1 /*
2 * linux/arch/m68k/mm/init.c
3 *
4 * Copyright (C) 1995 Hamish Macdonald
5 *
6 * Contains common initialization routines, specific init code moved
7 * to motorola.c and sun3mmu.c
8 */
9
10 #include <linux/config.h>
11 #include <linux/signal.h>
12 #include <linux/sched.h>
13 #include <linux/mm.h>
14 #include <linux/swap.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/init.h>
19 #include <linux/bootmem.h>
20 #ifdef CONFIG_BLK_DEV_RAM
21 #include <linux/blk.h>
22 #endif
23
24 #include <asm/setup.h>
25 #include <asm/uaccess.h>
26 #include <asm/page.h>
27 #include <asm/pgalloc.h>
28 #include <asm/system.h>
29 #include <asm/machdep.h>
30 #include <asm/io.h>
31 #ifdef CONFIG_ATARI
32 #include <asm/atari_stram.h>
33 #endif
34 #include <asm/tlb.h>
35
36 mmu_gather_t mmu_gathers[NR_CPUS];
37
38 unsigned long totalram_pages = 0;
39
do_check_pgt_cache(int low,int high)40 int do_check_pgt_cache(int low, int high)
41 {
42 int freed = 0;
43 if(pgtable_cache_size > high) {
44 do {
45 if(pmd_quicklist)
46 freed += free_pmd_slow(get_pmd_fast());
47 if(pte_quicklist)
48 free_pte_slow(get_pte_fast()), freed++;
49 } while(pgtable_cache_size > low);
50 }
51 return freed;
52 }
53
54 /*
55 * BAD_PAGE is the page that is used for page faults when linux
56 * is out-of-memory. Older versions of linux just did a
57 * do_exit(), but using this instead means there is less risk
58 * for a process dying in kernel mode, possibly leaving an inode
59 * unused etc..
60 *
61 * BAD_PAGETABLE is the accompanying page-table: it is initialized
62 * to point to BAD_PAGE entries.
63 *
64 * ZERO_PAGE is a special page that is used for zero-initialized
65 * data and COW.
66 */
67 unsigned long empty_bad_page_table;
68
__bad_pagetable(void)69 pte_t *__bad_pagetable(void)
70 {
71 memset((void *)empty_bad_page_table, 0, PAGE_SIZE);
72 return (pte_t *)empty_bad_page_table;
73 }
74
75 unsigned long empty_bad_page;
76
__bad_page(void)77 pte_t __bad_page(void)
78 {
79 memset ((void *)empty_bad_page, 0, PAGE_SIZE);
80 return pte_mkdirty(__mk_pte(empty_bad_page, PAGE_SHARED));
81 }
82
83 unsigned long empty_zero_page;
84
show_mem(void)85 void show_mem(void)
86 {
87 unsigned long i;
88 int free = 0, total = 0, reserved = 0, shared = 0;
89 int cached = 0;
90
91 printk("\nMem-info:\n");
92 show_free_areas();
93 printk("Free swap: %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
94 i = max_mapnr;
95 while (i-- > 0) {
96 total++;
97 if (PageReserved(mem_map+i))
98 reserved++;
99 else if (PageSwapCache(mem_map+i))
100 cached++;
101 else if (!page_count(mem_map+i))
102 free++;
103 else
104 shared += page_count(mem_map+i) - 1;
105 }
106 printk("%d pages of RAM\n",total);
107 printk("%d free pages\n",free);
108 printk("%d reserved pages\n",reserved);
109 printk("%d pages shared\n",shared);
110 printk("%d pages swap cached\n",cached);
111 printk("%ld pages in page table cache\n",pgtable_cache_size);
112 show_buffers();
113 }
114
115 extern void init_pointer_table(unsigned long ptable);
116
117 /* References to section boundaries */
118
119 extern char _text, _etext, _edata, __bss_start, _end;
120 extern char __init_begin, __init_end;
121
122 extern pmd_t *zero_pgtable;
123
mem_init(void)124 void __init mem_init(void)
125 {
126 int codepages = 0;
127 int datapages = 0;
128 int initpages = 0;
129 unsigned long tmp;
130 int i;
131
132 max_mapnr = num_physpages = MAP_NR(high_memory);
133
134 #ifdef CONFIG_ATARI
135 if (MACH_IS_ATARI)
136 atari_stram_mem_init_hook();
137 #endif
138
139 /* this will put all memory onto the freelists */
140 totalram_pages = free_all_bootmem();
141
142 for (tmp = PAGE_OFFSET ; tmp < (unsigned long)high_memory; tmp += PAGE_SIZE) {
143 #if 0
144 #ifndef CONFIG_SUN3
145 if (virt_to_phys ((void *)tmp) >= mach_max_dma_address)
146 clear_bit(PG_DMA, &virt_to_page(tmp)->flags);
147 #endif
148 #endif
149 if (PageReserved(virt_to_page(tmp))) {
150 if (tmp >= (unsigned long)&_text
151 && tmp < (unsigned long)&_etext)
152 codepages++;
153 else if (tmp >= (unsigned long) &__init_begin
154 && tmp < (unsigned long) &__init_end)
155 initpages++;
156 else
157 datapages++;
158 continue;
159 }
160 #if 0
161 set_page_count(virt_to_page(tmp), 1);
162 #ifdef CONFIG_BLK_DEV_INITRD
163 if (!initrd_start ||
164 (tmp < (initrd_start & PAGE_MASK) || tmp >= initrd_end))
165 #endif
166 free_page(tmp);
167 #endif
168 }
169
170 #ifndef CONFIG_SUN3
171 /* insert pointer tables allocated so far into the tablelist */
172 init_pointer_table((unsigned long)kernel_pg_dir);
173 for (i = 0; i < PTRS_PER_PGD; i++) {
174 if (pgd_present(kernel_pg_dir[i]))
175 init_pointer_table(__pgd_page(kernel_pg_dir[i]));
176 }
177
178 /* insert also pointer table that we used to unmap the zero page */
179 if (zero_pgtable)
180 init_pointer_table((unsigned long)zero_pgtable);
181 #endif
182
183 printk("Memory: %luk/%luk available (%dk kernel code, %dk data, %dk init)\n",
184 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
185 max_mapnr << (PAGE_SHIFT-10),
186 codepages << (PAGE_SHIFT-10),
187 datapages << (PAGE_SHIFT-10),
188 initpages << (PAGE_SHIFT-10));
189 }
190
191 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)192 void free_initrd_mem(unsigned long start, unsigned long end)
193 {
194 int pages = 0;
195 for (; start < end; start += PAGE_SIZE) {
196 ClearPageReserved(virt_to_page(start));
197 set_page_count(virt_to_page(start), 1);
198 free_page(start);
199 totalram_pages++;
200 pages++;
201 }
202 printk ("Freeing initrd memory: %dk freed\n", pages);
203 }
204 #endif
205
si_meminfo(struct sysinfo * val)206 void si_meminfo(struct sysinfo *val)
207 {
208 unsigned long i;
209
210 i = max_mapnr;
211 val->totalram = totalram_pages;
212 val->sharedram = 0;
213 val->freeram = nr_free_pages();
214 val->bufferram = atomic_read(&buffermem_pages);
215 val->totalhigh = 0;
216 val->freehigh = 0;
217 val->mem_unit = PAGE_SIZE;
218 return;
219 }
220