diff options
| author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
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| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 | 
| commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
| tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/lib/findbit.S | |
| download | olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz olio-linux-3.10-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip  | |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/arm/lib/findbit.S')
| -rw-r--r-- | arch/arm/lib/findbit.S | 168 | 
1 files changed, 168 insertions, 0 deletions
diff --git a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S new file mode 100644 index 00000000000..f055d56ea68 --- /dev/null +++ b/arch/arm/lib/findbit.S @@ -0,0 +1,168 @@ +/* + *  linux/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. + */ +#include <linux/linkage.h> +#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	 +		beq	3f +		mov	r2, #0 +1:		ldrb	r3, [r0, r2, lsr #3] +		eors	r3, r3, #0xff		@ invert bits +		bne	.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 +		RETINSTR(mov,pc,lr) + +/* + * Purpose  : Find next 'zero' bit + * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset) + */ +ENTRY(_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	.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); + */ +ENTRY(_find_first_bit_le) +		teq	r1, #0	 +		beq	3f +		mov	r2, #0 +1:		ldrb	r3, [r0, r2, lsr #3] +		movs	r3, r3 +		bne	.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 +		RETINSTR(mov,pc,lr) + +/* + * Purpose  : Find next 'one' bit + * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset) + */ +ENTRY(_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	.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__ + +ENTRY(_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	.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 +		RETINSTR(mov,pc,lr) + +ENTRY(_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	.found +		orr	r2, r2, #7		@ if zero, then no bits here +		add	r2, r2, #1		@ align bit pointer +		b	2b			@ loop for next bit + +ENTRY(_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	.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 +		RETINSTR(mov,pc,lr) + +ENTRY(_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	.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. + */ +.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 +		RETINSTR(mov,pc,lr) +  |