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 23 static void wbflush_kn01(void); 24 static void wbflush_kn210(void); 25 static void wbflush_mips(void); 26 27 void (*__wbflush) (void); 28 wbflush_setup(void)29 void __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 */ wbflush_kn01(void)53 static 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 */ wbflush_kn210(void)66 static 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 */ wbflush_mips(void)87 static void wbflush_mips(void) 88 { 89 __fast_iob(); 90 } 91 92 #include <linux/module.h> 93 94 EXPORT_SYMBOL(__wbflush); 95