arch/xtensa/include/asm/initialize_mmu.h

   1 /*
   2  * arch/xtensa/include/asm/initialize_mmu.h
   3  *
   4  * Initializes MMU:
   5  *
   6  *      For the new V3 MMU we remap the TLB from virtual == physical
   7  *      to the standard Linux mapping used in earlier MMU's.
   8  *
   9  *      The the MMU we also support a new configuration register that
  10  *      specifies how the S32C1I instruction operates with the cache
  11  *      controller.
  12  *
  13  * This file is subject to the terms and conditions of the GNU General
  14  * Public License.  See the file "COPYING" in the main directory of
  15  * this archive for more details.
  16  *
  17  * Copyright (C) 2008 - 2012 Tensilica, Inc.
  18  *
  19  *   Marc Gauthier <marc@tensilica.com>
  20  *   Pete Delaney <piet@tensilica.com>
  21  */
  22
  23 #ifndef _XTENSA_INITIALIZE_MMU_H
  24 #define _XTENSA_INITIALIZE_MMU_H
  25
  26 #include <asm/pgtable.h>
  27 #include <asm/vectors.h>
  28
  29 #if XCHAL_HAVE_PTP_MMU
  30 #define CA_BYPASS       (_PAGE_CA_BYPASS | _PAGE_HW_WRITE | _PAGE_HW_EXEC)
  31 #define CA_WRITEBACK    (_PAGE_CA_WB     | _PAGE_HW_WRITE | _PAGE_HW_EXEC)
  32 #else
  33 #define CA_WRITEBACK    (0x4)
  34 #endif
  35
  36 #ifndef XCHAL_SPANNING_WAY
  37 #define XCHAL_SPANNING_WAY 0
  38 #endif
  39
  40 #ifdef __ASSEMBLY__
  41
  42 #define XTENSA_HWVERSION_RC_2009_0 230000
  43
  44         .macro  initialize_mmu
  45
  46 #if XCHAL_HAVE_S32C1I && (XCHAL_HW_MIN_VERSION >= XTENSA_HWVERSION_RC_2009_0)
  47 /*
  48  * We Have Atomic Operation Control (ATOMCTL) Register; Initialize it.
  49  * For details see Documentation/xtensa/atomctl.txt
  50  */
  51 #if XCHAL_DCACHE_IS_COHERENT
  52         movi    a3, 0x25        /* For SMP/MX -- internal for writeback,
  53                                  * RCW otherwise
  54                                  */
  55 #else
  56         movi    a3, 0x29        /* non-MX -- Most cores use Std Memory
  57                                  * Controlers which usually can't use RCW
  58                                  */
  59 #endif
  60         wsr     a3, atomctl
  61 #endif  /* XCHAL_HAVE_S32C1I &&
  62          * (XCHAL_HW_MIN_VERSION >= XTENSA_HWVERSION_RC_2009_0)
  63          */
  64
  65 #if defined(CONFIG_MMU) && XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY
  66 /*
  67  * Have MMU v3
  68  */
  69
  70 #if !XCHAL_HAVE_VECBASE
  71 # error "MMU v3 requires reloc vectors"
  72 #endif
  73
  74         movi    a1, 0
  75         _call0  1f
  76         _j      2f
  77
  78         .align  4
  79 1:      movi    a2, 0x10000000
  80         movi    a3, 0x18000000
  81         add     a2, a2, a0
  82 9:      bgeu    a2, a3, 9b      /* PC is out of the expected range */
  83
  84         /* Step 1: invalidate mapping at 0x40000000..0x5FFFFFFF. */
  85
  86         movi    a2, 0x40000000 | XCHAL_SPANNING_WAY
  87         idtlb   a2
  88         iitlb   a2
  89         isync
  90
  91         /* Step 2: map 0x40000000..0x47FFFFFF to paddr containing this code
  92          * and jump to the new mapping.
  93          */
  94
  95         srli    a3, a0, 27
  96         slli    a3, a3, 27
  97         addi    a3, a3, CA_BYPASS
  98         addi    a7, a2, -1
  99         wdtlb   a3, a7
 100         witlb   a3, a7
 101         isync
 102
 103         slli    a4, a0, 5
 104         srli    a4, a4, 5
 105         addi    a5, a2, -6
 106         add     a4, a4, a5
 107         jx      a4
 108
 109         /* Step 3: unmap everything other than current area.
 110          *         Start at 0x60000000, wrap around, and end with 0x20000000
 111          */
 112 2:      movi    a4, 0x20000000
 113         add     a5, a2, a4
 114 3:      idtlb   a5
 115         iitlb   a5
 116         add     a5, a5, a4
 117         bne     a5, a2, 3b
 118
 119         /* Step 4: Setup MMU with the old V2 mappings. */
 120         movi    a6, 0x01000000
 121         wsr     a6, ITLBCFG
 122         wsr     a6, DTLBCFG
 123         isync
 124
 125         movi    a5, 0xd0000005
 126         movi    a4, CA_WRITEBACK
 127         wdtlb   a4, a5
 128         witlb   a4, a5
 129
 130         movi    a5, 0xd8000005
 131         movi    a4, CA_BYPASS
 132         wdtlb   a4, a5
 133         witlb   a4, a5
 134
 135         movi    a5, XCHAL_KIO_CACHED_VADDR + 6
 136         movi    a4, XCHAL_KIO_DEFAULT_PADDR + CA_WRITEBACK
 137         wdtlb   a4, a5
 138         witlb   a4, a5
 139
 140         movi    a5, XCHAL_KIO_BYPASS_VADDR + 6
 141         movi    a4, XCHAL_KIO_DEFAULT_PADDR + CA_BYPASS
 142         wdtlb   a4, a5
 143         witlb   a4, a5
 144
 145         isync
 146
 147         /* Jump to self, using MMU v2 mappings. */
 148         movi    a4, 1f
 149         jx      a4
 150
 151 1:
 152         /* Step 5: remove temporary mapping. */
 153         idtlb   a7
 154         iitlb   a7
 155         isync
 156
 157         movi    a0, 0
 158         wsr     a0, ptevaddr
 159         rsync
 160
 161 #endif /* defined(CONFIG_MMU) && XCHAL_HAVE_PTP_MMU &&
 162           XCHAL_HAVE_SPANNING_WAY */
 163
 164 #if !defined(CONFIG_MMU) && XCHAL_HAVE_TLBS
 165         /* Enable data and instruction cache in the DEFAULT_MEMORY region
 166          * if the processor has DTLB and ITLB.
 167          */
 168
 169         movi    a5, PLATFORM_DEFAULT_MEM_START | XCHAL_SPANNING_WAY
 170         movi    a6, ~_PAGE_ATTRIB_MASK
 171         movi    a7, CA_WRITEBACK
 172         movi    a8, 0x20000000
 173         movi    a9, PLATFORM_DEFAULT_MEM_SIZE
 174         j       2f
 175 1:
 176         sub     a9, a9, a8
 177 2:
 178         rdtlb1  a3, a5
 179         ritlb1  a4, a5
 180         and     a3, a3, a6
 181         and     a4, a4, a6
 182         or      a3, a3, a7
 183         or      a4, a4, a7
 184         wdtlb   a3, a5
 185         witlb   a4, a5
 186         add     a5, a5, a8
 187         bltu    a8, a9, 1b
 188
 189 #endif
 190
 191         .endm
 192
 193 #endif /*__ASSEMBLY__*/
 194
 195 #endif /* _XTENSA_INITIALIZE_MMU_H */