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1 /* MN10300 Memory management initialisation
2  *
3  * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5  * Modified by David Howells (dhowells@redhat.com)
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public Licence
9  * as published by the Free Software Foundation; either version
10  * 2 of the Licence, or (at your option) any later version.
11  */
12 #include <linux/signal.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/ptrace.h>
19 #include <linux/mman.h>
20 #include <linux/slab.h>
21 #include <linux/fs.h>
22 #include <linux/mm.h>
23 #include <linux/swap.h>
24 #include <linux/smp.h>
25 #include <linux/init.h>
26 #include <linux/initrd.h>
27 #include <linux/highmem.h>
28 #include <linux/pagemap.h>
29 #include <linux/bootmem.h>
30 
31 #include <asm/processor.h>
32 #include <asm/system.h>
33 #include <asm/uaccess.h>
34 #include <asm/pgtable.h>
35 #include <asm/pgalloc.h>
36 #include <asm/dma.h>
37 #include <asm/tlb.h>
38 #include <asm/sections.h>
39 
40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
41 
42 unsigned long highstart_pfn, highend_pfn;
43 
44 /*
45  * set up paging
46  */
paging_init(void)47 void __init paging_init(void)
48 {
49 	unsigned long zones_size[MAX_NR_ZONES] = {0,};
50 	pte_t *ppte;
51 	int loop;
52 
53 	/* main kernel space -> RAM mapping is handled as 1:1 transparent by
54 	 * the MMU */
55 	memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
56 	memset(kernel_vmalloc_ptes, 0, sizeof(kernel_vmalloc_ptes));
57 
58 	/* load the VMALLOC area PTE table addresses into the kernel PGD */
59 	ppte = kernel_vmalloc_ptes;
60 	for (loop = VMALLOC_START / (PAGE_SIZE * PTRS_PER_PTE);
61 	     loop < VMALLOC_END / (PAGE_SIZE * PTRS_PER_PTE);
62 	     loop++
63 	     ) {
64 		set_pgd(swapper_pg_dir + loop, __pgd(__pa(ppte) | _PAGE_TABLE));
65 		ppte += PAGE_SIZE / sizeof(pte_t);
66 	}
67 
68 	/* declare the sizes of the RAM zones (only use the normal zone) */
69 	zones_size[ZONE_NORMAL] =
70 		contig_page_data.bdata->node_low_pfn -
71 		contig_page_data.bdata->node_min_pfn;
72 
73 	/* pass the memory from the bootmem allocator to the main allocator */
74 	free_area_init(zones_size);
75 
76 	__flush_tlb_all();
77 }
78 
79 /*
80  * transfer all the memory from the bootmem allocator to the runtime allocator
81  */
mem_init(void)82 void __init mem_init(void)
83 {
84 	int codesize, reservedpages, datasize, initsize;
85 	int tmp;
86 
87 	if (!mem_map)
88 		BUG();
89 
90 #define START_PFN	(contig_page_data.bdata->node_min_pfn)
91 #define MAX_LOW_PFN	(contig_page_data.bdata->node_low_pfn)
92 
93 	max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;
94 	high_memory = (void *) __va(MAX_LOW_PFN * PAGE_SIZE);
95 
96 	/* clear the zero-page */
97 	memset(empty_zero_page, 0, PAGE_SIZE);
98 
99 	/* this will put all low memory onto the freelists */
100 	totalram_pages += free_all_bootmem();
101 
102 	reservedpages = 0;
103 	for (tmp = 0; tmp < num_physpages; tmp++)
104 		if (PageReserved(&mem_map[tmp]))
105 			reservedpages++;
106 
107 	codesize =  (unsigned long) &_etext - (unsigned long) &_stext;
108 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
109 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
110 
111 	printk(KERN_INFO
112 	       "Memory: %luk/%luk available"
113 	       " (%dk kernel code, %dk reserved, %dk data, %dk init,"
114 	       " %ldk highmem)\n",
115 	       (unsigned long) nr_free_pages() << (PAGE_SHIFT - 10),
116 	       max_mapnr << (PAGE_SHIFT - 10),
117 	       codesize >> 10,
118 	       reservedpages << (PAGE_SHIFT - 10),
119 	       datasize >> 10,
120 	       initsize >> 10,
121 	       (unsigned long) (totalhigh_pages << (PAGE_SHIFT - 10))
122 	       );
123 }
124 
125 /*
126  *
127  */
free_init_pages(char * what,unsigned long begin,unsigned long end)128 void free_init_pages(char *what, unsigned long begin, unsigned long end)
129 {
130 	unsigned long addr;
131 
132 	for (addr = begin; addr < end; addr += PAGE_SIZE) {
133 		ClearPageReserved(virt_to_page(addr));
134 		init_page_count(virt_to_page(addr));
135 		memset((void *) addr, 0xcc, PAGE_SIZE);
136 		free_page(addr);
137 		totalram_pages++;
138 	}
139 	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
140 }
141 
142 /*
143  * recycle memory containing stuff only required for initialisation
144  */
free_initmem(void)145 void free_initmem(void)
146 {
147 	free_init_pages("unused kernel memory",
148 			(unsigned long) &__init_begin,
149 			(unsigned long) &__init_end);
150 }
151 
152 /*
153  * dispose of the memory on which the initial ramdisk resided
154  */
155 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)156 void free_initrd_mem(unsigned long start, unsigned long end)
157 {
158 	free_init_pages("initrd memory", start, end);
159 }
160 #endif
161