1// SPDX-License-Identifier: GPL-2.0
2/*
3 * misc.c:  Miscellaneous prom functions that don't belong
4 *          anywhere else.
5 *
6 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
7 */
8
9#include <linux/types.h>
10#include <linux/kernel.h>
11#include <linux/sched.h>
12#include <linux/module.h>
13
14#include <asm/openprom.h>
15#include <asm/oplib.h>
16#include <asm/auxio.h>
17
18extern void restore_current(void);
19
20DEFINE_SPINLOCK(prom_lock);
21
22/* Reset and reboot the machine with the command 'bcommand'. */
23void
24prom_reboot(char *bcommand)
25{
26	unsigned long flags;
27	spin_lock_irqsave(&prom_lock, flags);
28	(*(romvec->pv_reboot))(bcommand);
29	/* Never get here. */
30	restore_current();
31	spin_unlock_irqrestore(&prom_lock, flags);
32}
33
34/* Forth evaluate the expression contained in 'fstring'. */
35void
36prom_feval(char *fstring)
37{
38	unsigned long flags;
39	if(!fstring || fstring[0] == 0)
40		return;
41	spin_lock_irqsave(&prom_lock, flags);
42	if(prom_vers == PROM_V0)
43		(*(romvec->pv_fortheval.v0_eval))(strlen(fstring), fstring);
44	else
45		(*(romvec->pv_fortheval.v2_eval))(fstring);
46	restore_current();
47	spin_unlock_irqrestore(&prom_lock, flags);
48}
49EXPORT_SYMBOL(prom_feval);
50
51/* Drop into the prom, with the chance to continue with the 'go'
52 * prom command.
53 */
54void
55prom_cmdline(void)
56{
57	unsigned long flags;
58
59	spin_lock_irqsave(&prom_lock, flags);
60	(*(romvec->pv_abort))();
61	restore_current();
62	spin_unlock_irqrestore(&prom_lock, flags);
63	set_auxio(AUXIO_LED, 0);
64}
65
66/* Drop into the prom, but completely terminate the program.
67 * No chance of continuing.
68 */
69void __noreturn
70prom_halt(void)
71{
72	unsigned long flags;
73again:
74	spin_lock_irqsave(&prom_lock, flags);
75	(*(romvec->pv_halt))();
76	/* Never get here. */
77	restore_current();
78	spin_unlock_irqrestore(&prom_lock, flags);
79	goto again; /* PROM is out to get me -DaveM */
80}
81
82typedef void (*sfunc_t)(void);
83
84/* Set prom sync handler to call function 'funcp'. */
85void
86prom_setsync(sfunc_t funcp)
87{
88	if(!funcp) return;
89	*romvec->pv_synchook = funcp;
90}
91
92/* Get the idprom and stuff it into buffer 'idbuf'.  Returns the
93 * format type.  'num_bytes' is the number of bytes that your idbuf
94 * has space for.  Returns 0xff on error.
95 */
96unsigned char
97prom_get_idprom(char *idbuf, int num_bytes)
98{
99	int len;
100
101	len = prom_getproplen(prom_root_node, "idprom");
102	if((len>num_bytes) || (len==-1)) return 0xff;
103	if(!prom_getproperty(prom_root_node, "idprom", idbuf, num_bytes))
104		return idbuf[0];
105
106	return 0xff;
107}
108
109/* Get the major prom version number. */
110int
111prom_version(void)
112{
113	return romvec->pv_romvers;
114}
115
116/* Get the prom plugin-revision. */
117int
118prom_getrev(void)
119{
120	return prom_rev;
121}
122
123/* Get the prom firmware print revision. */
124int
125prom_getprev(void)
126{
127	return prom_prev;
128}
129