linux/arch/unicore32/lib/findbit.S
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  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

  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 #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00

98 lines
2.2 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/unicore32/lib/findbit.S
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*/
#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)
cxor.a r1, #0
beq 3f
mov r2, #0
1: ldb r3, [r0+], r2 >> #3
xor.a r3, r3, #0xff @ invert bits
bne .L_found @ any now set - found zero bit
add r2, r2, #8 @ next bit pointer
2: csub.a r2, r1 @ any more?
bub 1b
3: mov r0, r1 @ no free bits
mov pc, lr
ENDPROC(find_first_zero_bit)
/*
* Purpose : Find next 'zero' bit
* Prototype: int find_next_zero_bit
* (void *addr, unsigned int maxbit, int offset)
*/
ENTRY(find_next_zero_bit)
cxor.a r1, #0
beq 3b
and.a ip, r2, #7
beq 1b @ If new byte, goto old routine
ldb r3, [r0+], r2 >> #3
xor r3, r3, #0xff @ now looking for a 1 bit
mov.a r3, r3 >> ip @ shift off unused bits
bne .L_found
or 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)
/*
* Purpose : Find a 'one' bit
* Prototype: int find_first_bit
* (const unsigned long *addr, unsigned int maxbit);
*/
ENTRY(find_first_bit)
cxor.a r1, #0
beq 3f
mov r2, #0
1: ldb r3, [r0+], r2 >> #3
mov.a r3, r3
bne .L_found @ any now set - found zero bit
add r2, r2, #8 @ next bit pointer
2: csub.a r2, r1 @ any more?
bub 1b
3: mov r0, r1 @ no free bits
mov pc, lr
ENDPROC(find_first_bit)
/*
* Purpose : Find next 'one' bit
* Prototype: int find_next_zero_bit
* (void *addr, unsigned int maxbit, int offset)
*/
ENTRY(find_next_bit)
cxor.a r1, #0
beq 3b
and.a ip, r2, #7
beq 1b @ If new byte, goto old routine
ldb r3, [r0+], r2 >> #3
mov.a r3, r3 >> ip @ shift off unused bits
bne .L_found
or 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)
/*
* One or more bits in the LSB of r3 are assumed to be set.
*/
.L_found:
rsub r1, r3, #0
and r3, r3, r1
cntlz r3, r3
rsub r3, r3, #31
add r0, r2, r3
mov pc, lr