xref: /linux/arch/sparc/prom/p1275.c (revision 47902f3611b392209e2a412bf7ec02dca95e666d)
1 /*
2  * p1275.c: Sun IEEE 1275 PROM low level interface routines
3  *
4  * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/init.h>
9 #include <linux/sched.h>
10 #include <linux/smp.h>
11 #include <linux/string.h>
12 #include <linux/spinlock.h>
13 
14 #include <asm/openprom.h>
15 #include <asm/oplib.h>
16 #include <asm/system.h>
17 #include <asm/spitfire.h>
18 #include <asm/pstate.h>
19 #include <asm/ldc.h>
20 
21 struct {
22 	long prom_callback;			/* 0x00 */
23 	void (*prom_cif_handler)(long *);	/* 0x08 */
24 	unsigned long prom_cif_stack;		/* 0x10 */
25 	unsigned long prom_args [23];		/* 0x18 */
26 	char prom_buffer [3000];
27 } p1275buf;
28 
29 extern void prom_world(int);
30 
31 extern void prom_cif_interface(void);
32 extern void prom_cif_callback(void);
33 
34 /*
35  * This provides SMP safety on the p1275buf.
36  */
37 DEFINE_RAW_SPINLOCK(prom_entry_lock);
38 
39 long p1275_cmd(const char *service, long fmt, ...)
40 {
41 	char *p, *q;
42 	unsigned long flags;
43 	int nargs, nrets, i;
44 	va_list list;
45 	long attrs, x;
46 
47 	p = p1275buf.prom_buffer;
48 
49 	raw_local_save_flags(flags);
50 	raw_local_irq_restore(PIL_NMI);
51 	raw_spin_lock(&prom_entry_lock);
52 
53 	p1275buf.prom_args[0] = (unsigned long)p;		/* service */
54 	strcpy (p, service);
55 	p = (char *)(((long)(strchr (p, 0) + 8)) & ~7);
56 	p1275buf.prom_args[1] = nargs = (fmt & 0x0f);		/* nargs */
57 	p1275buf.prom_args[2] = nrets = ((fmt & 0xf0) >> 4); 	/* nrets */
58 	attrs = fmt >> 8;
59 	va_start(list, fmt);
60 	for (i = 0; i < nargs; i++, attrs >>= 3) {
61 		switch (attrs & 0x7) {
62 		case P1275_ARG_NUMBER:
63 			p1275buf.prom_args[i + 3] =
64 						(unsigned)va_arg(list, long);
65 			break;
66 		case P1275_ARG_IN_64B:
67 			p1275buf.prom_args[i + 3] =
68 				va_arg(list, unsigned long);
69 			break;
70 		case P1275_ARG_IN_STRING:
71 			strcpy (p, va_arg(list, char *));
72 			p1275buf.prom_args[i + 3] = (unsigned long)p;
73 			p = (char *)(((long)(strchr (p, 0) + 8)) & ~7);
74 			break;
75 		case P1275_ARG_OUT_BUF:
76 			(void) va_arg(list, char *);
77 			p1275buf.prom_args[i + 3] = (unsigned long)p;
78 			x = va_arg(list, long);
79 			i++; attrs >>= 3;
80 			p = (char *)(((long)(p + (int)x + 7)) & ~7);
81 			p1275buf.prom_args[i + 3] = x;
82 			break;
83 		case P1275_ARG_IN_BUF:
84 			q = va_arg(list, char *);
85 			p1275buf.prom_args[i + 3] = (unsigned long)p;
86 			x = va_arg(list, long);
87 			i++; attrs >>= 3;
88 			memcpy (p, q, (int)x);
89 			p = (char *)(((long)(p + (int)x + 7)) & ~7);
90 			p1275buf.prom_args[i + 3] = x;
91 			break;
92 		case P1275_ARG_OUT_32B:
93 			(void) va_arg(list, char *);
94 			p1275buf.prom_args[i + 3] = (unsigned long)p;
95 			p += 32;
96 			break;
97 		case P1275_ARG_IN_FUNCTION:
98 			p1275buf.prom_args[i + 3] =
99 					(unsigned long)prom_cif_callback;
100 			p1275buf.prom_callback = va_arg(list, long);
101 			break;
102 		}
103 	}
104 	va_end(list);
105 
106 	prom_world(1);
107 	prom_cif_interface();
108 	prom_world(0);
109 
110 	attrs = fmt >> 8;
111 	va_start(list, fmt);
112 	for (i = 0; i < nargs; i++, attrs >>= 3) {
113 		switch (attrs & 0x7) {
114 		case P1275_ARG_NUMBER:
115 			(void) va_arg(list, long);
116 			break;
117 		case P1275_ARG_IN_STRING:
118 			(void) va_arg(list, char *);
119 			break;
120 		case P1275_ARG_IN_FUNCTION:
121 			(void) va_arg(list, long);
122 			break;
123 		case P1275_ARG_IN_BUF:
124 			(void) va_arg(list, char *);
125 			(void) va_arg(list, long);
126 			i++; attrs >>= 3;
127 			break;
128 		case P1275_ARG_OUT_BUF:
129 			p = va_arg(list, char *);
130 			x = va_arg(list, long);
131 			memcpy (p, (char *)(p1275buf.prom_args[i + 3]), (int)x);
132 			i++; attrs >>= 3;
133 			break;
134 		case P1275_ARG_OUT_32B:
135 			p = va_arg(list, char *);
136 			memcpy (p, (char *)(p1275buf.prom_args[i + 3]), 32);
137 			break;
138 		}
139 	}
140 	va_end(list);
141 	x = p1275buf.prom_args [nargs + 3];
142 
143 	raw_spin_unlock(&prom_entry_lock);
144 	raw_local_irq_restore(flags);
145 
146 	return x;
147 }
148 
149 void prom_cif_init(void *cif_handler, void *cif_stack)
150 {
151 	p1275buf.prom_cif_handler = (void (*)(long *))cif_handler;
152 	p1275buf.prom_cif_stack = (unsigned long)cif_stack;
153 }
154