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
6 * PROM library functions for acquiring/using memory descriptors given to
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>
14 #include <linux/init.h>
15 #include <linux/bootmem.h>
16 #include <linux/string.h>
18 #include <asm/bootinfo.h>
20 #include <asm/sections.h>
21 #include <asm/fw/fw.h>
23 static fw_memblock_t mdesc[FW_MAX_MEMBLOCKS];
25 /* determined physical memory size, not overridden by command line args */
26 unsigned long physical_memsize = 0L;
28 fw_memblock_t * __init fw_getmdesc(int eva)
30 char *memsize_str, *ememsize_str = NULL, *ptr;
31 unsigned long memsize = 0, ememsize = 0;
32 static char cmdline[COMMAND_LINE_SIZE] __initdata;
35 /* otherwise look in the environment */
37 memsize_str = fw_getenv("memsize");
39 tmp = kstrtoul(memsize_str, 0, &memsize);
41 pr_warn("Failed to read the 'memsize' env variable.\n");
44 /* Look for ememsize for EVA */
45 ememsize_str = fw_getenv("ememsize");
47 tmp = kstrtoul(ememsize_str, 0, &ememsize);
49 pr_warn("Failed to read the 'ememsize' env variable.\n");
52 if (!memsize && !ememsize) {
53 pr_warn("memsize not set in YAMON, set to default (32Mb)\n");
54 physical_memsize = 0x02000000;
56 if (memsize > (256 << 20)) { /* memsize should be capped to 256M */
57 pr_warn("Unsupported memsize value (0x%lx) detected! "
58 "Using 0x10000000 (256M) instead\n",
62 /* If ememsize is set, then set physical_memsize to that */
63 physical_memsize = ememsize ? : memsize;
66 #ifdef CONFIG_CPU_BIG_ENDIAN
67 /* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
68 word of physical memory */
69 physical_memsize -= PAGE_SIZE;
72 /* Check the command line for a memsize directive that overrides
73 the physical/default amount */
74 strcpy(cmdline, arcs_cmdline);
75 ptr = strstr(cmdline, "memsize=");
76 if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
77 ptr = strstr(ptr, " memsize=");
78 /* And now look for ememsize */
80 ptr = strstr(cmdline, "ememsize=");
81 if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
82 ptr = strstr(ptr, " ememsize=");
86 memsize = memparse(ptr + 8 + (eva ? 1 : 0), &ptr);
88 memsize = physical_memsize;
90 /* Last 64K for HIGHMEM arithmetics */
91 if (memsize > 0x7fff0000)
94 memset(mdesc, 0, sizeof(mdesc));
96 mdesc[0].type = fw_dontuse;
97 mdesc[0].base = PHYS_OFFSET;
98 mdesc[0].size = 0x00001000;
100 mdesc[1].type = fw_code;
101 mdesc[1].base = mdesc[0].base + 0x00001000UL;
102 mdesc[1].size = 0x000ef000;
105 * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
106 * south bridge and PCI access always forwarded to the ISA Bus and
107 * BIOSCS# is always generated.
108 * This mean that this area can't be used as DMA memory for PCI
111 mdesc[2].type = fw_dontuse;
112 mdesc[2].base = mdesc[0].base + 0x000f0000UL;
113 mdesc[2].size = 0x00010000;
115 mdesc[3].type = fw_dontuse;
116 mdesc[3].base = mdesc[0].base + 0x00100000UL;
117 mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) -
120 mdesc[4].type = fw_free;
121 mdesc[4].base = mdesc[0].base + CPHYSADDR(PFN_ALIGN(&_end));
122 mdesc[4].size = memsize - CPHYSADDR(mdesc[4].base);
127 static void free_init_pages_eva_malta(void *begin, void *end)
129 free_init_pages("unused kernel", __pa_symbol((unsigned long *)begin),
130 __pa_symbol((unsigned long *)end));
133 static int __init fw_memtype_classify(unsigned int type)
139 return BOOT_MEM_ROM_DATA;
141 return BOOT_MEM_RESERVED;
145 void __init fw_meminit(void)
149 p = fw_getmdesc(config_enabled(CONFIG_EVA));
150 free_init_pages_eva = (config_enabled(CONFIG_EVA) ?
151 free_init_pages_eva_malta : NULL);
155 unsigned long base, size;
157 type = fw_memtype_classify(p->type);
161 add_memory_region(base, size, type);
166 void __init prom_free_prom_memory(void)
171 for (i = 0; i < boot_mem_map.nr_map; i++) {
172 if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
175 addr = boot_mem_map.map[i].addr;
176 free_init_pages("YAMON memory",
177 addr, addr + boot_mem_map.map[i].size);
181 unsigned platform_maar_init(unsigned num_pairs)
183 phys_addr_t mem_end = (physical_memsize & ~0xffffull) - 1;
184 struct maar_config cfg[] = {
185 /* DRAM preceding I/O */
186 { 0x00000000, 0x0fffffff, MIPS_MAAR_S },
188 /* DRAM following I/O */
189 { 0x20000000, mem_end, MIPS_MAAR_S },
191 /* DRAM alias in upper half of physical */
192 { 0x80000000, 0x80000000 + mem_end, MIPS_MAAR_S },
194 unsigned i, num_cfg = ARRAY_SIZE(cfg);
196 /* If DRAM fits before I/O, drop the region following it */
197 if (physical_memsize <= 0x10000000) {
199 for (i = 1; i < num_cfg; i++)
203 return maar_config(cfg, num_cfg, num_pairs);