Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 *  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     .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)
 */
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     .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);
 */
ENTRY(_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)
 */
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     .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__

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     .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

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     .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

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     .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

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     .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