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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