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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/* init.c: memory initialisation for FRV
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Derived from:
* - linux/arch/m68knommu/mm/init.c
* - Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>, Kenneth Albanowski <kjahds@kjahds.com>,
* - Copyright (C) 2000 Lineo, Inc. (www.lineo.com)
* - linux/arch/m68k/mm/init.c
* - Copyright (C) 1995 Hamish Macdonald
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/mmu_context.h>
#include <asm/virtconvert.h>
#include <asm/sections.h>
#include <asm/tlb.h>
#undef DEBUG
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
/*
* BAD_PAGE is the page that is used for page faults when linux
* is out-of-memory. Older versions of linux just did a
* do_exit(), but using this instead means there is less risk
* for a process dying in kernel mode, possibly leaving a inode
* unused etc..
*
* BAD_PAGETABLE is the accompanying page-table: it is initialized
* to point to BAD_PAGE entries.
*
* ZERO_PAGE is a special page that is used for zero-initialized
* data and COW.
*/
static unsigned long empty_bad_page_table;
static unsigned long empty_bad_page;
unsigned long empty_zero_page;
/*****************************************************************************/
/*
*
*/
void show_mem(void)
{
unsigned long i;
int free = 0, total = 0, reserved = 0, shared = 0;
printk("\nMem-info:\n");
show_free_areas();
i = max_mapnr;
while (i-- > 0) {
struct page *page = &mem_map[i];
total++;
if (PageReserved(page))
reserved++;
else if (!page_count(page))
free++;
else
shared += page_count(page) - 1;
}
printk("%d pages of RAM\n",total);
printk("%d free pages\n",free);
printk("%d reserved pages\n",reserved);
printk("%d pages shared\n",shared);
} /* end show_mem() */
/*****************************************************************************/
/*
* paging_init() continues the virtual memory environment setup which
* was begun by the code in arch/head.S.
* The parameters are pointers to where to stick the starting and ending
* addresses of available kernel virtual memory.
*/
void __init paging_init(void)
{
unsigned long zones_size[MAX_NR_ZONES] = {0, };
/* allocate some pages for kernel housekeeping tasks */
empty_bad_page_table = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
empty_bad_page = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
empty_zero_page = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
memset((void *) empty_zero_page, 0, PAGE_SIZE);
#ifdef CONFIG_HIGHMEM
if (num_physpages - num_mappedpages) {
pgd_t *pge;
pud_t *pue;
pmd_t *pme;
pkmap_page_table = alloc_bootmem_pages(PAGE_SIZE);
memset(pkmap_page_table, 0, PAGE_SIZE);
pge = swapper_pg_dir + pgd_index_k(PKMAP_BASE);
pue = pud_offset(pge, PKMAP_BASE);
pme = pmd_offset(pue, PKMAP_BASE);
__set_pmd(pme, virt_to_phys(pkmap_page_table) | _PAGE_TABLE);
}
#endif
/* distribute the allocatable pages across the various zones and pass them to the allocator
*/
zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
#ifdef CONFIG_HIGHMEM
zones_size[ZONE_HIGHMEM] = num_physpages - num_mappedpages;
#endif
free_area_init(zones_size);
#ifdef CONFIG_MMU
/* initialise init's MMU context */
init_new_context(&init_task, &init_mm);
#endif
} /* end paging_init() */
/*****************************************************************************/
/*
*
*/
void __init mem_init(void)
{
unsigned long npages = (memory_end - memory_start) >> PAGE_SHIFT;
unsigned long tmp;
#ifdef CONFIG_MMU
unsigned long loop, pfn;
int datapages = 0;
#endif
int codek = 0, datak = 0;
/* this will put all memory onto the freelists */
totalram_pages = free_all_bootmem();
#ifdef CONFIG_MMU
for (loop = 0 ; loop < npages ; loop++)
if (PageReserved(&mem_map[loop]))
datapages++;
#ifdef CONFIG_HIGHMEM
for (pfn = num_physpages - 1; pfn >= num_mappedpages; pfn--) {
struct page *page = &mem_map[pfn];
ClearPageReserved(page);
init_page_count(page);
__free_page(page);
totalram_pages++;
}
#endif
codek = ((unsigned long) &_etext - (unsigned long) &_stext) >> 10;
datak = datapages << (PAGE_SHIFT - 10);
#else
codek = (_etext - _stext) >> 10;
datak = 0; //(_ebss - _sdata) >> 10;
#endif
tmp = nr_free_pages() << PAGE_SHIFT;
printk("Memory available: %luKiB/%luKiB RAM, %luKiB/%luKiB ROM (%dKiB kernel code, %dKiB data)\n",
tmp >> 10,
npages << (PAGE_SHIFT - 10),
(rom_length > 0) ? ((rom_length >> 10) - codek) : 0,
rom_length >> 10,
codek,
datak
);
} /* end mem_init() */
/*****************************************************************************/
/*
* free the memory that was only required for initialisation
*/
void free_initmem(void)
{
#if defined(CONFIG_RAMKERNEL) && !defined(CONFIG_PROTECT_KERNEL)
unsigned long start, end, addr;
start = PAGE_ALIGN((unsigned long) &__init_begin); /* round up */
end = ((unsigned long) &__init_end) & PAGE_MASK; /* round down */
/* next to check that the page we free is not a partial page */
for (addr = start; addr < end; addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
free_page(addr);
totalram_pages++;
}
printk("Freeing unused kernel memory: %ldKiB freed (0x%lx - 0x%lx)\n",
(end - start) >> 10, start, end);
#endif
} /* end free_initmem() */
/*****************************************************************************/
/*
* free the initial ramdisk memory
*/
#ifdef CONFIG_BLK_DEV_INITRD
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
int pages = 0;
for (; start < end; start += PAGE_SIZE) {
ClearPageReserved(virt_to_page(start));
init_page_count(virt_to_page(start));
free_page(start);
totalram_pages++;
pages++;
}
printk("Freeing initrd memory: %dKiB freed\n", (pages * PAGE_SIZE) >> 10);
} /* end free_initrd_mem() */
#endif
|
