Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* init.c: memory initialisation for FRV |
| 2 | * |
| 3 | * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * Derived from: |
| 12 | * - linux/arch/m68knommu/mm/init.c |
| 13 | * - Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>, Kenneth Albanowski <kjahds@kjahds.com>, |
| 14 | * - Copyright (C) 2000 Lineo, Inc. (www.lineo.com) |
| 15 | * - linux/arch/m68k/mm/init.c |
| 16 | * - Copyright (C) 1995 Hamish Macdonald |
| 17 | */ |
| 18 | |
| 19 | #include <linux/config.h> |
| 20 | #include <linux/signal.h> |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/pagemap.h> |
| 23 | #include <linux/swap.h> |
| 24 | #include <linux/mm.h> |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/string.h> |
| 27 | #include <linux/types.h> |
| 28 | #include <linux/bootmem.h> |
| 29 | #include <linux/highmem.h> |
| 30 | |
| 31 | #include <asm/setup.h> |
| 32 | #include <asm/segment.h> |
| 33 | #include <asm/page.h> |
| 34 | #include <asm/pgtable.h> |
| 35 | #include <asm/system.h> |
| 36 | #include <asm/mmu_context.h> |
| 37 | #include <asm/virtconvert.h> |
| 38 | #include <asm/sections.h> |
| 39 | #include <asm/tlb.h> |
| 40 | |
| 41 | #undef DEBUG |
| 42 | |
| 43 | DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); |
| 44 | |
| 45 | /* |
| 46 | * BAD_PAGE is the page that is used for page faults when linux |
| 47 | * is out-of-memory. Older versions of linux just did a |
| 48 | * do_exit(), but using this instead means there is less risk |
| 49 | * for a process dying in kernel mode, possibly leaving a inode |
| 50 | * unused etc.. |
| 51 | * |
| 52 | * BAD_PAGETABLE is the accompanying page-table: it is initialized |
| 53 | * to point to BAD_PAGE entries. |
| 54 | * |
| 55 | * ZERO_PAGE is a special page that is used for zero-initialized |
| 56 | * data and COW. |
| 57 | */ |
| 58 | static unsigned long empty_bad_page_table; |
| 59 | static unsigned long empty_bad_page; |
| 60 | unsigned long empty_zero_page; |
| 61 | |
| 62 | /*****************************************************************************/ |
| 63 | /* |
| 64 | * |
| 65 | */ |
| 66 | void show_mem(void) |
| 67 | { |
| 68 | unsigned long i; |
| 69 | int free = 0, total = 0, reserved = 0, shared = 0; |
| 70 | |
| 71 | printk("\nMem-info:\n"); |
| 72 | show_free_areas(); |
| 73 | i = max_mapnr; |
| 74 | while (i-- > 0) { |
| 75 | struct page *page = &mem_map[i]; |
| 76 | |
| 77 | total++; |
| 78 | if (PageReserved(page)) |
| 79 | reserved++; |
| 80 | else if (!page_count(page)) |
| 81 | free++; |
| 82 | else |
| 83 | shared += page_count(page) - 1; |
| 84 | } |
| 85 | |
| 86 | printk("%d pages of RAM\n",total); |
| 87 | printk("%d free pages\n",free); |
| 88 | printk("%d reserved pages\n",reserved); |
| 89 | printk("%d pages shared\n",shared); |
| 90 | |
| 91 | } /* end show_mem() */ |
| 92 | |
| 93 | /*****************************************************************************/ |
| 94 | /* |
| 95 | * paging_init() continues the virtual memory environment setup which |
| 96 | * was begun by the code in arch/head.S. |
| 97 | * The parameters are pointers to where to stick the starting and ending |
| 98 | * addresses of available kernel virtual memory. |
| 99 | */ |
| 100 | void __init paging_init(void) |
| 101 | { |
| 102 | unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0}; |
| 103 | |
| 104 | /* allocate some pages for kernel housekeeping tasks */ |
| 105 | empty_bad_page_table = (unsigned long) alloc_bootmem_pages(PAGE_SIZE); |
| 106 | empty_bad_page = (unsigned long) alloc_bootmem_pages(PAGE_SIZE); |
| 107 | empty_zero_page = (unsigned long) alloc_bootmem_pages(PAGE_SIZE); |
| 108 | |
| 109 | memset((void *) empty_zero_page, 0, PAGE_SIZE); |
| 110 | |
| 111 | #if CONFIG_HIGHMEM |
| 112 | if (num_physpages - num_mappedpages) { |
| 113 | pgd_t *pge; |
| 114 | pud_t *pue; |
| 115 | pmd_t *pme; |
| 116 | |
| 117 | pkmap_page_table = alloc_bootmem_pages(PAGE_SIZE); |
| 118 | |
| 119 | memset(pkmap_page_table, 0, PAGE_SIZE); |
| 120 | |
| 121 | pge = swapper_pg_dir + pgd_index_k(PKMAP_BASE); |
| 122 | pue = pud_offset(pge, PKMAP_BASE); |
| 123 | pme = pmd_offset(pue, PKMAP_BASE); |
| 124 | __set_pmd(pme, virt_to_phys(pkmap_page_table) | _PAGE_TABLE); |
| 125 | } |
| 126 | #endif |
| 127 | |
| 128 | /* distribute the allocatable pages across the various zones and pass them to the allocator |
| 129 | */ |
| 130 | zones_size[ZONE_DMA] = max_low_pfn - min_low_pfn; |
| 131 | zones_size[ZONE_NORMAL] = 0; |
| 132 | #ifdef CONFIG_HIGHMEM |
| 133 | zones_size[ZONE_HIGHMEM] = num_physpages - num_mappedpages; |
| 134 | #endif |
| 135 | |
| 136 | free_area_init(zones_size); |
| 137 | |
| 138 | #ifdef CONFIG_MMU |
| 139 | /* initialise init's MMU context */ |
| 140 | init_new_context(&init_task, &init_mm); |
| 141 | #endif |
| 142 | |
| 143 | } /* end paging_init() */ |
| 144 | |
| 145 | /*****************************************************************************/ |
| 146 | /* |
| 147 | * |
| 148 | */ |
| 149 | void __init mem_init(void) |
| 150 | { |
| 151 | unsigned long npages = (memory_end - memory_start) >> PAGE_SHIFT; |
| 152 | unsigned long tmp; |
| 153 | #ifdef CONFIG_MMU |
| 154 | unsigned long loop, pfn; |
| 155 | int datapages = 0; |
| 156 | #endif |
| 157 | int codek = 0, datak = 0; |
| 158 | |
| 159 | /* this will put all memory onto the freelists */ |
| 160 | totalram_pages = free_all_bootmem(); |
| 161 | |
| 162 | #ifdef CONFIG_MMU |
| 163 | for (loop = 0 ; loop < npages ; loop++) |
| 164 | if (PageReserved(&mem_map[loop])) |
| 165 | datapages++; |
| 166 | |
| 167 | #ifdef CONFIG_HIGHMEM |
| 168 | for (pfn = num_physpages - 1; pfn >= num_mappedpages; pfn--) { |
| 169 | struct page *page = &mem_map[pfn]; |
| 170 | |
| 171 | ClearPageReserved(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | set_page_count(page, 1); |
| 173 | __free_page(page); |
| 174 | totalram_pages++; |
| 175 | } |
| 176 | #endif |
| 177 | |
| 178 | codek = ((unsigned long) &_etext - (unsigned long) &_stext) >> 10; |
| 179 | datak = datapages << (PAGE_SHIFT - 10); |
| 180 | |
| 181 | #else |
| 182 | codek = (_etext - _stext) >> 10; |
| 183 | datak = 0; //(_ebss - _sdata) >> 10; |
| 184 | #endif |
| 185 | |
| 186 | tmp = nr_free_pages() << PAGE_SHIFT; |
| 187 | printk("Memory available: %luKiB/%luKiB RAM, %luKiB/%luKiB ROM (%dKiB kernel code, %dKiB data)\n", |
| 188 | tmp >> 10, |
| 189 | npages << (PAGE_SHIFT - 10), |
| 190 | (rom_length > 0) ? ((rom_length >> 10) - codek) : 0, |
| 191 | rom_length >> 10, |
| 192 | codek, |
| 193 | datak |
| 194 | ); |
| 195 | |
| 196 | } /* end mem_init() */ |
| 197 | |
| 198 | /*****************************************************************************/ |
| 199 | /* |
| 200 | * free the memory that was only required for initialisation |
| 201 | */ |
| 202 | void __init free_initmem(void) |
| 203 | { |
| 204 | #if defined(CONFIG_RAMKERNEL) && !defined(CONFIG_PROTECT_KERNEL) |
| 205 | unsigned long start, end, addr; |
| 206 | |
| 207 | start = PAGE_ALIGN((unsigned long) &__init_begin); /* round up */ |
| 208 | end = ((unsigned long) &__init_end) & PAGE_MASK; /* round down */ |
| 209 | |
| 210 | /* next to check that the page we free is not a partial page */ |
| 211 | for (addr = start; addr < end; addr += PAGE_SIZE) { |
| 212 | ClearPageReserved(virt_to_page(addr)); |
| 213 | set_page_count(virt_to_page(addr), 1); |
| 214 | free_page(addr); |
| 215 | totalram_pages++; |
| 216 | } |
| 217 | |
| 218 | printk("Freeing unused kernel memory: %ldKiB freed (0x%lx - 0x%lx)\n", |
| 219 | (end - start) >> 10, start, end); |
| 220 | #endif |
| 221 | } /* end free_initmem() */ |
| 222 | |
| 223 | /*****************************************************************************/ |
| 224 | /* |
| 225 | * free the initial ramdisk memory |
| 226 | */ |
| 227 | #ifdef CONFIG_BLK_DEV_INITRD |
| 228 | void __init free_initrd_mem(unsigned long start, unsigned long end) |
| 229 | { |
| 230 | int pages = 0; |
| 231 | for (; start < end; start += PAGE_SIZE) { |
| 232 | ClearPageReserved(virt_to_page(start)); |
| 233 | set_page_count(virt_to_page(start), 1); |
| 234 | free_page(start); |
| 235 | totalram_pages++; |
| 236 | pages++; |
| 237 | } |
| 238 | printk("Freeing initrd memory: %dKiB freed\n", (pages * PAGE_SIZE) >> 10); |
| 239 | } /* end free_initrd_mem() */ |
| 240 | #endif |