summaryrefslogtreecommitdiffstats
path: root/arch/mips/include/asm/war.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/include/asm/war.h')
-rw-r--r--arch/mips/include/asm/war.h244
1 files changed, 244 insertions, 0 deletions
diff --git a/arch/mips/include/asm/war.h b/arch/mips/include/asm/war.h
new file mode 100644
index 0000000..22361d5
--- /dev/null
+++ b/arch/mips/include/asm/war.h
@@ -0,0 +1,244 @@
+/*
+ * 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
+
+/*
+ * On the RM9000 there is a problem which makes the CreateDirtyExclusive
+ * eache operation unusable on SMP systems.
+ */
+#ifndef RM9000_CDEX_SMP_WAR
+#error Check setting of RM9000_CDEX_SMP_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 upto 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 */
OpenPOWER on IntegriCloud