arch/mips/mm/sc-mips.c

   1 /*
   2  * Copyright (C) 2006 Chris Dearman (chris@mips.com),
   3  */
   4 #include <linux/init.h>
   5 #include <linux/kernel.h>
   6 #include <linux/sched.h>
   7 #include <linux/mm.h>
   8
   9 #include <asm/mipsregs.h>
  10 #include <asm/bcache.h>
  11 #include <asm/cacheops.h>
  12 #include <asm/page.h>
  13 #include <asm/pgtable.h>
  14 #include <asm/system.h>
  15 #include <asm/mmu_context.h>
  16 #include <asm/r4kcache.h>
  17
  18 /*
  19  * MIPS32/MIPS64 L2 cache handling
  20  */
  21
  22 /*
  23  * Writeback and invalidate the secondary cache before DMA.
  24  */
  25 static void mips_sc_wback_inv(unsigned long addr, unsigned long size)
  26 {
  27         blast_scache_range(addr, addr + size);
  28 }
  29
  30 /*
  31  * Invalidate the secondary cache before DMA.
  32  */
  33 static void mips_sc_inv(unsigned long addr, unsigned long size)
  34 {
  35         blast_inv_scache_range(addr, addr + size);
  36 }
  37
  38 static void mips_sc_enable(void)
  39 {
  40         /* L2 cache is permanently enabled */
  41 }
  42
  43 static void mips_sc_disable(void)
  44 {
  45         /* L2 cache is permanently enabled */
  46 }
  47
  48 static struct bcache_ops mips_sc_ops = {
  49         .bc_enable = mips_sc_enable,
  50         .bc_disable = mips_sc_disable,
  51         .bc_wback_inv = mips_sc_wback_inv,
  52         .bc_inv = mips_sc_inv
  53 };
  54
  55 static inline int __init mips_sc_probe(void)
  56 {
  57         struct cpuinfo_mips *c = &current_cpu_data;
  58         unsigned int config1, config2;
  59         unsigned int tmp;
  60
  61         /* Mark as not present until probe completed */
  62         c->scache.flags |= MIPS_CACHE_NOT_PRESENT;
  63
  64         /* Ignore anything but MIPSxx processors */
  65         if (c->isa_level != MIPS_CPU_ISA_M32R1 &&
  66             c->isa_level != MIPS_CPU_ISA_M32R2 &&
  67             c->isa_level != MIPS_CPU_ISA_M64R1 &&
  68             c->isa_level != MIPS_CPU_ISA_M64R2)
  69                 return 0;
  70
  71         /* Does this MIPS32/MIPS64 CPU have a config2 register? */
  72         config1 = read_c0_config1();
  73         if (!(config1 & MIPS_CONF_M))
  74                 return 0;
  75
  76         config2 = read_c0_config2();
  77         tmp = (config2 >> 4) & 0x0f;
  78         if (0 < tmp && tmp <= 7)
  79                 c->scache.linesz = 2 << tmp;
  80         else
  81                 return 0;
  82
  83         tmp = (config2 >> 8) & 0x0f;
  84         if (0 <= tmp && tmp <= 7)
  85                 c->scache.sets = 64 << tmp;
  86         else
  87                 return 0;
  88
  89         tmp = (config2 >> 0) & 0x0f;
  90         if (0 <= tmp && tmp <= 7)
  91                 c->scache.ways = tmp + 1;
  92         else
  93                 return 0;
  94
  95         c->scache.waysize = c->scache.sets * c->scache.linesz;
  96         c->scache.waybit = __ffs(c->scache.waysize);
  97
  98         c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
  99
 100         return 1;
 101 }
 102
 103 int __init mips_sc_init(void)
 104 {
 105         int found = mips_sc_probe ();
 106         if (found) {
 107                 mips_sc_enable();
 108                 bcops = &mips_sc_ops;
 109         }
 110         return found;
 111 }
 112