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 #include <asm/war.h>
20
21 #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
22 #define GCC_DADDI_IMM_ASM() "I"
23 #else
24 #define GCC_DADDI_IMM_ASM() "r"
25 #endif
26
__delay(unsigned long loops)27 void __delay(unsigned long loops)
28 {
29 __asm__ __volatile__ (
30 " .set noreorder \n"
31 " .align 3 \n"
32 "1: bnez %0, 1b \n"
33 " " __stringify(LONG_SUBU) " %0, %1 \n"
34 " .set reorder \n"
35 : "=r" (loops)
36 : GCC_DADDI_IMM_ASM() (1), "0" (loops));
37 }
38 EXPORT_SYMBOL(__delay);
39
40 /*
41 * Division by multiplication: you don't have to worry about
42 * loss of precision.
43 *
44 * Use only for very small delays ( < 1 msec). Should probably use a
45 * lookup table, really, as the multiplications take much too long with
46 * short delays. This is a "reasonable" implementation, though (and the
47 * first constant multiplications gets optimized away if the delay is
48 * a constant)
49 */
50
__udelay(unsigned long us)51 void __udelay(unsigned long us)
52 {
53 unsigned int lpj = raw_current_cpu_data.udelay_val;
54
55 __delay((us * 0x000010c7ull * HZ * lpj) >> 32);
56 }
57 EXPORT_SYMBOL(__udelay);
58
__ndelay(unsigned long ns)59 void __ndelay(unsigned long ns)
60 {
61 unsigned int lpj = raw_current_cpu_data.udelay_val;
62
63 __delay((ns * 0x00000005ull * HZ * lpj) >> 32);
64 }
65 EXPORT_SYMBOL(__ndelay);
66