/* SPDX-License-Identifier: GPL-2.0-only */
/*
 *  linux/arch/arm/lib/delay.S
 *
 *  Copyright (C) 1995, 1996 Russell King
 */
#include <linux/linkage.h>
#include <linux/cfi_types.h>
#include <asm/assembler.h>
#include <asm/delay.h>

#ifdef CONFIG_ARCH_RPC
                .arch   armv4
#endif

                .text

.LC0:           .word   loops_per_jiffy
.LC1:           .word   UDELAY_MULT

/*
 * loops = r0 * HZ * loops_per_jiffy / 1000000
 *
 * r0  <= 2000
 * HZ  <= 1000
 */

SYM_TYPED_FUNC_START(__loop_udelay)
                ldr     r2, .LC1
                mul     r0, r2, r0              @ r0 = delay_us * UDELAY_MULT
                b       __loop_const_udelay
SYM_FUNC_END(__loop_udelay)

SYM_TYPED_FUNC_START(__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
                b       __loop_delay
SYM_FUNC_END(__loop_const_udelay)

                .align 3

@ Delay routine
SYM_TYPED_FUNC_START(__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
SYM_FUNC_END(__loop_delay)