Commit b6370b33 authored by Koakuma's avatar Koakuma Committed by Andreas Larsson
Browse files

sparc/vdso: Add helper function for 64-bit right shift on 32-bit target 



Add helper function for 64-bit right shift on 32-bit target so that
clang does not emit a runtime library call.

Signed-off-by: default avatarKoakuma <koachan@protonmail.com>
Reviewed-by: default avatarAndreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20240808-sparc-shr64-v2-1-fd18f1b2cea9@protonmail.com


Signed-off-by: default avatarAndreas Larsson <andreas@gaisler.com>
parent 8467d8b2

arch/sparc/vdso/vclock_gettime.c

+24 −4
Original line number Diff line number Diff line
@@ -86,6 +86,11 @@ notrace static long vdso_fallback_gettimeofday(struct __kernel_old_timeval *tv, 
}



#ifdef	CONFIG_SPARC64

notrace static __always_inline u64 __shr64(u64 val, int amt)

{

	return val >> amt;

}



notrace static __always_inline u64 vread_tick(void)

{

	u64	ret;
@@ -102,6 +107,21 @@ notrace static __always_inline u64 vread_tick_stick(void) 
	return ret;

}

#else

notrace static __always_inline u64 __shr64(u64 val, int amt)

{

	u64 ret;



	__asm__ __volatile__("sllx %H1, 32, %%g1\n\t"

			     "srl %L1, 0, %L1\n\t"

			     "or %%g1, %L1, %%g1\n\t"

			     "srlx %%g1, %2, %L0\n\t"

			     "srlx %L0, 32, %H0"

			     : "=r" (ret)

			     : "r" (val), "r" (amt)

			     : "g1");

	return ret;

}



notrace static __always_inline u64 vread_tick(void)

{

	register unsigned long long ret asm("o4");
@@ -154,7 +174,7 @@ notrace static __always_inline int do_realtime(struct vvar_data *vvar, 
		ts->tv_sec = vvar->wall_time_sec;

		ns = vvar->wall_time_snsec;

		ns += vgetsns(vvar);

		ns >>= vvar->clock.shift;

		ns = __shr64(ns, vvar->clock.shift);

	} while (unlikely(vvar_read_retry(vvar, seq)));



	ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
@@ -174,7 +194,7 @@ notrace static __always_inline int do_realtime_stick(struct vvar_data *vvar, 
		ts->tv_sec = vvar->wall_time_sec;

		ns = vvar->wall_time_snsec;

		ns += vgetsns_stick(vvar);

		ns >>= vvar->clock.shift;

		ns = __shr64(ns, vvar->clock.shift);

	} while (unlikely(vvar_read_retry(vvar, seq)));



	ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
@@ -194,7 +214,7 @@ notrace static __always_inline int do_monotonic(struct vvar_data *vvar, 
		ts->tv_sec = vvar->monotonic_time_sec;

		ns = vvar->monotonic_time_snsec;

		ns += vgetsns(vvar);

		ns >>= vvar->clock.shift;

		ns = __shr64(ns, vvar->clock.shift);

	} while (unlikely(vvar_read_retry(vvar, seq)));



	ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
@@ -214,7 +234,7 @@ notrace static __always_inline int do_monotonic_stick(struct vvar_data *vvar, 
		ts->tv_sec = vvar->monotonic_time_sec;

		ns = vvar->monotonic_time_snsec;

		ns += vgetsns_stick(vvar);

		ns >>= vvar->clock.shift;

		ns = __shr64(ns, vvar->clock.shift);

	} while (unlikely(vvar_read_retry(vvar, seq)));



	ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);