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/export.h>
18#include <linux/init.h>
19
20#include <asm/bootinfo.h>
21#include <asm/wbflush.h>
22#include <asm/barrier.h>
23
24static void wbflush_kn01(void);
25static void wbflush_kn210(void);
26static void wbflush_mips(void);
27
28void (*__wbflush) (void);
29
30void __init wbflush_setup(void)
31{
32	switch (mips_machtype) {
33	case MACH_DS23100:
34	case MACH_DS5000_200:	/* DS5000 3max */
35		__wbflush = wbflush_kn01;
36		break;
37	case MACH_DS5100:	/* DS5100 MIPSMATE */
38		__wbflush = wbflush_kn210;
39		break;
40	case MACH_DS5000_1XX:	/* DS5000/100 3min */
41	case MACH_DS5000_XX:	/* Personal DS5000/2x */
42	case MACH_DS5000_2X0:	/* DS5000/240 3max+ */
43	case MACH_DS5900:	/* DS5900 bigmax */
44	default:
45		__wbflush = wbflush_mips;
46		break;
47	}
48}
49
50/*
51 * For the DS3100 and DS5000/200 the R2020/R3220 writeback buffer functions
52 * as part of Coprocessor 0.
53 */
54static void wbflush_kn01(void)
55{
56    asm(".set\tpush\n\t"
57	".set\tnoreorder\n\t"
58	"1:\tbc0f\t1b\n\t"
59	"nop\n\t"
60	".set\tpop");
61}
62
63/*
64 * For the DS5100 the writeback buffer seems to be a part of Coprocessor 3.
65 * But CP3 has to enabled first.
66 */
67static void wbflush_kn210(void)
68{
69    asm(".set\tpush\n\t"
70	".set\tnoreorder\n\t"
71	"mfc0\t$2,$12\n\t"
72	"lui\t$3,0x8000\n\t"
73	"or\t$3,$2,$3\n\t"
74	"mtc0\t$3,$12\n\t"
75	"nop\n"
76	"1:\tbc3f\t1b\n\t"
77	"nop\n\t"
78	"mtc0\t$2,$12\n\t"
79	"nop\n\t"
80	".set\tpop"
81	: : : "$2", "$3");
82}
83
84/*
85 * I/O ASIC systems use a standard writeback buffer that gets flushed
86 * upon an uncached read.
87 */
88static void wbflush_mips(void)
89{
90	__fast_iob();
91}
92EXPORT_SYMBOL(__wbflush);
93