1 /*
2 * linux/arch/h8300/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/m68knommu/mm/init.c
11 * linux/arch/m68k/mm/init.c
12 *
13 * Copyright (C) 1995 Hamish Macdonald
14 *
15 * JAN/1999 -- hacked to support ColdFire (gerg@snapgear.com)
16 * DEC/2000 -- linux 2.4 support <davidm@snapgear.com>
17 */
18
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/gfp.h>
34
35 #include <asm/setup.h>
36 #include <asm/segment.h>
37 #include <asm/page.h>
38 #include <asm/pgtable.h>
39
40 #undef DEBUG
41
42 /*
43 * BAD_PAGE is the page that is used for page faults when linux
44 * is out-of-memory. Older versions of linux just did a
45 * do_exit(), but using this instead means there is less risk
46 * for a process dying in kernel mode, possibly leaving a inode
47 * unused etc..
48 *
49 * BAD_PAGETABLE is the accompanying page-table: it is initialized
50 * to point to BAD_PAGE entries.
51 *
52 * ZERO_PAGE is a special page that is used for zero-initialized
53 * data and COW.
54 */
55 static unsigned long empty_bad_page_table;
56
57 static unsigned long empty_bad_page;
58
59 unsigned long empty_zero_page;
60
61 extern unsigned long rom_length;
62
63 extern unsigned long memory_start;
64 extern unsigned long memory_end;
65
66 /*
67 * paging_init() continues the virtual memory environment setup which
68 * was begun by the code in arch/head.S.
69 * The parameters are pointers to where to stick the starting and ending
70 * addresses of available kernel virtual memory.
71 */
paging_init(void)72 void __init paging_init(void)
73 {
74 /*
75 * Make sure start_mem is page aligned, otherwise bootmem and
76 * page_alloc get different views og the world.
77 */
78 #ifdef DEBUG
79 unsigned long start_mem = PAGE_ALIGN(memory_start);
80 #endif
81 unsigned long end_mem = memory_end & PAGE_MASK;
82
83 #ifdef DEBUG
84 printk ("start_mem is %#lx\nvirtual_end is %#lx\n",
85 start_mem, end_mem);
86 #endif
87
88 /*
89 * Initialize the bad page table and bad page to point
90 * to a couple of allocated pages.
91 */
92 empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
93 empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
94 empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
95 memset((void *)empty_zero_page, 0, PAGE_SIZE);
96
97 /*
98 * Set up SFC/DFC registers (user data space).
99 */
100 set_fs (USER_DS);
101
102 #ifdef DEBUG
103 printk ("before free_area_init\n");
104
105 printk ("free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
106 start_mem, end_mem);
107 #endif
108
109 {
110 unsigned long zones_size[MAX_NR_ZONES] = {0, };
111
112 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
113 zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
114 #ifdef CONFIG_HIGHMEM
115 zones_size[ZONE_HIGHMEM] = 0;
116 #endif
117 free_area_init(zones_size);
118 }
119 }
120
mem_init(void)121 void __init mem_init(void)
122 {
123 int codek = 0, datak = 0, initk = 0;
124 /* DAVIDM look at setup memory map generically with reserved area */
125 unsigned long tmp;
126 extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
127 extern unsigned long _ramend, _ramstart;
128 unsigned long len = &_ramend - &_ramstart;
129 unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
130 unsigned long end_mem = memory_end; /* DAVIDM - this must not include kernel stack at top */
131
132 #ifdef DEBUG
133 printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
134 #endif
135
136 end_mem &= PAGE_MASK;
137 high_memory = (void *) end_mem;
138
139 start_mem = PAGE_ALIGN(start_mem);
140 max_mapnr = num_physpages = MAP_NR(high_memory);
141
142 /* this will put all memory onto the freelists */
143 totalram_pages = free_all_bootmem();
144
145 codek = (&_etext - &_stext) >> 10;
146 datak = (&_ebss - &_sdata) >> 10;
147 initk = (&__init_begin - &__init_end) >> 10;
148
149 tmp = nr_free_pages() << PAGE_SHIFT;
150 printk(KERN_INFO "Memory available: %luk/%luk RAM, %luk/%luk ROM (%dk kernel code, %dk data)\n",
151 tmp >> 10,
152 len >> 10,
153 (rom_length > 0) ? ((rom_length >> 10) - codek) : 0,
154 rom_length >> 10,
155 codek,
156 datak
157 );
158 }
159
160
161 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)162 void free_initrd_mem(unsigned long start, unsigned long end)
163 {
164 int pages = 0;
165 for (; start < end; start += PAGE_SIZE) {
166 ClearPageReserved(virt_to_page(start));
167 init_page_count(virt_to_page(start));
168 free_page(start);
169 totalram_pages++;
170 pages++;
171 }
172 printk ("Freeing initrd memory: %dk freed\n", pages);
173 }
174 #endif
175
176 void
free_initmem(void)177 free_initmem(void)
178 {
179 #ifdef CONFIG_RAMKERNEL
180 unsigned long addr;
181 extern char __init_begin, __init_end;
182 /*
183 * the following code should be cool even if these sections
184 * are not page aligned.
185 */
186 addr = PAGE_ALIGN((unsigned long)(&__init_begin));
187 /* next to check that the page we free is not a partial page */
188 for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
189 ClearPageReserved(virt_to_page(addr));
190 init_page_count(virt_to_page(addr));
191 free_page(addr);
192 totalram_pages++;
193 }
194 printk(KERN_INFO "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
195 (addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
196 (int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
197 (int)(addr - PAGE_SIZE));
198 #endif
199 }
200
201