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  * PROM library functions for acquiring/using memory descriptors given to
7  * us from the YAMON.
8  *
9  * Copyright (C) 1999,2000,2012  MIPS Technologies, Inc.
10  * All rights reserved.
11  * Authors: Carsten Langgaard <carstenl@mips.com>
12  *          Steven J. Hill <sjhill@mips.com>
13  */
14 #include <linux/init.h>
15 #include <linux/bootmem.h>
16 #include <linux/string.h>
17 
18 #include <asm/bootinfo.h>
19 #include <asm/maar.h>
20 #include <asm/sections.h>
21 #include <asm/fw/fw.h>
22 
23 static fw_memblock_t mdesc[FW_MAX_MEMBLOCKS];
24 
25 /* determined physical memory size, not overridden by command line args	 */
26 unsigned long physical_memsize = 0L;
27 
28 fw_memblock_t * __init fw_getmdesc(int eva)
29 {
30 	char *memsize_str, *ememsize_str = NULL, *ptr;
31 	unsigned long memsize = 0, ememsize = 0;
32 	static char cmdline[COMMAND_LINE_SIZE] __initdata;
33 	int tmp;
34 
35 	/* otherwise look in the environment */
36 
37 	memsize_str = fw_getenv("memsize");
38 	if (memsize_str)
39 		tmp = kstrtol(memsize_str, 0, &memsize);
40 	if (eva) {
41 	/* Look for ememsize for EVA */
42 		ememsize_str = fw_getenv("ememsize");
43 		if (ememsize_str)
44 			tmp = kstrtol(ememsize_str, 0, &ememsize);
45 	}
46 	if (!memsize && !ememsize) {
47 		pr_warn("memsize not set in YAMON, set to default (32Mb)\n");
48 		physical_memsize = 0x02000000;
49 	} else {
50 		/* If ememsize is set, then set physical_memsize to that */
51 		physical_memsize = ememsize ? : memsize;
52 	}
53 
54 #ifdef CONFIG_CPU_BIG_ENDIAN
55 	/* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
56 	   word of physical memory */
57 	physical_memsize -= PAGE_SIZE;
58 #endif
59 
60 	/* Check the command line for a memsize directive that overrides
61 	   the physical/default amount */
62 	strcpy(cmdline, arcs_cmdline);
63 	ptr = strstr(cmdline, "memsize=");
64 	if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
65 		ptr = strstr(ptr, " memsize=");
66 	/* And now look for ememsize */
67 	if (eva) {
68 		ptr = strstr(cmdline, "ememsize=");
69 		if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
70 			ptr = strstr(ptr, " ememsize=");
71 	}
72 
73 	if (ptr)
74 		memsize = memparse(ptr + 8 + (eva ? 1 : 0), &ptr);
75 	else
76 		memsize = physical_memsize;
77 
78 	/* Last 64K for HIGHMEM arithmetics */
79 	if (memsize > 0x7fff0000)
80 		memsize = 0x7fff0000;
81 
82 	memset(mdesc, 0, sizeof(mdesc));
83 
84 	mdesc[0].type = fw_dontuse;
85 	mdesc[0].base = PHYS_OFFSET;
86 	mdesc[0].size = 0x00001000;
87 
88 	mdesc[1].type = fw_code;
89 	mdesc[1].base = mdesc[0].base + 0x00001000UL;
90 	mdesc[1].size = 0x000ef000;
91 
92 	/*
93 	 * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
94 	 * south bridge and PCI access always forwarded to the ISA Bus and
95 	 * BIOSCS# is always generated.
96 	 * This mean that this area can't be used as DMA memory for PCI
97 	 * devices.
98 	 */
99 	mdesc[2].type = fw_dontuse;
100 	mdesc[2].base = mdesc[0].base + 0x000f0000UL;
101 	mdesc[2].size = 0x00010000;
102 
103 	mdesc[3].type = fw_dontuse;
104 	mdesc[3].base = mdesc[0].base + 0x00100000UL;
105 	mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) -
106 		0x00100000UL;
107 
108 	mdesc[4].type = fw_free;
109 	mdesc[4].base = mdesc[0].base + CPHYSADDR(PFN_ALIGN(&_end));
110 	mdesc[4].size = memsize - CPHYSADDR(mdesc[4].base);
111 
112 	return &mdesc[0];
113 }
114 
115 static void free_init_pages_eva_malta(void *begin, void *end)
116 {
117 	free_init_pages("unused kernel", __pa_symbol((unsigned long *)begin),
118 			__pa_symbol((unsigned long *)end));
119 }
120 
121 static int __init fw_memtype_classify(unsigned int type)
122 {
123 	switch (type) {
124 	case fw_free:
125 		return BOOT_MEM_RAM;
126 	case fw_code:
127 		return BOOT_MEM_ROM_DATA;
128 	default:
129 		return BOOT_MEM_RESERVED;
130 	}
131 }
132 
133 void __init fw_meminit(void)
134 {
135 	fw_memblock_t *p;
136 
137 	p = fw_getmdesc(config_enabled(CONFIG_EVA));
138 	free_init_pages_eva = (config_enabled(CONFIG_EVA) ?
139 			       free_init_pages_eva_malta : NULL);
140 
141 	while (p->size) {
142 		long type;
143 		unsigned long base, size;
144 
145 		type = fw_memtype_classify(p->type);
146 		base = p->base;
147 		size = p->size;
148 
149 		add_memory_region(base, size, type);
150 		p++;
151 	}
152 }
153 
154 void __init prom_free_prom_memory(void)
155 {
156 	unsigned long addr;
157 	int i;
158 
159 	for (i = 0; i < boot_mem_map.nr_map; i++) {
160 		if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
161 			continue;
162 
163 		addr = boot_mem_map.map[i].addr;
164 		free_init_pages("YAMON memory",
165 				addr, addr + boot_mem_map.map[i].size);
166 	}
167 }
168 
169 unsigned platform_maar_init(unsigned num_pairs)
170 {
171 	phys_addr_t mem_end = (physical_memsize & ~0xffffull) - 1;
172 	struct maar_config cfg[] = {
173 		/* DRAM preceding I/O */
174 		{ 0x00000000, 0x0fffffff, MIPS_MAAR_S },
175 
176 		/* DRAM following I/O */
177 		{ 0x20000000, mem_end, MIPS_MAAR_S },
178 
179 		/* DRAM alias in upper half of physical */
180 		{ 0x80000000, 0x80000000 + mem_end, MIPS_MAAR_S },
181 	};
182 	unsigned i, num_cfg = ARRAY_SIZE(cfg);
183 
184 	/* If DRAM fits before I/O, drop the region following it */
185 	if (physical_memsize <= 0x10000000) {
186 		num_cfg--;
187 		for (i = 1; i < num_cfg; i++)
188 			cfg[i] = cfg[i + 1];
189 	}
190 
191 	return maar_config(cfg, num_cfg, num_pairs);
192 }
193