include/asm-mips/war.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2002, 2004 by Ralf Baechle
   7  */
   8 #ifndef _ASM_WAR_H
   9 #define _ASM_WAR_H
  10
  11
  12 /*
  13  * Another R4600 erratum.  Due to the lack of errata information the exact
  14  * technical details aren't known.  I've experimentally found that disabling
  15  * interrupts during indexed I-cache flushes seems to be sufficient to deal
  16  * with the issue.
  17  *
  18  * #define R4600_V1_INDEX_ICACHEOP_WAR 1
  19  */
  20
  21 /*
  22  * Pleasures of the R4600 V1.x.  Cite from the IDT R4600 V1.7 errata:
  23  *
  24  *  18. The CACHE instructions Hit_Writeback_Invalidate_D, Hit_Writeback_D,
  25  *      Hit_Invalidate_D and Create_Dirty_Excl_D should only be
  26  *      executed if there is no other dcache activity. If the dcache is
  27  *      accessed for another instruction immeidately preceding when these
  28  *      cache instructions are executing, it is possible that the dcache
  29  *      tag match outputs used by these cache instructions will be
  30  *      incorrect. These cache instructions should be preceded by at least
  31  *      four instructions that are not any kind of load or store
  32  *      instruction.
  33  *
  34  *      This is not allowed:    lw
  35  *                              nop
  36  *                              nop
  37  *                              nop
  38  *                              cache       Hit_Writeback_Invalidate_D
  39  *
  40  *      This is allowed:        lw
  41  *                              nop
  42  *                              nop
  43  *                              nop
  44  *                              nop
  45  *                              cache       Hit_Writeback_Invalidate_D
  46  *
  47  * #define R4600_V1_HIT_CACHEOP_WAR 1
  48  */
  49
  50
  51 /*
  52  * Writeback and invalidate the primary cache dcache before DMA.
  53  *
  54  * R4600 v2.0 bug: "The CACHE instructions Hit_Writeback_Inv_D,
  55  * Hit_Writeback_D, Hit_Invalidate_D and Create_Dirty_Exclusive_D will only
  56  * operate correctly if the internal data cache refill buffer is empty.  These
  57  * CACHE instructions should be separated from any potential data cache miss
  58  * by a load instruction to an uncached address to empty the response buffer."
  59  * (Revision 2.0 device errata from IDT available on http://www.idt.com/
  60  * in .pdf format.)
  61  *
  62  * #define R4600_V2_HIT_CACHEOP_WAR 1
  63  */
  64
  65 /*
  66  * R4600 CPU modules for the Indy come with both V1.7 and V2.0 processors.
  67  */
  68 #ifdef CONFIG_SGI_IP22
  69
  70 #define R4600_V1_INDEX_ICACHEOP_WAR     1
  71 #define R4600_V1_HIT_CACHEOP_WAR        1
  72 #define R4600_V2_HIT_CACHEOP_WAR        1
  73
  74 #endif
  75
  76 /*
  77  * But the RM200C seems to have been shipped only with V2.0 R4600s
  78  */
  79 #ifdef CONFIG_SNI_RM200_PCI
  80
  81 #define R4600_V2_HIT_CACHEOP_WAR        1
  82
  83 #endif
  84
  85 #ifdef CONFIG_CPU_R5432
  86
  87 /*
  88  * When an interrupt happens on a CP0 register read instruction, CPU may
  89  * lock up or read corrupted values of CP0 registers after it enters
  90  * the exception handler.
  91  *
  92  * This workaround makes sure that we read a "safe" CP0 register as the
  93  * first thing in the exception handler, which breaks one of the
  94  * pre-conditions for this problem.
  95  */
  96 #define R5432_CP0_INTERRUPT_WAR 1
  97
  98 #endif
  99
 100 #if defined(CONFIG_SB1_PASS_1_WORKAROUNDS) || \
 101     defined(CONFIG_SB1_PASS_2_WORKAROUNDS)
 102
 103 /*
 104  * Workaround for the Sibyte M3 errata the text of which can be found at
 105  *
 106  *   http://sibyte.broadcom.com/hw/bcm1250/docs/pass2errata.txt
 107  *
 108  * This will enable the use of a special TLB refill handler which does a
 109  * consistency check on the information in c0_badvaddr and c0_entryhi and
 110  * will just return and take the exception again if the information was
 111  * found to be inconsistent.
 112  */
 113 #define BCM1250_M3_WAR 1
 114
 115 /*
 116  * This is a DUART workaround related to glitches around register accesses
 117  */
 118 #define SIBYTE_1956_WAR 1
 119
 120 #endif
 121
 122 /*
 123  * Fill buffers not flushed on CACHE instructions
 124  *
 125  * Hit_Invalidate_I cacheops invalidate an icache line but the refill
 126  * for that line can get stale data from the fill buffer instead of
 127  * accessing memory if the previous icache miss was also to that line.
 128  *
 129  * Workaround: generate an icache refill from a different line
 130  *
 131  * Affects:
 132  *  MIPS 4K             RTL revision <3.0, PRID revision <4
 133  */
 134 #if defined(CONFIG_MIPS_MALTA) || defined(CONFIG_MIPS_ATLAS) || \
 135     defined(CONFIG_MIPS_SEAD)
 136 #define MIPS4K_ICACHE_REFILL_WAR 1
 137 #endif
 138
 139 /*
 140  * Missing implicit forced flush of evictions caused by CACHE
 141  * instruction
 142  *
 143  * Evictions caused by a CACHE instructions are not forced on to the
 144  * bus. The BIU gives higher priority to fetches than to the data from
 145  * the eviction buffer and no collision detection is performed between
 146  * fetches and pending data from the eviction buffer.
 147  *
 148  * Workaround: Execute a SYNC instruction after the cache instruction
 149  *
 150  * Affects:
 151  *   MIPS 5Kc,5Kf       RTL revision <2.3, PRID revision <8
 152  *   MIPS 20Kc          RTL revision <4.0, PRID revision <?
 153  */
 154 #if defined(CONFIG_MIPS_MALTA) || defined(CONFIG_MIPS_ATLAS) || \
 155     defined(CONFIG_MIPS_SEAD)
 156 #define MIPS_CACHE_SYNC_WAR 1
 157 #endif
 158
 159 /*
 160  * From TX49/H2 manual: "If the instruction (i.e. CACHE) is issued for
 161  * the line which this instruction itself exists, the following
 162  * operation is not guaranteed."
 163  *
 164  * Workaround: do two phase flushing for Index_Invalidate_I
 165  */
 166 #ifdef CONFIG_CPU_TX49XX
 167 #define TX49XX_ICACHE_INDEX_INV_WAR 1
 168 #endif
 169
 170 /*
 171  * On the RM9000 there is a problem which makes the CreateDirtyExclusive
 172  * cache operation unusable on SMP systems.
 173  */
 174 #if defined(CONFIG_MOMENCO_JAGUAR_ATX) || defined(CONFIG_PMC_YOSEMITE) || \
 175     defined(CONFIG_BASLER_EXCITE)
 176 #define  RM9000_CDEX_SMP_WAR            1
 177 #endif
 178
 179 /*
 180  * The RM9000 has a bug (though PMC-Sierra opposes it being called that)
 181  * where invalid instructions in the same I-cache line worth of instructions
 182  * being fetched may case spurious exceptions.
 183  */
 184 #if defined(CONFIG_MOMENCO_JAGUAR_ATX) || defined(CONFIG_MOMENCO_OCELOT_3) || \
 185     defined(CONFIG_PMC_YOSEMITE) || defined(CONFIG_BASLER_EXCITE)
 186 #define ICACHE_REFILLS_WORKAROUND_WAR   1
 187 #endif
 188
 189
 190 /*
 191  * ON the R10000 upto version 2.6 (not sure about 2.7) there is a bug that
 192  * may cause ll / sc and lld / scd sequences to execute non-atomically.
 193  */
 194 #ifdef CONFIG_SGI_IP27
 195 #define R10000_LLSC_WAR 1
 196 #endif
 197
 198 /*
 199  * Workarounds default to off
 200  */
 201 #ifndef ICACHE_REFILLS_WORKAROUND_WAR
 202 #define ICACHE_REFILLS_WORKAROUND_WAR   0
 203 #endif
 204 #ifndef R4600_V1_INDEX_ICACHEOP_WAR
 205 #define R4600_V1_INDEX_ICACHEOP_WAR     0
 206 #endif
 207 #ifndef R4600_V1_HIT_CACHEOP_WAR
 208 #define R4600_V1_HIT_CACHEOP_WAR        0
 209 #endif
 210 #ifndef R4600_V2_HIT_CACHEOP_WAR
 211 #define R4600_V2_HIT_CACHEOP_WAR        0
 212 #endif
 213 #ifndef R5432_CP0_INTERRUPT_WAR
 214 #define R5432_CP0_INTERRUPT_WAR         0
 215 #endif
 216 #ifndef BCM1250_M3_WAR
 217 #define BCM1250_M3_WAR                  0
 218 #endif
 219 #ifndef SIBYTE_1956_WAR
 220 #define SIBYTE_1956_WAR                 0
 221 #endif
 222 #ifndef MIPS4K_ICACHE_REFILL_WAR
 223 #define MIPS4K_ICACHE_REFILL_WAR        0
 224 #endif
 225 #ifndef MIPS_CACHE_SYNC_WAR
 226 #define MIPS_CACHE_SYNC_WAR             0
 227 #endif
 228 #ifndef TX49XX_ICACHE_INDEX_INV_WAR
 229 #define TX49XX_ICACHE_INDEX_INV_WAR     0
 230 #endif
 231 #ifndef RM9000_CDEX_SMP_WAR
 232 #define RM9000_CDEX_SMP_WAR             0
 233 #endif
 234 #ifndef R10000_LLSC_WAR
 235 #define R10000_LLSC_WAR                 0
 236 #endif
 237
 238 #endif /* _ASM_WAR_H */