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/bootinfo.h>
26
27#undef DEBUG
28
29#define MAX_PROM_MEM 5
30static phys_addr_t prom_mem_base[MAX_PROM_MEM] __initdata;
31static phys_addr_t prom_mem_size[MAX_PROM_MEM] __initdata;
32static unsigned int nr_prom_mem __initdata;
33
34/*
35 * For ARC firmware memory functions the unit of measuring memory is always
36 * a 4k page of memory
37 */
38#define ARC_PAGE_SHIFT	12
39
40static struct linux_mdesc * __init ArcGetMemoryDescriptor(struct linux_mdesc *Current)
41{
42	return (struct linux_mdesc *) ARC_CALL1(get_mdesc, Current);
43}
44
45#ifdef DEBUG /* convenient for debugging */
46static char *arcs_mtypes[8] = {
47	"Exception Block",
48	"ARCS Romvec Page",
49	"Free/Contig RAM",
50	"Generic Free RAM",
51	"Bad Memory",
52	"Standalone Program Pages",
53	"ARCS Temp Storage Area",
54	"ARCS Permanent Storage Area"
55};
56
57static char *arc_mtypes[8] = {
58	"Exception Block",
59	"SystemParameterBlock",
60	"FreeMemory",
61	"Bad Memory",
62	"LoadedProgram",
63	"FirmwareTemporary",
64	"FirmwarePermanent",
65	"FreeContiguous"
66};
67#define mtypes(a) (prom_flags & PROM_FLAG_ARCS) ? arcs_mtypes[a.arcs] \
68						: arc_mtypes[a.arc]
69#endif
70
71enum {
72	mem_free, mem_prom_used, mem_reserved
73};
74
75static inline int memtype_classify_arcs(union linux_memtypes type)
76{
77	switch (type.arcs) {
78	case arcs_fcontig:
79	case arcs_free:
80		return mem_free;
81	case arcs_atmp:
82		return mem_prom_used;
83	case arcs_eblock:
84	case arcs_rvpage:
85	case arcs_bmem:
86	case arcs_prog:
87	case arcs_aperm:
88		return mem_reserved;
89	default:
90		BUG();
91	}
92	while(1);				/* Nuke warning.  */
93}
94
95static inline int memtype_classify_arc(union linux_memtypes type)
96{
97	switch (type.arc) {
98	case arc_free:
99	case arc_fcontig:
100		return mem_free;
101	case arc_atmp:
102		return mem_prom_used;
103	case arc_eblock:
104	case arc_rvpage:
105	case arc_bmem:
106	case arc_prog:
107	case arc_aperm:
108		return mem_reserved;
109	default:
110		BUG();
111	}
112	while(1);				/* Nuke warning.  */
113}
114
115static int __init prom_memtype_classify(union linux_memtypes type)
116{
117	if (prom_flags & PROM_FLAG_ARCS)	/* SGI is ``different'' ... */
118		return memtype_classify_arcs(type);
119
120	return memtype_classify_arc(type);
121}
122
123void __weak __init prom_meminit(void)
124{
125	struct linux_mdesc *p;
126
127#ifdef DEBUG
128	int i = 0;
129
130	printk("ARCS MEMORY DESCRIPTOR dump:\n");
131	p = ArcGetMemoryDescriptor(PROM_NULL_MDESC);
132	while(p) {
133		printk("[%d,%p]: base<%08lx> pages<%08lx> type<%s>\n",
134		       i, p, p->base, p->pages, mtypes(p->type));
135		p = ArcGetMemoryDescriptor(p);
136		i++;
137	}
138#endif
139
140	nr_prom_mem = 0;
141	p = PROM_NULL_MDESC;
142	while ((p = ArcGetMemoryDescriptor(p))) {
143		unsigned long base, size;
144		long type;
145
146		base = p->base << ARC_PAGE_SHIFT;
147		size = p->pages << ARC_PAGE_SHIFT;
148		type = prom_memtype_classify(p->type);
149
150		/* ignore mirrored RAM on IP28/IP30 */
151		if (base < PHYS_OFFSET)
152			continue;
153
154		memblock_add(base, size);
155
156		if (type == mem_reserved)
157			memblock_reserve(base, size);
158
159		if (type == mem_prom_used) {
160			memblock_reserve(base, size);
161			if (nr_prom_mem >= 5) {
162				pr_err("Too many ROM DATA regions");
163				continue;
164			}
165			prom_mem_base[nr_prom_mem] = base;
166			prom_mem_size[nr_prom_mem] = size;
167			nr_prom_mem++;
168		}
169	}
170}
171
172void __weak __init prom_cleanup(void)
173{
174}
175
176void __init prom_free_prom_memory(void)
177{
178	int i;
179
180	if (prom_flags & PROM_FLAG_DONT_FREE_TEMP)
181		return;
182
183	for (i = 0; i < nr_prom_mem; i++) {
184		free_init_pages("prom memory",
185			prom_mem_base[i], prom_mem_base[i] + prom_mem_size[i]);
186	}
187	/*
188	 * at this point it isn't safe to call PROM functions
189	 * give platforms a way to do PROM cleanups
190	 */
191	prom_cleanup();
192}
193