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/arch/m68knommu/mm/init.c

https://bitbucket.org/evzijst/gittest
C | 231 lines | 149 code | 30 blank | 52 comment | 8 complexity | 1ea93bd6ed2a58cd102960a0f49460ae MD5 | raw file
  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/config.h>
 19#include <linux/signal.h>
 20#include <linux/sched.h>
 21#include <linux/kernel.h>
 22#include <linux/errno.h>
 23#include <linux/string.h>
 24#include <linux/types.h>
 25#include <linux/ptrace.h>
 26#include <linux/mman.h>
 27#include <linux/mm.h>
 28#include <linux/swap.h>
 29#include <linux/init.h>
 30#include <linux/highmem.h>
 31#include <linux/pagemap.h>
 32#include <linux/bootmem.h>
 33#include <linux/slab.h>
 34
 35#include <asm/setup.h>
 36#include <asm/segment.h>
 37#include <asm/page.h>
 38#include <asm/pgtable.h>
 39#include <asm/system.h>
 40#include <asm/machdep.h>
 41
 42#undef DEBUG
 43
 44extern void die_if_kernel(char *,struct pt_regs *,long);
 45extern void free_initmem(void);
 46
 47/*
 48 * BAD_PAGE is the page that is used for page faults when linux
 49 * is out-of-memory. Older versions of linux just did a
 50 * do_exit(), but using this instead means there is less risk
 51 * for a process dying in kernel mode, possibly leaving a inode
 52 * unused etc..
 53 *
 54 * BAD_PAGETABLE is the accompanying page-table: it is initialized
 55 * to point to BAD_PAGE entries.
 56 *
 57 * ZERO_PAGE is a special page that is used for zero-initialized
 58 * data and COW.
 59 */
 60static unsigned long empty_bad_page_table;
 61
 62static unsigned long empty_bad_page;
 63
 64unsigned long empty_zero_page;
 65
 66extern unsigned long rom_length;
 67
 68void show_mem(void)
 69{
 70    unsigned long i;
 71    int free = 0, total = 0, reserved = 0, shared = 0;
 72    int cached = 0;
 73
 74    printk(KERN_INFO "\nMem-info:\n");
 75    show_free_areas();
 76    i = max_mapnr;
 77    while (i-- > 0) {
 78	total++;
 79	if (PageReserved(mem_map+i))
 80	    reserved++;
 81	else if (PageSwapCache(mem_map+i))
 82	    cached++;
 83	else if (!page_count(mem_map+i))
 84	    free++;
 85	else
 86	    shared += page_count(mem_map+i) - 1;
 87    }
 88    printk(KERN_INFO "%d pages of RAM\n",total);
 89    printk(KERN_INFO "%d free pages\n",free);
 90    printk(KERN_INFO "%d reserved pages\n",reserved);
 91    printk(KERN_INFO "%d pages shared\n",shared);
 92    printk(KERN_INFO "%d pages swap cached\n",cached);
 93}
 94
 95extern unsigned long memory_start;
 96extern unsigned long memory_end;
 97
 98/*
 99 * paging_init() continues the virtual memory environment setup which
100 * was begun by the code in arch/head.S.
101 * The parameters are pointers to where to stick the starting and ending
102 * addresses of available kernel virtual memory.
103 */
104void paging_init(void)
105{
106	/*
107	 * Make sure start_mem is page aligned, otherwise bootmem and
108	 * page_alloc get different views of the world.
109	 */
110#ifdef DEBUG
111	unsigned long start_mem = PAGE_ALIGN(memory_start);
112#endif
113	unsigned long end_mem   = memory_end & PAGE_MASK;
114
115#ifdef DEBUG
116	printk (KERN_DEBUG "start_mem is %#lx\nvirtual_end is %#lx\n",
117		start_mem, end_mem);
118#endif
119
120	/*
121	 * Initialize the bad page table and bad page to point
122	 * to a couple of allocated pages.
123	 */
124	empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
125	empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
126	empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
127	memset((void *)empty_zero_page, 0, PAGE_SIZE);
128
129	/*
130	 * Set up SFC/DFC registers (user data space).
131	 */
132	set_fs (USER_DS);
133
134#ifdef DEBUG
135	printk (KERN_DEBUG "before free_area_init\n");
136
137	printk (KERN_DEBUG "free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
138		start_mem, end_mem);
139#endif
140
141	{
142		unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
143
144		zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
145		zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
146#ifdef CONFIG_HIGHMEM
147		zones_size[ZONE_HIGHMEM] = 0;
148#endif
149		free_area_init(zones_size);
150	}
151}
152
153void mem_init(void)
154{
155	int codek = 0, datak = 0, initk = 0;
156	unsigned long tmp;
157	extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
158	extern unsigned int _ramend, _rambase;
159	unsigned long len = _ramend - _rambase;
160	unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
161	unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
162
163#ifdef DEBUG
164	printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
165#endif
166
167	end_mem &= PAGE_MASK;
168	high_memory = (void *) end_mem;
169
170	start_mem = PAGE_ALIGN(start_mem);
171	max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;
172
173	/* this will put all memory onto the freelists */
174	totalram_pages = free_all_bootmem();
175
176	codek = (&_etext - &_stext) >> 10;
177	datak = (&_ebss - &_sdata) >> 10;
178	initk = (&__init_begin - &__init_end) >> 10;
179
180	tmp = nr_free_pages() << PAGE_SHIFT;
181	printk(KERN_INFO "Memory available: %luk/%luk RAM, %luk/%luk ROM (%dk kernel code, %dk data)\n",
182	       tmp >> 10,
183	       len >> 10,
184	       (rom_length > 0) ? ((rom_length >> 10) - codek) : 0,
185	       rom_length >> 10,
186	       codek,
187	       datak
188	       );
189}
190
191
192#ifdef CONFIG_BLK_DEV_INITRD
193void free_initrd_mem(unsigned long start, unsigned long end)
194{
195	int pages = 0;
196	for (; start < end; start += PAGE_SIZE) {
197		ClearPageReserved(virt_to_page(start));
198		set_page_count(virt_to_page(start), 1);
199		free_page(start);
200		totalram_pages++;
201		pages++;
202	}
203	printk (KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages);
204}
205#endif
206
207void
208free_initmem()
209{
210#ifdef CONFIG_RAMKERNEL
211	unsigned long addr;
212	extern char __init_begin, __init_end;
213	/*
214	 * The following code should be cool even if these sections
215	 * are not page aligned.
216	 */
217	addr = PAGE_ALIGN((unsigned long)(&__init_begin));
218	/* next to check that the page we free is not a partial page */
219	for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
220		ClearPageReserved(virt_to_page(addr));
221		set_page_count(virt_to_page(addr), 1);
222		free_page(addr);
223		totalram_pages++;
224	}
225	printk(KERN_NOTICE "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
226			(addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
227			(int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
228			(int)(addr - PAGE_SIZE));
229#endif
230}
231