Linux Kernel  3.7.1
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init.c
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1 /*
2  * linux/arch/h8300/mm/init.c
3  *
4  * Copyright (C) 1998 D. Jeff Dionne <[email protected]>,
5  * Kenneth Albanowski <[email protected]>,
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 ([email protected])
16  * DEC/2000 -- linux 2.4 support <[email protected]>
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 #include <asm/sections.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  */
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);
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 
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 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);
141 
142  /* this will put all memory onto the freelists */
143  totalram_pages = free_all_bootmem();
144 
145  codek = (_etext - _stext) >> 10;
146  datak = (__bss_stop - _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
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
178 {
179 #ifdef CONFIG_RAMKERNEL
180  unsigned long addr;
181 /*
182  * the following code should be cool even if these sections
183  * are not page aligned.
184  */
185  addr = PAGE_ALIGN((unsigned long)(__init_begin));
186  /* next to check that the page we free is not a partial page */
187  for (; addr + PAGE_SIZE < (unsigned long)__init_end; addr +=PAGE_SIZE) {
188  ClearPageReserved(virt_to_page(addr));
189  init_page_count(virt_to_page(addr));
190  free_page(addr);
191  totalram_pages++;
192  }
193  printk(KERN_INFO "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
194  (addr - PAGE_ALIGN((long) __init_begin)) >> 10,
195  (int)(PAGE_ALIGN((unsigned long)__init_begin)),
196  (int)(addr - PAGE_SIZE));
197 #endif
198 }
199