1 /*
2 * linux/arch/m68knommu/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/m68k/mm/init.c
11 *
12 * Copyright (C) 1995 Hamish Macdonald
13 *
14 * JAN/1999 -- hacked to support ColdFire (gerg@snapgear.com)
15 * DEC/2000 -- linux 2.4 support <davidm@snapgear.com>
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/system.h>
40 #include <asm/machdep.h>
41
42 /*
43 * ZERO_PAGE is a special page that is used for zero-initialized
44 * data and COW.
45 */
46 void *empty_zero_page;
47
48 /*
49 * paging_init() continues the virtual memory environment setup which
50 * was begun by the code in arch/head.S.
51 * The parameters are pointers to where to stick the starting and ending
52 * addresses of available kernel virtual memory.
53 */
paging_init(void)54 void __init paging_init(void)
55 {
56 /*
57 * Make sure start_mem is page aligned, otherwise bootmem and
58 * page_alloc get different views of the world.
59 */
60 unsigned long end_mem = memory_end & PAGE_MASK;
61 unsigned long zones_size[MAX_NR_ZONES] = {0, };
62
63 empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
64 memset(empty_zero_page, 0, PAGE_SIZE);
65
66 /*
67 * Set up SFC/DFC registers (user data space).
68 */
69 set_fs (USER_DS);
70
71 zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
72 free_area_init(zones_size);
73 }
74
mem_init(void)75 void __init mem_init(void)
76 {
77 int codek = 0, datak = 0, initk = 0;
78 unsigned long tmp;
79 unsigned long len = _ramend - _rambase;
80 unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
81 unsigned long end_mem = memory_end; /* DAVIDM - this must not include kernel stack at top */
82
83 pr_debug("Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
84
85 end_mem &= PAGE_MASK;
86 high_memory = (void *) end_mem;
87
88 start_mem = PAGE_ALIGN(start_mem);
89 max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;
90
91 /* this will put all memory onto the freelists */
92 totalram_pages = free_all_bootmem();
93
94 codek = (_etext - _stext) >> 10;
95 datak = (_ebss - _sdata) >> 10;
96 initk = (__init_begin - __init_end) >> 10;
97
98 tmp = nr_free_pages() << PAGE_SHIFT;
99 printk(KERN_INFO "Memory available: %luk/%luk RAM, (%dk kernel code, %dk data)\n",
100 tmp >> 10,
101 len >> 10,
102 codek,
103 datak
104 );
105 }
106
107
108 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)109 void free_initrd_mem(unsigned long start, unsigned long end)
110 {
111 int pages = 0;
112 for (; start < end; start += PAGE_SIZE) {
113 ClearPageReserved(virt_to_page(start));
114 init_page_count(virt_to_page(start));
115 free_page(start);
116 totalram_pages++;
117 pages++;
118 }
119 pr_notice("Freeing initrd memory: %luk freed\n",
120 pages * (PAGE_SIZE / 1024));
121 }
122 #endif
123
free_initmem(void)124 void free_initmem(void)
125 {
126 #ifdef CONFIG_RAMKERNEL
127 unsigned long addr;
128 /*
129 * The following code should be cool even if these sections
130 * are not page aligned.
131 */
132 addr = PAGE_ALIGN((unsigned long) __init_begin);
133 /* next to check that the page we free is not a partial page */
134 for (; addr + PAGE_SIZE < ((unsigned long) __init_end); addr += PAGE_SIZE) {
135 ClearPageReserved(virt_to_page(addr));
136 init_page_count(virt_to_page(addr));
137 free_page(addr);
138 totalram_pages++;
139 }
140 pr_notice("Freeing unused kernel memory: %luk freed (0x%x - 0x%x)\n",
141 (addr - PAGE_ALIGN((unsigned long) __init_begin)) >> 10,
142 (int)(PAGE_ALIGN((unsigned long) __init_begin)),
143 (int)(addr - PAGE_SIZE));
144 #endif
145 }
146
147