xref: /openbmc/linux/arch/mips/fw/arc/memory.c (revision 50df3be7)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * memory.c: PROM library functions for acquiring/using memory descriptors
4  *	     given to us from the ARCS firmware.
5  *
6  * Copyright (C) 1996 by David S. Miller
7  * Copyright (C) 1999, 2000, 2001 by Ralf Baechle
8  * Copyright (C) 1999, 2000 by Silicon Graphics, Inc.
9  *
10  * PROM library functions for acquiring/using memory descriptors given to us
11  * from the ARCS firmware.  This is only used when CONFIG_ARC_MEMORY is set
12  * because on some machines like SGI IP27 the ARC memory configuration data
13  * completely bogus and alternate easier to use mechanisms are available.
14  */
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/types.h>
18 #include <linux/sched.h>
19 #include <linux/mm.h>
20 #include <linux/memblock.h>
21 #include <linux/swap.h>
22 
23 #include <asm/sgialib.h>
24 #include <asm/page.h>
25 #include <asm/pgtable.h>
26 #include <asm/bootinfo.h>
27 
28 #undef DEBUG
29 
30 #define MAX_PROM_MEM 5
31 static phys_addr_t prom_mem_base[MAX_PROM_MEM] __initdata;
32 static phys_addr_t prom_mem_size[MAX_PROM_MEM] __initdata;
33 static unsigned int nr_prom_mem __initdata;
34 
35 /*
36  * For ARC firmware memory functions the unit of meassuring memory is always
37  * a 4k page of memory
38  */
39 #define ARC_PAGE_SHIFT	12
40 
41 struct linux_mdesc * __init ArcGetMemoryDescriptor(struct linux_mdesc *Current)
42 {
43 	return (struct linux_mdesc *) ARC_CALL1(get_mdesc, Current);
44 }
45 
46 #ifdef DEBUG /* convenient for debugging */
47 static char *arcs_mtypes[8] = {
48 	"Exception Block",
49 	"ARCS Romvec Page",
50 	"Free/Contig RAM",
51 	"Generic Free RAM",
52 	"Bad Memory",
53 	"Standalone Program Pages",
54 	"ARCS Temp Storage Area",
55 	"ARCS Permanent Storage Area"
56 };
57 
58 static char *arc_mtypes[8] = {
59 	"Exception Block",
60 	"SystemParameterBlock",
61 	"FreeMemory",
62 	"Bad Memory",
63 	"LoadedProgram",
64 	"FirmwareTemporary",
65 	"FirmwarePermanent",
66 	"FreeContiguous"
67 };
68 #define mtypes(a) (prom_flags & PROM_FLAG_ARCS) ? arcs_mtypes[a.arcs] \
69 						: arc_mtypes[a.arc]
70 #endif
71 
72 static inline int memtype_classify_arcs(union linux_memtypes type)
73 {
74 	switch (type.arcs) {
75 	case arcs_fcontig:
76 	case arcs_free:
77 		return BOOT_MEM_RAM;
78 	case arcs_atmp:
79 		return BOOT_MEM_ROM_DATA;
80 	case arcs_eblock:
81 	case arcs_rvpage:
82 	case arcs_bmem:
83 	case arcs_prog:
84 	case arcs_aperm:
85 		return BOOT_MEM_RESERVED;
86 	default:
87 		BUG();
88 	}
89 	while(1);				/* Nuke warning.  */
90 }
91 
92 static inline int memtype_classify_arc(union linux_memtypes type)
93 {
94 	switch (type.arc) {
95 	case arc_free:
96 	case arc_fcontig:
97 		return BOOT_MEM_RAM;
98 	case arc_atmp:
99 		return BOOT_MEM_ROM_DATA;
100 	case arc_eblock:
101 	case arc_rvpage:
102 	case arc_bmem:
103 	case arc_prog:
104 	case arc_aperm:
105 		return BOOT_MEM_RESERVED;
106 	default:
107 		BUG();
108 	}
109 	while(1);				/* Nuke warning.  */
110 }
111 
112 static int __init prom_memtype_classify(union linux_memtypes type)
113 {
114 	if (prom_flags & PROM_FLAG_ARCS)	/* SGI is ``different'' ... */
115 		return memtype_classify_arcs(type);
116 
117 	return memtype_classify_arc(type);
118 }
119 
120 void __init prom_meminit(void)
121 {
122 	struct linux_mdesc *p;
123 
124 #ifdef DEBUG
125 	int i = 0;
126 
127 	printk("ARCS MEMORY DESCRIPTOR dump:\n");
128 	p = ArcGetMemoryDescriptor(PROM_NULL_MDESC);
129 	while(p) {
130 		printk("[%d,%p]: base<%08lx> pages<%08lx> type<%s>\n",
131 		       i, p, p->base, p->pages, mtypes(p->type));
132 		p = ArcGetMemoryDescriptor(p);
133 		i++;
134 	}
135 #endif
136 
137 	nr_prom_mem = 0;
138 	p = PROM_NULL_MDESC;
139 	while ((p = ArcGetMemoryDescriptor(p))) {
140 		unsigned long base, size;
141 		long type;
142 
143 		base = p->base << ARC_PAGE_SHIFT;
144 		size = p->pages << ARC_PAGE_SHIFT;
145 		type = prom_memtype_classify(p->type);
146 
147 		add_memory_region(base, size, type);
148 
149 		if (type == BOOT_MEM_ROM_DATA) {
150 			if (nr_prom_mem >= 5) {
151 				pr_err("Too many ROM DATA regions");
152 				continue;
153 			}
154 			prom_mem_base[nr_prom_mem] = base;
155 			prom_mem_size[nr_prom_mem] = size;
156 			nr_prom_mem++;
157 		}
158 	}
159 }
160 
161 void __init prom_free_prom_memory(void)
162 {
163 	unsigned long addr;
164 	int i;
165 
166 	if (prom_flags & PROM_FLAG_DONT_FREE_TEMP)
167 		return;
168 
169 	for (i = 0; i < nr_prom_mem; i++) {
170 		free_init_pages("prom memory",
171 			prom_mem_base[i], prom_mem_base[i] + prom_mem_size[i]);
172 	}
173 }
174