1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * linux/arch/arm/lib/delay.S
4 *
5 * Copyright (C) 1995, 1996 Russell King
6 */
7 #include <linux/linkage.h>
8 #include <linux/cfi_types.h>
9 #include <asm/assembler.h>
10 #include <asm/delay.h>
11
12 #ifdef CONFIG_ARCH_RPC
13 .arch armv4
14 #endif
15
16 .text
17
18 .LC0: .word loops_per_jiffy
19 .LC1: .word UDELAY_MULT
20
21 /*
22 * loops = r0 * HZ * loops_per_jiffy / 1000000
23 *
24 * r0 <= 2000
25 * HZ <= 1000
26 */
27
28 SYM_TYPED_FUNC_START(__loop_udelay)
29 ldr r2, .LC1
30 mul r0, r2, r0
31 b __loop_const_udelay
32 SYM_FUNC_END(__loop_udelay)
33
34 SYM_TYPED_FUNC_START(__loop_const_udelay)
35 ldr r2, .LC0
36 ldr r2, [r2]
37 umull r1, r0, r2, r0
38 adds r1, r1, #0xffffffff
39 adcs r0, r0, r0
40 reteq lr
41 b __loop_delay
42 SYM_FUNC_END(__loop_const_udelay)
43
44 .align 3
45
46 @ Delay routine
47 SYM_TYPED_FUNC_START(__loop_delay)
48 subs r0, r0, #1
49 #if 0
50 retls lr
51 subs r0, r0, #1
52 retls lr
53 subs r0, r0, #1
54 retls lr
55 subs r0, r0, #1
56 retls lr
57 subs r0, r0, #1
58 retls lr
59 subs r0, r0, #1
60 retls lr
61 subs r0, r0, #1
62 retls lr
63 subs r0, r0, #1
64 #endif
65 bhi __loop_delay
66 ret lr
67 SYM_FUNC_END(__loop_delay)
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