| 12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667 |
- /* 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)
|
