tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * arch/sh64/mm/init.c
7 *
8 * Copyright (C) 2000, 2001 Paolo Alberelli
9 * Copyright (C) 2003, 2004 Paul Mundt
10 *
11 */
12
13#include <linux/init.h>
14#include <linux/rwsem.h>
15#include <linux/mm.h>
16#include <linux/swap.h>
17#include <linux/bootmem.h>
18
19#include <asm/mmu_context.h>
20#include <asm/page.h>
21#include <asm/pgalloc.h>
22#include <asm/pgtable.h>
23#include <asm/tlb.h>
24
25#ifdef CONFIG_BLK_DEV_INITRD
26#include <linux/blk.h>
27#endif
28
29DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
30
31/*
32 * Cache of MMU context last used.
33 */
34unsigned long mmu_context_cache;
35pgd_t * mmu_pdtp_cache;
36int after_bootmem = 0;
37
38/*
39 * BAD_PAGE is the page that is used for page faults when linux
40 * is out-of-memory. Older versions of linux just did a
41 * do_exit(), but using this instead means there is less risk
42 * for a process dying in kernel mode, possibly leaving an inode
43 * unused etc..
44 *
45 * BAD_PAGETABLE is the accompanying page-table: it is initialized
46 * to point to BAD_PAGE entries.
47 *
48 * ZERO_PAGE is a special page that is used for zero-initialized
49 * data and COW.
50 */
51
52extern unsigned char empty_zero_page[PAGE_SIZE];
53extern unsigned char empty_bad_page[PAGE_SIZE];
54extern pte_t empty_bad_pte_table[PTRS_PER_PTE];
55extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
56
57extern char _text, _etext, _edata, __bss_start, _end;
58extern char __init_begin, __init_end;
59
60/* It'd be good if these lines were in the standard header file. */
61#define START_PFN (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
62#define MAX_LOW_PFN (NODE_DATA(0)->bdata->node_low_pfn)
63
64
65void show_mem(void)
66{
67 int i, total = 0, reserved = 0;
68 int shared = 0, cached = 0;
69
70 printk("Mem-info:\n");
71 show_free_areas();
72 printk("Free swap: %6ldkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
73 i = max_mapnr;
74 while (i-- > 0) {
75 total++;
76 if (PageReserved(mem_map+i))
77 reserved++;
78 else if (PageSwapCache(mem_map+i))
79 cached++;
80 else if (page_count(mem_map+i))
81 shared += page_count(mem_map+i) - 1;
82 }
83 printk("%d pages of RAM\n",total);
84 printk("%d reserved pages\n",reserved);
85 printk("%d pages shared\n",shared);
86 printk("%d pages swap cached\n",cached);
87 printk("%ld pages in page table cache\n",pgtable_cache_size);
88}
89
90/*
91 * paging_init() sets up the page tables.
92 *
93 * head.S already did a lot to set up address translation for the kernel.
94 * Here we comes with:
95 * . MMU enabled
96 * . ASID set (SR)
97 * . some 512MB regions being mapped of which the most relevant here is:
98 * . CACHED segment (ASID 0 [irrelevant], shared AND NOT user)
99 * . possible variable length regions being mapped as:
100 * . UNCACHED segment (ASID 0 [irrelevant], shared AND NOT user)
101 * . All of the memory regions are placed, independently from the platform
102 * on high addresses, above 0x80000000.
103 * . swapper_pg_dir is already cleared out by the .space directive
104 * in any case swapper does not require a real page directory since
105 * it's all kernel contained.
106 *
107 * Those pesky NULL-reference errors in the kernel are then
108 * dealt with by not mapping address 0x00000000 at all.
109 *
110 */
111void __init paging_init(void)
112{
113 unsigned long zones_size[MAX_NR_ZONES] = {0, };
114
115 pgd_init((unsigned long)swapper_pg_dir);
116 pgd_init((unsigned long)swapper_pg_dir +
117 sizeof(pgd_t) * USER_PTRS_PER_PGD);
118
119 mmu_context_cache = MMU_CONTEXT_FIRST_VERSION;
120
121 zones_size[ZONE_NORMAL] = MAX_LOW_PFN - START_PFN;
122 NODE_DATA(0)->node_mem_map = NULL;
123 free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0);
124}
125
126void __init mem_init(void)
127{
128 int codesize, reservedpages, datasize, initsize;
129 int tmp;
130
131 max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;
132 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE);
133
134 /*
135 * Clear the zero-page.
136 * This is not required but we might want to re-use
137 * this very page to pass boot parameters, one day.
138 */
139 memset(empty_zero_page, 0, PAGE_SIZE);
140
141 /* this will put all low memory onto the freelists */
142 totalram_pages += free_all_bootmem_node(NODE_DATA(0));
143 reservedpages = 0;
144 for (tmp = 0; tmp < num_physpages; tmp++)
145 /*
146 * Only count reserved RAM pages
147 */
148 if (PageReserved(mem_map+tmp))
149 reservedpages++;
150
151 after_bootmem = 1;
152
153 codesize = (unsigned long) &_etext - (unsigned long) &_text;
154 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
155 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
156
157 printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n",
158 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
159 max_mapnr << (PAGE_SHIFT-10),
160 codesize >> 10,
161 reservedpages << (PAGE_SHIFT-10),
162 datasize >> 10,
163 initsize >> 10);
164}
165
166void free_initmem(void)
167{
168 unsigned long addr;
169
170 addr = (unsigned long)(&__init_begin);
171 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
172 ClearPageReserved(virt_to_page(addr));
173 init_page_count(virt_to_page(addr));
174 free_page(addr);
175 totalram_pages++;
176 }
177 printk ("Freeing unused kernel memory: %ldk freed\n", (&__init_end - &__init_begin) >> 10);
178}
179
180#ifdef CONFIG_BLK_DEV_INITRD
181void free_initrd_mem(unsigned long start, unsigned long end)
182{
183 unsigned long p;
184 for (p = start; p < end; p += PAGE_SIZE) {
185 ClearPageReserved(virt_to_page(p));
186 init_page_count(virt_to_page(p));
187 free_page(p);
188 totalram_pages++;
189 }
190 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
191}
192#endif
193