1/* 2 * linux/arch/m68knommu/mm/init.c 3 * 4 * Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>, 5 * Kenneth Albanowski <kjahds@kjahds.com>, 6 * Copyright (C) 2000 Lineo, Inc. (www.lineo.com) 7 * 8 * Based on: 9 * 10 * linux/arch/m68k/mm/init.c 11 * 12 * Copyright (C) 1995 Hamish Macdonald 13 * 14 * JAN/1999 -- hacked to support ColdFire (gerg@snapgear.com) 15 * DEC/2000 -- linux 2.4 support <davidm@snapgear.com> 16 */ 17 18#include <linux/signal.h> 19#include <linux/sched.h> 20#include <linux/kernel.h> 21#include <linux/errno.h> 22#include <linux/string.h> 23#include <linux/types.h> 24#include <linux/ptrace.h> 25#include <linux/mman.h> 26#include <linux/mm.h> 27#include <linux/swap.h> 28#include <linux/init.h> 29#include <linux/highmem.h> 30#include <linux/pagemap.h> 31#include <linux/bootmem.h> 32#include <linux/slab.h> 33 34#include <asm/setup.h> 35#include <asm/segment.h> 36#include <asm/page.h> 37#include <asm/pgtable.h> 38#include <asm/system.h> 39#include <asm/machdep.h> 40 41#undef DEBUG 42 43extern void die_if_kernel(char *,struct pt_regs *,long); 44extern void free_initmem(void); 45 46/* 47 * BAD_PAGE is the page that is used for page faults when linux 48 * is out-of-memory. Older versions of linux just did a 49 * do_exit(), but using this instead means there is less risk 50 * for a process dying in kernel mode, possibly leaving a inode 51 * unused etc.. 52 * 53 * BAD_PAGETABLE is the accompanying page-table: it is initialized 54 * to point to BAD_PAGE entries. 55 * 56 * ZERO_PAGE is a special page that is used for zero-initialized 57 * data and COW. 58 */ 59static unsigned long empty_bad_page_table; 60 61static unsigned long empty_bad_page; 62 63unsigned long empty_zero_page; 64 65void show_mem(void) 66{ 67 unsigned long i; 68 int free = 0, total = 0, reserved = 0, shared = 0; 69 int cached = 0; 70 71 printk(KERN_INFO "\nMem-info:\n"); 72 show_free_areas(); 73 i = max_mapnr; 74 while (i-- > 0) { 75 total++; 76 if (PageReserved(mem_map+i)) 77 reserved++; 78 else if (PageSwapCache(mem_map+i)) 79 cached++; 80 else if (!page_count(mem_map+i)) 81 free++; 82 else 83 shared += page_count(mem_map+i) - 1; 84 } 85 printk(KERN_INFO "%d pages of RAM\n",total); 86 printk(KERN_INFO "%d free pages\n",free); 87 printk(KERN_INFO "%d reserved pages\n",reserved); 88 printk(KERN_INFO "%d pages shared\n",shared); 89 printk(KERN_INFO "%d pages swap cached\n",cached); 90} 91 92extern unsigned long memory_start; 93extern unsigned long memory_end; 94 95/* 96 * paging_init() continues the virtual memory environment setup which 97 * was begun by the code in arch/head.S. 98 * The parameters are pointers to where to stick the starting and ending 99 * addresses of available kernel virtual memory. 100 */ 101void paging_init(void) 102{ 103 /* 104 * Make sure start_mem is page aligned, otherwise bootmem and 105 * page_alloc get different views of the world. 106 */ 107#ifdef DEBUG 108 unsigned long start_mem = PAGE_ALIGN(memory_start); 109#endif 110 unsigned long end_mem = memory_end & PAGE_MASK; 111 112#ifdef DEBUG 113 printk (KERN_DEBUG "start_mem is %#lx\nvirtual_end is %#lx\n", 114 start_mem, end_mem); 115#endif 116 117 /* 118 * Initialize the bad page table and bad page to point 119 * to a couple of allocated pages. 120 */ 121 empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE); 122 empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE); 123 empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE); 124 memset((void *)empty_zero_page, 0, PAGE_SIZE); 125 126 /* 127 * Set up SFC/DFC registers (user data space). 128 */ 129 set_fs (USER_DS); 130 131#ifdef DEBUG 132 printk (KERN_DEBUG "before free_area_init\n"); 133 134 printk (KERN_DEBUG "free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n", 135 start_mem, end_mem); 136#endif 137 138 { 139 unsigned long zones_size[MAX_NR_ZONES] = {0, }; 140 141 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT; 142 zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT; 143#ifdef CONFIG_HIGHMEM 144 zones_size[ZONE_HIGHMEM] = 0; 145#endif 146 free_area_init(zones_size); 147 } 148} 149 150void mem_init(void) 151{ 152 int codek = 0, datak = 0, initk = 0; 153 unsigned long tmp; 154 extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end; 155 extern unsigned int _ramend, _rambase; 156 unsigned long len = _ramend - _rambase; 157 unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */ 158 unsigned long end_mem = memory_end; /* DAVIDM - this must not include kernel stack at top */ 159 160#ifdef DEBUG 161 printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem); 162#endif 163 164 end_mem &= PAGE_MASK; 165 high_memory = (void *) end_mem; 166 167 start_mem = PAGE_ALIGN(start_mem); 168 max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT; 169 170 /* this will put all memory onto the freelists */ 171 totalram_pages = free_all_bootmem(); 172 173 codek = (&_etext - &_stext) >> 10; 174 datak = (&_ebss - &_sdata) >> 10; 175 initk = (&__init_begin - &__init_end) >> 10; 176 177 tmp = nr_free_pages() << PAGE_SHIFT; 178 printk(KERN_INFO "Memory available: %luk/%luk RAM, (%dk kernel code, %dk data)\n", 179 tmp >> 10, 180 len >> 10, 181 codek, 182 datak 183 ); 184} 185 186 187#ifdef CONFIG_BLK_DEV_INITRD 188void free_initrd_mem(unsigned long start, unsigned long end) 189{ 190 int pages = 0; 191 for (; start < end; start += PAGE_SIZE) { 192 ClearPageReserved(virt_to_page(start)); 193 init_page_count(virt_to_page(start)); 194 free_page(start); 195 totalram_pages++; 196 pages++; 197 } 198 printk (KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages); 199} 200#endif 201 202void 203free_initmem() 204{ 205#ifdef CONFIG_RAMKERNEL 206 unsigned long addr; 207 extern char __init_begin, __init_end; 208 /* 209 * The following code should be cool even if these sections 210 * are not page aligned. 211 */ 212 addr = PAGE_ALIGN((unsigned long)(&__init_begin)); 213 /* next to check that the page we free is not a partial page */ 214 for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) { 215 ClearPageReserved(virt_to_page(addr)); 216 init_page_count(virt_to_page(addr)); 217 free_page(addr); 218 totalram_pages++; 219 } 220 printk(KERN_NOTICE "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n", 221 (addr - PAGE_ALIGN((long) &__init_begin)) >> 10, 222 (int)(PAGE_ALIGN((unsigned long)(&__init_begin))), 223 (int)(addr - PAGE_SIZE)); 224#endif 225} 226