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
18 extern void restore_current(void);
19
20 DEFINE_SPINLOCK(prom_lock);
21
22 /* Reset and reboot the machine with the command 'bcommand'. */
23 void
prom_reboot(char * bcommand)24 prom_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'. */
35 void
prom_feval(char * fstring)36 prom_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 }
49 EXPORT_SYMBOL(prom_feval);
50
51 /* Drop into the prom, with the chance to continue with the 'go'
52 * prom command.
53 */
54 void
prom_cmdline(void)55 prom_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 */
69 void __noreturn
prom_halt(void)70 prom_halt(void)
71 {
72 unsigned long flags;
73 again:
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
82 typedef void (*sfunc_t)(void);
83
84 /* Set prom sync handler to call function 'funcp'. */
85 void
prom_setsync(sfunc_t funcp)86 prom_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 */
96 unsigned char
prom_get_idprom(char * idbuf,int num_bytes)97 prom_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. */
110 int
prom_version(void)111 prom_version(void)
112 {
113 return romvec->pv_romvers;
114 }
115
116 /* Get the prom plugin-revision. */
117 int
prom_getrev(void)118 prom_getrev(void)
119 {
120 return prom_rev;
121 }
122
123 /* Get the prom firmware print revision. */
124 int
prom_getprev(void)125 prom_getprev(void)
126 {
127 return prom_prev;
128 }
129