arch/sh/kernel/cpu/sh3/probe.c

   1 /*
   2  * arch/sh/kernel/cpu/sh3/probe.c
   3  *
   4  * CPU Subtype Probing for SH-3.
   5  *
   6  * Copyright (C) 1999, 2000  Niibe Yutaka
   7  * Copyright (C) 2002  Paul Mundt
   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
  14 #include <linux/init.h>
  15 #include <asm/processor.h>
  16 #include <asm/cache.h>
  17 #include <asm/io.h>
  18
  19 int __init detect_cpu_and_cache_system(void)
  20 {
  21         unsigned long addr0, addr1, data0, data1, data2, data3;
  22
  23         jump_to_P2();
  24         /*
  25          * Check if the entry shadows or not.
  26          * When shadowed, it's 128-entry system.
  27          * Otherwise, it's 256-entry system.
  28          */
  29         addr0 = CACHE_OC_ADDRESS_ARRAY + (3 << 12);
  30         addr1 = CACHE_OC_ADDRESS_ARRAY + (1 << 12);
  31
  32         /* First, write back & invalidate */
  33         data0  = ctrl_inl(addr0);
  34         ctrl_outl(data0&~(SH_CACHE_VALID|SH_CACHE_UPDATED), addr0);
  35         data1  = ctrl_inl(addr1);
  36         ctrl_outl(data1&~(SH_CACHE_VALID|SH_CACHE_UPDATED), addr1);
  37
  38         /* Next, check if there's shadow or not */
  39         data0 = ctrl_inl(addr0);
  40         data0 ^= SH_CACHE_VALID;
  41         ctrl_outl(data0, addr0);
  42         data1 = ctrl_inl(addr1);
  43         data2 = data1 ^ SH_CACHE_VALID;
  44         ctrl_outl(data2, addr1);
  45         data3 = ctrl_inl(addr0);
  46
  47         /* Lastly, invaliate them. */
  48         ctrl_outl(data0&~SH_CACHE_VALID, addr0);
  49         ctrl_outl(data2&~SH_CACHE_VALID, addr1);
  50
  51         back_to_P1();
  52
  53         cpu_data->dcache.ways           = 4;
  54         cpu_data->dcache.entry_shift    = 4;
  55         cpu_data->dcache.linesz         = L1_CACHE_BYTES;
  56         cpu_data->dcache.flags          = 0;
  57
  58         /*
  59          * 7709A/7729 has 16K cache (256-entry), while 7702 has only
  60          * 2K(direct) 7702 is not supported (yet)
  61          */
  62         if (data0 == data1 && data2 == data3) { /* Shadow */
  63                 cpu_data->dcache.way_incr       = (1 << 11);
  64                 cpu_data->dcache.entry_mask     = 0x7f0;
  65                 cpu_data->dcache.sets           = 128;
  66                 cpu_data->type = CPU_SH7708;
  67
  68                 cpu_data->flags |= CPU_HAS_MMU_PAGE_ASSOC;
  69         } else {                                /* 7709A or 7729  */
  70                 cpu_data->dcache.way_incr       = (1 << 12);
  71                 cpu_data->dcache.entry_mask     = 0xff0;
  72                 cpu_data->dcache.sets           = 256;
  73                 cpu_data->type = CPU_SH7729;
  74
  75 #if defined(CONFIG_CPU_SUBTYPE_SH7705)
  76                 cpu_data->type = CPU_SH7705;
  77
  78 #if defined(CONFIG_SH7705_CACHE_32KB)
  79                 cpu_data->dcache.way_incr       = (1 << 13);
  80                 cpu_data->dcache.entry_mask     = 0x1ff0;
  81                 cpu_data->dcache.sets           = 512;
  82                 ctrl_outl(CCR_CACHE_32KB, CCR3);
  83 #else
  84                 ctrl_outl(CCR_CACHE_16KB, CCR3);
  85 #endif
  86 #endif
  87         }
  88
  89         /*
  90          * SH-3 doesn't have separate caches
  91          */
  92         cpu_data->dcache.flags |= SH_CACHE_COMBINED;
  93         cpu_data->icache = cpu_data->dcache;
  94
  95         return 0;
  96 }
  97