mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-11-20 08:38:24 +08:00
20d60d9973
This is the gereric part of R4000/R4400 errata workarounds. They include compiler and assembler support as well as some source code modifications to address the problems with some combinations of multiply/divide+shift instructions as well as the daddi and daddiu instructions. Changes included are as follows: 1. New Kconfig options to select workarounds by platforms as necessary. 2. Arch top-level Makefile to pass necessary options to the compiler; also incompatible configurations are detected (-mno-sym32 unsupported as horribly intrusive for little gain). 3. Bug detection updated and shuffled -- the multiply/divide+shift problem is lethal enough that if not worked around it makes the kernel crash in time_init() because of a division by zero; the daddiu erratum might also trigger early potentially, though I have not observed it. On the other hand the daddi detection code requires the exception subsystem to have been initialised (and is there mainly for information). 4. r4k_daddiu_bug() added so that the existence of the erratum can be queried by code at the run time as necessary; useful for generated code like TLB fault and copy/clear page handlers. 5. __udelay() updated as it uses multiplication in inline assembly. Note that -mdaddi requires modified toolchain (which has been maintained by myself and available from my site for ~4years now -- versions covered are GCC 2.95.4 - 4.1.2 and binutils from 2.13 onwards). The -mfix-r4000 and -mfix-r4400 have been standard for a while though. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
245 lines
8.0 KiB
C
245 lines
8.0 KiB
C
/*
|
|
* 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 */
|