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authorRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2022-08-11 16:53:41 +0200
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2022-11-14 13:00:58 +0100
commit2953a3e187e054a4cfba4190a2037dc16b327372 (patch)
tree891b573875b4db880f99e1357e1d9edb3941ceea /arch/arm/lib
parentARM: findbit: provide more efficient ARMv7 implementation (diff)
downloadlinux-2953a3e187e054a4cfba4190a2037dc16b327372.tar.xz
linux-2953a3e187e054a4cfba4190a2037dc16b327372.zip
ARM: findbit: convert to macros
Since the pairs of _find_first and _find_next functions are pretty similar, use macros to generate this code. This commit does not change the generated code. Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/lib')
-rw-r--r--arch/arm/lib/findbit.S158
1 files changed, 42 insertions, 116 deletions
diff --git a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S
index 256e095d490b..8280f66d38a5 100644
--- a/arch/arm/lib/findbit.S
+++ b/arch/arm/lib/findbit.S
@@ -14,155 +14,81 @@
#include <asm/assembler.h>
.text
-/*
- * Purpose : Find a 'zero' bit
- * Prototype: int find_first_zero_bit(void *addr, unsigned int maxbit);
- */
-ENTRY(_find_first_zero_bit_le)
- teq r1, #0
+ .macro find_first, endian, set, name
+ENTRY(_find_first_\name\()bit_\endian)
+ teq r1, #0
beq 3f
mov r2, #0
1:
+ .ifc \endian, be
+ eor r3, r2, #0x18
+ ARM( ldrb r3, [r0, r3, lsr #3] )
+ THUMB( lsr r3, #3 )
+ THUMB( ldrb r3, [r0, r3] )
+ .else
ARM( ldrb r3, [r0, r2, lsr #3] )
THUMB( lsr r3, r2, #3 )
THUMB( ldrb r3, [r0, r3] )
+ .endif
+ .ifeq \set
eors r3, r3, #0xff @ invert bits
+ .else
+ movs r3, r3
+ .endif
bne .L_found @ any now set - found zero bit
add r2, r2, #8 @ next bit pointer
2: cmp r2, r1 @ any more?
blo 1b
3: mov r0, r1 @ no free bits
ret lr
-ENDPROC(_find_first_zero_bit_le)
+ENDPROC(_find_first_\name\()bit_\endian)
+ .endm
-/*
- * Purpose : Find next 'zero' bit
- * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset)
- */
-ENTRY(_find_next_zero_bit_le)
+ .macro find_next, endian, set, name
+ENTRY(_find_next_\name\()bit_\endian)
cmp r2, r1
bhs 3b
ands ip, r2, #7
beq 1b @ If new byte, goto old routine
+ .ifc \endian, be
+ eor r3, r2, #0x18
+ ARM( ldrb r3, [r0, r3, lsr #3] )
+ THUMB( lsr r3, #3 )
+ THUMB( ldrb r3, [r0, r3] )
+ .else
ARM( ldrb r3, [r0, r2, lsr #3] )
THUMB( lsr r3, r2, #3 )
THUMB( ldrb r3, [r0, r3] )
+ .endif
+ .ifeq \set
eor r3, r3, #0xff @ now looking for a 1 bit
+ .endif
movs r3, r3, lsr ip @ shift off unused bits
bne .L_found
orr r2, r2, #7 @ if zero, then no bits here
add r2, r2, #1 @ align bit pointer
b 2b @ loop for next bit
-ENDPROC(_find_next_zero_bit_le)
+ENDPROC(_find_next_\name\()bit_\endian)
+ .endm
-/*
- * Purpose : Find a 'one' bit
- * Prototype: int find_first_bit(const unsigned long *addr, unsigned int maxbit);
- */
-ENTRY(_find_first_bit_le)
- teq r1, #0
- beq 3f
- mov r2, #0
-1:
- ARM( ldrb r3, [r0, r2, lsr #3] )
- THUMB( lsr r3, r2, #3 )
- THUMB( ldrb r3, [r0, r3] )
- movs r3, r3
- bne .L_found @ any now set - found zero bit
- add r2, r2, #8 @ next bit pointer
-2: cmp r2, r1 @ any more?
- blo 1b
-3: mov r0, r1 @ no free bits
- ret lr
-ENDPROC(_find_first_bit_le)
+ .macro find_bit, endian, set, name
+ find_first \endian, \set, \name
+ find_next \endian, \set, \name
+ .endm
-/*
- * Purpose : Find next 'one' bit
- * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset)
- */
-ENTRY(_find_next_bit_le)
- cmp r2, r1
- bhs 3b
- ands ip, r2, #7
- beq 1b @ If new byte, goto old routine
- ARM( ldrb r3, [r0, r2, lsr #3] )
- THUMB( lsr r3, r2, #3 )
- THUMB( ldrb r3, [r0, r3] )
- movs r3, r3, lsr ip @ shift off unused bits
- bne .L_found
- orr r2, r2, #7 @ if zero, then no bits here
- add r2, r2, #1 @ align bit pointer
- b 2b @ loop for next bit
-ENDPROC(_find_next_bit_le)
+/* _find_first_zero_bit_le and _find_next_zero_bit_le */
+ find_bit le, 0, zero_
-#ifdef __ARMEB__
+/* _find_first_bit_le and _find_next_bit_le */
+ find_bit le, 1
-ENTRY(_find_first_zero_bit_be)
- teq r1, #0
- beq 3f
- mov r2, #0
-1: eor r3, r2, #0x18 @ big endian byte ordering
- ARM( ldrb r3, [r0, r3, lsr #3] )
- THUMB( lsr r3, #3 )
- THUMB( ldrb r3, [r0, r3] )
- eors r3, r3, #0xff @ invert bits
- bne .L_found @ any now set - found zero bit
- add r2, r2, #8 @ next bit pointer
-2: cmp r2, r1 @ any more?
- blo 1b
-3: mov r0, r1 @ no free bits
- ret lr
-ENDPROC(_find_first_zero_bit_be)
+#ifdef __ARMEB__
-ENTRY(_find_next_zero_bit_be)
- cmp r2, r1
- bhs 3b
- ands ip, r2, #7
- beq 1b @ If new byte, goto old routine
- eor r3, r2, #0x18 @ big endian byte ordering
- ARM( ldrb r3, [r0, r3, lsr #3] )
- THUMB( lsr r3, #3 )
- THUMB( ldrb r3, [r0, r3] )
- eor r3, r3, #0xff @ now looking for a 1 bit
- movs r3, r3, lsr ip @ shift off unused bits
- bne .L_found
- orr r2, r2, #7 @ if zero, then no bits here
- add r2, r2, #1 @ align bit pointer
- b 2b @ loop for next bit
-ENDPROC(_find_next_zero_bit_be)
+/* _find_first_zero_bit_be and _find_next_zero_bit_be */
+ find_bit be, 0, zero_
-ENTRY(_find_first_bit_be)
- teq r1, #0
- beq 3f
- mov r2, #0
-1: eor r3, r2, #0x18 @ big endian byte ordering
- ARM( ldrb r3, [r0, r3, lsr #3] )
- THUMB( lsr r3, #3 )
- THUMB( ldrb r3, [r0, r3] )
- movs r3, r3
- bne .L_found @ any now set - found zero bit
- add r2, r2, #8 @ next bit pointer
-2: cmp r2, r1 @ any more?
- blo 1b
-3: mov r0, r1 @ no free bits
- ret lr
-ENDPROC(_find_first_bit_be)
-
-ENTRY(_find_next_bit_be)
- cmp r2, r1
- bhs 3b
- ands ip, r2, #7
- beq 1b @ If new byte, goto old routine
- eor r3, r2, #0x18 @ big endian byte ordering
- ARM( ldrb r3, [r0, r3, lsr #3] )
- THUMB( lsr r3, #3 )
- THUMB( ldrb r3, [r0, r3] )
- movs r3, r3, lsr ip @ shift off unused bits
- bne .L_found
- orr r2, r2, #7 @ if zero, then no bits here
- add r2, r2, #1 @ align bit pointer
- b 2b @ loop for next bit
-ENDPROC(_find_next_bit_be)
+/* _find_first_bit_be and _find_next_bit_be */
+ find_bit be, 1
#endif