linux/arch/mips/mm/sc-ip22.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * sc-ip22.c: Indy cache management functions.
   4 *
   5 * Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org),
   6 * derived from r4xx0.c by David S. Miller (davem@davemloft.net).
   7 */
   8#include <linux/init.h>
   9#include <linux/kernel.h>
  10#include <linux/sched.h>
  11#include <linux/mm.h>
  12
  13#include <asm/bcache.h>
  14#include <asm/page.h>
  15#include <asm/bootinfo.h>
  16#include <asm/sgi/ip22.h>
  17#include <asm/sgi/mc.h>
  18
  19/* Secondary cache size in bytes, if present.  */
  20static unsigned long scache_size;
  21
  22#undef DEBUG_CACHE
  23
  24#define SC_SIZE 0x00080000
  25#define SC_LINE 32
  26#define CI_MASK (SC_SIZE - SC_LINE)
  27#define SC_INDEX(n) ((n) & CI_MASK)
  28
  29static inline void indy_sc_wipe(unsigned long first, unsigned long last)
  30{
  31        unsigned long tmp;
  32
  33        __asm__ __volatile__(
  34        "       .set    push                    # indy_sc_wipe          \n"
  35        "       .set    noreorder                                       \n"
  36        "       .set    mips3                                           \n"
  37        "       .set    noat                                            \n"
  38        "       mfc0    %2, $12                                         \n"
  39        "       li      $1, 0x80                # Go 64 bit             \n"
  40        "       mtc0    $1, $12                                         \n"
  41        "                                                               \n"
  42        "       #                                                       \n"
  43        "       # Open code a dli $1, 0x9000000080000000                \n"
  44        "       #                                                       \n"
  45        "       # Required because binutils 2.25 will happily accept    \n"
  46        "       # 64 bit instructions in .set mips3 mode but puke on    \n"
  47        "       # 64 bit constants when generating 32 bit ELF           \n"
  48        "       #                                                       \n"
  49        "       lui     $1,0x9000                                       \n"
  50        "       dsll    $1,$1,0x10                                      \n"
  51        "       ori     $1,$1,0x8000                                    \n"
  52        "       dsll    $1,$1,0x10                                      \n"
  53        "                                                               \n"
  54        "       or      %0, $1                  # first line to flush   \n"
  55        "       or      %1, $1                  # last line to flush    \n"
  56        "       .set    at                                              \n"
  57        "                                                               \n"
  58        "1:     sw      $0, 0(%0)                                       \n"
  59        "       bne     %0, %1, 1b                                      \n"
  60        "        daddu  %0, 32                                          \n"
  61        "                                                               \n"
  62        "       mtc0    %2, $12                 # Back to 32 bit        \n"
  63        "       nop                             # pipeline hazard       \n"
  64        "       nop                                                     \n"
  65        "       nop                                                     \n"
  66        "       nop                                                     \n"
  67        "       .set    pop                                             \n"
  68        : "=r" (first), "=r" (last), "=&r" (tmp)
  69        : "0" (first), "1" (last));
  70}
  71
  72static void indy_sc_wback_invalidate(unsigned long addr, unsigned long size)
  73{
  74        unsigned long first_line, last_line;
  75        unsigned long flags;
  76
  77#ifdef DEBUG_CACHE
  78        printk("indy_sc_wback_invalidate[%08lx,%08lx]", addr, size);
  79#endif
  80
  81        /* Catch bad driver code */
  82        BUG_ON(size == 0);
  83
  84        /* Which lines to flush?  */
  85        first_line = SC_INDEX(addr);
  86        last_line = SC_INDEX(addr + size - 1);
  87
  88        local_irq_save(flags);
  89        if (first_line <= last_line) {
  90                indy_sc_wipe(first_line, last_line);
  91                goto out;
  92        }
  93
  94        indy_sc_wipe(first_line, SC_SIZE - SC_LINE);
  95        indy_sc_wipe(0, last_line);
  96out:
  97        local_irq_restore(flags);
  98}
  99
 100static void indy_sc_enable(void)
 101{
 102        unsigned long addr, tmp1, tmp2;
 103
 104        /* This is really cool... */
 105#ifdef DEBUG_CACHE
 106        printk("Enabling R4600 SCACHE\n");
 107#endif
 108        __asm__ __volatile__(
 109        ".set\tpush\n\t"
 110        ".set\tnoreorder\n\t"
 111        ".set\tmips3\n\t"
 112        "mfc0\t%2, $12\n\t"
 113        "nop; nop; nop; nop;\n\t"
 114        "li\t%1, 0x80\n\t"
 115        "mtc0\t%1, $12\n\t"
 116        "nop; nop; nop; nop;\n\t"
 117        "li\t%0, 0x1\n\t"
 118        "dsll\t%0, 31\n\t"
 119        "lui\t%1, 0x9000\n\t"
 120        "dsll32\t%1, 0\n\t"
 121        "or\t%0, %1, %0\n\t"
 122        "sb\t$0, 0(%0)\n\t"
 123        "mtc0\t$0, $12\n\t"
 124        "nop; nop; nop; nop;\n\t"
 125        "mtc0\t%2, $12\n\t"
 126        "nop; nop; nop; nop;\n\t"
 127        ".set\tpop"
 128        : "=r" (tmp1), "=r" (tmp2), "=r" (addr));
 129}
 130
 131static void indy_sc_disable(void)
 132{
 133        unsigned long tmp1, tmp2, tmp3;
 134
 135#ifdef DEBUG_CACHE
 136        printk("Disabling R4600 SCACHE\n");
 137#endif
 138        __asm__ __volatile__(
 139        ".set\tpush\n\t"
 140        ".set\tnoreorder\n\t"
 141        ".set\tmips3\n\t"
 142        "li\t%0, 0x1\n\t"
 143        "dsll\t%0, 31\n\t"
 144        "lui\t%1, 0x9000\n\t"
 145        "dsll32\t%1, 0\n\t"
 146        "or\t%0, %1, %0\n\t"
 147        "mfc0\t%2, $12\n\t"
 148        "nop; nop; nop; nop\n\t"
 149        "li\t%1, 0x80\n\t"
 150        "mtc0\t%1, $12\n\t"
 151        "nop; nop; nop; nop\n\t"
 152        "sh\t$0, 0(%0)\n\t"
 153        "mtc0\t$0, $12\n\t"
 154        "nop; nop; nop; nop\n\t"
 155        "mtc0\t%2, $12\n\t"
 156        "nop; nop; nop; nop\n\t"
 157        ".set\tpop"
 158        : "=r" (tmp1), "=r" (tmp2), "=r" (tmp3));
 159}
 160
 161static inline int __init indy_sc_probe(void)
 162{
 163        unsigned int size = ip22_eeprom_read(&sgimc->eeprom, 17);
 164        if (size == 0)
 165                return 0;
 166
 167        size <<= PAGE_SHIFT;
 168        printk(KERN_INFO "R4600/R5000 SCACHE size %dK, linesize 32 bytes.\n",
 169               size >> 10);
 170        scache_size = size;
 171
 172        return 1;
 173}
 174
 175/* XXX Check with wje if the Indy caches can differentiate between
 176   writeback + invalidate and just invalidate.  */
 177static struct bcache_ops indy_sc_ops = {
 178        .bc_enable = indy_sc_enable,
 179        .bc_disable = indy_sc_disable,
 180        .bc_wback_inv = indy_sc_wback_invalidate,
 181        .bc_inv = indy_sc_wback_invalidate
 182};
 183
 184void indy_sc_init(void)
 185{
 186        if (indy_sc_probe()) {
 187                indy_sc_enable();
 188                bcops = &indy_sc_ops;
 189        }
 190}
 191