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Commit f0fbf0ab authored by Glauber Costa's avatar Glauber Costa Committed by Ingo Molnar
Browse files

x86: integrate delay functions. 



delay_32.c, delay_64.c are now equal, and are integrated into delay.c.

Signed-off-by: default avatarGlauber Costa <gcosta@redhat.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 7e58818d

arch/x86/lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 


obj-$(CONFIG_SMP) := msr-on-cpu.o



lib-y := delay_$(BITS).o

lib-y := delay.o

lib-y += usercopy_$(BITS).o getuser_$(BITS).o putuser_$(BITS).o

lib-y += memcpy_$(BITS).o

arch/x86/lib/delay_32.c→arch/x86/lib/delay.c

+5 −6
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ 
/* simple loop based delay: */

static void delay_loop(unsigned long loops)

{

	__asm__ __volatile__(

	asm volatile(

		"	test %0,%0	\n"

		"	jz 3f		\n"

		"	jmp 1f		\n"
@@ -108,31 +108,30 @@ void __delay(unsigned long loops) 
{

	delay_fn(loops);

}

EXPORT_SYMBOL(__delay);



inline void __const_udelay(unsigned long xloops)

{

	int d0;



	xloops *= 4;

	__asm__("mull %%edx"

	asm("mull %%edx"

		:"=d" (xloops), "=&a" (d0)

		:"1" (xloops), "0"

		(cpu_data(raw_smp_processor_id()).loops_per_jiffy * (HZ/4)));



	__delay(++xloops);

}

EXPORT_SYMBOL(__const_udelay);



void __udelay(unsigned long usecs)

{

	__const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */

}

EXPORT_SYMBOL(__udelay);



void __ndelay(unsigned long nsecs)

{

	__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */

}



EXPORT_SYMBOL(__delay);

EXPORT_SYMBOL(__const_udelay);

EXPORT_SYMBOL(__udelay);

EXPORT_SYMBOL(__ndelay);

arch/x86/lib/delay_64.c

deleted100644 → 0
+0 −128
Original line number Diff line number Diff line 
/*

 *	Precise Delay Loops for x86-64

 *

 *	Copyright (C) 1993 Linus Torvalds

 *	Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>

 *

 *	The __delay function must _NOT_ be inlined as its execution time

 *	depends wildly on alignment on many x86 processors. 

 */



#include <linux/module.h>

#include <linux/sched.h>

#include <linux/timex.h>

#include <linux/preempt.h>

#include <linux/delay.h>

#include <linux/init.h>



#include <asm/delay.h>

#include <asm/msr.h>



#ifdef CONFIG_SMP

#include <asm/smp.h>

#endif



/* simple loop based delay: */

static void delay_loop(unsigned long loops)

{

	asm volatile(

		"	test %0,%0	\n"

		"	jz 3f		\n"

		"	jmp 1f		\n"



		".align 16		\n"

		"1:	jmp 2f		\n"



		".align 16		\n"

		"2:	dec %0		\n"

		"	jnz 2b		\n"

		"3:	dec %0		\n"



		: /* we don't need output */

		:"a" (loops)

	);

}



static void delay_tsc(unsigned long loops)

{

	unsigned bclock, now;

	int cpu;



	preempt_disable();

	cpu = smp_processor_id();

	rdtscl(bclock);

	for (;;) {

		rdtscl(now);

		if ((now - bclock) >= loops)

			break;



		/* Allow RT tasks to run */

		preempt_enable();

		rep_nop();

		preempt_disable();



		/*

		 * It is possible that we moved to another CPU, and

		 * since TSC's are per-cpu we need to calculate

		 * that. The delay must guarantee that we wait "at

		 * least" the amount of time. Being moved to another

		 * CPU could make the wait longer but we just need to

		 * make sure we waited long enough. Rebalance the

		 * counter for this CPU.

		 */

		if (unlikely(cpu != smp_processor_id())) {

			loops -= (now - bclock);

			cpu = smp_processor_id();

			rdtscl(bclock);

		}

	}

	preempt_enable();

}



static void (*delay_fn)(unsigned long) = delay_loop;



void use_tsc_delay(void)

{

	delay_fn = delay_tsc;

}



int __devinit read_current_timer(unsigned long *timer_value)

{

	if (delay_fn == delay_tsc) {

		rdtscll(*timer_value);

		return 0;

	}

	return -1;

}



void __delay(unsigned long loops)

{

	delay_fn(loops);

}

EXPORT_SYMBOL(__delay);



inline void __const_udelay(unsigned long xloops)

{

	int d0;

	xloops *= 4;

	__asm__("mull %%edx"

		:"=d" (xloops), "=&a" (d0)

		:"1" (xloops), "0"

		(cpu_data(raw_smp_processor_id()).loops_per_jiffy * (HZ/4)));



	__delay(++xloops);

}



EXPORT_SYMBOL(__const_udelay);



void __udelay(unsigned long usecs)

{

	__const_udelay(usecs * 0x000010c7);  /* 2**32 / 1000000 (rounded up) */

}

EXPORT_SYMBOL(__udelay);



void __ndelay(unsigned long nsecs)

{

	__const_udelay(nsecs * 0x00005);  /* 2**32 / 1000000000 (rounded up) */

}

EXPORT_SYMBOL(__ndelay);