Add linux-like bitops definitions - this is based on 2.6.25 rc5 kernel
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, #0 + beq 3f + mov r2, #0 +1: ldrb r3, [r0, r2, lsr #3] + 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 + 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, #0 + beq 3b + ands ip, r2, #7 + beq 1b @ If new byte, goto old routine + ldrb r3, [r0, r2, lsr #3] + 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 + +/* + * 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, #0 + beq 3f + mov r2, #0 +1: ldrb r3, [r0, r2, lsr #3] + 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 + 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, #0 + beq 3b + ands ip, r2, #7 + beq 1b @ If new byte, goto old routine + ldrb r3, [r0, r2, lsr #3] + 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 + +#ifdef __ARMEB__ + + .globl _find_first_zero_bit_be; +_find_first_zero_bit_be: + teq r1, #0 + beq 3f + mov r2, #0 +1: eor r3, r2, #0x18 @ big endian byte ordering + ldrb r3, [r0, r3, lsr #3] + 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 + mov pc, lr + + .globl _find_next_zero_bit_be; +_find_next_zero_bit_be: + teq r1, #0 + beq 3b + ands ip, r2, #7 + beq 1b @ If new byte, goto old routine + eor r3, r2, #0x18 @ big endian byte ordering + ldrb r3, [r0, r3, lsr #3] + 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 + + .globl _find_first_bit_be; +_find_first_bit_be: + teq r1, #0 + beq 3f + mov r2, #0 +1: eor r3, r2, #0x18 @ big endian byte ordering + ldrb r3, [r0, r3, lsr #3] + 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 + mov pc, lr + + .globl _find_next_bit_be; +_find_next_bit_be: + teq r1, #0 + beq 3b + ands ip, r2, #7 + beq 1b @ If new byte, goto old routine + eor r3, r2, #0x18 @ big endian byte ordering + ldrb r3, [r0, r3, lsr #3] + 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 + +#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, #0 + and r3, r3, r1 + clz r3, r3 + rsb r3, r3, #31 + add r0, r2, r3 +#else + tst r3, #0x0f + addeq r2, r2, #4 + movne r3, r3, lsl #4 + tst r3, #0x30 + addeq r2, r2, #2 + movne r3, r3, lsl #2 + tst r3, #0x40 + addeq r2, r2, #1 + mov r0, r2 +#endif + mov pc, lr + Index: 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