firmware/target/mips/mmu-mips.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2009 by Maurus Cuelenaere
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include "config.h"
  23 #include "mips.h"
  24 #include "mipsregs.h"
  25 #include "system.h"
  26 #include "mmu-mips.h"
  27
  28 #define BARRIER                            \
  29     __asm__ __volatile__(                  \
  30     "    .set    noreorder          \n"    \
  31     "    nop                        \n"    \
  32     "    nop                        \n"    \
  33     "    nop                        \n"    \
  34     "    nop                        \n"    \
  35     "    nop                        \n"    \
  36     "    nop                        \n"    \
  37     "    .set    reorder            \n");
  38
  39 #define DEFAULT_PAGE_SHIFT       PL_4K
  40 #define DEFAULT_PAGE_MASK        PM_4K
  41 #define UNIQUE_ENTRYHI(idx, ps)  (A_K0BASE + ((idx) << (ps + 1)))
  42 #define ASID_MASK                M_EntryHiASID
  43 #define VPN2_SHIFT               S_EntryHiVPN2
  44 #define PFN_SHIFT                S_EntryLoPFN
  45 #define PFN_MASK                 0xffffff
  46 static void local_flush_tlb_all(void)
  47 {
  48     unsigned long old_ctx;
  49     int entry;
  50     unsigned int old_irq = disable_irq_save();
  51
  52     /* Save old context and create impossible VPN2 value */
  53     old_ctx = read_c0_entryhi();
  54     write_c0_entrylo0(0);
  55     write_c0_entrylo1(0);
  56     BARRIER;
  57
  58     /* Blast 'em all away. */
  59     for(entry = 0; entry < 32; entry++)
  60     {
  61         /* Make sure all entries differ. */
  62         write_c0_entryhi(UNIQUE_ENTRYHI(entry, DEFAULT_PAGE_SHIFT));
  63         write_c0_index(entry);
  64         BARRIER;
  65         tlb_write_indexed();
  66     }
  67     BARRIER;
  68     write_c0_entryhi(old_ctx);
  69
  70     restore_irq(old_irq);
  71 }
  72
  73 static void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
  74                             unsigned long entryhi,  unsigned long pagemask)
  75 {
  76     unsigned long wired;
  77     unsigned long old_pagemask;
  78     unsigned long old_ctx;
  79     unsigned int  old_irq = disable_irq_save();
  80
  81     old_ctx = read_c0_entryhi() & ASID_MASK;
  82     old_pagemask = read_c0_pagemask();
  83     wired = read_c0_wired();
  84     write_c0_wired(wired + 1);
  85     write_c0_index(wired);
  86     BARRIER;
  87     write_c0_pagemask(pagemask);
  88     write_c0_entryhi(entryhi);
  89     write_c0_entrylo0(entrylo0);
  90     write_c0_entrylo1(entrylo1);
  91     BARRIER;
  92     tlb_write_indexed();
  93     BARRIER;
  94
  95     write_c0_entryhi(old_ctx);
  96     BARRIER;
  97     write_c0_pagemask(old_pagemask);
  98     local_flush_tlb_all();
  99     restore_irq(old_irq);
 100 }
 101
 102 void map_address(unsigned long virtual, unsigned long physical,
 103                  unsigned long length, unsigned int cache_flags)
 104 {
 105     unsigned long entry0  = (physical & PFN_MASK) << PFN_SHIFT;
 106     unsigned long entry1  = ((physical+length) & PFN_MASK) << PFN_SHIFT;
 107     unsigned long entryhi = virtual & ~VPN2_SHIFT;
 108
 109     entry0 |= (M_EntryLoG | M_EntryLoV | (cache_flags << S_EntryLoC) );
 110     entry1 |= (M_EntryLoG | M_EntryLoV | (cache_flags << S_EntryLoC) );
 111
 112     add_wired_entry(entry0, entry1, entryhi, DEFAULT_PAGE_MASK);
 113 }
 114
 115 void mmu_init(void)
 116 {
 117     write_c0_pagemask(DEFAULT_PAGE_MASK);
 118     write_c0_wired(0);
 119     write_c0_framemask(0);
 120
 121     local_flush_tlb_all();
 122 /*
 123     map_address(0x80000000, 0x80000000, 0x4000, K_CacheAttrC);
 124     map_address(0x80004000, 0x80004000, MEMORYSIZE * 0x100000, K_CacheAttrC);
 125 */
 126 }
 127
 128 #define SYNC_WB() __asm__ __volatile__ ("sync")
 129
 130 #define __CACHE_OP(op, addr)                 \
 131     __asm__ __volatile__(                    \
 132     "    .set    noreorder        \n"        \
 133     "    .set    mips32\n\t       \n"        \
 134     "    cache   %0, %1           \n"        \
 135     "    .set    mips0            \n"        \
 136     "    .set    reorder          \n"        \
 137     :                                        \
 138     : "i" (op), "m" (*(unsigned char *)(addr)))
 139
 140 void __flush_dcache_line(unsigned long addr)
 141 {
 142     __CACHE_OP(DCHitWBInv, addr);
 143     SYNC_WB();
 144 }
 145
 146 void __icache_invalidate_all(void)
 147 {
 148     unsigned int i;
 149
 150     asm volatile (".set   noreorder  \n"
 151                   ".set   mips32     \n"
 152                   "mtc0   $0, $28    \n" /* TagLo */
 153                   "mtc0   $0, $29    \n" /* TagHi */
 154                   ".set   mips0      \n"
 155                   ".set   reorder    \n"
 156                   );
 157     for(i=A_K0BASE; i<A_K0BASE+CACHE_SIZE; i+=CACHE_LINE_SIZE)
 158         __CACHE_OP(ICIndexStTag, i);
 159
 160     /* invalidate btb */
 161     asm volatile (
 162         ".set mips32        \n"
 163         "mfc0 %0, $16, 7    \n"
 164         "nop                \n"
 165         "ori  %0, 2         \n"
 166         "mtc0 %0, $16, 7    \n"
 167         ".set mips0         \n"
 168         :
 169         : "r" (i));
 170 }
 171
 172 void cpucache_commit_discard(void)
 173 {
 174     __icache_invalidate_all();
 175 }
 176 void cpucache_invalidate(void) __attribute__((alias("cpucache_commit_discard")));
 177
 178 void __dcache_invalidate_all(void)
 179 {
 180     unsigned int i;
 181
 182     asm volatile (".set   noreorder  \n"
 183                   ".set   mips32     \n"
 184                   "mtc0   $0, $28    \n"
 185                   "mtc0   $0, $29    \n"
 186                   ".set   mips0      \n"
 187                   ".set   reorder    \n"
 188                   );
 189     for (i=A_K0BASE; i<A_K0BASE+CACHE_SIZE; i+=CACHE_LINE_SIZE)
 190         __CACHE_OP(DCIndexStTag, i);
 191 }
 192
 193 void __dcache_writeback_all(void) __attribute__ ((section(".icode")));
 194 void __dcache_writeback_all(void)
 195 {
 196     unsigned int i;
 197     for(i=A_K0BASE; i<A_K0BASE+CACHE_SIZE; i+=CACHE_LINE_SIZE)
 198         __CACHE_OP(DCIndexWBInv, i);
 199
 200     SYNC_WB();
 201 }
 202
 203 void dma_cache_wback_inv(unsigned long addr, unsigned long size)
 204 {
 205     unsigned long end, a;
 206
 207     if (size >= CACHE_SIZE)
 208         __dcache_writeback_all();
 209     else
 210     {
 211         unsigned long dc_lsize = CACHE_LINE_SIZE;
 212
 213         a = addr & ~(dc_lsize - 1);
 214         end = (addr + size - 1) & ~(dc_lsize - 1);
 215         for(; a < end; a += dc_lsize)
 216             __flush_dcache_line(a);
 217     }
 218 }