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
24 static void wbflush_kn01(void);
25 static void wbflush_kn210(void);
26 static void wbflush_mips(void);
27
28 void (*__wbflush) (void);
29
30 void __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 */
54 static 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 */
67 static 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 */
88 static void wbflush_mips(void)
89 {
90 __fast_iob();
91 }
92 EXPORT_SYMBOL(__wbflush);