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/machdep.h>
40
41 /*
42 * ZERO_PAGE is a special page that is used for zero-initialized
43 * data and COW.
44 */
45 void *empty_zero_page;
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 */
paging_init(void)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
62 empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
63 memset(empty_zero_page, 0, PAGE_SIZE);
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
mem_init(void)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);
88 max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;
89
90 /* this will put all memory onto the freelists */
91 totalram_pages = free_all_bootmem();
92
93 codek = (_etext - _stext) >> 10;
94 datak = (_ebss - _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
free_initrd_mem(unsigned long start,unsigned long end)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
free_initmem(void)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
146