1 // SPDX-License-Identifier: GPL-2.0 <<
2 /* 1 /*
3 * Precise Delay Loops for S390 !! 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.
4 * 5 *
5 * Copyright IBM Corp. 1999, 2008 !! 6 * Copyright (C) 1994 by Waldorf Electronics
6 * Author(s): Martin Schwidefsky <schwidefs !! 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
7 */ 10 */
8 <<
9 #include <linux/processor.h> <<
10 #include <linux/delay.h> 11 #include <linux/delay.h>
11 #include <asm/div64.h> !! 12 #include <linux/export.h>
12 #include <asm/timex.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
13 27
14 void __delay(unsigned long loops) 28 void __delay(unsigned long loops)
15 { 29 {
16 /* !! 30 __asm__ __volatile__ (
17 * Loop 'loops' times. Callers must no !! 31 " .set noreorder \n"
18 * amount of time passes before this f !! 32 " .align 3 \n"
19 */ !! 33 "1: bnez %0, 1b \n"
20 asm volatile("0: brct %0,0b" : : "d" ( !! 34 " " __stringify(LONG_SUBU) " %0, %1 \n"
>> 35 " .set reorder \n"
>> 36 : "=r" (loops)
>> 37 : GCC_DADDI_IMM_ASM() (1), "" (loops));
21 } 38 }
22 EXPORT_SYMBOL(__delay); 39 EXPORT_SYMBOL(__delay);
23 40
24 static void delay_loop(unsigned long delta) !! 41 /*
25 { !! 42 * Division by multiplication: you don't have to worry about
26 unsigned long end; !! 43 * loss of precision.
27 !! 44 *
28 end = get_tod_clock_monotonic() + delt !! 45 * Use only for very small delays ( < 1 msec). Should probably use a
29 while (!tod_after(get_tod_clock_monoto !! 46 * lookup table, really, as the multiplications take much too long with
30 cpu_relax(); !! 47 * short delays. This is a "reasonable" implementation, though (and the
31 } !! 48 * first constant multiplications gets optimized away if the delay is
>> 49 * a constant)
>> 50 */
32 51
33 void __udelay(unsigned long usecs) !! 52 void __udelay(unsigned long us)
34 { 53 {
35 delay_loop(usecs << 12); !! 54 unsigned int lpj = raw_current_cpu_data.udelay_val;
>> 55
>> 56 __delay((us * 0x000010c7ull * HZ * lpj) >> 32);
36 } 57 }
37 EXPORT_SYMBOL(__udelay); 58 EXPORT_SYMBOL(__udelay);
38 59
39 void __ndelay(unsigned long nsecs) !! 60 void __ndelay(unsigned long ns)
40 { 61 {
41 nsecs <<= 9; !! 62 unsigned int lpj = raw_current_cpu_data.udelay_val;
42 do_div(nsecs, 125); !! 63
43 delay_loop(nsecs); !! 64 __delay((ns * 0x00000005ull * HZ * lpj) >> 32);
44 } 65 }
45 EXPORT_SYMBOL(__ndelay); 66 EXPORT_SYMBOL(__ndelay);
>> 67
>> 68 #endif
46 69
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