Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ac0d94ff authored by Pavel Tatashin's avatar Pavel Tatashin Committed by Greg Kroah-Hartman
Browse files

x86/xen/time: Output xen sched_clock time from 0 



commit 38669ba205d178d2d38bfd194a196d65a44d5af2 upstream.

It is expected for sched_clock() to output data from 0, when system boots.

Add an offset xen_sched_clock_offset (similarly how it is done in other
hypervisors i.e. kvm_sched_clock_offset) to count sched_clock() from 0,
when time is first initialized.

Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-14-pasha.tatashin@oracle.com


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9fb9a543

arch/x86/xen/time.c

+10 −1
Original line number Diff line number Diff line
@@ -31,6 +31,8 @@ 
/* Xen may fire a timer up to this many ns early */

#define TIMER_SLOP	100000



static u64 xen_sched_clock_offset __read_mostly;



/* Get the TSC speed from Xen */

static unsigned long xen_tsc_khz(void)

{
@@ -57,6 +59,11 @@ static u64 xen_clocksource_get_cycles(struct clocksource *cs) 
	return xen_clocksource_read();

}



static u64 xen_sched_clock(void)

{

	return xen_clocksource_read() - xen_sched_clock_offset;

}



static void xen_read_wallclock(struct timespec *ts)

{

	struct shared_info *s = HYPERVISOR_shared_info;
@@ -367,7 +374,7 @@ void xen_timer_resume(void) 
}



static const struct pv_time_ops xen_time_ops __initconst = {

	.sched_clock = xen_clocksource_read,

	.sched_clock = xen_sched_clock,

	.steal_clock = xen_steal_clock,

};
@@ -505,6 +512,7 @@ static void __init xen_time_init(void) 


void __ref xen_init_time_ops(void)

{

	xen_sched_clock_offset = xen_clocksource_read();

	pv_time_ops = xen_time_ops;



	x86_init.timers.timer_init = xen_time_init;
@@ -547,6 +555,7 @@ void __init xen_hvm_init_time_ops(void) 
		return;

	}



	xen_sched_clock_offset = xen_clocksource_read();

	pv_time_ops = xen_time_ops;

	x86_init.timers.setup_percpu_clockev = xen_time_init;

	x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents;