Commit f8bd2258 authored by Roman Zippel's avatar Roman Zippel Committed by Linus Torvalds
Browse files

remove div_long_long_rem 



x86 is the only arch right now, which provides an optimized for
div_long_long_rem and it has the downside that one has to be very careful that
the divide doesn't overflow.

The API is a little akward, as the arguments for the unsigned divide are
signed.  The signed version also doesn't handle a negative divisor and
produces worse code on 64bit archs.

There is little incentive to keep this API alive, so this converts the few
users to the new API.

Signed-off-by: default avatarRoman Zippel <zippel@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6f6d6a1a

arch/mips/kernel/binfmt_elfn32.c

+3 −2
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG]; 
#include <linux/module.h>

#include <linux/elfcore.h>

#include <linux/compat.h>

#include <linux/math64.h>



#define elf_prstatus elf_prstatus32

struct elf_prstatus32
@@ -102,8 +103,8 @@ jiffies_to_compat_timeval(unsigned long jiffies, struct compat_timeval *value) 
	 * one divide.

	 */

	u64 nsec = (u64)jiffies * TICK_NSEC;

	long rem;

	value->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &rem);

	u32 rem;

	value->tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);

	value->tv_usec = rem / NSEC_PER_USEC;

}

arch/mips/kernel/binfmt_elfo32.c

+3 −2
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG]; 
#include <linux/module.h>

#include <linux/elfcore.h>

#include <linux/compat.h>

#include <linux/math64.h>



#define elf_prstatus elf_prstatus32

struct elf_prstatus32
@@ -104,8 +105,8 @@ jiffies_to_compat_timeval(unsigned long jiffies, struct compat_timeval *value) 
	 * one divide.

	 */

	u64 nsec = (u64)jiffies * TICK_NSEC;

	long rem;

	value->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &rem);

	u32 rem;

	value->tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);

	value->tv_usec = rem / NSEC_PER_USEC;

}

drivers/char/mmtimer.c

+11 −13
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ 
#include <linux/miscdevice.h>

#include <linux/posix-timers.h>

#include <linux/interrupt.h>

#include <linux/time.h>

#include <linux/math64.h>



#include <asm/uaccess.h>

#include <asm/sn/addrs.h>
@@ -472,8 +474,8 @@ static int sgi_clock_get(clockid_t clockid, struct timespec *tp) 


	nsec = rtc_time() * sgi_clock_period

			+ sgi_clock_offset.tv_nsec;

	tp->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &tp->tv_nsec)

			+ sgi_clock_offset.tv_sec;

	*tp = ns_to_timespec(nsec);

	tp->tv_sec += sgi_clock_offset.tv_sec;

	return 0;

};
@@ -481,11 +483,11 @@ static int sgi_clock_set(clockid_t clockid, struct timespec *tp) 
{



	u64 nsec;

	u64 rem;

	u32 rem;



	nsec = rtc_time() * sgi_clock_period;



	sgi_clock_offset.tv_sec = tp->tv_sec - div_long_long_rem(nsec, NSEC_PER_SEC, &rem);

	sgi_clock_offset.tv_sec = tp->tv_sec - div_u64_rem(nsec, NSEC_PER_SEC, &rem);



	if (rem <= tp->tv_nsec)

		sgi_clock_offset.tv_nsec = tp->tv_sec - rem;
@@ -644,9 +646,6 @@ static int sgi_timer_del(struct k_itimer *timr) 
	return 0;

}



#define timespec_to_ns(x) ((x).tv_nsec + (x).tv_sec * NSEC_PER_SEC)

#define ns_to_timespec(ts, nsec) (ts).tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &(ts).tv_nsec)



/* Assumption: it_lock is already held with irq's disabled */

static void sgi_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)

{
@@ -659,9 +658,8 @@ static void sgi_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting) 
		return;

	}



	ns_to_timespec(cur_setting->it_interval, timr->it.mmtimer.incr * sgi_clock_period);

	ns_to_timespec(cur_setting->it_value, (timr->it.mmtimer.expires - rtc_time())* sgi_clock_period);

	return;

	cur_setting->it_interval = ns_to_timespec(timr->it.mmtimer.incr * sgi_clock_period);

	cur_setting->it_value = ns_to_timespec((timr->it.mmtimer.expires - rtc_time()) * sgi_clock_period);

}
@@ -679,8 +677,8 @@ static int sgi_timer_set(struct k_itimer *timr, int flags, 
		sgi_timer_get(timr, old_setting);



	sgi_timer_del(timr);

	when = timespec_to_ns(new_setting->it_value);

	period = timespec_to_ns(new_setting->it_interval);

	when = timespec_to_ns(&new_setting->it_value);

	period = timespec_to_ns(&new_setting->it_interval);



	if (when == 0)

		/* Clear timer */
@@ -695,7 +693,7 @@ static int sgi_timer_set(struct k_itimer *timr, int flags, 
		unsigned long now;



		getnstimeofday(&n);

		now = timespec_to_ns(n);

		now = timespec_to_ns(&n);

		if (when > now)

			when -= now;

		else

include/asm-x86/div64.h

+0 −18
Original line number Diff line number Diff line
@@ -33,24 +33,6 @@ 
	__mod;							\

})



/*

 * (long)X = ((long long)divs) / (long)div

 * (long)rem = ((long long)divs) % (long)div

 *

 * Warning, this will do an exception if X overflows.

 */

#define div_long_long_rem(a, b, c) div_ll_X_l_rem(a, b, c)



static inline long div_ll_X_l_rem(long long divs, long div, long *rem)

{

	long dum2;

	asm("divl %2":"=a"(dum2), "=d"(*rem)

	    : "rm"(div), "A"(divs));



	return dum2;



}



static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)

{

	union {

include/linux/calc64.h

deleted100644 → 0
+0 −49
Original line number Diff line number Diff line 
#ifndef _LINUX_CALC64_H

#define _LINUX_CALC64_H



#include <linux/types.h>

#include <asm/div64.h>



/*

 * This is a generic macro which is used when the architecture

 * specific div64.h does not provide a optimized one.

 *

 * The 64bit dividend is divided by the divisor (data type long), the

 * result is returned and the remainder stored in the variable

 * referenced by remainder (data type long *). In contrast to the

 * do_div macro the dividend is kept intact.

 */

#ifndef div_long_long_rem

#define div_long_long_rem(dividend, divisor, remainder)	\

	do_div_llr((dividend), divisor, remainder)



static inline unsigned long do_div_llr(const long long dividend,

				       const long divisor, long *remainder)

{

	u64 result = dividend;



	*(remainder) = do_div(result, divisor);

	return (unsigned long) result;

}

#endif



/*

 * Sign aware variation of the above. On some architectures a

 * negative dividend leads to an divide overflow exception, which

 * is avoided by the sign check.

 */

static inline long div_long_long_rem_signed(const long long dividend,

					    const long divisor, long *remainder)

{

	long res;



	if (unlikely(dividend < 0)) {

		res = -div_long_long_rem(-dividend, divisor, remainder);

		*remainder = -(*remainder);

	} else

		res = div_long_long_rem(dividend, divisor, remainder);



	return res;

}



#endif

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