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/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
41 #undef DEBUG
42
43 /*
44 * BAD_PAGE is the page that is used for page faults when linux
45 * is out-of-memory. Older versions of linux just did a
46 * do_exit(), but using this instead means there is less risk
47 * for a process dying in kernel mode, possibly leaving a inode
48 * unused etc..
49 *
50 * BAD_PAGETABLE is the accompanying page-table: it is initialized
51 * to point to BAD_PAGE entries.
52 *
53 * ZERO_PAGE is a special page that is used for zero-initialized
54 * data and COW.
55 */
56 static unsigned long empty_bad_page_table;
57
58 static unsigned long empty_bad_page;
59
60 unsigned long empty_zero_page;
61
62 extern unsigned long rom_length;
63
64 extern unsigned long memory_start;
65 extern unsigned long memory_end;
66
67 /*
68 * paging_init() continues the virtual memory environment setup which
69 * was begun by the code in arch/head.S.
70 * The parameters are pointers to where to stick the starting and ending
71 * addresses of available kernel virtual memory.
72 */
paging_init(void)73 void __init paging_init(void)
74 {
75 /*
76 * Make sure start_mem is page aligned, otherwise bootmem and
77 * page_alloc get different views og the world.
78 */
79 #ifdef DEBUG
80 unsigned long start_mem = PAGE_ALIGN(memory_start);
81 #endif
82 unsigned long end_mem = memory_end & PAGE_MASK;
83
84 #ifdef DEBUG
85 printk ("start_mem is %#lx\nvirtual_end is %#lx\n",
86 start_mem, end_mem);
87 #endif
88
89 /*
90 * Initialize the bad page table and bad page to point
91 * to a couple of allocated pages.
92 */
93 empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
94 empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
95 empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
96 memset((void *)empty_zero_page, 0, PAGE_SIZE);
97
98 /*
99 * Set up SFC/DFC registers (user data space).
100 */
101 set_fs (USER_DS);
102
103 #ifdef DEBUG
104 printk ("before free_area_init\n");
105
106 printk ("free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
107 start_mem, end_mem);
108 #endif
109
110 {
111 unsigned long zones_size[MAX_NR_ZONES] = {0, };
112
113 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
114 zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
115 #ifdef CONFIG_HIGHMEM
116 zones_size[ZONE_HIGHMEM] = 0;
117 #endif
118 free_area_init(zones_size);
119 }
120 }
121
mem_init(void)122 void __init mem_init(void)
123 {
124 int codek = 0, datak = 0, initk = 0;
125 /* DAVIDM look at setup memory map generically with reserved area */
126 unsigned long tmp;
127 extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
128 extern unsigned long _ramend, _ramstart;
129 unsigned long len = &_ramend - &_ramstart;
130 unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
131 unsigned long end_mem = memory_end; /* DAVIDM - this must not include kernel stack at top */
132
133 #ifdef DEBUG
134 printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
135 #endif
136
137 end_mem &= PAGE_MASK;
138 high_memory = (void *) end_mem;
139
140 start_mem = PAGE_ALIGN(start_mem);
141 max_mapnr = num_physpages = MAP_NR(high_memory);
142
143 /* this will put all memory onto the freelists */
144 totalram_pages = free_all_bootmem();
145
146 codek = (&_etext - &_stext) >> 10;
147 datak = (&_ebss - &_sdata) >> 10;
148 initk = (&__init_begin - &__init_end) >> 10;
149
150 tmp = nr_free_pages() << PAGE_SHIFT;
151 printk(KERN_INFO "Memory available: %luk/%luk RAM, %luk/%luk ROM (%dk kernel code, %dk data)\n",
152 tmp >> 10,
153 len >> 10,
154 (rom_length > 0) ? ((rom_length >> 10) - codek) : 0,
155 rom_length >> 10,
156 codek,
157 datak
158 );
159 }
160
161
162 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)163 void free_initrd_mem(unsigned long start, unsigned long end)
164 {
165 int pages = 0;
166 for (; start < end; start += PAGE_SIZE) {
167 ClearPageReserved(virt_to_page(start));
168 init_page_count(virt_to_page(start));
169 free_page(start);
170 totalram_pages++;
171 pages++;
172 }
173 printk ("Freeing initrd memory: %dk freed\n", pages);
174 }
175 #endif
176
177 void
free_initmem(void)178 free_initmem(void)
179 {
180 #ifdef CONFIG_RAMKERNEL
181 unsigned long addr;
182 extern char __init_begin, __init_end;
183 /*
184 * the following code should be cool even if these sections
185 * are not page aligned.
186 */
187 addr = PAGE_ALIGN((unsigned long)(&__init_begin));
188 /* next to check that the page we free is not a partial page */
189 for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
190 ClearPageReserved(virt_to_page(addr));
191 init_page_count(virt_to_page(addr));
192 free_page(addr);
193 totalram_pages++;
194 }
195 printk(KERN_INFO "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
196 (addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
197 (int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
198 (int)(addr - PAGE_SIZE));
199 #endif
200 }
201
202