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authorAtsushi Nemoto <anemo@mba.ocn.ne.jp>2006-02-02 11:34:01 -0500
committerRalf Baechle <ralf@linux-mips.org>2006-02-07 08:30:26 -0500
commitc226f2601f55010936f0f3c77ae167a02339f566 (patch)
treea0b178eef5c305881beaf0e76c8e82a03b74772d /include/asm-mips
parentdbee90b7f90df6398f0877cd38dfaa76addb0619 (diff)
[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')
-rw-r--r--include/asm-mips/interrupt.h23
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)
47 * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs 47 * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
48 * no nops at all. 48 * no nops at all.
49 */ 49 */
50/*
51 * For TX49, operating only IE bit is not enough.
52 *
53 * If mfc0 $12 follows store and the mfc0 is last instruction of a
54 * page and fetching the next instruction causes TLB miss, the result
55 * of the mfc0 might wrongly contain EXL bit.
56 *
57 * ERT-TX49H2-027, ERT-TX49H3-012, ERT-TX49HL3-006, ERT-TX49H4-008
58 *
59 * Workaround: mask EXL bit of the result or place a nop before mfc0.
60 */
50__asm__ ( 61__asm__ (
51 " .macro local_irq_disable\n" 62 " .macro local_irq_disable\n"
52 " .set push \n" 63 " .set push \n"
@@ -55,8 +66,8 @@ __asm__ (
55 " di \n" 66 " di \n"
56#else 67#else
57 " mfc0 $1,$12 \n" 68 " mfc0 $1,$12 \n"
58 " ori $1,1 \n" 69 " ori $1,0x1f \n"
59 " xori $1,1 \n" 70 " xori $1,0x1f \n"
60 " .set noreorder \n" 71 " .set noreorder \n"
61 " mtc0 $1,$12 \n" 72 " mtc0 $1,$12 \n"
62#endif 73#endif
@@ -96,8 +107,8 @@ __asm__ (
96 " andi \\result, 1 \n" 107 " andi \\result, 1 \n"
97#else 108#else
98 " mfc0 \\result, $12 \n" 109 " mfc0 \\result, $12 \n"
99 " ori $1, \\result, 1 \n" 110 " ori $1, \\result, 0x1f \n"
100 " xori $1, 1 \n" 111 " xori $1, 0x1f \n"
101 " .set noreorder \n" 112 " .set noreorder \n"
102 " mtc0 $1, $12 \n" 113 " mtc0 $1, $12 \n"
103#endif 114#endif
@@ -136,8 +147,8 @@ __asm__ (
136#else 147#else
137 " mfc0 $1, $12 \n" 148 " mfc0 $1, $12 \n"
138 " andi \\flags, 1 \n" 149 " andi \\flags, 1 \n"
139 " ori $1, 1 \n" 150 " ori $1, 0x1f \n"
140 " xori $1, 1 \n" 151 " xori $1, 0x1f \n"
141 " or \\flags, $1 \n" 152 " or \\flags, $1 \n"
142 " mtc0 \\flags, $12 \n" 153 " mtc0 \\flags, $12 \n"
143#endif 154#endif