hv_utils: fix TimeSync work on pre-TimeSync-v4 hosts

[karo-tx-linux.git] / drivers / hv / hv_util.c

diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index 2849143bf6f0b8279fd3b2969dfd9bd8540102c9..14dce25c104f4b9dcb11627811a5f1241f1369f4 100644 (file)
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -202,27 +202,39 @@ static void shutdown_onchannelcallback(void *context)
 /*
  * Set the host time in a process context.
  */
+static struct work_struct adj_time_work;
 
-struct adj_time_work {
-       struct work_struct work;
-       u64     host_time;
-       u64     ref_time;
-       u8      flags;
-};
+/*
+ * The last time sample, received from the host. PTP device responds to
+ * requests by using this data and the current partition-wide time reference
+ * count.
+ */
+static struct {
+       u64                             host_time;
+       u64                             ref_time;
+       spinlock_t                      lock;
+} host_ts;
 
-static void hv_set_host_time(struct work_struct *work)
+static struct timespec64 hv_get_adj_host_time(void)
 {
-       struct adj_time_work *wrk;
-       struct timespec64 host_ts;
-       u64 reftime, newtime;
-
-       wrk = container_of(work, struct adj_time_work, work);
+       struct timespec64 ts;
+       u64 newtime, reftime;
+       unsigned long flags;
 
+       spin_lock_irqsave(&host_ts.lock, flags);
        reftime = hyperv_cs->read(hyperv_cs);
-       newtime = wrk->host_time + (reftime - wrk->ref_time);
-       host_ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
+       newtime = host_ts.host_time + (reftime - host_ts.ref_time);
+       ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
+       spin_unlock_irqrestore(&host_ts.lock, flags);
 
-       do_settimeofday64(&host_ts);
+       return ts;
+}
+
+static void hv_set_host_time(struct work_struct *work)
+{
+       struct timespec64 ts = hv_get_adj_host_time();
+
+       do_settimeofday64(&ts);
 }
 
 /*
@@ -238,60 +250,35 @@ static void hv_set_host_time(struct work_struct *work)
  * typically used as a hint to the guest. The guest is under no obligation
  * to discipline the clock.
  */
-static struct adj_time_work  wrk;
-
-/*
- * The last time sample, received from the host. PTP device responds to
- * requests by using this data and the current partition-wide time reference
- * count.
- */
-static struct {
-       u64                             host_time;
-       u64                             ref_time;
-       spinlock_t                      lock;
-} host_ts;
-
 static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
 {
        unsigned long flags;
        u64 cur_reftime;
 
        /*
-        * This check is safe since we are executing in the
-        * interrupt context and time synch messages are always
-        * delivered on the same CPU.
+        * Save the adjusted time sample from the host and the snapshot
+        * of the current system time.
         */
-       if (adj_flags & ICTIMESYNCFLAG_SYNC) {
-               /* Queue a job to do do_settimeofday64() */
-               if (work_pending(&wrk.work))
-                       return;
-
-               wrk.host_time = hosttime;
-               wrk.ref_time = reftime;
-               wrk.flags = adj_flags;
-               schedule_work(&wrk.work);
-       } else {
-               /*
-                * Save the adjusted time sample from the host and the snapshot
-                * of the current system time for PTP device.
-                */
-               spin_lock_irqsave(&host_ts.lock, flags);
-
-               cur_reftime = hyperv_cs->read(hyperv_cs);
-               host_ts.host_time = hosttime;
-               host_ts.ref_time = cur_reftime;
-
-               /*
-                * TimeSync v4 messages contain reference time (guest's Hyper-V
-                * clocksource read when the time sample was generated), we can
-                * improve the precision by adding the delta between now and the
-                * time of generation.
-                */
-               if (ts_srv_version > TS_VERSION_3)
-                       host_ts.host_time += (cur_reftime - reftime);
-
-               spin_unlock_irqrestore(&host_ts.lock, flags);
-       }
+       spin_lock_irqsave(&host_ts.lock, flags);
+
+       cur_reftime = hyperv_cs->read(hyperv_cs);
+       host_ts.host_time = hosttime;
+       host_ts.ref_time = cur_reftime;
+
+       /*
+        * TimeSync v4 messages contain reference time (guest's Hyper-V
+        * clocksource read when the time sample was generated), we can
+        * improve the precision by adding the delta between now and the
+        * time of generation. For older protocols we set
+        * reftime == cur_reftime on call.
+        */
+       host_ts.host_time += (cur_reftime - reftime);
+
+       spin_unlock_irqrestore(&host_ts.lock, flags);
+
+       /* Schedule work to do do_settimeofday64() */
+       if (adj_flags & ICTIMESYNCFLAG_SYNC)
+               schedule_work(&adj_time_work);
 }
 
 /*
@@ -339,8 +326,8 @@ static void timesync_onchannelcallback(void *context)
                                        sizeof(struct vmbuspipe_hdr) +
                                        sizeof(struct icmsg_hdr)];
                                adj_guesttime(timedatap->parenttime,
-                                               0,
-                                               timedatap->flags);
+                                             hyperv_cs->read(hyperv_cs),
+                                             timedatap->flags);
                        }
                }
 
@@ -524,14 +511,7 @@ static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 
 static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
 {
-       unsigned long flags;
-       u64 newtime, reftime;
-
-       spin_lock_irqsave(&host_ts.lock, flags);
-       reftime = hyperv_cs->read(hyperv_cs);
-       newtime = host_ts.host_time + (reftime - host_ts.ref_time);
-       *ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
-       spin_unlock_irqrestore(&host_ts.lock, flags);
+       *ts = hv_get_adj_host_time();
 
        return 0;
 }
@@ -556,7 +536,7 @@ static int hv_timesync_init(struct hv_util_service *srv)
 
        spin_lock_init(&host_ts.lock);
 
-       INIT_WORK(&wrk.work, hv_set_host_time);
+       INIT_WORK(&adj_time_work, hv_set_host_time);
 
        /*
         * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
@@ -577,7 +557,7 @@ static void hv_timesync_deinit(void)
 {
        if (hv_ptp_clock)
                ptp_clock_unregister(hv_ptp_clock);
-       cancel_work_sync(&wrk.work);
+       cancel_work_sync(&adj_time_work);
 }
 
 static int __init init_hyperv_utils(void)