Linux Kernel  3.7.1
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init_no.c
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1 /*
2  * linux/arch/m68knommu/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/m68k/mm/init.c
11  *
12  * Copyright (C) 1995 Hamish Macdonald
13  *
14  * JAN/1999 -- hacked to support ColdFire ([email protected])
15  * DEC/2000 -- linux 2.4 support <[email protected]>
16  */
17 
18 #include <linux/signal.h>
19 #include <linux/sched.h>
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/string.h>
23 #include <linux/types.h>
24 #include <linux/ptrace.h>
25 #include <linux/mman.h>
26 #include <linux/mm.h>
27 #include <linux/swap.h>
28 #include <linux/init.h>
29 #include <linux/highmem.h>
30 #include <linux/pagemap.h>
31 #include <linux/bootmem.h>
32 #include <linux/gfp.h>
33 
34 #include <asm/setup.h>
35 #include <asm/sections.h>
36 #include <asm/segment.h>
37 #include <asm/page.h>
38 #include <asm/pgtable.h>
39 #include <asm/machdep.h>
40 
41 /*
42  * ZERO_PAGE is a special page that is used for zero-initialized
43  * data and COW.
44  */
46 
47 /*
48  * paging_init() continues the virtual memory environment setup which
49  * was begun by the code in arch/head.S.
50  * The parameters are pointers to where to stick the starting and ending
51  * addresses of available kernel virtual memory.
52  */
53 void __init paging_init(void)
54 {
55  /*
56  * Make sure start_mem is page aligned, otherwise bootmem and
57  * page_alloc get different views of the world.
58  */
59  unsigned long end_mem = memory_end & PAGE_MASK;
60  unsigned long zones_size[MAX_NR_ZONES] = {0, };
61 
64 
65  /*
66  * Set up SFC/DFC registers (user data space).
67  */
68  set_fs (USER_DS);
69 
70  zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
71  free_area_init(zones_size);
72 }
73 
74 void __init mem_init(void)
75 {
76  int codek = 0, datak = 0, initk = 0;
77  unsigned long tmp;
78  unsigned long len = _ramend - _rambase;
79  unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
80  unsigned long end_mem = memory_end; /* DAVIDM - this must not include kernel stack at top */
81 
82  pr_debug("Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
83 
84  end_mem &= PAGE_MASK;
85  high_memory = (void *) end_mem;
86 
87  start_mem = PAGE_ALIGN(start_mem);
89 
90  /* this will put all memory onto the freelists */
91  totalram_pages = free_all_bootmem();
92 
93  codek = (_etext - _stext) >> 10;
94  datak = (__bss_stop - _sdata) >> 10;
95  initk = (__init_begin - __init_end) >> 10;
96 
97  tmp = nr_free_pages() << PAGE_SHIFT;
98  printk(KERN_INFO "Memory available: %luk/%luk RAM, (%dk kernel code, %dk data)\n",
99  tmp >> 10,
100  len >> 10,
101  codek,
102  datak
103  );
104 }
105 
106 
107 #ifdef CONFIG_BLK_DEV_INITRD
108 void free_initrd_mem(unsigned long start, unsigned long end)
109 {
110  int pages = 0;
111  for (; start < end; start += PAGE_SIZE) {
112  ClearPageReserved(virt_to_page(start));
113  init_page_count(virt_to_page(start));
114  free_page(start);
115  totalram_pages++;
116  pages++;
117  }
118  pr_notice("Freeing initrd memory: %luk freed\n",
119  pages * (PAGE_SIZE / 1024));
120 }
121 #endif
122 
123 void free_initmem(void)
124 {
125 #ifdef CONFIG_RAMKERNEL
126  unsigned long addr;
127  /*
128  * The following code should be cool even if these sections
129  * are not page aligned.
130  */
131  addr = PAGE_ALIGN((unsigned long) __init_begin);
132  /* next to check that the page we free is not a partial page */
133  for (; addr + PAGE_SIZE < ((unsigned long) __init_end); addr += PAGE_SIZE) {
134  ClearPageReserved(virt_to_page(addr));
135  init_page_count(virt_to_page(addr));
136  free_page(addr);
137  totalram_pages++;
138  }
139  pr_notice("Freeing unused kernel memory: %luk freed (0x%x - 0x%x)\n",
140  (addr - PAGE_ALIGN((unsigned long) __init_begin)) >> 10,
141  (int)(PAGE_ALIGN((unsigned long) __init_begin)),
142  (int)(addr - PAGE_SIZE));
143 #endif
144 }
145