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/sections.h>
20 #include <asm/fw/fw.h>
21 
22 static fw_memblock_t mdesc[FW_MAX_MEMBLOCKS];
23 
24 /* determined physical memory size, not overridden by command line args	 */
25 unsigned long physical_memsize = 0L;
26 
27 fw_memblock_t * __init fw_getmdesc(int eva)
28 {
29 	char *memsize_str, *ememsize_str __maybe_unused = NULL, *ptr;
30 	unsigned long memsize, ememsize __maybe_unused = 0;
31 	static char cmdline[COMMAND_LINE_SIZE] __initdata;
32 	int tmp;
33 
34 	/* otherwise look in the environment */
35 
36 	memsize_str = fw_getenv("memsize");
37 	if (memsize_str)
38 		tmp = kstrtol(memsize_str, 0, &memsize);
39 	if (eva) {
40 	/* Look for ememsize for EVA */
41 		ememsize_str = fw_getenv("ememsize");
42 		if (ememsize_str)
43 			tmp = kstrtol(ememsize_str, 0, &ememsize);
44 	}
45 	if (!memsize && !ememsize) {
46 		pr_warn("memsize not set in YAMON, set to default (32Mb)\n");
47 		physical_memsize = 0x02000000;
48 	} else {
49 		/* If ememsize is set, then set physical_memsize to that */
50 		physical_memsize = ememsize ? : memsize;
51 	}
52 
53 #ifdef CONFIG_CPU_BIG_ENDIAN
54 	/* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
55 	   word of physical memory */
56 	physical_memsize -= PAGE_SIZE;
57 #endif
58 
59 	/* Check the command line for a memsize directive that overrides
60 	   the physical/default amount */
61 	strcpy(cmdline, arcs_cmdline);
62 	ptr = strstr(cmdline, "memsize=");
63 	if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
64 		ptr = strstr(ptr, " memsize=");
65 	/* And now look for ememsize */
66 	if (eva) {
67 		ptr = strstr(cmdline, "ememsize=");
68 		if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
69 			ptr = strstr(ptr, " ememsize=");
70 	}
71 
72 	if (ptr)
73 		memsize = memparse(ptr + 8 + (eva ? 1 : 0), &ptr);
74 	else
75 		memsize = physical_memsize;
76 
77 	/* Last 64K for HIGHMEM arithmetics */
78 	if (memsize > 0x7fff0000)
79 		memsize = 0x7fff0000;
80 
81 	memset(mdesc, 0, sizeof(mdesc));
82 
83 	mdesc[0].type = fw_dontuse;
84 	mdesc[0].base = PHYS_OFFSET;
85 	mdesc[0].size = 0x00001000;
86 
87 	mdesc[1].type = fw_code;
88 	mdesc[1].base = mdesc[0].base + 0x00001000UL;
89 	mdesc[1].size = 0x000ef000;
90 
91 	/*
92 	 * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
93 	 * south bridge and PCI access always forwarded to the ISA Bus and
94 	 * BIOSCS# is always generated.
95 	 * This mean that this area can't be used as DMA memory for PCI
96 	 * devices.
97 	 */
98 	mdesc[2].type = fw_dontuse;
99 	mdesc[2].base = mdesc[0].base + 0x000f0000UL;
100 	mdesc[2].size = 0x00010000;
101 
102 	mdesc[3].type = fw_dontuse;
103 	mdesc[3].base = mdesc[0].base + 0x00100000UL;
104 	mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) -
105 		0x00100000UL;
106 
107 	mdesc[4].type = fw_free;
108 	mdesc[4].base = mdesc[0].base + CPHYSADDR(PFN_ALIGN(&_end));
109 	mdesc[4].size = memsize - CPHYSADDR(mdesc[4].base);
110 
111 	return &mdesc[0];
112 }
113 
114 static void free_init_pages_eva_malta(void *begin, void *end)
115 {
116 	free_init_pages("unused kernel", __pa_symbol((unsigned long *)begin),
117 			__pa_symbol((unsigned long *)end));
118 }
119 
120 static int __init fw_memtype_classify(unsigned int type)
121 {
122 	switch (type) {
123 	case fw_free:
124 		return BOOT_MEM_RAM;
125 	case fw_code:
126 		return BOOT_MEM_ROM_DATA;
127 	default:
128 		return BOOT_MEM_RESERVED;
129 	}
130 }
131 
132 void __init fw_meminit(void)
133 {
134 	fw_memblock_t *p;
135 
136 	p = fw_getmdesc(config_enabled(CONFIG_EVA));
137 	free_init_pages_eva = (config_enabled(CONFIG_EVA) ?
138 			       free_init_pages_eva_malta : NULL);
139 
140 	while (p->size) {
141 		long type;
142 		unsigned long base, size;
143 
144 		type = fw_memtype_classify(p->type);
145 		base = p->base;
146 		size = p->size;
147 
148 		add_memory_region(base, size, type);
149 		p++;
150 	}
151 }
152 
153 void __init prom_free_prom_memory(void)
154 {
155 	unsigned long addr;
156 	int i;
157 
158 	for (i = 0; i < boot_mem_map.nr_map; i++) {
159 		if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
160 			continue;
161 
162 		addr = boot_mem_map.map[i].addr;
163 		free_init_pages("YAMON memory",
164 				addr, addr + boot_mem_map.map[i].size);
165 	}
166 }
167