 104 * Check for command-line options that affect what MMU_init will do. 105 */ 106 void MMU_setup(void) 107 { 108 /* Check for nobats option (used in mapin_ram). */ 109 if (strstr(cmd_line, "nobats")) { 110 __map_without_bats = 1; 111 } 112 113 if (strstr(cmd_line, "noltlbs")) { 114 __map_without_ltlbs = 1; 115 } 116 #ifdef CONFIG_DEBUG_PAGEALLOC 117 __map_without_bats = 1; 118 __map_without_ltlbs = 1; 119 #endif 120 } 121 122 /* 123 * MMU_init sets up the basic memory mappings for the kernel, 124 * including both RAM and possibly some I/O regions, 125 * and sets up the page tables and the MMU hardware ready to go. 126 */ 127 void __init MMU_init(void) 128 { 129 if (ppc_md.progress) 130 ppc_md.progress("MMU:enter", 0x111); 131 132 /* 601 can only access 16MB at the moment */ 133 if (PVR_VER(mfspr(SPRN_PVR)) == 1) 134 __initial_memory_limit = 0x01000000; 135 /* 8xx can only access 8MB at the moment */ 136 if (PVR_VER(mfspr(SPRN_PVR)) == 0x50) 137 __initial_memory_limit = 0x00800000; 138 139 /* parse args from command line */ 140 MMU_setup(); 141 142 if (lmb.memory.cnt > 1) { 143 lmb.memory.cnt = 1; 144 lmb_analyze(); 145 printk(KERN_WARNING "Only using first contiguous memory region"); 146 } 147 148 total_memory = lmb_end_of_DRAM(); 149 total_lowmem = total_memory; 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 #ifndef CONFIG_HIGHMEM 161 total_memory = total_lowmem; 162 lmb_enforce_memory_limit(total_lowmem); 163 lmb_analyze(); 164 #endif /* CONFIG_HIGHMEM */ 165 } 166 167 /* Initialize the MMU hardware */ 168 if (ppc_md.progress) 169 ppc_md.progress("MMU:hw init", 0x300); 170 MMU_init_hw(); 171 172 /* Map in all of RAM starting at KERNELBASE */ 173 if (ppc_md.progress) 174 ppc_md.progress("MMU:mapin", 0x301); 175 mapin_ram(); 176 177 #ifdef CONFIG_HIGHMEM 178 ioremap_base = PKMAP_BASE; 179 #else 180 ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */ 181 #endif /* CONFIG_HIGHMEM */ 182 ioremap_bot = ioremap_base; 183 184 /* Map in I/O resources */ 185 if (ppc_md.progress) 186 ppc_md.progress("MMU:setio", 0x302); 187 if (ppc_md.setup_io_mappings) 188 ppc_md.setup_io_mappings(); 189 190 /* Initialize the context management stuff */ 191 mmu_context_init(); 192 193 if (ppc_md.progress) 194 ppc_md.progress("MMU:exit", 0x211); 195 196 /* From now on, btext is no longer BAT mapped if it was at all */ 197 #ifdef CONFIG_BOOTX_TEXT 198 btext_unmap(); 199 #endif 200 } 201 202 /* This is only called until mem_init is done. */ 203 void __init *early_get_page(void) 204 { 205 void *p; 206 207 if (init_bootmem_done) { 208 p = alloc_bootmem_pages(PAGE_SIZE); 209 } else { 210 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE, 211 __initial_memory_limit)); 212 } 213 return p; 214 } 215 216 /* Free up now-unused memory */ 217 static void free_sec(unsigned long start, unsigned long end, const char *name) 218 { 219 unsigned long cnt = 0; 220 221 while (start < end) { 222 ClearPageReserved(virt_to_page(start)); 223 init_page_count(virt_to_page(start)); 224 free_page(start); 225 cnt++; 226 start += PAGE_SIZE; 227 } 228 if (cnt) { 229 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name); 230 totalram_pages += cnt; 231 } 232 } 233 234 void free_initmem(void) 235 { 236 #define FREESEC(TYPE) \ 237 free_sec((unsigned long)(&__ ## TYPE ## _begin), \ 238 (unsigned long)(&__ ## TYPE ## _end), \ 239 #TYPE); 240 241 printk ("Freeing unused kernel memory:"); 242 FREESEC(init); 243 printk("\n"); 244 ppc_md.progress = NULL; 245 #undef FREESEC 246 } 247 248 #ifdef CONFIG_BLK_DEV_INITRD 249 void free_initrd_mem(unsigned long start, unsigned long end) 250 { 251 if (start < end) 252 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 253 for (; start < end; start += PAGE_SIZE) { 254 ClearPageReserved(virt_to_page(start)); 255 init_page_count(virt_to_page(start)); 256 free_page(start); 257 totalram_pages++; 258 } 259 } 260 #endif 261 262 #ifdef CONFIG_PROC_KCORE 263 static struct kcore_list kcore_vmem; 264 265 static int __init setup_kcore(void) 266 { 267 int i; 268 269 for (i = 0; i < lmb.memory.cnt; i++) { 270 unsigned long base; 271 unsigned long size; 272 struct kcore_list *kcore_mem; 273 274 base = lmb.memory.region[i].base; 275 size = lmb.memory.region[i].size; 276 277 kcore_mem = kmalloc(sizeof(struct kcore_list), GFP_ATOMIC); 278 if (!kcore_mem) 279 panic("%s: kmalloc failed\n", __FUNCTION__); 280 281 /* must stay under 32 bits */ 282 if ( 0xfffffffful - (unsigned long)__va(base) < size) { 283 size = 0xfffffffful - (unsigned long)(__va(base)); 284 printk(KERN_DEBUG "setup_kcore: restrict size=%lx\n", 285 size); 286 } 287 288 kclist_add(kcore_mem, __va(base), size); 289 } 290 291 kclist_add(&kcore_vmem, (void *)VMALLOC_START, 292 VMALLOC_END-VMALLOC_START); 293 294 return 0; 295 } 296 module_init(setup_kcore); 297 #endif 298