1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) Paul Mackerras 1997.
4 */
5#include <stddef.h>
6#include "types.h"
7#include "elf.h"
8#include "string.h"
9#include "stdio.h"
10#include "page.h"
11#include "ops.h"
12
13#include "of.h"
14
15typedef u32 prom_arg_t;
16
17/* The following structure is used to communicate with open firmware.
18 * All arguments in and out are in big endian format. */
19struct prom_args {
20	__be32 service;	/* Address of service name string. */
21	__be32 nargs;	/* Number of input arguments. */
22	__be32 nret;	/* Number of output arguments. */
23	__be32 args[10];	/* Input/output arguments. */
24};
25
26#ifdef __powerpc64__
27extern int prom(void *);
28#else
29static int (*prom) (void *);
30#endif
31
32void of_init(void *promptr)
33{
34#ifndef __powerpc64__
35	prom = (int (*)(void *))promptr;
36#endif
37}
38
39#define ADDR(x)		(u32)(unsigned long)(x)
40
41int of_call_prom(const char *service, int nargs, int nret, ...)
42{
43	int i;
44	struct prom_args args;
45	va_list list;
46
47	args.service = cpu_to_be32(ADDR(service));
48	args.nargs = cpu_to_be32(nargs);
49	args.nret = cpu_to_be32(nret);
50
51	va_start(list, nret);
52	for (i = 0; i < nargs; i++)
53		args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
54	va_end(list);
55
56	for (i = 0; i < nret; i++)
57		args.args[nargs+i] = 0;
58
59	if (prom(&args) < 0)
60		return PROM_ERROR;
61
62	return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
63}
64
65static int of_call_prom_ret(const char *service, int nargs, int nret,
66			    prom_arg_t *rets, ...)
67{
68	int i;
69	struct prom_args args;
70	va_list list;
71
72	args.service = cpu_to_be32(ADDR(service));
73	args.nargs = cpu_to_be32(nargs);
74	args.nret = cpu_to_be32(nret);
75
76	va_start(list, rets);
77	for (i = 0; i < nargs; i++)
78		args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
79	va_end(list);
80
81	for (i = 0; i < nret; i++)
82		args.args[nargs+i] = 0;
83
84	if (prom(&args) < 0)
85		return PROM_ERROR;
86
87	if (rets != NULL)
88		for (i = 1; i < nret; ++i)
89			rets[i-1] = be32_to_cpu(args.args[nargs+i]);
90
91	return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
92}
93
94/* returns true if s2 is a prefix of s1 */
95static int string_match(const char *s1, const char *s2)
96{
97	for (; *s2; ++s2)
98		if (*s1++ != *s2)
99			return 0;
100	return 1;
101}
102
103/*
104 * Older OF's require that when claiming a specific range of addresses,
105 * we claim the physical space in the /memory node and the virtual
106 * space in the chosen mmu node, and then do a map operation to
107 * map virtual to physical.
108 */
109static int need_map = -1;
110static ihandle chosen_mmu;
111static ihandle memory;
112
113static int check_of_version(void)
114{
115	phandle oprom, chosen;
116	char version[64];
117
118	oprom = of_finddevice("/openprom");
119	if (oprom == (phandle) -1)
120		return 0;
121	if (of_getprop(oprom, "model", version, sizeof(version)) <= 0)
122		return 0;
123	version[sizeof(version)-1] = 0;
124	printf("OF version = '%s'\r\n", version);
125	if (!string_match(version, "Open Firmware, 1.")
126	    && !string_match(version, "FirmWorks,3."))
127		return 0;
128	chosen = of_finddevice("/chosen");
129	if (chosen == (phandle) -1) {
130		chosen = of_finddevice("/chosen@0");
131		if (chosen == (phandle) -1) {
132			printf("no chosen\n");
133			return 0;
134		}
135	}
136	if (of_getprop(chosen, "mmu", &chosen_mmu, sizeof(chosen_mmu)) <= 0) {
137		printf("no mmu\n");
138		return 0;
139	}
140	memory = of_call_prom("open", 1, 1, "/memory");
141	if (memory == PROM_ERROR) {
142		memory = of_call_prom("open", 1, 1, "/memory@0");
143		if (memory == PROM_ERROR) {
144			printf("no memory node\n");
145			return 0;
146		}
147	}
148	printf("old OF detected\r\n");
149	return 1;
150}
151
152unsigned int of_claim(unsigned long virt, unsigned long size,
153		      unsigned long align)
154{
155	int ret;
156	prom_arg_t result;
157
158	if (need_map < 0)
159		need_map = check_of_version();
160	if (align || !need_map)
161		return of_call_prom("claim", 3, 1, virt, size, align);
162
163	ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", memory,
164			       align, size, virt);
165	if (ret != 0 || result == -1)
166		return  -1;
167	ret = of_call_prom_ret("call-method", 5, 2, &result, "claim", chosen_mmu,
168			       align, size, virt);
169	/* 0x12 == coherent + read/write */
170	ret = of_call_prom("call-method", 6, 1, "map", chosen_mmu,
171			   0x12, size, virt, virt);
172	return virt;
173}
174
175void *of_vmlinux_alloc(unsigned long size)
176{
177	unsigned long start = (unsigned long)_start, end = (unsigned long)_end;
178	unsigned long addr;
179	void *p;
180
181	/* With some older POWER4 firmware we need to claim the area the kernel
182	 * will reside in.  Newer firmwares don't need this so we just ignore
183	 * the return value.
184	 */
185	addr = (unsigned long) of_claim(start, end - start, 0);
186	printf("Trying to claim from 0x%lx to 0x%lx (0x%lx) got %lx\r\n",
187	       start, end, end - start, addr);
188
189	p = malloc(size);
190	if (!p)
191		fatal("Can't allocate memory for kernel image!\n\r");
192
193	return p;
194}
195
196void of_exit(void)
197{
198	of_call_prom("exit", 0, 0);
199}
200
201/*
202 * OF device tree routines
203 */
204void *of_finddevice(const char *name)
205{
206	return (void *) (unsigned long) of_call_prom("finddevice", 1, 1, name);
207}
208
209int of_getprop(const void *phandle, const char *name, void *buf,
210	       const int buflen)
211{
212	return of_call_prom("getprop", 4, 1, phandle, name, buf, buflen);
213}
214
215int of_setprop(const void *phandle, const char *name, const void *buf,
216	       const int buflen)
217{
218	return of_call_prom("setprop", 4, 1, phandle, name, buf, buflen);
219}
220