1 /*
2  * Carsten Langgaard, carstenl@mips.com
3  * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
4  *
5  *  This program is free software; you can distribute it and/or modify it
6  *  under the terms of the GNU General Public License (Version 2) as
7  *  published by the Free Software Foundation.
8  *
9  *  This program is distributed in the hope it will be useful, but WITHOUT
10  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  *  for more details.
13  *
14  *  You should have received a copy of the GNU General Public License along
15  *  with this program; if not, write to the Free Software Foundation, Inc.,
16  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
17  *
18  * PROM library functions for acquiring/using memory descriptors given to
19  * us from the YAMON.
20  */
21 #include <linux/init.h>
22 #include <linux/mm.h>
23 #include <linux/bootmem.h>
24 #include <linux/pfn.h>
25 #include <linux/string.h>
26 
27 #include <asm/bootinfo.h>
28 #include <asm/page.h>
29 #include <asm/sections.h>
30 
31 #include <asm/mips-boards/prom.h>
32 
33 /*#define DEBUG*/
34 
35 enum yamon_memtypes {
36 	yamon_dontuse,
37 	yamon_prom,
38 	yamon_free,
39 };
40 static struct prom_pmemblock mdesc[PROM_MAX_PMEMBLOCKS];
41 
42 #ifdef DEBUG
43 static char *mtypes[3] = {
44 	"Dont use memory",
45 	"YAMON PROM memory",
46 	"Free memory",
47 };
48 #endif
49 
50 /* determined physical memory size, not overridden by command line args  */
51 unsigned long physical_memsize = 0L;
52 
53 static struct prom_pmemblock * __init prom_getmdesc(void)
54 {
55 	char *memsize_str;
56 	unsigned int memsize;
57 	char *ptr;
58 	static char cmdline[COMMAND_LINE_SIZE] __initdata;
59 
60 	/* otherwise look in the environment */
61 	memsize_str = prom_getenv("memsize");
62 	if (!memsize_str) {
63 		printk(KERN_WARNING
64 		       "memsize not set in boot prom, set to default (32Mb)\n");
65 		physical_memsize = 0x02000000;
66 	} else {
67 #ifdef DEBUG
68 		pr_debug("prom_memsize = %s\n", memsize_str);
69 #endif
70 		physical_memsize = simple_strtol(memsize_str, NULL, 0);
71 	}
72 
73 #ifdef CONFIG_CPU_BIG_ENDIAN
74 	/* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
75 	   word of physical memory */
76 	physical_memsize -= PAGE_SIZE;
77 #endif
78 
79 	/* Check the command line for a memsize directive that overrides
80 	   the physical/default amount */
81 	strcpy(cmdline, arcs_cmdline);
82 	ptr = strstr(cmdline, "memsize=");
83 	if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
84 		ptr = strstr(ptr, " memsize=");
85 
86 	if (ptr)
87 		memsize = memparse(ptr + 8, &ptr);
88 	else
89 		memsize = physical_memsize;
90 
91 	memset(mdesc, 0, sizeof(mdesc));
92 
93 	mdesc[0].type = yamon_dontuse;
94 	mdesc[0].base = 0x00000000;
95 	mdesc[0].size = 0x00001000;
96 
97 	mdesc[1].type = yamon_prom;
98 	mdesc[1].base = 0x00001000;
99 	mdesc[1].size = 0x000ef000;
100 
101 	/*
102 	 * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
103 	 * south bridge and PCI access always forwarded to the ISA Bus and
104 	 * BIOSCS# is always generated.
105 	 * This mean that this area can't be used as DMA memory for PCI
106 	 * devices.
107 	 */
108 	mdesc[2].type = yamon_dontuse;
109 	mdesc[2].base = 0x000f0000;
110 	mdesc[2].size = 0x00010000;
111 
112 	mdesc[3].type = yamon_dontuse;
113 	mdesc[3].base = 0x00100000;
114 	mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) - mdesc[3].base;
115 
116 	mdesc[4].type = yamon_free;
117 	mdesc[4].base = CPHYSADDR(PFN_ALIGN(&_end));
118 	mdesc[4].size = memsize - mdesc[4].base;
119 
120 	return &mdesc[0];
121 }
122 
123 static int __init prom_memtype_classify(unsigned int type)
124 {
125 	switch (type) {
126 	case yamon_free:
127 		return BOOT_MEM_RAM;
128 	case yamon_prom:
129 		return BOOT_MEM_ROM_DATA;
130 	default:
131 		return BOOT_MEM_RESERVED;
132 	}
133 }
134 
135 void __init prom_meminit(void)
136 {
137 	struct prom_pmemblock *p;
138 
139 #ifdef DEBUG
140 	pr_debug("YAMON MEMORY DESCRIPTOR dump:\n");
141 	p = prom_getmdesc();
142 	while (p->size) {
143 		int i = 0;
144 		pr_debug("[%d,%p]: base<%08lx> size<%08lx> type<%s>\n",
145 			 i, p, p->base, p->size, mtypes[p->type]);
146 		p++;
147 		i++;
148 	}
149 #endif
150 	p = prom_getmdesc();
151 
152 	while (p->size) {
153 		long type;
154 		unsigned long base, size;
155 
156 		type = prom_memtype_classify(p->type);
157 		base = p->base;
158 		size = p->size;
159 
160 		add_memory_region(base, size, type);
161                 p++;
162 	}
163 }
164 
165 void __init prom_free_prom_memory(void)
166 {
167 	unsigned long addr;
168 	int i;
169 
170 	for (i = 0; i < boot_mem_map.nr_map; i++) {
171 		if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
172 			continue;
173 
174 		addr = boot_mem_map.map[i].addr;
175 		free_init_pages("prom memory",
176 				addr, addr + boot_mem_map.map[i].size);
177 	}
178 }
179