luckfox-pico-sdk/sysdrv/source/kernel/arch/arm/lib/findbit.S
luckfox-eng29 8f34c2760d project:build.sh: Added fastboot support; custom modifications to U-Boot and kernel implemented using patches.
project:cfg:BoardConfig_IPC: Added fastboot BoardConfig file and firmware post-scripts, distinguishing between
the BoardConfigs for Luckfox Pico Pro and Luckfox Pico Max. project:app: Added fastboot_client and rk_smart_door
for quick boot applications; updated rkipc app to adapt to the latest media library. media:samples: Added more
usage examples. media:rockit: Fixed bugs; removed support for retrieving data frames from VPSS. media:isp:
Updated rkaiq library and related tools to support connection to RKISP_Tuner. sysdrv:Makefile: Added support for
compiling drv_ko on Luckfox Pico Ultra W using Ubuntu; added support for custom root filesystem.
sysdrv:tools:board: Updated Buildroot optional mirror sources, updated some software versions, and stored device
tree files and configuration files that undergo multiple modifications for U-Boot and kernel separately.
sysdrv:source:mcu: Used RISC-V MCU SDK with RT-Thread system, mainly for initializing camera AE during quick
boot. sysdrv:source:uboot: Added support for fastboot; added high baud rate DDR bin for serial firmware upgrades.
sysdrv:source:kernel: Upgraded to version 5.10.160; increased NPU frequency for RV1106G3; added support for
fastboot.

Signed-off-by: luckfox-eng29 <eng29@luckfox.com>
2024-10-14 09:47:04 +08:00

194 lines
4.7 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/lib/findbit.S
*
* Copyright (C) 1995-2000 Russell King
*
* 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:
ARM( ldrb r3, [r0, r2, lsr #3] )
THUMB( lsr r3, r2, #3 )
THUMB( ldrb r3, [r0, r3] )
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
ret lr
ENDPROC(_find_first_zero_bit_le)
/*
* Purpose : Find next 'zero' bit
* Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset)
*/
ENTRY(_find_next_zero_bit_le)
cmp r2, r1
bhs 3b
ands ip, r2, #7
beq 1b @ If new byte, goto old routine
ARM( ldrb r3, [r0, r2, lsr #3] )
THUMB( lsr r3, r2, #3 )
THUMB( ldrb r3, [r0, r3] )
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
ENDPROC(_find_next_zero_bit_le)
/*
* 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:
ARM( ldrb r3, [r0, r2, lsr #3] )
THUMB( lsr r3, r2, #3 )
THUMB( ldrb r3, [r0, r3] )
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
ret lr
ENDPROC(_find_first_bit_le)
/*
* Purpose : Find next 'one' bit
* Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset)
*/
ENTRY(_find_next_bit_le)
cmp r2, r1
bhs 3b
ands ip, r2, #7
beq 1b @ If new byte, goto old routine
ARM( ldrb r3, [r0, r2, lsr #3] )
THUMB( lsr r3, r2, #3 )
THUMB( ldrb r3, [r0, r3] )
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
ENDPROC(_find_next_bit_le)
#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
ARM( ldrb r3, [r0, r3, lsr #3] )
THUMB( lsr r3, #3 )
THUMB( ldrb r3, [r0, r3] )
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
ret lr
ENDPROC(_find_first_zero_bit_be)
ENTRY(_find_next_zero_bit_be)
cmp r2, r1
bhs 3b
ands ip, r2, #7
beq 1b @ If new byte, goto old routine
eor r3, r2, #0x18 @ big endian byte ordering
ARM( ldrb r3, [r0, r3, lsr #3] )
THUMB( lsr r3, #3 )
THUMB( ldrb r3, [r0, r3] )
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
ENDPROC(_find_next_zero_bit_be)
ENTRY(_find_first_bit_be)
teq r1, #0
beq 3f
mov r2, #0
1: eor r3, r2, #0x18 @ big endian byte ordering
ARM( ldrb r3, [r0, r3, lsr #3] )
THUMB( lsr r3, #3 )
THUMB( ldrb r3, [r0, r3] )
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
ret lr
ENDPROC(_find_first_bit_be)
ENTRY(_find_next_bit_be)
cmp r2, r1
bhs 3b
ands ip, r2, #7
beq 1b @ If new byte, goto old routine
eor r3, r2, #0x18 @ big endian byte ordering
ARM( ldrb r3, [r0, r3, lsr #3] )
THUMB( lsr r3, #3 )
THUMB( ldrb r3, [r0, r3] )
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
ENDPROC(_find_next_bit_be)
#endif
/*
* One or more bits in the LSB of r3 are assumed to be set.
*/
.L_found:
#if __LINUX_ARM_ARCH__ >= 5
rsb r0, r3, #0
and r3, r3, r0
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
cmp r1, r0 @ Clamp to maxbit
movlo r0, r1
ret lr