1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994 by Waldorf Electronics
7 * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 * Copyright (C) 2007, 2014 Maciej W. Rozycki
10 */
11#include <linux/delay.h>
12#include <linux/export.h>
13#include <linux/param.h>
14#include <linux/smp.h>
15#include <linux/stringify.h>
16
17#include <asm/asm.h>
18#include <asm/compiler.h>
19
20#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
21#define GCC_DADDI_IMM_ASM() "I"
22#else
23#define GCC_DADDI_IMM_ASM() "r"
24#endif
25
26#ifndef CONFIG_HAVE_PLAT_DELAY
27
28void __delay(unsigned long loops)
29{
30	__asm__ __volatile__ (
31	"	.set	noreorder				\n"
32	"	.align	3					\n"
33	"1:	bnez	%0, 1b					\n"
34	"	 " __stringify(LONG_SUBU) "	%0, %1		\n"
35	"	.set	reorder					\n"
36	: "=r" (loops)
37	: GCC_DADDI_IMM_ASM() (1), "0" (loops));
38}
39EXPORT_SYMBOL(__delay);
40
41/*
42 * Division by multiplication: you don't have to worry about
43 * loss of precision.
44 *
45 * Use only for very small delays ( < 1 msec).	Should probably use a
46 * lookup table, really, as the multiplications take much too long with
47 * short delays.  This is a "reasonable" implementation, though (and the
48 * first constant multiplications gets optimized away if the delay is
49 * a constant)
50 */
51
52void __udelay(unsigned long us)
53{
54	unsigned int lpj = raw_current_cpu_data.udelay_val;
55
56	__delay((us * 0x000010c7ull * HZ * lpj) >> 32);
57}
58EXPORT_SYMBOL(__udelay);
59
60void __ndelay(unsigned long ns)
61{
62	unsigned int lpj = raw_current_cpu_data.udelay_val;
63
64	__delay((ns * 0x00000005ull * HZ * lpj) >> 32);
65}
66EXPORT_SYMBOL(__ndelay);
67
68#endif
69