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, 2007 by Ralf Baechle 7 * Copyright (C) 2007 Maciej W. Rozycki 8 */ 9 #ifndef _ASM_WAR_H 10 #define _ASM_WAR_H 11 12 #include <war.h> 13 14 /* 15 * Work around certain R4000 CPU errata (as implemented by GCC): 16 * 17 * - A double-word or a variable shift may give an incorrect result 18 * if executed immediately after starting an integer division: 19 * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", 20 * erratum #28 21 * "MIPS R4000MC Errata, Processor Revision 2.2 and 3.0", erratum 22 * #19 23 * 24 * - A double-word or a variable shift may give an incorrect result 25 * if executed while an integer multiplication is in progress: 26 * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", 27 * errata #16 & #28 28 * 29 * - An integer division may give an incorrect result if started in 30 * a delay slot of a taken branch or a jump: 31 * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", 32 * erratum #52 33 */ 34 #ifdef CONFIG_CPU_R4000_WORKAROUNDS 35 #define R4000_WAR 1 36 #else 37 #define R4000_WAR 0 38 #endif 39 40 /* 41 * Work around certain R4400 CPU errata (as implemented by GCC): 42 * 43 * - A double-word or a variable shift may give an incorrect result 44 * if executed immediately after starting an integer division: 45 * "MIPS R4400MC Errata, Processor Revision 1.0", erratum #10 46 * "MIPS R4400MC Errata, Processor Revision 2.0 & 3.0", erratum #4 47 */ 48 #ifdef CONFIG_CPU_R4400_WORKAROUNDS 49 #define R4400_WAR 1 50 #else 51 #define R4400_WAR 0 52 #endif 53 54 /* 55 * Work around the "daddi" and "daddiu" CPU errata: 56 * 57 * - The `daddi' instruction fails to trap on overflow. 58 * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", 59 * erratum #23 60 * 61 * - The `daddiu' instruction can produce an incorrect result. 62 * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", 63 * erratum #41 64 * "MIPS R4000MC Errata, Processor Revision 2.2 and 3.0", erratum 65 * #15 66 * "MIPS R4400PC/SC Errata, Processor Revision 1.0", erratum #7 67 * "MIPS R4400MC Errata, Processor Revision 1.0", erratum #5 68 */ 69 #ifdef CONFIG_CPU_DADDI_WORKAROUNDS 70 #define DADDI_WAR 1 71 #else 72 #define DADDI_WAR 0 73 #endif 74 75 /* 76 * Another R4600 erratum. Due to the lack of errata information the exact 77 * technical details aren't known. I've experimentally found that disabling 78 * interrupts during indexed I-cache flushes seems to be sufficient to deal 79 * with the issue. 80 */ 81 #ifndef R4600_V1_INDEX_ICACHEOP_WAR 82 #error Check setting of R4600_V1_INDEX_ICACHEOP_WAR for your platform 83 #endif 84 85 /* 86 * Pleasures of the R4600 V1.x. Cite from the IDT R4600 V1.7 errata: 87 * 88 * 18. The CACHE instructions Hit_Writeback_Invalidate_D, Hit_Writeback_D, 89 * Hit_Invalidate_D and Create_Dirty_Excl_D should only be 90 * executed if there is no other dcache activity. If the dcache is 91 * accessed for another instruction immeidately preceding when these 92 * cache instructions are executing, it is possible that the dcache 93 * tag match outputs used by these cache instructions will be 94 * incorrect. These cache instructions should be preceded by at least 95 * four instructions that are not any kind of load or store 96 * instruction. 97 * 98 * This is not allowed: lw 99 * nop 100 * nop 101 * nop 102 * cache Hit_Writeback_Invalidate_D 103 * 104 * This is allowed: lw 105 * nop 106 * nop 107 * nop 108 * nop 109 * cache Hit_Writeback_Invalidate_D 110 */ 111 #ifndef R4600_V1_HIT_CACHEOP_WAR 112 #error Check setting of R4600_V1_HIT_CACHEOP_WAR for your platform 113 #endif 114 115 116 /* 117 * Writeback and invalidate the primary cache dcache before DMA. 118 * 119 * R4600 v2.0 bug: "The CACHE instructions Hit_Writeback_Inv_D, 120 * Hit_Writeback_D, Hit_Invalidate_D and Create_Dirty_Exclusive_D will only 121 * operate correctly if the internal data cache refill buffer is empty. These 122 * CACHE instructions should be separated from any potential data cache miss 123 * by a load instruction to an uncached address to empty the response buffer." 124 * (Revision 2.0 device errata from IDT available on http://www.idt.com/ 125 * in .pdf format.) 126 */ 127 #ifndef R4600_V2_HIT_CACHEOP_WAR 128 #error Check setting of R4600_V2_HIT_CACHEOP_WAR for your platform 129 #endif 130 131 /* 132 * When an interrupt happens on a CP0 register read instruction, CPU may 133 * lock up or read corrupted values of CP0 registers after it enters 134 * the exception handler. 135 * 136 * This workaround makes sure that we read a "safe" CP0 register as the 137 * first thing in the exception handler, which breaks one of the 138 * pre-conditions for this problem. 139 */ 140 #ifndef R5432_CP0_INTERRUPT_WAR 141 #error Check setting of R5432_CP0_INTERRUPT_WAR for your platform 142 #endif 143 144 /* 145 * Workaround for the Sibyte M3 errata the text of which can be found at 146 * 147 * http://sibyte.broadcom.com/hw/bcm1250/docs/pass2errata.txt 148 * 149 * This will enable the use of a special TLB refill handler which does a 150 * consistency check on the information in c0_badvaddr and c0_entryhi and 151 * will just return and take the exception again if the information was 152 * found to be inconsistent. 153 */ 154 #ifndef BCM1250_M3_WAR 155 #error Check setting of BCM1250_M3_WAR for your platform 156 #endif 157 158 /* 159 * This is a DUART workaround related to glitches around register accesses 160 */ 161 #ifndef SIBYTE_1956_WAR 162 #error Check setting of SIBYTE_1956_WAR for your platform 163 #endif 164 165 /* 166 * Fill buffers not flushed on CACHE instructions 167 * 168 * Hit_Invalidate_I cacheops invalidate an icache line but the refill 169 * for that line can get stale data from the fill buffer instead of 170 * accessing memory if the previous icache miss was also to that line. 171 * 172 * Workaround: generate an icache refill from a different line 173 * 174 * Affects: 175 * MIPS 4K RTL revision <3.0, PRID revision <4 176 */ 177 #ifndef MIPS4K_ICACHE_REFILL_WAR 178 #error Check setting of MIPS4K_ICACHE_REFILL_WAR for your platform 179 #endif 180 181 /* 182 * Missing implicit forced flush of evictions caused by CACHE 183 * instruction 184 * 185 * Evictions caused by a CACHE instructions are not forced on to the 186 * bus. The BIU gives higher priority to fetches than to the data from 187 * the eviction buffer and no collision detection is performed between 188 * fetches and pending data from the eviction buffer. 189 * 190 * Workaround: Execute a SYNC instruction after the cache instruction 191 * 192 * Affects: 193 * MIPS 5Kc,5Kf RTL revision <2.3, PRID revision <8 194 * MIPS 20Kc RTL revision <4.0, PRID revision <? 195 */ 196 #ifndef MIPS_CACHE_SYNC_WAR 197 #error Check setting of MIPS_CACHE_SYNC_WAR for your platform 198 #endif 199 200 /* 201 * From TX49/H2 manual: "If the instruction (i.e. CACHE) is issued for 202 * the line which this instruction itself exists, the following 203 * operation is not guaranteed." 204 * 205 * Workaround: do two phase flushing for Index_Invalidate_I 206 */ 207 #ifndef TX49XX_ICACHE_INDEX_INV_WAR 208 #error Check setting of TX49XX_ICACHE_INDEX_INV_WAR for your platform 209 #endif 210 211 /* 212 * On the RM9000 there is a problem which makes the CreateDirtyExclusive 213 * eache operation unusable on SMP systems. 214 */ 215 #ifndef RM9000_CDEX_SMP_WAR 216 #error Check setting of RM9000_CDEX_SMP_WAR for your platform 217 #endif 218 219 /* 220 * The RM7000 processors and the E9000 cores have a bug (though PMC-Sierra 221 * opposes it being called that) where invalid instructions in the same 222 * I-cache line worth of instructions being fetched may case spurious 223 * exceptions. 224 */ 225 #ifndef ICACHE_REFILLS_WORKAROUND_WAR 226 #error Check setting of ICACHE_REFILLS_WORKAROUND_WAR for your platform 227 #endif 228 229 /* 230 * On the R10000 upto version 2.6 (not sure about 2.7) there is a bug that 231 * may cause ll / sc and lld / scd sequences to execute non-atomically. 232 */ 233 #ifndef R10000_LLSC_WAR 234 #error Check setting of R10000_LLSC_WAR for your platform 235 #endif 236 237 /* 238 * 34K core erratum: "Problems Executing the TLBR Instruction" 239 */ 240 #ifndef MIPS34K_MISSED_ITLB_WAR 241 #error Check setting of MIPS34K_MISSED_ITLB_WAR for your platform 242 #endif 243 244 #endif /* _ASM_WAR_H */ 245
