diff options
| author |   Atsushi Nemoto <anemo@mba.ocn.ne.jp> | 2006-02-03 01:34:01 +0900 |
|---|---|---|
| committer |   Ralf Baechle <ralf@linux-mips.org> | 2006-02-07 13:30:26 +0000 |
| commit | c226f2601f55010936f0f3c77ae167a02339f566 (patch) | |
| tree | a0b178eef5c305881beaf0e76c8e82a03b74772d /include/asm-mips/interrupt.h | |
| parent | [MIPS] Fix linker script to work for non-4K page size. (diff) | |
| download | linux-dev-c226f2601f55010936f0f3c77ae167a02339f566.tar.xz linux-dev-c226f2601f55010936f0f3c77ae167a02339f566.zip | |
[MIPS] TX49 MFC0 bug workaround
If mfc0 $12 follows store and the mfc0 is last instruction of a
page and fetching the next instruction causes TLB miss, the result
of the mfc0 might wrongly contain EXL bit.
ERT-TX49H2-027, ERT-TX49H3-012, ERT-TX49HL3-006, ERT-TX49H4-008
Workaround: mask EXL bit of the result or place a nop before mfc0. It
doesn't harm to always clear those bits, so we change the code to do so.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'include/asm-mips/interrupt.h')
| -rw-r--r-- | include/asm-mips/interrupt.h | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/include/asm-mips/interrupt.h b/include/asm-mips/interrupt.h index 0da5818a2d62..774348734fa0 100644 --- a/include/asm-mips/interrupt.h +++ b/include/asm-mips/interrupt.h @@ -47,6 +47,17 @@ static inline void local_irq_enable(void) * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs * no nops at all. */ +/* + * For TX49, operating only IE bit is not enough. + * + * If mfc0 $12 follows store and the mfc0 is last instruction of a + * page and fetching the next instruction causes TLB miss, the result + * of the mfc0 might wrongly contain EXL bit. + * + * ERT-TX49H2-027, ERT-TX49H3-012, ERT-TX49HL3-006, ERT-TX49H4-008 + * + * Workaround: mask EXL bit of the result or place a nop before mfc0. + */ __asm__ ( " .macro local_irq_disable\n" " .set push \n" @@ -55,8 +66,8 @@ __asm__ ( " di \n" #else " mfc0 $1,$12 \n" - " ori $1,1 \n" - " xori $1,1 \n" + " ori $1,0x1f \n" + " xori $1,0x1f \n" " .set noreorder \n" " mtc0 $1,$12 \n" #endif @@ -96,8 +107,8 @@ __asm__ ( " andi \\result, 1 \n" #else " mfc0 \\result, $12 \n" - " ori $1, \\result, 1 \n" - " xori $1, 1 \n" + " ori $1, \\result, 0x1f \n" + " xori $1, 0x1f \n" " .set noreorder \n" " mtc0 $1, $12 \n" #endif @@ -136,8 +147,8 @@ __asm__ ( #else " mfc0 $1, $12 \n" " andi \\flags, 1 \n" - " ori $1, 1 \n" - " xori $1, 1 \n" + " ori $1, 0x1f \n" + " xori $1, 0x1f \n" " or \\flags, $1 \n" " mtc0 \\flags, $12 \n" #endif |