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 memmory",
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 cmdline[CL_SIZE], *ptr;
58 
59 	/* otherwise look in the environment */
60 	memsize_str = prom_getenv("memsize");
61 	if (!memsize_str) {
62 		printk(KERN_WARNING
63 		       "memsize not set in boot prom, set to default (32Mb)\n");
64 		physical_memsize = 0x02000000;
65 	} else {
66 #ifdef DEBUG
67 		pr_debug("prom_memsize = %s\n", memsize_str);
68 #endif
69 		physical_memsize = simple_strtol(memsize_str, NULL, 0);
70 	}
71 
72 #ifdef CONFIG_CPU_BIG_ENDIAN
73 	/* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
74 	   word of physical memory */
75 	physical_memsize -= PAGE_SIZE;
76 #endif
77 
78 	/* Check the command line for a memsize directive that overrides
79 	   the physical/default amount */
80 	strcpy(cmdline, arcs_cmdline);
81 	ptr = strstr(cmdline, "memsize=");
82 	if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
83 		ptr = strstr(ptr, " memsize=");
84 
85 	if (ptr)
86 		memsize = memparse(ptr + 8, &ptr);
87 	else
88 		memsize = physical_memsize;
89 
90 	memset(mdesc, 0, sizeof(mdesc));
91 
92 	mdesc[0].type = yamon_dontuse;
93 	mdesc[0].base = 0x00000000;
94 	mdesc[0].size = 0x00001000;
95 
96 	mdesc[1].type = yamon_prom;
97 	mdesc[1].base = 0x00001000;
98 	mdesc[1].size = 0x000ef000;
99 
100 	/*
101 	 * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
102 	 * south bridge and PCI access always forwarded to the ISA Bus and
103 	 * BIOSCS# is always generated.
104 	 * This mean that this area can't be used as DMA memory for PCI
105 	 * devices.
106 	 */
107 	mdesc[2].type = yamon_dontuse;
108 	mdesc[2].base = 0x000f0000;
109 	mdesc[2].size = 0x00010000;
110 
111 	mdesc[3].type = yamon_dontuse;
112 	mdesc[3].base = 0x00100000;
113 	mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) - mdesc[3].base;
114 
115 	mdesc[4].type = yamon_free;
116 	mdesc[4].base = CPHYSADDR(PFN_ALIGN(&_end));
117 	mdesc[4].size = memsize - mdesc[4].base;
118 
119 	return &mdesc[0];
120 }
121 
122 static int __init prom_memtype_classify(unsigned int type)
123 {
124 	switch (type) {
125 	case yamon_free:
126 		return BOOT_MEM_RAM;
127 	case yamon_prom:
128 		return BOOT_MEM_ROM_DATA;
129 	default:
130 		return BOOT_MEM_RESERVED;
131 	}
132 }
133 
134 void __init prom_meminit(void)
135 {
136 	struct prom_pmemblock *p;
137 
138 #ifdef DEBUG
139 	pr_debug("YAMON MEMORY DESCRIPTOR dump:\n");
140 	p = prom_getmdesc();
141 	while (p->size) {
142 		int i = 0;
143 		pr_debug("[%d,%p]: base<%08lx> size<%08lx> type<%s>\n",
144 			 i, p, p->base, p->size, mtypes[p->type]);
145 		p++;
146 		i++;
147 	}
148 #endif
149 	p = prom_getmdesc();
150 
151 	while (p->size) {
152 		long type;
153 		unsigned long base, size;
154 
155 		type = prom_memtype_classify(p->type);
156 		base = p->base;
157 		size = p->size;
158 
159 		add_memory_region(base, size, type);
160                 p++;
161 	}
162 }
163 
164 void __init prom_free_prom_memory(void)
165 {
166 	unsigned long addr;
167 	int i;
168 
169 	for (i = 0; i < boot_mem_map.nr_map; i++) {
170 		if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
171 			continue;
172 
173 		addr = boot_mem_map.map[i].addr;
174 		free_init_pages("prom memory",
175 				addr, addr + boot_mem_map.map[i].size);
176 	}
177 }
178