/* SPDX-License-Identifier: GPL-2.0-only *//* * linux/arch/arm/lib/delay.S * * Copyright (C) 1995, 1996 Russell King */#include <linux/linkage.h>#include <asm/assembler.h>#include <asm/delay.h> .text .LC0: .word loops_per_jiffy.LC1: .word UDELAY_MULT /* * loops = r0 * HZ * loops_per_jiffy / 1000000 * * r0 <= 2000 * HZ <= 1000 */ ENTRY(__loop_udelay) ldr r2, .LC1 mul r0, r2, r0 @ r0 = delay_us * UDELAY_MULTENTRY(__loop_const_udelay) @ 0 <= r0 <= 0xfffffaf0 ldr r2, .LC0 ldr r2, [r2] umull r1, r0, r2, r0 @ r0-r1 = r0 * loops_per_jiffy adds r1, r1, #0xffffffff @ rounding up ... adcs r0, r0, r0 @ and right shift by 31 reteq lr .align 3 @ Delay routineENTRY(__loop_delay) subs r0, r0, #1#if 0 retls lr subs r0, r0, #1 retls lr subs r0, r0, #1 retls lr subs r0, r0, #1 retls lr subs r0, r0, #1 retls lr subs r0, r0, #1 retls lr subs r0, r0, #1 retls lr subs r0, r0, #1#endif bhi __loop_delay ret lrENDPROC(__loop_udelay)ENDPROC(__loop_const_udelay)ENDPROC(__loop_delay)
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/lib/delay.S
*
* Copyright (C) 1995, 1996 Russell King
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/delay.h>
.text
.LC0: .word loops_per_jiffy
.LC1: .word UDELAY_MULT
/*
* loops = r0 * HZ * loops_per_jiffy / 1000000
*
* r0 <= 2000
* HZ <= 1000
*/
ENTRY(__loop_udelay)
ldr r2, .LC1
mul r0, r2, r0 @ r0 = delay_us * UDELAY_MULT
ENTRY(__loop_const_udelay) @ 0 <= r0 <= 0xfffffaf0
ldr r2, .LC0
ldr r2, [r2]
umull r1, r0, r2, r0 @ r0-r1 = r0 * loops_per_jiffy
adds r1, r1, #0xffffffff @ rounding up ...
adcs r0, r0, r0 @ and right shift by 31
reteq lr
.align 3
@ Delay routine
ENTRY(__loop_delay)
subs r0, r0, #1
#if 0
retls lr
subs r0, r0, #1
retls lr
subs r0, r0, #1
retls lr
subs r0, r0, #1
retls lr
subs r0, r0, #1
retls lr
subs r0, r0, #1
retls lr
subs r0, r0, #1
retls lr
subs r0, r0, #1
#endif
bhi __loop_delay
ret lr
ENDPROC(__loop_udelay)
ENDPROC(__loop_const_udelay)
ENDPROC(__loop_delay)