summaryrefslogtreecommitdiffstats
path: root/arch/avr32/mm/init.c
blob: af6890fd731912d045ae152ddd71742881105077 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
/*
 * Copyright (C) 2004-2006 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/mmzone.h>
#include <linux/module.h>
#include <linux/bootmem.h>
#include <linux/pagemap.h>
#include <linux/nodemask.h>

#include <asm/page.h>
#include <asm/mmu_context.h>
#include <asm/tlb.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/setup.h>
#include <asm/sections.h>

pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_data;

struct page *empty_zero_page;
EXPORT_SYMBOL(empty_zero_page);

/*
 * Cache of MMU context last used.
 */
unsigned long mmu_context_cache = NO_CONTEXT;

/*
 * paging_init() sets up the page tables
 *
 * This routine also unmaps the page at virtual kernel address 0, so
 * that we can trap those pesky NULL-reference errors in the kernel.
 */
void __init paging_init(void)
{
	extern unsigned long _evba;
	void *zero_page;
	int nid;

	/*
	 * Make sure we can handle exceptions before enabling
	 * paging. Not that we should ever _get_ any exceptions this
	 * early, but you never know...
	 */
	printk("Exception vectors start at %p\n", &_evba);
	sysreg_write(EVBA, (unsigned long)&_evba);

	/*
	 * Since we are ready to handle exceptions now, we should let
	 * the CPU generate them...
	 */
	__asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));

	/*
	 * Allocate the zero page. The allocator will panic if it
	 * can't satisfy the request, so no need to check.
	 */
	zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
						 PAGE_SIZE);

	sysreg_write(PTBR, (unsigned long)swapper_pg_dir);
	enable_mmu();
	printk ("CPU: Paging enabled\n");

	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
		unsigned long zones_size[MAX_NR_ZONES];
		unsigned long low, start_pfn;

		start_pfn = pgdat->bdata->node_min_pfn;
		low = pgdat->bdata->node_low_pfn;

		memset(zones_size, 0, sizeof(zones_size));
		zones_size[ZONE_NORMAL] = low - start_pfn;

		printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
		       nid, start_pfn, low);

		free_area_init_node(nid, zones_size, start_pfn, NULL);

		printk("Node %u: mem_map starts at %p\n",
		       pgdat->node_id, pgdat->node_mem_map);
	}

	mem_map = NODE_DATA(0)->node_mem_map;

	empty_zero_page = virt_to_page(zero_page);
	flush_dcache_page(empty_zero_page);
}

void __init mem_init(void)
{
	int codesize, reservedpages, datasize, initsize;
	int nid, i;

	reservedpages = 0;
	high_memory = NULL;

	/* this will put all low memory onto the freelists */
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
		unsigned long node_pages = 0;
		void *node_high_memory;

		num_physpages += pgdat->node_present_pages;

		if (pgdat->node_spanned_pages != 0)
			node_pages = free_all_bootmem_node(pgdat);

		for (i = 0; i < node_pages; i++)
			if (PageReserved(pgdat->node_mem_map + i))
				reservedpages++;

		node_high_memory = (void *)((pgdat->node_start_pfn
					     + pgdat->node_spanned_pages)
					    << PAGE_SHIFT);
		if (node_high_memory > high_memory)
			high_memory = node_high_memory;
	}

	max_mapnr = MAP_NR(high_memory);

	codesize = (unsigned long)_etext - (unsigned long)_text;
	datasize = (unsigned long)_edata - (unsigned long)_data;
	initsize = (unsigned long)__init_end - (unsigned long)__init_begin;

	printk ("Memory: %luk/%luk available (%dk kernel code, "
		"%dk reserved, %dk data, %dk init)\n",
		nr_free_pages() << (PAGE_SHIFT - 10),
		totalram_pages << (PAGE_SHIFT - 10),
		codesize >> 10,
		reservedpages << (PAGE_SHIFT - 10),
		datasize >> 10,
		initsize >> 10);
}

void free_initmem(void)
{
	free_initmem_default(-1);
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
	free_reserved_area((void *)start, (void *)end, -1, "initrd");
}
#endif
OpenPOWER on IntegriCloud