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List:       linuxppc-embedded
Subject:    [PATCH 3/3] powerpc/lib/sstep: Fix fixed-point shift instructions that set CA32
From:       Sandipan Das <sandipan () linux ! vnet ! ibm ! com>
Date:       2017-09-29 5:56:10
Message-ID: 20170929054410.12600-3-sandipan () linux ! vnet ! ibm ! com
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This fixes the emulated behaviour of existing fixed-point shift right
algebraic instructions that are supposed to set both the CA and CA32
bits of XER when running on a system that is compliant with POWER ISA
v3.0 independent of whether the system is executing in 32-bit mode or
64-bit mode. The following instructions are affected:
  * Shift Right Algebraic Word Immediate (srawi[.])
  * Shift Right Algebraic Word (sraw[.])
  * Shift Right Algebraic Doubleword Immediate (sradi[.])
  * Shift Right Algebraic Doubleword (srad[.])

Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
---
 arch/powerpc/lib/sstep.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index fe1910733e55..5118110c3983 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -1804,6 +1804,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 				op->xerval |= XER_CA;
 			else
 				op->xerval &= ~XER_CA;
+			set_ca32(op, op->xerval & XER_CA);
 			goto logical_done;
 
 		case 824:	/* srawi */
@@ -1816,6 +1817,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 				op->xerval |= XER_CA;
 			else
 				op->xerval &= ~XER_CA;
+			set_ca32(op, op->xerval & XER_CA);
 			goto logical_done;
 
 #ifdef __powerpc64__
@@ -1845,6 +1847,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 				op->xerval |= XER_CA;
 			else
 				op->xerval &= ~XER_CA;
+			set_ca32(op, op->xerval & XER_CA);
 			goto logical_done;
 
 		case 826:	/* sradi with sh_5 = 0 */
@@ -1858,6 +1861,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
 				op->xerval |= XER_CA;
 			else
 				op->xerval &= ~XER_CA;
+			set_ca32(op, op->xerval & XER_CA);
 			goto logical_done;
 #endif /* __powerpc64__ */
 
-- 
2.13.5

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