Commit c0015f91 authored by Jan Glauber's avatar Jan Glauber Committed by Heiko Carstens
Browse files

[S390] switch sched_clock to store-clock-extended. 



Add get_clock_xt to read an 8 byte clock value using store clock
extended (STCKE) and use get_clock_xt for sched_clock. STCKE should
be faster than STCK on newer machines.

Signed-off-by: default avatarJan Glauber <jan.glauber@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
parent 2f7c8bd6

arch/s390/kernel/time.c

+1 −1
Original line number Diff line number Diff line
@@ -66,7 +66,7 @@ static u64 xtime_cc; 
 */

unsigned long long sched_clock(void)

{

	return ((get_clock() - jiffies_timer_cc) * 125) >> 9;

	return ((get_clock_xt() - jiffies_timer_cc) * 125) >> 9;

}



/*

include/asm-s390/timex.h

+7 −5
Original line number Diff line number Diff line
@@ -62,16 +62,18 @@ static inline unsigned long long get_clock (void) 
	return clk;

}



static inline void get_clock_extended(void *dest)

static inline unsigned long long get_clock_xt(void)

{

	typedef struct { unsigned long long clk[2]; } __clock_t;

	unsigned char clk[16];



#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)

	asm volatile("stcke %0" : "=Q" (*((__clock_t *)dest)) : : "cc");

	asm volatile("stcke %0" : "=Q" (clk) : : "cc");

#else /* __GNUC__ */

	asm volatile("stcke 0(%1)" : "=m" (*((__clock_t *)dest))

				   : "a" ((__clock_t *)dest) : "cc");

	asm volatile("stcke 0(%1)" : "=m" (clk)

				   : "a" (clk) : "cc");

#endif /* __GNUC__ */



	return *((unsigned long long *)&clk[1]);

}



static inline cycles_t get_cycles(void)

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