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); 93