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/include/asm/bitops.h b/arch/arm/include/asm/bitops.h
index 7b1bb2b..af54ed1 100644 (file)
--- a/arch/arm/include/asm/bitops.h
+++ b/arch/arm/include/asm/bitops.h
@@ -148,15 +148,19 @@ ____atomic_test_and_change_bit(unsigned int bit, volatile unsigned long *p)
  * Note that bit 0 is defined to be 32-bit word bit 0, not byte 0 bit 0.
  */
 
+/*
+ * 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 (file)
--- 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 bd00551..a9d9d15 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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)