Release 4.14 arch/microblaze/include/asm/delay.h

/*
 * include/asm-microblaze/delay.h
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2008 Michal Simek
 * Copyright (C) 2007 John Williams
 * Copyright (C) 2006 Atmark Techno, Inc.
 */

#ifndef _ASM_MICROBLAZE_DELAY_H

#define _ASM_MICROBLAZE_DELAY_H

#include <linux/param.h>



static inline void __delay(unsigned long loops)
{
	asm volatile ("# __delay             \n\t"           \
                        "1: addi        %0, %0, -1\t\n"         \
                        "bneid  %0, 1b          \t\n"           \
                        "nop                    \t\n"
                        : "=r" (loops)
                        : "0" (loops));
}

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/*
 * Note that 19 * 226 == 4294 ==~ 2^32 / 10^6, so
 * loops = (4294 * usecs * loops_per_jiffy * HZ) / 2^32.
 *
 * The mul instruction gives us loops = (a * b) / 2^32.
 * We choose a = usecs * 19 * HZ and b = loops_per_jiffy * 226
 * because this lets us support a wide range of HZ and
 * loops_per_jiffy values without either a or b overflowing 2^32.
 * Thus we need usecs * HZ <= (2^32 - 1) / 19 = 226050910 and
 * loops_per_jiffy <= (2^32 - 1) / 226 = 19004280
 * (which corresponds to ~3800 bogomips at HZ = 100).
 * -- paulus
 */

#define __MAX_UDELAY	(226050910UL/HZ)	
/* maximum udelay argument */

#define __MAX_NDELAY	(4294967295UL/HZ)	
/* maximum ndelay argument */

extern unsigned long loops_per_jiffy;



static inline void __udelay(unsigned int x)
{

	unsigned long long tmp =
		(unsigned long long)x * (unsigned long long)loops_per_jiffy \
			* 226LL;
	unsigned loops = tmp >> 32;

/*
        __asm__("mulxuu %0,%1,%2" : "=r" (loops) :
                "r" (x), "r" (loops_per_jiffy * 226));
*/
	__delay(loops);
}

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extern void __bad_udelay(void);		/* deliberately undefined */
extern void __bad_ndelay(void);		/* deliberately undefined */


#define udelay(n)						\
	({                                                      \
                if (__builtin_constant_p(n)) {                  \
                        if ((n) / __MAX_UDELAY >= 1)            \
                                __bad_udelay();                 \
                        else                                    \
                                __udelay((n) * (19 * HZ));      \
                } else {                                        \
                        __udelay((n) * (19 * HZ));              \
                }                                               \
        })


#define ndelay(n)						\
	({                                                      \
                if (__builtin_constant_p(n)) {                  \
                        if ((n) / __MAX_NDELAY >= 1)            \
                                __bad_ndelay();                 \
                        else                                    \
                                __udelay((n) * HZ);             \
                } else {                                        \
                        __udelay((n) * HZ);                     \
                }                                               \
        })


#define muldiv(a, b, c)		(((a)*(b))/(c))

#endif /* _ASM_MICROBLAZE_DELAY_H */
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Directory: arch/microblaze/include/asm

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