blob: d79503fe6e42f4d81a4cf9331d7cba0e387191ec [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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));
Nick Piggin7835e982006-03-22 00:08:40 -0800198 init_page_count(virt_to_page(start));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 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));
Nick Piggin7835e982006-03-22 00:08:40 -0800221 init_page_count(virt_to_page(addr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 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