arch/mips/dec/wbflush.c

   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  */
  15
  16 #include <asm/bootinfo.h>
  17 #include <asm/init.h>
  18
  19 static void wbflush_kn01(void);
  20 static void wbflush_kn210(void);
  21 static void wbflush_kn02ba(void);
  22 static void wbflush_kn03(void);
  23
  24 void (*__wbflush) (void);
  25
  26 __initfunc(void wbflush_setup(void))
  27 {
  28         switch (mips_machtype) {
  29         case MACH_DS23100:
  30             __wbflush = wbflush_kn01;
  31             break;
  32         case MACH_DS5100:       /*  DS5100 MIPSMATE */
  33             __wbflush = wbflush_kn210;
  34             break;
  35         case MACH_DS5000_200:   /* DS5000 3max */
  36             __wbflush = wbflush_kn01;
  37             break;
  38         case MACH_DS5000_1XX:   /* DS5000/100 3min */
  39             __wbflush = wbflush_kn02ba;
  40             break;
  41         case MACH_DS5000_2X0:   /* DS5000/240 3max+ */
  42             __wbflush = wbflush_kn03;
  43             break;
  44         case MACH_DS5000_XX:    /* Personal DS5000/2x */
  45             __wbflush = wbflush_kn02ba;
  46             break;
  47         }
  48 }
  49
  50 /*
  51  * For the DS3100 and DS5000/200 the 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  * Looks like some magic with the System Interrupt Mask Register
  86  * in the famous IOASIC for kmins and maxines.
  87  */
  88 static void wbflush_kn02ba(void)
  89 {
  90     asm(".set\tpush\n\t"
  91         ".set\tnoreorder\n\t"
  92         "lui\t$2,0xbc04\n\t"
  93         "lw\t$3,0x120($2)\n\t"
  94         "lw\t$3,0x120($2)\n\t"
  95         ".set\tpop"
  96   : : :"$2", "$3");
  97 }
  98
  99 /*
 100  * The DS500/2x0 doesnt need to write back the WB.
 101  */
 102 static void wbflush_kn03(void)
 103 {
 104 }