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Diffstat (limited to 'arch/mips/include/asm/war.h')
| -rw-r--r-- | arch/mips/include/asm/war.h | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/arch/mips/include/asm/war.h b/arch/mips/include/asm/war.h new file mode 100644 index 000000000..9344e247a --- /dev/null +++ b/arch/mips/include/asm/war.h @@ -0,0 +1,236 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2002, 2004, 2007 by Ralf Baechle + * Copyright (C) 2007 Maciej W. Rozycki + */ +#ifndef _ASM_WAR_H +#define _ASM_WAR_H + +#include <war.h> + +/* + * Work around certain R4000 CPU errata (as implemented by GCC): + * + * - A double-word or a variable shift may give an incorrect result + * if executed immediately after starting an integer division: + * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", + * erratum #28 + * "MIPS R4000MC Errata, Processor Revision 2.2 and 3.0", erratum + * #19 + * + * - A double-word or a variable shift may give an incorrect result + * if executed while an integer multiplication is in progress: + * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", + * errata #16 & #28 + * + * - An integer division may give an incorrect result if started in + * a delay slot of a taken branch or a jump: + * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", + * erratum #52 + */ +#ifdef CONFIG_CPU_R4000_WORKAROUNDS +#define R4000_WAR 1 +#else +#define R4000_WAR 0 +#endif + +/* + * Work around certain R4400 CPU errata (as implemented by GCC): + * + * - A double-word or a variable shift may give an incorrect result + * if executed immediately after starting an integer division: + * "MIPS R4400MC Errata, Processor Revision 1.0", erratum #10 + * "MIPS R4400MC Errata, Processor Revision 2.0 & 3.0", erratum #4 + */ +#ifdef CONFIG_CPU_R4400_WORKAROUNDS +#define R4400_WAR 1 +#else +#define R4400_WAR 0 +#endif + +/* + * Work around the "daddi" and "daddiu" CPU errata: + * + * - The `daddi' instruction fails to trap on overflow. + * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", + * erratum #23 + * + * - The `daddiu' instruction can produce an incorrect result. + * "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", + * erratum #41 + * "MIPS R4000MC Errata, Processor Revision 2.2 and 3.0", erratum + * #15 + * "MIPS R4400PC/SC Errata, Processor Revision 1.0", erratum #7 + * "MIPS R4400MC Errata, Processor Revision 1.0", erratum #5 + */ +#ifdef CONFIG_CPU_DADDI_WORKAROUNDS +#define DADDI_WAR 1 +#else +#define DADDI_WAR 0 +#endif + +/* + * Another R4600 erratum. Due to the lack of errata information the exact + * technical details aren't known. I've experimentally found that disabling + * interrupts during indexed I-cache flushes seems to be sufficient to deal + * with the issue. + */ +#ifndef R4600_V1_INDEX_ICACHEOP_WAR +#error Check setting of R4600_V1_INDEX_ICACHEOP_WAR for your platform +#endif + +/* + * Pleasures of the R4600 V1.x. Cite from the IDT R4600 V1.7 errata: + * + * 18. The CACHE instructions Hit_Writeback_Invalidate_D, Hit_Writeback_D, + * Hit_Invalidate_D and Create_Dirty_Excl_D should only be + * executed if there is no other dcache activity. If the dcache is + * accessed for another instruction immeidately preceding when these + * cache instructions are executing, it is possible that the dcache + * tag match outputs used by these cache instructions will be + * incorrect. These cache instructions should be preceded by at least + * four instructions that are not any kind of load or store + * instruction. + * + * This is not allowed: lw + * nop + * nop + * nop + * cache Hit_Writeback_Invalidate_D + * + * This is allowed: lw + * nop + * nop + * nop + * nop + * cache Hit_Writeback_Invalidate_D + */ +#ifndef R4600_V1_HIT_CACHEOP_WAR +#error Check setting of R4600_V1_HIT_CACHEOP_WAR for your platform +#endif + + +/* + * Writeback and invalidate the primary cache dcache before DMA. + * + * R4600 v2.0 bug: "The CACHE instructions Hit_Writeback_Inv_D, + * Hit_Writeback_D, Hit_Invalidate_D and Create_Dirty_Exclusive_D will only + * operate correctly if the internal data cache refill buffer is empty. These + * CACHE instructions should be separated from any potential data cache miss + * by a load instruction to an uncached address to empty the response buffer." + * (Revision 2.0 device errata from IDT available on http://www.idt.com/ + * in .pdf format.) + */ +#ifndef R4600_V2_HIT_CACHEOP_WAR +#error Check setting of R4600_V2_HIT_CACHEOP_WAR for your platform +#endif + +/* + * When an interrupt happens on a CP0 register read instruction, CPU may + * lock up or read corrupted values of CP0 registers after it enters + * the exception handler. + * + * This workaround makes sure that we read a "safe" CP0 register as the + * first thing in the exception handler, which breaks one of the + * pre-conditions for this problem. + */ +#ifndef R5432_CP0_INTERRUPT_WAR +#error Check setting of R5432_CP0_INTERRUPT_WAR for your platform +#endif + +/* + * Workaround for the Sibyte M3 errata the text of which can be found at + * + * http://sibyte.broadcom.com/hw/bcm1250/docs/pass2errata.txt + * + * This will enable the use of a special TLB refill handler which does a + * consistency check on the information in c0_badvaddr and c0_entryhi and + * will just return and take the exception again if the information was + * found to be inconsistent. + */ +#ifndef BCM1250_M3_WAR +#error Check setting of BCM1250_M3_WAR for your platform +#endif + +/* + * This is a DUART workaround related to glitches around register accesses + */ +#ifndef SIBYTE_1956_WAR +#error Check setting of SIBYTE_1956_WAR for your platform +#endif + +/* + * Fill buffers not flushed on CACHE instructions + * + * Hit_Invalidate_I cacheops invalidate an icache line but the refill + * for that line can get stale data from the fill buffer instead of + * accessing memory if the previous icache miss was also to that line. + * + * Workaround: generate an icache refill from a different line + * + * Affects: + * MIPS 4K RTL revision <3.0, PRID revision <4 + */ +#ifndef MIPS4K_ICACHE_REFILL_WAR +#error Check setting of MIPS4K_ICACHE_REFILL_WAR for your platform +#endif + +/* + * Missing implicit forced flush of evictions caused by CACHE + * instruction + * + * Evictions caused by a CACHE instructions are not forced on to the + * bus. The BIU gives higher priority to fetches than to the data from + * the eviction buffer and no collision detection is performed between + * fetches and pending data from the eviction buffer. + * + * Workaround: Execute a SYNC instruction after the cache instruction + * + * Affects: + * MIPS 5Kc,5Kf RTL revision <2.3, PRID revision <8 + * MIPS 20Kc RTL revision <4.0, PRID revision <? + */ +#ifndef MIPS_CACHE_SYNC_WAR +#error Check setting of MIPS_CACHE_SYNC_WAR for your platform +#endif + +/* + * From TX49/H2 manual: "If the instruction (i.e. CACHE) is issued for + * the line which this instruction itself exists, the following + * operation is not guaranteed." + * + * Workaround: do two phase flushing for Index_Invalidate_I + */ +#ifndef TX49XX_ICACHE_INDEX_INV_WAR +#error Check setting of TX49XX_ICACHE_INDEX_INV_WAR for your platform +#endif + +/* + * The RM7000 processors and the E9000 cores have a bug (though PMC-Sierra + * opposes it being called that) where invalid instructions in the same + * I-cache line worth of instructions being fetched may case spurious + * exceptions. + */ +#ifndef ICACHE_REFILLS_WORKAROUND_WAR +#error Check setting of ICACHE_REFILLS_WORKAROUND_WAR for your platform +#endif + +/* + * On the R10000 up to version 2.6 (not sure about 2.7) there is a bug that + * may cause ll / sc and lld / scd sequences to execute non-atomically. + */ +#ifndef R10000_LLSC_WAR +#error Check setting of R10000_LLSC_WAR for your platform +#endif + +/* + * 34K core erratum: "Problems Executing the TLBR Instruction" + */ +#ifndef MIPS34K_MISSED_ITLB_WAR +#error Check setting of MIPS34K_MISSED_ITLB_WAR for your platform +#endif + +#endif /* _ASM_WAR_H */ |