/* * 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 /* * 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