1 // SPDX-License-Identifier: GPL-2.0-only !! 1 /*
2 /* Copyright Altera Corporation (C) 2014. All !! 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 Maciej W. Rozycki
3 */ 10 */
4 <<
5 #include <linux/module.h> 11 #include <linux/module.h>
6 #include <asm/delay.h> !! 12 #include <linux/param.h>
7 #include <asm/param.h> !! 13 #include <linux/smp.h>
8 #include <asm/processor.h> <<
9 #include <asm/timex.h> <<
10 14
11 void __delay(unsigned long cycles) !! 15 #include <asm/compiler.h>
12 { !! 16 #include <asm/war.h>
13 cycles_t start = get_cycles(); <<
14 17
15 while ((get_cycles() - start) < cycles !! 18 void __delay(unsigned long loops)
16 cpu_relax(); !! 19 {
>> 20 __asm__ __volatile__ (
>> 21 " .set noreorder \n"
>> 22 " .align 3 \n"
>> 23 "1: bnez %0, 1b \n"
>> 24 #if BITS_PER_LONG == 32
>> 25 " subu %0, 1 \n"
>> 26 #else
>> 27 " dsubu %0, 1 \n"
>> 28 #endif
>> 29 " .set reorder \n"
>> 30 : "=r" (loops)
>> 31 : "" (loops));
17 } 32 }
18 EXPORT_SYMBOL(__delay); 33 EXPORT_SYMBOL(__delay);
19 34
20 void __const_udelay(unsigned long xloops) !! 35 /*
21 { !! 36 * Division by multiplication: you don't have to worry about
22 u64 loops; !! 37 * loss of precision.
23 !! 38 *
24 loops = (u64)xloops * loops_per_jiffy !! 39 * Use only for very small delays ( < 1 msec). Should probably use a
25 !! 40 * lookup table, really, as the multiplications take much too long with
26 __delay(loops >> 32); !! 41 * short delays. This is a "reasonable" implementation, though (and the
27 } !! 42 * first constant multiplications gets optimized away if the delay is
28 EXPORT_SYMBOL(__const_udelay); !! 43 * a constant)
>> 44 */
29 45
30 void __udelay(unsigned long usecs) !! 46 void __udelay(unsigned long us)
31 { 47 {
32 __const_udelay(usecs * 0x10C7UL); /* 2 !! 48 unsigned int lpj = raw_current_cpu_data.udelay_val;
>> 49
>> 50 __delay((us * 0x000010c7ull * HZ * lpj) >> 32);
33 } 51 }
34 EXPORT_SYMBOL(__udelay); 52 EXPORT_SYMBOL(__udelay);
35 53
36 void __ndelay(unsigned long nsecs) !! 54 void __ndelay(unsigned long ns)
37 { 55 {
38 __const_udelay(nsecs * 0x5UL); /* 2**3 !! 56 unsigned int lpj = raw_current_cpu_data.udelay_val;
>> 57
>> 58 __delay((ns * 0x00000005ull * HZ * lpj) >> 32);
39 } 59 }
40 EXPORT_SYMBOL(__ndelay); 60 EXPORT_SYMBOL(__ndelay);
41 61
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