File: /usr/src/linux/arch/mips/mips-boards/generic/memory.c
1 /*
2 * Carsten Langgaard, carstenl@mips.com
3 * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved.
4 *
5 * ########################################################################
6 *
7 * This program is free software; you can distribute it and/or modify it
8 * under the terms of the GNU General Public License (Version 2) as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
19 *
20 * ########################################################################
21 *
22 * PROM library functions for acquiring/using memory descriptors given to
23 * us from the YAMON.
24 *
25 */
26 #include <linux/config.h>
27 #include <linux/init.h>
28 #include <linux/mm.h>
29 #include <linux/bootmem.h>
30
31 #include <asm/bootinfo.h>
32 #include <asm/page.h>
33
34 #include <asm/mips-boards/prom.h>
35
36 /*#define DEBUG*/
37
38 enum yamon_memtypes {
39 yamon_dontuse,
40 yamon_prom,
41 yamon_free,
42 };
43 struct prom_pmemblock mdesc[PROM_MAX_PMEMBLOCKS];
44
45 #ifdef DEBUG
46 static char *mtypes[3] = {
47 "Dont use memory",
48 "YAMON PROM memory",
49 "Free memmory",
50 };
51 #endif
52
53 /* References to section boundaries */
54 extern char _end;
55
56 #define PFN_ALIGN(x) (((unsigned long)(x) + (PAGE_SIZE - 1)) & PAGE_MASK)
57
58
59 struct prom_pmemblock * __init prom_getmdesc(void)
60 {
61 char *memsize_str;
62 unsigned int memsize;
63
64 memsize_str = prom_getenv("memsize");
65 if (!memsize_str) {
66 prom_printf("memsize not set in boot prom, set to default (32Mb)\n");
67 memsize = 0x02000000;
68 } else {
69 #ifdef DEBUG
70 prom_printf("prom_memsize = %s\n", memsize_str);
71 #endif
72 memsize = simple_strtol(memsize_str, NULL, 0);
73 }
74
75 memset(mdesc, 0, sizeof(mdesc));
76
77 mdesc[0].type = yamon_dontuse;
78 mdesc[0].base = 0x00000000;
79 mdesc[0].size = 0x00001000;
80
81 mdesc[1].type = yamon_prom;
82 mdesc[1].base = 0x00001000;
83 mdesc[1].size = 0x000ef000;
84
85 #if (CONFIG_MIPS_MALTA)
86 /*
87 * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
88 * south bridge and PCI access always forwarded to the ISA Bus and
89 * BIOSCS# is always generated.
90 * This mean that this area can't be used as DMA memory for PCI
91 * devices.
92 */
93 mdesc[2].type = yamon_dontuse;
94 mdesc[2].base = 0x000f0000;
95 mdesc[2].size = 0x00010000;
96 #else
97 mdesc[2].type = yamon_prom;
98 mdesc[2].base = 0x000f0000;
99 mdesc[2].size = 0x00010000;
100 #endif
101
102 mdesc[3].type = yamon_dontuse;
103 mdesc[3].base = 0x00100000;
104 mdesc[3].size = PHYSADDR(PFN_ALIGN(&_end)) - mdesc[3].base;
105
106 mdesc[4].type = yamon_free;
107 mdesc[4].base = PHYSADDR(PFN_ALIGN(&_end));
108 mdesc[4].size = memsize - mdesc[4].base;
109
110 return &mdesc[0];
111 }
112
113 static int __init prom_memtype_classify (unsigned int type)
114 {
115 switch (type) {
116 case yamon_free:
117 return BOOT_MEM_RAM;
118 case yamon_prom:
119 return BOOT_MEM_ROM_DATA;
120 default:
121 return BOOT_MEM_RESERVED;
122 }
123 }
124
125 void __init prom_meminit(void)
126 {
127 struct prom_pmemblock *p;
128
129 #ifdef DEBUG
130 prom_printf("YAMON MEMORY DESCRIPTOR dump:\n");
131 p = prom_getmdesc();
132 while (p->size) {
133 int i = 0;
134 prom_printf("[%d,%p]: base<%08lx> size<%08lx> type<%s>\n",
135 i, p, p->base, p->size, mtypes[p->type]);
136 p++;
137 i++;
138 }
139 #endif
140 p = prom_getmdesc();
141
142 while (p->size) {
143 long type;
144 unsigned long base, size;
145
146 type = prom_memtype_classify (p->type);
147 base = p->base;
148 size = p->size;
149
150 add_memory_region(base, size, type);
151 p++;
152 }
153 }
154
155 void __init
156 prom_free_prom_memory (void)
157 {
158 int i;
159 unsigned long freed = 0;
160 unsigned long addr;
161
162 for (i = 0; i < boot_mem_map.nr_map; i++) {
163 if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
164 continue;
165
166 addr = boot_mem_map.map[i].addr;
167 while (addr < boot_mem_map.map[i].addr
168 + boot_mem_map.map[i].size) {
169 ClearPageReserved(virt_to_page(__va(addr)));
170 set_page_count(virt_to_page(__va(addr)), 1);
171 free_page(__va(addr));
172 addr += PAGE_SIZE;
173 freed += PAGE_SIZE;
174 }
175 }
176 printk("Freeing prom memory: %ldkb freed\n", freed >> 10);
177 }
178