On Wed, Jun 18, 2008 at 07:34:05AM -0500, Menon, Nishanth wrote:
Add linux-like bitops definitions - this is based on 2.6.25 rc5 kernel
I haven't looked at it, but I guess you need these for the following patches. It would be better to first introduce generic bitops. Otherwise we end up with i2c only working on arm.
Sascha
Signed-off-by: Nishanth Menon x0nishan@ti.com
arch/arm/lib/Makefile | 1 arch/arm/lib/findbit.S | 181 +++++++++++++++++++++++++++++++++++++++++++++++ include/asm-arm/bitops.h | 86 +++++++++++++++++++++- 3 files changed, 265 insertions(+), 3 deletions(-)
Index: u-boot-v2.git/arch/arm/lib/findbit.S
--- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ u-boot-v2.git/arch/arm/lib/findbit.S 2008-06-17 17:01:06.000000000 -0500 @@ -0,0 +1,181 @@ +/**
- @file
- @brief common bitops
- */
+/*
- Originally from Linux kernel
- arch/arm/lib/findbit.S
- Copyright (C) 1995-2000 Russell King
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License version 2 as
- published by the Free Software Foundation.
- 16th March 2001 - John Ripley jripley@sonicblue.com
- Fixed so that "size" is an exclusive not an inclusive quantity.
- All users of these functions expect exclusive sizes, and may
- also call with zero size.
- Reworked by rmk.
- */
.text+/*
- Purpose : Find a 'zero' bit
- Prototype: int find_first_zero_bit(void *addr, unsigned int maxbit);
- */
.globl _find_first_zero_bit_le;+_find_first_zero_bit_le:
teq r1, #0beq 3fmov r2, #0+1: ldrb r3, [r0, r2, lsr #3]
eors r3, r3, #0xff @ invert bitsbne .L_found @ any now set - found zero bitadd r2, r2, #8 @ next bit pointer+2: cmp r2, r1 @ any more?
blo 1b+3: mov r0, r1 @ no free bits
mov pc, lr+/*
- Purpose : Find next 'zero' bit
- Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit,
int offset)- */
.globl _find_next_zero_bit_le;+_find_next_zero_bit_le:
teq r1, #0beq 3bands ip, r2, #7beq 1b @ If new byte, goto old routineldrb r3, [r0, r2, lsr #3]eor r3, r3, #0xff @ now looking for a 1 bitmovs r3, r3, lsr ip @ shift off unused bitsbne .L_foundorr r2, r2, #7 @ if zero, then no bits hereadd r2, r2, #1 @ align bit pointerb 2b @ loop for next bit+/*
- Purpose : Find a 'one' bit
- Prototype: int find_first_bit(const unsigned long *addr, unsigned int maxbit)
- */
.globl _find_first_bit_le;+_find_first_bit_le:
teq r1, #0beq 3fmov r2, #0+1: ldrb r3, [r0, r2, lsr #3]
movs r3, r3bne .L_found @ any now set - found zero bitadd r2, r2, #8 @ next bit pointer+2: cmp r2, r1 @ any more?
blo 1b+3: mov r0, r1 @ no free bits
mov pc, lr+/*
- Purpose : Find next 'one' bit
- Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit,
int offset)- */
.globl _find_next_bit_le;+_find_next_bit_le:
teq r1, #0beq 3bands ip, r2, #7beq 1b @ If new byte, goto old routineldrb r3, [r0, r2, lsr #3]movs r3, r3, lsr ip @ shift off unused bitsbne .L_foundorr r2, r2, #7 @ if zero, then no bits hereadd r2, r2, #1 @ align bit pointerb 2b @ loop for next bit+#ifdef __ARMEB__
.globl _find_first_zero_bit_be;+_find_first_zero_bit_be:
teq r1, #0beq 3fmov r2, #0+1: eor r3, r2, #0x18 @ big endian byte ordering
ldrb r3, [r0, r3, lsr #3]eors r3, r3, #0xff @ invert bitsbne .L_found @ any now set - found zero bitadd r2, r2, #8 @ next bit pointer+2: cmp r2, r1 @ any more?
blo 1b+3: mov r0, r1 @ no free bits
mov pc, lr.globl _find_next_zero_bit_be;+_find_next_zero_bit_be:
teq r1, #0beq 3bands ip, r2, #7beq 1b @ If new byte, goto old routineeor r3, r2, #0x18 @ big endian byte orderingldrb r3, [r0, r3, lsr #3]eor r3, r3, #0xff @ now looking for a 1 bitmovs r3, r3, lsr ip @ shift off unused bitsbne .L_foundorr r2, r2, #7 @ if zero, then no bits hereadd r2, r2, #1 @ align bit pointerb 2b @ loop for next bit.globl _find_first_bit_be;+_find_first_bit_be:
teq r1, #0beq 3fmov r2, #0+1: eor r3, r2, #0x18 @ big endian byte ordering
ldrb r3, [r0, r3, lsr #3]movs r3, r3bne .L_found @ any now set - found zero bitadd r2, r2, #8 @ next bit pointer+2: cmp r2, r1 @ any more?
blo 1b+3: mov r0, r1 @ no free bits
mov pc, lr.globl _find_next_bit_be;+_find_next_bit_be:
teq r1, #0beq 3bands ip, r2, #7beq 1b @ If new byte, goto old routineeor r3, r2, #0x18 @ big endian byte orderingldrb r3, [r0, r3, lsr #3]movs r3, r3, lsr ip @ shift off unused bitsbne .L_foundorr r2, r2, #7 @ if zero, then no bits hereadd r2, r2, #1 @ align bit pointerb 2b @ loop for next bit+#endif
+/*
- One or more bits in the LSB of r3 are assumed to be set.
- */
+.L_found: +#if __LINUX_ARM_ARCH__ >= 5
rsb r1, r3, #0and r3, r3, r1clz r3, r3rsb r3, r3, #31add r0, r2, r3+#else
tst r3, #0x0faddeq r2, r2, #4movne r3, r3, lsl #4tst r3, #0x30addeq r2, r2, #2movne r3, r3, lsl #2tst r3, #0x40addeq r2, r2, #1mov r0, r2+#endif
mov pc, lrIndex: u-boot-v2.git/arch/arm/lib/Makefile
--- u-boot-v2.git.orig/arch/arm/lib/Makefile 2008-06-17 16:52:31.000000000 -0500 +++ u-boot-v2.git/arch/arm/lib/Makefile 2008-06-17 17:01:06.000000000 -0500 @@ -8,6 +8,7 @@ obj-y += _udivsi3.o obj-y += _umodsi3.o obj-y += _lshrdi3.o +obj-y += findbit.o obj-y += arm.o obj-$(CONFIG_MODULES) += module.o extra-$(CONFIG_GENERIC_LINKER_SCRIPT) += u-boot.lds Index: u-boot-v2.git/include/asm-arm/bitops.h =================================================================== --- u-boot-v2.git.orig/include/asm-arm/bitops.h 2008-06-17 16:52:31.000000000 -0500 +++ u-boot-v2.git/include/asm-arm/bitops.h 2008-06-17 17:01:06.000000000 -0500 @@ -75,9 +75,6 @@ return oldval & mask; }
-extern int find_first_zero_bit(void * addr, unsigned size); -extern int find_next_zero_bit(void * addr, int size, int offset);
/*
- This routine doesn't need to be atomic.
*/ @@ -86,6 +83,44 @@ return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7)); }
+#ifndef __ARMEB__ +/*
- These are the little endian definitions.
- */
+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); +extern int _find_next_bit_le(const unsigned long *p, int size, int offset); +#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) +#define find_next_bit(p, sz, off) _find_next_bit_le(p, sz, off)
+#define WORD_BITOFF_TO_LE(x) ((x))
+#else
+/*
- These are the big endian definitions.
- */
+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); +extern int _find_next_bit_be(const unsigned long *p, int size, int offset); +#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) +#define find_next_bit(p, sz, off) _find_next_bit_be(p, sz, off)
+#define WORD_BITOFF_TO_LE(x) ((x) ^ 0x18)
+#endif
+#if (defined(__LINUX_ARM_ARCH__) && (__LINUX_ARM_ARCH__ < 5))
/*
- ffz = Find First Zero in word. Undefined if no zero exists,
- so code should check against ~0UL first..
@@ -112,6 +147,51 @@
#define ffs(x) generic_ffs(x)
+#else
+static inline int constant_fls(int x) +{
int r = 32;if (!x)return 0;if (!(x & 0xffff0000u)) {x <<= 16;r -= 16;}if (!(x & 0xff000000u)) {x <<= 8;r -= 8;}if (!(x & 0xf0000000u)) {x <<= 4;r -= 4;}if (!(x & 0xc0000000u)) {x <<= 2;r -= 2;}if (!(x & 0x80000000u)) {x <<= 1;r -= 1;}return r;+}
+/*
- On ARMv5 and above those functions can be implemented around
- the clz instruction for much better code efficiency.
- */
+#define fls(x) \
(__builtin_constant_p(x) ? constant_fls(x) : \({ int __r; asm("clz\t%0, %1" : "=r"(__r) : "r"(x) : "cc"); 32-__r; }))+#define ffs(x) ({ unsigned long __t = (x); fls(__t &-__t); }) +#define __ffs(x) (ffs(x) - 1) +#define ffz(x) __ffs(~(x))
+#endif
/*
- hweightN: returns the hamming weight (i.e. the number
- of bits set) of a N-bit word