xref: /OK3568_Linux_fs/kernel/arch/mips/dec/wbflush.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Setup the right wbflush routine for the different DECstations.
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * Created with information from:
5*4882a593Smuzhiyun  *	DECstation 3100 Desktop Workstation Functional Specification
6*4882a593Smuzhiyun  *	DECstation 5000/200 KN02 System Module Functional Specification
7*4882a593Smuzhiyun  *	mipsel-linux-objdump --disassemble vmunix | grep "wbflush" :-)
8*4882a593Smuzhiyun  *
9*4882a593Smuzhiyun  * This file is subject to the terms and conditions of the GNU General Public
10*4882a593Smuzhiyun  * License.  See the file "COPYING" in the main directory of this archive
11*4882a593Smuzhiyun  * for more details.
12*4882a593Smuzhiyun  *
13*4882a593Smuzhiyun  * Copyright (C) 1998 Harald Koerfgen
14*4882a593Smuzhiyun  * Copyright (C) 2002 Maciej W. Rozycki
15*4882a593Smuzhiyun  */
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun #include <linux/export.h>
18*4882a593Smuzhiyun #include <linux/init.h>
19*4882a593Smuzhiyun 
20*4882a593Smuzhiyun #include <asm/bootinfo.h>
21*4882a593Smuzhiyun #include <asm/wbflush.h>
22*4882a593Smuzhiyun #include <asm/barrier.h>
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun static void wbflush_kn01(void);
25*4882a593Smuzhiyun static void wbflush_kn210(void);
26*4882a593Smuzhiyun static void wbflush_mips(void);
27*4882a593Smuzhiyun 
28*4882a593Smuzhiyun void (*__wbflush) (void);
29*4882a593Smuzhiyun 
wbflush_setup(void)30*4882a593Smuzhiyun void __init wbflush_setup(void)
31*4882a593Smuzhiyun {
32*4882a593Smuzhiyun 	switch (mips_machtype) {
33*4882a593Smuzhiyun 	case MACH_DS23100:
34*4882a593Smuzhiyun 	case MACH_DS5000_200:	/* DS5000 3max */
35*4882a593Smuzhiyun 		__wbflush = wbflush_kn01;
36*4882a593Smuzhiyun 		break;
37*4882a593Smuzhiyun 	case MACH_DS5100:	/* DS5100 MIPSMATE */
38*4882a593Smuzhiyun 		__wbflush = wbflush_kn210;
39*4882a593Smuzhiyun 		break;
40*4882a593Smuzhiyun 	case MACH_DS5000_1XX:	/* DS5000/100 3min */
41*4882a593Smuzhiyun 	case MACH_DS5000_XX:	/* Personal DS5000/2x */
42*4882a593Smuzhiyun 	case MACH_DS5000_2X0:	/* DS5000/240 3max+ */
43*4882a593Smuzhiyun 	case MACH_DS5900:	/* DS5900 bigmax */
44*4882a593Smuzhiyun 	default:
45*4882a593Smuzhiyun 		__wbflush = wbflush_mips;
46*4882a593Smuzhiyun 		break;
47*4882a593Smuzhiyun 	}
48*4882a593Smuzhiyun }
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun /*
51*4882a593Smuzhiyun  * For the DS3100 and DS5000/200 the R2020/R3220 writeback buffer functions
52*4882a593Smuzhiyun  * as part of Coprocessor 0.
53*4882a593Smuzhiyun  */
wbflush_kn01(void)54*4882a593Smuzhiyun static void wbflush_kn01(void)
55*4882a593Smuzhiyun {
56*4882a593Smuzhiyun     asm(".set\tpush\n\t"
57*4882a593Smuzhiyun 	".set\tnoreorder\n\t"
58*4882a593Smuzhiyun 	"1:\tbc0f\t1b\n\t"
59*4882a593Smuzhiyun 	"nop\n\t"
60*4882a593Smuzhiyun 	".set\tpop");
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun 
63*4882a593Smuzhiyun /*
64*4882a593Smuzhiyun  * For the DS5100 the writeback buffer seems to be a part of Coprocessor 3.
65*4882a593Smuzhiyun  * But CP3 has to enabled first.
66*4882a593Smuzhiyun  */
wbflush_kn210(void)67*4882a593Smuzhiyun static void wbflush_kn210(void)
68*4882a593Smuzhiyun {
69*4882a593Smuzhiyun     asm(".set\tpush\n\t"
70*4882a593Smuzhiyun 	".set\tnoreorder\n\t"
71*4882a593Smuzhiyun 	"mfc0\t$2,$12\n\t"
72*4882a593Smuzhiyun 	"lui\t$3,0x8000\n\t"
73*4882a593Smuzhiyun 	"or\t$3,$2,$3\n\t"
74*4882a593Smuzhiyun 	"mtc0\t$3,$12\n\t"
75*4882a593Smuzhiyun 	"nop\n"
76*4882a593Smuzhiyun 	"1:\tbc3f\t1b\n\t"
77*4882a593Smuzhiyun 	"nop\n\t"
78*4882a593Smuzhiyun 	"mtc0\t$2,$12\n\t"
79*4882a593Smuzhiyun 	"nop\n\t"
80*4882a593Smuzhiyun 	".set\tpop"
81*4882a593Smuzhiyun 	: : : "$2", "$3");
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun 
84*4882a593Smuzhiyun /*
85*4882a593Smuzhiyun  * I/O ASIC systems use a standard writeback buffer that gets flushed
86*4882a593Smuzhiyun  * upon an uncached read.
87*4882a593Smuzhiyun  */
wbflush_mips(void)88*4882a593Smuzhiyun static void wbflush_mips(void)
89*4882a593Smuzhiyun {
90*4882a593Smuzhiyun 	__fast_iob();
91*4882a593Smuzhiyun }
92*4882a593Smuzhiyun EXPORT_SYMBOL(__wbflush);
93