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Commit 6defa38b authored by Paul Mackerras's avatar Paul Mackerras
Browse files

powerpc: Fix delay functions for 601 processors 



My earlier merge of delay.h introduced a timebase-based udelay for
32-bit machines but also broke the 601, which doesn't have the
timebase register.  This fixes it by using the 601's RTC register on
the 601, and also moves __delay() and udelay() to be out-of-line in
arch/powerpc/kernel/time.c.  These functions aren't really performance
critical, after all.

Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent fe7bce5e

arch/powerpc/kernel/misc_32.S

+0 −8
Original line number Diff line number Diff line
@@ -27,14 +27,6 @@ 


	.text



	.align	5

_GLOBAL(__delay)

	cmpwi	0,r3,0

	mtctr	r3

	beqlr

1:	bdnz	1b

	blr



/*

 * This returns the high 64 bits of the product of two 64-bit numbers.

 */

arch/powerpc/kernel/time.c

+28 −0
Original line number Diff line number Diff line
@@ -130,6 +130,34 @@ unsigned long tb_last_stamp; 
 */

DEFINE_PER_CPU(unsigned long, last_jiffy);



void __delay(unsigned long loops)

{

	unsigned long start;

	int diff;



	if (__USE_RTC()) {

		start = get_rtcl();

		do {

			/* the RTCL register wraps at 1000000000 */

			diff = get_rtcl() - start;

			if (diff < 0)

				diff += 1000000000;

		} while (diff < loops);

	} else {

		start = get_tbl();

		while (get_tbl() - start < loops)

			HMT_low();

		HMT_medium();

	}

}

EXPORT_SYMBOL(__delay);



void udelay(unsigned long usecs)

{

	__delay(tb_ticks_per_usec * usecs);

}

EXPORT_SYMBOL(udelay);



static __inline__ void timer_check_rtc(void)

{

        /*

include/asm-powerpc/delay.h

+2 −38
Original line number Diff line number Diff line
@@ -13,43 +13,7 @@ 
 * Anton Blanchard.

 */



extern unsigned long tb_ticks_per_usec;



#ifdef CONFIG_PPC64

/* define these here to prevent circular dependencies */

/* these instructions control the thread priority on multi-threaded cpus */

#define __HMT_low()	asm volatile("or 1,1,1")

#define __HMT_medium()	asm volatile("or 2,2,2")

#else

#define __HMT_low()

#define __HMT_medium()

#endif



#define __barrier()	asm volatile("" ::: "memory")



static inline unsigned long __get_tb(void)

{

	unsigned long rval;



	asm volatile("mftb %0" : "=r" (rval));

	return rval;

}



static inline void __delay(unsigned long loops)

{

	unsigned long start = __get_tb();



	while((__get_tb() - start) < loops)

		__HMT_low();

	__HMT_medium();

	__barrier();

}



static inline void udelay(unsigned long usecs)

{

	unsigned long loops = tb_ticks_per_usec * usecs;



	__delay(loops);

}

extern void __delay(unsigned long loops);

extern void udelay(unsigned long usecs);



#endif /* _ASM_POWERPC_DELAY_H */