ARM: bitops: switch set/clear/change bitops to use ldrex/strex
Switch the set/clear/change bitops to use the word-based exclusive
operations, which are only present in a wider range of ARM architectures
than the byte-based exclusive operations.
Tested record:
- Nicolas Pitre: ext3,rw,le
- Sourav Poddar: nfs,le
- Will Deacon: ext3,rw,le
- Tony Lindgren: ext3+nfs,le
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/lib/bitops.h b/arch/arm/lib/bitops.h
index bd00551f..a9d9d15 100644
--- a/arch/arm/lib/bitops.h
+++ b/arch/arm/lib/bitops.h
@@ -1,15 +1,15 @@
-
-#if __LINUX_ARM_ARCH__ >= 6 && defined(CONFIG_CPU_32v6K)
+#if __LINUX_ARM_ARCH__ >= 6
.macro bitop, instr
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
mov r2, #1
- and r3, r0, #7 @ Get bit offset
- add r1, r1, r0, lsr #3 @ Get byte offset
+ and r3, r0, #31 @ Get bit offset
+ mov r0, r0, lsr #5
+ add r1, r1, r0, lsl #2 @ Get word offset
mov r3, r2, lsl r3
-1: ldrexb r2, [r1]
+1: ldrex r2, [r1]
\instr r2, r2, r3
- strexb r0, r2, [r1]
+ strex r0, r2, [r1]
cmp r0, #0
bne 1b
mov pc, lr
@@ -18,15 +18,16 @@
.macro testop, instr, store
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
- and r3, r0, #7 @ Get bit offset
mov r2, #1
- add r1, r1, r0, lsr #3 @ Get byte offset
+ and r3, r0, #31 @ Get bit offset
+ mov r0, r0, lsr #5
+ add r1, r1, r0, lsl #2 @ Get word offset
mov r3, r2, lsl r3 @ create mask
smp_dmb
-1: ldrexb r2, [r1]
+1: ldrex r2, [r1]
ands r0, r2, r3 @ save old value of bit
- \instr r2, r2, r3 @ toggle bit
- strexb ip, r2, [r1]
+ \instr r2, r2, r3 @ toggle bit
+ strex ip, r2, [r1]
cmp ip, #0
bne 1b
smp_dmb
@@ -38,13 +39,14 @@
.macro bitop, instr
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
- and r2, r0, #7
+ and r2, r0, #31
+ mov r0, r0, lsr #5
mov r3, #1
mov r3, r3, lsl r2
save_and_disable_irqs ip
- ldrb r2, [r1, r0, lsr #3]
+ ldr r2, [r1, r0, lsl #2]
\instr r2, r2, r3
- strb r2, [r1, r0, lsr #3]
+ str r2, [r1, r0, lsl #2]
restore_irqs ip
mov pc, lr
.endm
@@ -60,11 +62,11 @@
.macro testop, instr, store
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
- add r1, r1, r0, lsr #3
- and r3, r0, #7
- mov r0, #1
+ and r3, r0, #31
+ mov r0, r0, lsr #5
save_and_disable_irqs ip
- ldrb r2, [r1]
+ ldr r2, [r1, r0, lsl #2]!
+ mov r0, #1
tst r2, r0, lsl r3
\instr r2, r2, r0, lsl r3
\store r2, [r1]
diff --git a/arch/arm/lib/changebit.S b/arch/arm/lib/changebit.S
index 80f3115..68ed5b6 100644
--- a/arch/arm/lib/changebit.S
+++ b/arch/arm/lib/changebit.S
@@ -12,12 +12,6 @@
#include "bitops.h"
.text
-/* Purpose : Function to change a bit
- * Prototype: int change_bit(int bit, void *addr)
- */
-ENTRY(_change_bit_be)
- eor r0, r0, #0x18 @ big endian byte ordering
-ENTRY(_change_bit_le)
+ENTRY(_change_bit)
bitop eor
-ENDPROC(_change_bit_be)
-ENDPROC(_change_bit_le)
+ENDPROC(_change_bit)
diff --git a/arch/arm/lib/clearbit.S b/arch/arm/lib/clearbit.S
index 1a63e43..4c04c3b 100644
--- a/arch/arm/lib/clearbit.S
+++ b/arch/arm/lib/clearbit.S
@@ -12,13 +12,6 @@
#include "bitops.h"
.text
-/*
- * Purpose : Function to clear a bit
- * Prototype: int clear_bit(int bit, void *addr)
- */
-ENTRY(_clear_bit_be)
- eor r0, r0, #0x18 @ big endian byte ordering
-ENTRY(_clear_bit_le)
+ENTRY(_clear_bit)
bitop bic
-ENDPROC(_clear_bit_be)
-ENDPROC(_clear_bit_le)
+ENDPROC(_clear_bit)
diff --git a/arch/arm/lib/setbit.S b/arch/arm/lib/setbit.S
index 1dd7176..bbee5c6 100644
--- a/arch/arm/lib/setbit.S
+++ b/arch/arm/lib/setbit.S
@@ -12,13 +12,6 @@
#include "bitops.h"
.text
-/*
- * Purpose : Function to set a bit
- * Prototype: int set_bit(int bit, void *addr)
- */
-ENTRY(_set_bit_be)
- eor r0, r0, #0x18 @ big endian byte ordering
-ENTRY(_set_bit_le)
+ENTRY(_set_bit)
bitop orr
-ENDPROC(_set_bit_be)
-ENDPROC(_set_bit_le)
+ENDPROC(_set_bit)
diff --git a/arch/arm/lib/testchangebit.S b/arch/arm/lib/testchangebit.S
index 5c98dc5..15a4d43 100644
--- a/arch/arm/lib/testchangebit.S
+++ b/arch/arm/lib/testchangebit.S
@@ -12,9 +12,6 @@
#include "bitops.h"
.text
-ENTRY(_test_and_change_bit_be)
- eor r0, r0, #0x18 @ big endian byte ordering
-ENTRY(_test_and_change_bit_le)
- testop eor, strb
-ENDPROC(_test_and_change_bit_be)
-ENDPROC(_test_and_change_bit_le)
+ENTRY(_test_and_change_bit)
+ testop eor, str
+ENDPROC(_test_and_change_bit)
diff --git a/arch/arm/lib/testclearbit.S b/arch/arm/lib/testclearbit.S
index 543d709..521b66b 100644
--- a/arch/arm/lib/testclearbit.S
+++ b/arch/arm/lib/testclearbit.S
@@ -12,9 +12,6 @@
#include "bitops.h"
.text
-ENTRY(_test_and_clear_bit_be)
- eor r0, r0, #0x18 @ big endian byte ordering
-ENTRY(_test_and_clear_bit_le)
- testop bicne, strneb
-ENDPROC(_test_and_clear_bit_be)
-ENDPROC(_test_and_clear_bit_le)
+ENTRY(_test_and_clear_bit)
+ testop bicne, strne
+ENDPROC(_test_and_clear_bit)
diff --git a/arch/arm/lib/testsetbit.S b/arch/arm/lib/testsetbit.S
index 0b3f390..1c98cc2 100644
--- a/arch/arm/lib/testsetbit.S
+++ b/arch/arm/lib/testsetbit.S
@@ -12,9 +12,6 @@
#include "bitops.h"
.text
-ENTRY(_test_and_set_bit_be)
- eor r0, r0, #0x18 @ big endian byte ordering
-ENTRY(_test_and_set_bit_le)
- testop orreq, streqb
-ENDPROC(_test_and_set_bit_be)
-ENDPROC(_test_and_set_bit_le)
+ENTRY(_test_and_set_bit)
+ testop orreq, streq
+ENDPROC(_test_and_set_bit)