1/* $Id: p1275.c,v 1.1.1.1 2007/08/03 18:52:19 Exp $
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
20struct {
21	long prom_callback;			/* 0x00 */
22	void (*prom_cif_handler)(long *);	/* 0x08 */
23	unsigned long prom_cif_stack;		/* 0x10 */
24	unsigned long prom_args [23];		/* 0x18 */
25	char prom_buffer [3000];
26} p1275buf;
27
28extern void prom_world(int);
29
30extern void prom_cif_interface(void);
31extern void prom_cif_callback(void);
32
33/*
34 * This provides SMP safety on the p1275buf. prom_callback() drops this lock
35 * to allow recursuve acquisition.
36 */
37DEFINE_SPINLOCK(prom_entry_lock);
38
39long 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	spin_lock_irqsave(&prom_entry_lock, flags);
50
51	p1275buf.prom_args[0] = (unsigned long)p;		/* service */
52	strcpy (p, service);
53	p = (char *)(((long)(strchr (p, 0) + 8)) & ~7);
54	p1275buf.prom_args[1] = nargs = (fmt & 0x0f);		/* nargs */
55	p1275buf.prom_args[2] = nrets = ((fmt & 0xf0) >> 4); 	/* nrets */
56	attrs = fmt >> 8;
57	va_start(list, fmt);
58	for (i = 0; i < nargs; i++, attrs >>= 3) {
59		switch (attrs & 0x7) {
60		case P1275_ARG_NUMBER:
61			p1275buf.prom_args[i + 3] =
62						(unsigned)va_arg(list, long);
63			break;
64		case P1275_ARG_IN_64B:
65			p1275buf.prom_args[i + 3] =
66				va_arg(list, unsigned long);
67			break;
68		case P1275_ARG_IN_STRING:
69			strcpy (p, va_arg(list, char *));
70			p1275buf.prom_args[i + 3] = (unsigned long)p;
71			p = (char *)(((long)(strchr (p, 0) + 8)) & ~7);
72			break;
73		case P1275_ARG_OUT_BUF:
74			(void) va_arg(list, char *);
75			p1275buf.prom_args[i + 3] = (unsigned long)p;
76			x = va_arg(list, long);
77			i++; attrs >>= 3;
78			p = (char *)(((long)(p + (int)x + 7)) & ~7);
79			p1275buf.prom_args[i + 3] = x;
80			break;
81		case P1275_ARG_IN_BUF:
82			q = va_arg(list, char *);
83			p1275buf.prom_args[i + 3] = (unsigned long)p;
84			x = va_arg(list, long);
85			i++; attrs >>= 3;
86			memcpy (p, q, (int)x);
87			p = (char *)(((long)(p + (int)x + 7)) & ~7);
88			p1275buf.prom_args[i + 3] = x;
89			break;
90		case P1275_ARG_OUT_32B:
91			(void) va_arg(list, char *);
92			p1275buf.prom_args[i + 3] = (unsigned long)p;
93			p += 32;
94			break;
95		case P1275_ARG_IN_FUNCTION:
96			p1275buf.prom_args[i + 3] =
97					(unsigned long)prom_cif_callback;
98			p1275buf.prom_callback = va_arg(list, long);
99			break;
100		}
101	}
102	va_end(list);
103
104	prom_world(1);
105	prom_cif_interface();
106	prom_world(0);
107
108	attrs = fmt >> 8;
109	va_start(list, fmt);
110	for (i = 0; i < nargs; i++, attrs >>= 3) {
111		switch (attrs & 0x7) {
112		case P1275_ARG_NUMBER:
113			(void) va_arg(list, long);
114			break;
115		case P1275_ARG_IN_STRING:
116			(void) va_arg(list, char *);
117			break;
118		case P1275_ARG_IN_FUNCTION:
119			(void) va_arg(list, long);
120			break;
121		case P1275_ARG_IN_BUF:
122			(void) va_arg(list, char *);
123			(void) va_arg(list, long);
124			i++; attrs >>= 3;
125			break;
126		case P1275_ARG_OUT_BUF:
127			p = va_arg(list, char *);
128			x = va_arg(list, long);
129			memcpy (p, (char *)(p1275buf.prom_args[i + 3]), (int)x);
130			i++; attrs >>= 3;
131			break;
132		case P1275_ARG_OUT_32B:
133			p = va_arg(list, char *);
134			memcpy (p, (char *)(p1275buf.prom_args[i + 3]), 32);
135			break;
136		}
137	}
138	va_end(list);
139	x = p1275buf.prom_args [nargs + 3];
140
141	spin_unlock_irqrestore(&prom_entry_lock, flags);
142
143	return x;
144}
145
146void prom_cif_init(void *cif_handler, void *cif_stack)
147{
148	p1275buf.prom_cif_handler = (void (*)(long *))cif_handler;
149	p1275buf.prom_cif_stack = (unsigned long)cif_stack;
150}
151