[PATCH 02/14] ARM: bitops: switch set/clear/change bitops to use ldrex/strex
Russell King - ARM Linux
linux at arm.linux.org.uk
Mon Jan 17 14:21:40 EST 2011
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.
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
arch/arm/include/asm/bitops.h | 60 +++++++++++++++--------------------------
arch/arm/kernel/armksyms.c | 18 ++++--------
arch/arm/lib/bitops.h | 38 +++++++++++++------------
arch/arm/lib/changebit.S | 10 +-----
arch/arm/lib/clearbit.S | 11 +------
arch/arm/lib/setbit.S | 11 +------
arch/arm/lib/testchangebit.S | 9 ++----
arch/arm/lib/testclearbit.S | 9 ++----
arch/arm/lib/testsetbit.S | 9 ++----
9 files changed, 63 insertions(+), 112 deletions(-)
diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h
index 7b1bb2b..af54ed1 100644
--- a/arch/arm/include/asm/bitops.h
+++ b/arch/arm/include/asm/bitops.h
@@ -149,14 +149,18 @@ ____atomic_test_and_change_bit(unsigned int bit, volatile unsigned long *p)
*/
/*
+ * Native endian assembly bitops. nr = 0 -> word 0 bit 0.
+ */
+extern void _set_bit(int nr, volatile unsigned long * p);
+extern void _clear_bit(int nr, volatile unsigned long * p);
+extern void _change_bit(int nr, volatile unsigned long * p);
+extern int _test_and_set_bit(int nr, volatile unsigned long * p);
+extern int _test_and_clear_bit(int nr, volatile unsigned long * p);
+extern int _test_and_change_bit(int nr, volatile unsigned long * p);
+
+/*
* Little endian assembly bitops. nr = 0 -> byte 0 bit 0.
*/
-extern void _set_bit_le(int nr, volatile unsigned long * p);
-extern void _clear_bit_le(int nr, volatile unsigned long * p);
-extern void _change_bit_le(int nr, volatile unsigned long * p);
-extern int _test_and_set_bit_le(int nr, volatile unsigned long * p);
-extern int _test_and_clear_bit_le(int nr, volatile unsigned long * p);
-extern int _test_and_change_bit_le(int nr, volatile unsigned long * p);
extern int _find_first_zero_bit_le(const void * p, unsigned size);
extern int _find_next_zero_bit_le(const void * p, int size, int offset);
extern int _find_first_bit_le(const unsigned long *p, unsigned size);
@@ -165,12 +169,6 @@ extern int _find_next_bit_le(const unsigned long *p, int size, int offset);
/*
* Big endian assembly bitops. nr = 0 -> byte 3 bit 0.
*/
-extern void _set_bit_be(int nr, volatile unsigned long * p);
-extern void _clear_bit_be(int nr, volatile unsigned long * p);
-extern void _change_bit_be(int nr, volatile unsigned long * p);
-extern int _test_and_set_bit_be(int nr, volatile unsigned long * p);
-extern int _test_and_clear_bit_be(int nr, volatile unsigned long * p);
-extern int _test_and_change_bit_be(int nr, volatile unsigned long * p);
extern int _find_first_zero_bit_be(const void * p, unsigned size);
extern int _find_next_zero_bit_be(const void * p, int size, int offset);
extern int _find_first_bit_be(const unsigned long *p, unsigned size);
@@ -180,33 +178,26 @@ extern int _find_next_bit_be(const unsigned long *p, int size, int offset);
/*
* The __* form of bitops are non-atomic and may be reordered.
*/
-#define ATOMIC_BITOP_LE(name,nr,p) \
- (__builtin_constant_p(nr) ? \
- ____atomic_##name(nr, p) : \
- _##name##_le(nr,p))
-
-#define ATOMIC_BITOP_BE(name,nr,p) \
- (__builtin_constant_p(nr) ? \
- ____atomic_##name(nr, p) : \
- _##name##_be(nr,p))
+#define ATOMIC_BITOP(name,nr,p) \
+ (__builtin_constant_p(nr) ? ____atomic_##name(nr, p) : _##name(nr,p))
#else
-#define ATOMIC_BITOP_LE(name,nr,p) _##name##_le(nr,p)
-#define ATOMIC_BITOP_BE(name,nr,p) _##name##_be(nr,p)
+#define ATOMIC_BITOP(name,nr,p) _##name(nr,p)
#endif
-#define NONATOMIC_BITOP(name,nr,p) \
- (____nonatomic_##name(nr, p))
+/*
+ * Native endian atomic definitions.
+ */
+#define set_bit(nr,p) ATOMIC_BITOP(set_bit,nr,p)
+#define clear_bit(nr,p) ATOMIC_BITOP(clear_bit,nr,p)
+#define change_bit(nr,p) ATOMIC_BITOP(change_bit,nr,p)
+#define test_and_set_bit(nr,p) ATOMIC_BITOP(test_and_set_bit,nr,p)
+#define test_and_clear_bit(nr,p) ATOMIC_BITOP(test_and_clear_bit,nr,p)
+#define test_and_change_bit(nr,p) ATOMIC_BITOP(test_and_change_bit,nr,p)
#ifndef __ARMEB__
/*
* These are the little endian, atomic definitions.
*/
-#define set_bit(nr,p) ATOMIC_BITOP_LE(set_bit,nr,p)
-#define clear_bit(nr,p) ATOMIC_BITOP_LE(clear_bit,nr,p)
-#define change_bit(nr,p) ATOMIC_BITOP_LE(change_bit,nr,p)
-#define test_and_set_bit(nr,p) ATOMIC_BITOP_LE(test_and_set_bit,nr,p)
-#define test_and_clear_bit(nr,p) ATOMIC_BITOP_LE(test_and_clear_bit,nr,p)
-#define test_and_change_bit(nr,p) ATOMIC_BITOP_LE(test_and_change_bit,nr,p)
#define find_first_zero_bit(p,sz) _find_first_zero_bit_le(p,sz)
#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_le(p,sz,off)
#define find_first_bit(p,sz) _find_first_bit_le(p,sz)
@@ -215,16 +206,9 @@ extern int _find_next_bit_be(const unsigned long *p, int size, int offset);
#define WORD_BITOFF_TO_LE(x) ((x))
#else
-
/*
* These are the big endian, atomic definitions.
*/
-#define set_bit(nr,p) ATOMIC_BITOP_BE(set_bit,nr,p)
-#define clear_bit(nr,p) ATOMIC_BITOP_BE(clear_bit,nr,p)
-#define change_bit(nr,p) ATOMIC_BITOP_BE(change_bit,nr,p)
-#define test_and_set_bit(nr,p) ATOMIC_BITOP_BE(test_and_set_bit,nr,p)
-#define test_and_clear_bit(nr,p) ATOMIC_BITOP_BE(test_and_clear_bit,nr,p)
-#define test_and_change_bit(nr,p) ATOMIC_BITOP_BE(test_and_change_bit,nr,p)
#define find_first_zero_bit(p,sz) _find_first_zero_bit_be(p,sz)
#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_be(p,sz,off)
#define find_first_bit(p,sz) _find_first_bit_be(p,sz)
diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index e5e1e53..d5d4185 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -140,24 +140,18 @@ EXPORT_SYMBOL(__aeabi_ulcmp);
#endif
/* bitops */
-EXPORT_SYMBOL(_set_bit_le);
-EXPORT_SYMBOL(_test_and_set_bit_le);
-EXPORT_SYMBOL(_clear_bit_le);
-EXPORT_SYMBOL(_test_and_clear_bit_le);
-EXPORT_SYMBOL(_change_bit_le);
-EXPORT_SYMBOL(_test_and_change_bit_le);
+EXPORT_SYMBOL(_set_bit);
+EXPORT_SYMBOL(_test_and_set_bit);
+EXPORT_SYMBOL(_clear_bit);
+EXPORT_SYMBOL(_test_and_clear_bit);
+EXPORT_SYMBOL(_change_bit);
+EXPORT_SYMBOL(_test_and_change_bit);
EXPORT_SYMBOL(_find_first_zero_bit_le);
EXPORT_SYMBOL(_find_next_zero_bit_le);
EXPORT_SYMBOL(_find_first_bit_le);
EXPORT_SYMBOL(_find_next_bit_le);
#ifdef __ARMEB__
-EXPORT_SYMBOL(_set_bit_be);
-EXPORT_SYMBOL(_test_and_set_bit_be);
-EXPORT_SYMBOL(_clear_bit_be);
-EXPORT_SYMBOL(_test_and_clear_bit_be);
-EXPORT_SYMBOL(_change_bit_be);
-EXPORT_SYMBOL(_test_and_change_bit_be);
EXPORT_SYMBOL(_find_first_zero_bit_be);
EXPORT_SYMBOL(_find_next_zero_bit_be);
EXPORT_SYMBOL(_find_first_bit_be);
diff --git a/arch/arm/lib/bitops.h b/arch/arm/lib/bitops.h
index 910d599..f8a2bd3 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
tst r1, #3
strne r1, [r1, -r1] @ 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
tst r1, #3
strne r1, [r1, -r1] @ 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
tst r1, #3
strne r1, [r1, -r1] @ 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
tst r1, #3
strne r1, [r1, -r1] @ 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)
--
1.6.2.5
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