[PATCH v2 07/10] ARM: mm: improve do_ldrd_abort macro

[Russell King]

Improve the do_ldrd_abort macro code - firstly, it inefficiently checks
for the LDRD encoding by doing a multi-stage test of various bits.  This
can be simplified by generating a mask, bitmasking the instruction and
then comparing the result.

Secondly, we want to be able to test the result rather than branching
to do_DataAbort, so remove the branch at the end and rename the macro
to 'teq_ldrd' to reflect it's new usage.  teq_ldrd macro returns 'eq'
if the instruction was a LDRD.

Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
 arch/arm/mm/abort-ev5t.S  |  3 ++-
 arch/arm/mm/abort-ev5tj.S |  3 ++-
 arch/arm/mm/abort-ev6.S   |  3 ++-
 arch/arm/mm/abort-macro.S | 13 +++++--------
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/arch/arm/mm/abort-ev5t.S b/arch/arm/mm/abort-ev5t.S
index a0908d4653a3..c913031b79cc 100644
--- a/arch/arm/mm/abort-ev5t.S
+++ b/arch/arm/mm/abort-ev5t.S
@@ -22,7 +22,8 @@ ENTRY(v5t_early_abort)
 	do_thumb_abort fsr=r1, pc=r4, psr=r5, tmp=r3
 	ldreq	r3, [r4]			@ read aborted ARM instruction
 	bic	r1, r1, #1 << 11		@ clear bits 11 of FSR
-	do_ldrd_abort tmp=ip, insn=r3
+	teq_ldrd tmp=ip, insn=r3		@ insn was LDRD?
+	beq	do_DataAbort			@ yes
 	tst	r3, #1 << 20			@ check write
 	orreq	r1, r1, #1 << 11
 	b	do_DataAbort
diff --git a/arch/arm/mm/abort-ev5tj.S b/arch/arm/mm/abort-ev5tj.S
index 4006b7a61264..1b80d71adb0f 100644
--- a/arch/arm/mm/abort-ev5tj.S
+++ b/arch/arm/mm/abort-ev5tj.S
@@ -24,7 +24,8 @@ ENTRY(v5tj_early_abort)
 	bne	do_DataAbort
 	do_thumb_abort fsr=r1, pc=r4, psr=r5, tmp=r3
 	ldreq	r3, [r4]			@ read aborted ARM instruction
-	do_ldrd_abort tmp=ip, insn=r3
+	teq_ldrd tmp=ip, insn=r3		@ insn was LDRD?
+	beq	do_DataAbort			@ yes
 	tst	r3, #1 << 20			@ L = 0 -> write
 	orreq	r1, r1, #1 << 11		@ yes.
 	b	do_DataAbort
diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
index 8c48c5c22a33..113704f30e9f 100644
--- a/arch/arm/mm/abort-ev6.S
+++ b/arch/arm/mm/abort-ev6.S
@@ -34,7 +34,8 @@ ENTRY(v6_early_abort)
 	ldr	r3, [r4]			@ read aborted ARM instruction
  ARM_BE8(rev	r3, r3)
 
-	do_ldrd_abort tmp=ip, insn=r3
+	teq_ldrd tmp=ip, insn=r3		@ insn was LDRD?
+	beq	do_DataAbort			@ yes
 	tst	r3, #1 << 20			@ L = 0 -> write
 	orreq	r1, r1, #1 << 11		@ yes.
 #endif
diff --git a/arch/arm/mm/abort-macro.S b/arch/arm/mm/abort-macro.S
index 2cbf68ef0e83..50d6c0a900b1 100644
--- a/arch/arm/mm/abort-macro.S
+++ b/arch/arm/mm/abort-macro.S
@@ -29,12 +29,9 @@ not_thumb:
  *   [7:4] == 1101
  *    [20] == 0
  */
-	.macro	do_ldrd_abort, tmp, insn
-	tst	\insn, #0x0e100000		@ [27:25,20] == 0
-	bne	not_ldrd
-	and	\tmp, \insn, #0x000000f0	@ [7:4] == 1101
-	cmp	\tmp, #0x000000d0
-	beq	do_DataAbort
-not_ldrd:
+	.macro	teq_ldrd, tmp, insn
+	mov	\tmp, #0x0e100000
+	orr	\tmp, #0x000000f0
+	and	\tmp, \insn, \tmp
+	teq	\tmp, #0x000000d0
 	.endm
-
-- 
2.1.0