1 /*
2 * Copyright (C) 2004-2006 Atmel Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/gfp.h>
11 #include <linux/mm.h>
12 #include <linux/swap.h>
13 #include <linux/init.h>
14 #include <linux/mmzone.h>
15 #include <linux/module.h>
16 #include <linux/bootmem.h>
17 #include <linux/pagemap.h>
18 #include <linux/nodemask.h>
19
20 #include <asm/page.h>
21 #include <asm/mmu_context.h>
22 #include <asm/tlb.h>
23 #include <asm/io.h>
24 #include <asm/dma.h>
25 #include <asm/setup.h>
26 #include <asm/sections.h>
27
28 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_data;
29
30 struct page *empty_zero_page;
31 EXPORT_SYMBOL(empty_zero_page);
32
33 /*
34 * Cache of MMU context last used.
35 */
36 unsigned long mmu_context_cache = NO_CONTEXT;
37
38 /*
39 * paging_init() sets up the page tables
40 *
41 * This routine also unmaps the page at virtual kernel address 0, so
42 * that we can trap those pesky NULL-reference errors in the kernel.
43 */
paging_init(void)44 void __init paging_init(void)
45 {
46 extern unsigned long _evba;
47 void *zero_page;
48 int nid;
49
50 /*
51 * Make sure we can handle exceptions before enabling
52 * paging. Not that we should ever _get_ any exceptions this
53 * early, but you never know...
54 */
55 printk("Exception vectors start at %p\n", &_evba);
56 sysreg_write(EVBA, (unsigned long)&_evba);
57
58 /*
59 * Since we are ready to handle exceptions now, we should let
60 * the CPU generate them...
61 */
62 __asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));
63
64 /*
65 * Allocate the zero page. The allocator will panic if it
66 * can't satisfy the request, so no need to check.
67 */
68 zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
69 PAGE_SIZE);
70
71 sysreg_write(PTBR, (unsigned long)swapper_pg_dir);
72 enable_mmu();
73 printk ("CPU: Paging enabled\n");
74
75 for_each_online_node(nid) {
76 pg_data_t *pgdat = NODE_DATA(nid);
77 unsigned long zones_size[MAX_NR_ZONES];
78 unsigned long low, start_pfn;
79
80 start_pfn = pgdat->bdata->node_min_pfn;
81 low = pgdat->bdata->node_low_pfn;
82
83 memset(zones_size, 0, sizeof(zones_size));
84 zones_size[ZONE_NORMAL] = low - start_pfn;
85
86 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
87 nid, start_pfn, low);
88
89 free_area_init_node(nid, zones_size, start_pfn, NULL);
90
91 printk("Node %u: mem_map starts at %p\n",
92 pgdat->node_id, pgdat->node_mem_map);
93 }
94
95 mem_map = NODE_DATA(0)->node_mem_map;
96
97 empty_zero_page = virt_to_page(zero_page);
98 flush_dcache_page(empty_zero_page);
99 }
100
mem_init(void)101 void __init mem_init(void)
102 {
103 int codesize, reservedpages, datasize, initsize;
104 int nid, i;
105
106 reservedpages = 0;
107 high_memory = NULL;
108
109 /* this will put all low memory onto the freelists */
110 for_each_online_node(nid) {
111 pg_data_t *pgdat = NODE_DATA(nid);
112 unsigned long node_pages = 0;
113 void *node_high_memory;
114
115 num_physpages += pgdat->node_present_pages;
116
117 if (pgdat->node_spanned_pages != 0)
118 node_pages = free_all_bootmem_node(pgdat);
119
120 totalram_pages += node_pages;
121
122 for (i = 0; i < node_pages; i++)
123 if (PageReserved(pgdat->node_mem_map + i))
124 reservedpages++;
125
126 node_high_memory = (void *)((pgdat->node_start_pfn
127 + pgdat->node_spanned_pages)
128 << PAGE_SHIFT);
129 if (node_high_memory > high_memory)
130 high_memory = node_high_memory;
131 }
132
133 max_mapnr = MAP_NR(high_memory);
134
135 codesize = (unsigned long)_etext - (unsigned long)_text;
136 datasize = (unsigned long)_edata - (unsigned long)_data;
137 initsize = (unsigned long)__init_end - (unsigned long)__init_begin;
138
139 printk ("Memory: %luk/%luk available (%dk kernel code, "
140 "%dk reserved, %dk data, %dk init)\n",
141 nr_free_pages() << (PAGE_SHIFT - 10),
142 totalram_pages << (PAGE_SHIFT - 10),
143 codesize >> 10,
144 reservedpages << (PAGE_SHIFT - 10),
145 datasize >> 10,
146 initsize >> 10);
147 }
148
free_area(unsigned long addr,unsigned long end,char * s)149 static inline void free_area(unsigned long addr, unsigned long end, char *s)
150 {
151 unsigned int size = (end - addr) >> 10;
152
153 for (; addr < end; addr += PAGE_SIZE) {
154 struct page *page = virt_to_page(addr);
155 ClearPageReserved(page);
156 init_page_count(page);
157 free_page(addr);
158 totalram_pages++;
159 }
160
161 if (size && s)
162 printk(KERN_INFO "Freeing %s memory: %dK (%lx - %lx)\n",
163 s, size, end - (size << 10), end);
164 }
165
free_initmem(void)166 void free_initmem(void)
167 {
168 free_area((unsigned long)__init_begin, (unsigned long)__init_end,
169 "init");
170 }
171
172 #ifdef CONFIG_BLK_DEV_INITRD
173
free_initrd_mem(unsigned long start,unsigned long end)174 void free_initrd_mem(unsigned long start, unsigned long end)
175 {
176 free_area(start, end, "initrd");
177 }
178
179 #endif
180