1/*
2 * Setup the right wbflush routine for the different DECstations.
3 *
4 * Created with information from:
5 *	DECstation 3100 Desktop Workstation Functional Specification
6 *	DECstation 5000/200 KN02 System Module Functional Specification
7 *	mipsel-linux-objdump --disassemble vmunix | grep "wbflush" :-)
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License.  See the file "COPYING" in the main directory of this archive
11 * for more details.
12 *
13 * Copyright (C) 1998 Harald Koerfgen
14 * Copyright (C) 2002 Maciej W. Rozycki
15 */
16
17#include <linux/init.h>
18
19#include <asm/bootinfo.h>
20#include <asm/wbflush.h>
21#include <asm/barrier.h>
22
23static void wbflush_kn01(void);
24static void wbflush_kn210(void);
25static void wbflush_mips(void);
26
27void (*__wbflush) (void);
28
29void __init wbflush_setup(void)
30{
31	switch (mips_machtype) {
32	case MACH_DS23100:
33	case MACH_DS5000_200:	/* DS5000 3max */
34		__wbflush = wbflush_kn01;
35		break;
36	case MACH_DS5100:	/* DS5100 MIPSMATE */
37		__wbflush = wbflush_kn210;
38		break;
39	case MACH_DS5000_1XX:	/* DS5000/100 3min */
40	case MACH_DS5000_XX:	/* Personal DS5000/2x */
41	case MACH_DS5000_2X0:	/* DS5000/240 3max+ */
42	case MACH_DS5900:	/* DS5900 bigmax */
43	default:
44		__wbflush = wbflush_mips;
45		break;
46	}
47}
48
49/*
50 * For the DS3100 and DS5000/200 the R2020/R3220 writeback buffer functions
51 * as part of Coprocessor 0.
52 */
53static void wbflush_kn01(void)
54{
55    asm(".set\tpush\n\t"
56	".set\tnoreorder\n\t"
57	"1:\tbc0f\t1b\n\t"
58	"nop\n\t"
59	".set\tpop");
60}
61
62/*
63 * For the DS5100 the writeback buffer seems to be a part of Coprocessor 3.
64 * But CP3 has to enabled first.
65 */
66static void wbflush_kn210(void)
67{
68    asm(".set\tpush\n\t"
69	".set\tnoreorder\n\t"
70	"mfc0\t$2,$12\n\t"
71	"lui\t$3,0x8000\n\t"
72	"or\t$3,$2,$3\n\t"
73	"mtc0\t$3,$12\n\t"
74	"nop\n"
75	"1:\tbc3f\t1b\n\t"
76	"nop\n\t"
77	"mtc0\t$2,$12\n\t"
78	"nop\n\t"
79	".set\tpop"
80	: : : "$2", "$3");
81}
82
83/*
84 * I/O ASIC systems use a standard writeback buffer that gets flushed
85 * upon an uncached read.
86 */
87static void wbflush_mips(void)
88{
89	__fast_iob();
90}
91
92#include <linux/module.h>
93
94EXPORT_SYMBOL(__wbflush);
95