[PATCH v4 7/7] xen/x86: support XENPF_settime64

From: Stefano Stabellini
Date: Thu Nov 12 2015 - 12:31:25 EST


Try XENPF_settime64 first, if it is not available fall back to
XENPF_settime32.

No need to call __current_kernel_time() when all the info needed are
already passed via the struct timekeeper * argument.

Return NOTIFY_BAD in case of errors.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
CC: konrad.wilk@xxxxxxxxxx
CC: david.vrabel@xxxxxxxxxx
CC: boris.ostrovsky@xxxxxxxxxx
---
arch/x86/xen/time.c | 35 ++++++++++++++++++++++++++++-------
1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 3bbd377..4b8af45 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -16,6 +16,7 @@
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/pvclock_gtod.h>
+#include <linux/timekeeper_internal.h>

#include <asm/pvclock.h>
#include <asm/xen/hypervisor.h>
@@ -123,9 +124,13 @@ static int xen_pvclock_gtod_notify(struct notifier_block *nb,
static struct timespec next_sync;

struct xen_platform_op op;
- struct timespec now;
+ struct timespec64 now;
+ struct timekeeper *tk = priv;
+ static bool settime64_supported = true;
+ int ret;

- now = __current_kernel_time();
+ now.tv_sec = tk->xtime_sec;
+ now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);

/*
* We only take the expensive HV call when the clock was set
@@ -134,12 +139,28 @@ static int xen_pvclock_gtod_notify(struct notifier_block *nb,
if (!was_set && timespec_compare(&now, &next_sync) < 0)
return NOTIFY_OK;

- op.cmd = XENPF_settime32;
- op.u.settime32.secs = now.tv_sec;
- op.u.settime32.nsecs = now.tv_nsec;
- op.u.settime32.system_time = xen_clocksource_read();
+again:
+ if (settime64_supported) {
+ op.cmd = XENPF_settime64;
+ op.u.settime64.mbz = 0;
+ op.u.settime64.secs = now.tv_sec;
+ op.u.settime64.nsecs = now.tv_nsec;
+ op.u.settime64.system_time = xen_clocksource_read();
+ } else {
+ op.cmd = XENPF_settime32;
+ op.u.settime32.secs = now.tv_sec;
+ op.u.settime32.nsecs = now.tv_nsec;
+ op.u.settime32.system_time = xen_clocksource_read();
+ }
+
+ ret = HYPERVISOR_platform_op(&op);

- (void)HYPERVISOR_platform_op(&op);
+ if (ret == -ENOSYS && settime64_supported) {
+ settime64_supported = false;
+ goto again;
+ }
+ if (ret < 0)
+ return NOTIFY_BAD;

/*
* Move the next drift compensation time 11 minutes
--
1.7.10.4

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