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Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -07001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090010#include <linux/gfp.h>
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070011#include <linux/mm.h>
12#include <linux/swap.h>
13#include <linux/init.h>
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070014#include <linux/mmzone.h>
Haavard Skinnemoen8bd89742008-06-08 23:28:45 +020015#include <linux/module.h>
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070016#include <linux/bootmem.h>
17#include <linux/pagemap.h>
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070018#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
28DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
29
Tim Abbottabe1ee32009-09-20 18:14:15 -040030pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_data;
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070031
32struct page *empty_zero_page;
Haavard Skinnemoen8bd89742008-06-08 23:28:45 +020033EXPORT_SYMBOL(empty_zero_page);
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070034
35/*
36 * Cache of MMU context last used.
37 */
38unsigned long mmu_context_cache = NO_CONTEXT;
39
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070040/*
41 * paging_init() sets up the page tables
42 *
43 * This routine also unmaps the page at virtual kernel address 0, so
44 * that we can trap those pesky NULL-reference errors in the kernel.
45 */
46void __init paging_init(void)
47{
48 extern unsigned long _evba;
49 void *zero_page;
50 int nid;
51
52 /*
53 * Make sure we can handle exceptions before enabling
54 * paging. Not that we should ever _get_ any exceptions this
55 * early, but you never know...
56 */
57 printk("Exception vectors start at %p\n", &_evba);
58 sysreg_write(EVBA, (unsigned long)&_evba);
59
60 /*
61 * Since we are ready to handle exceptions now, we should let
62 * the CPU generate them...
63 */
64 __asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));
65
66 /*
67 * Allocate the zero page. The allocator will panic if it
68 * can't satisfy the request, so no need to check.
69 */
70 zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
71 PAGE_SIZE);
72
Haavard Skinnemoenebe74592008-01-14 22:16:50 +010073 sysreg_write(PTBR, (unsigned long)swapper_pg_dir);
74 enable_mmu();
75 printk ("CPU: Paging enabled\n");
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070076
77 for_each_online_node(nid) {
78 pg_data_t *pgdat = NODE_DATA(nid);
79 unsigned long zones_size[MAX_NR_ZONES];
80 unsigned long low, start_pfn;
81
Johannes Weiner3560e242008-07-23 21:28:09 -070082 start_pfn = pgdat->bdata->node_min_pfn;
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070083 low = pgdat->bdata->node_low_pfn;
84
85 memset(zones_size, 0, sizeof(zones_size));
86 zones_size[ZONE_NORMAL] = low - start_pfn;
87
88 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
89 nid, start_pfn, low);
90
Johannes Weiner9109fb72008-07-23 21:27:20 -070091 free_area_init_node(nid, zones_size, start_pfn, NULL);
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070092
93 printk("Node %u: mem_map starts at %p\n",
94 pgdat->node_id, pgdat->node_mem_map);
95 }
96
97 mem_map = NODE_DATA(0)->node_mem_map;
98
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -070099 empty_zero_page = virt_to_page(zero_page);
100 flush_dcache_page(empty_zero_page);
101}
102
103void __init mem_init(void)
104{
105 int codesize, reservedpages, datasize, initsize;
106 int nid, i;
107
108 reservedpages = 0;
109 high_memory = NULL;
110
111 /* this will put all low memory onto the freelists */
112 for_each_online_node(nid) {
113 pg_data_t *pgdat = NODE_DATA(nid);
114 unsigned long node_pages = 0;
115 void *node_high_memory;
116
117 num_physpages += pgdat->node_present_pages;
118
119 if (pgdat->node_spanned_pages != 0)
120 node_pages = free_all_bootmem_node(pgdat);
121
122 totalram_pages += node_pages;
123
124 for (i = 0; i < node_pages; i++)
125 if (PageReserved(pgdat->node_mem_map + i))
126 reservedpages++;
127
128 node_high_memory = (void *)((pgdat->node_start_pfn
129 + pgdat->node_spanned_pages)
130 << PAGE_SHIFT);
131 if (node_high_memory > high_memory)
132 high_memory = node_high_memory;
133 }
134
135 max_mapnr = MAP_NR(high_memory);
136
137 codesize = (unsigned long)_etext - (unsigned long)_text;
138 datasize = (unsigned long)_edata - (unsigned long)_data;
139 initsize = (unsigned long)__init_end - (unsigned long)__init_begin;
140
141 printk ("Memory: %luk/%luk available (%dk kernel code, "
142 "%dk reserved, %dk data, %dk init)\n",
Geert Uytterhoevencc013a82009-09-21 17:02:36 -0700143 nr_free_pages() << (PAGE_SHIFT - 10),
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -0700144 totalram_pages << (PAGE_SHIFT - 10),
145 codesize >> 10,
146 reservedpages << (PAGE_SHIFT - 10),
147 datasize >> 10,
148 initsize >> 10);
149}
150
151static inline void free_area(unsigned long addr, unsigned long end, char *s)
152{
153 unsigned int size = (end - addr) >> 10;
154
155 for (; addr < end; addr += PAGE_SIZE) {
156 struct page *page = virt_to_page(addr);
157 ClearPageReserved(page);
158 init_page_count(page);
159 free_page(addr);
160 totalram_pages++;
161 }
162
163 if (size && s)
164 printk(KERN_INFO "Freeing %s memory: %dK (%lx - %lx)\n",
165 s, size, end - (size << 10), end);
166}
167
168void free_initmem(void)
169{
170 free_area((unsigned long)__init_begin, (unsigned long)__init_end,
171 "init");
172}
173
174#ifdef CONFIG_BLK_DEV_INITRD
175
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -0700176void free_initrd_mem(unsigned long start, unsigned long end)
177{
Robert P. J. Day193fdd12007-09-19 08:43:42 -0400178 free_area(start, end, "initrd");
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -0700179}
180
Haavard Skinnemoen5f97f7f2006-09-25 23:32:13 -0700181#endif