arch/mips/mm/sc-ip22.c

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