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
 28pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_data;
 29
 30struct page *empty_zero_page;
 31EXPORT_SYMBOL(empty_zero_page);
 32
 33/*
 34 * Cache of MMU context last used.
 35 */
 36unsigned 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 */
 44void __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
101void __init mem_init(void)
102{
103	pg_data_t *pgdat;
104
105	high_memory = NULL;
106	for_each_online_pgdat(pgdat)
107		high_memory = max_t(void *, high_memory,
108				    __va(pgdat_end_pfn(pgdat) << PAGE_SHIFT));
109
110	set_max_mapnr(MAP_NR(high_memory));
111	free_all_bootmem();
112	mem_init_print_info(NULL);
113}
114
115void free_initmem(void)
116{
117	free_initmem_default(-1);
118}
119
120#ifdef CONFIG_BLK_DEV_INITRD
121void free_initrd_mem(unsigned long start, unsigned long end)
122{
123	free_reserved_area((void *)start, (void *)end, -1, "initrd");
124}
125#endif