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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-26 10:44:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-26 10:44:15 -0700
commit51c4518ab77c6d3e917675891a9a529daabfaef1 (patch)
treeefcdd068ff7698ca8b4b62405ac5d3e70297b6c3 /drivers/hv
parente652049b2018e3a2e32d71c74cf7d359e07e7618 (diff)
parentb46b4a8a57c377b72a98c7930a9f6969d2d4784e (diff)
Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv fixes from Wei Liu: "Two patches from Vineeth to improve Hyper-V timesync facility" * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hv_utils: drain the timesync packets on onchannelcallback hv_utils: return error if host timesysnc update is stale
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/hv_util.c65
1 files changed, 51 insertions, 14 deletions
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index 92ee0fe4c919..a4e8d96513c2 100644
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -282,26 +282,52 @@ static struct {
spinlock_t lock;
} host_ts;
-static struct timespec64 hv_get_adj_host_time(void)
+static inline u64 reftime_to_ns(u64 reftime)
{
- struct timespec64 ts;
- u64 newtime, reftime;
+ return (reftime - WLTIMEDELTA) * 100;
+}
+
+/*
+ * Hard coded threshold for host timesync delay: 600 seconds
+ */
+static const u64 HOST_TIMESYNC_DELAY_THRESH = 600 * (u64)NSEC_PER_SEC;
+
+static int hv_get_adj_host_time(struct timespec64 *ts)
+{
+ u64 newtime, reftime, timediff_adj;
unsigned long flags;
+ int ret = 0;
spin_lock_irqsave(&host_ts.lock, flags);
reftime = hv_read_reference_counter();
- newtime = host_ts.host_time + (reftime - host_ts.ref_time);
- ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
+
+ /*
+ * We need to let the caller know that last update from host
+ * is older than the max allowable threshold. clock_gettime()
+ * and PTP ioctl do not have a documented error that we could
+ * return for this specific case. Use ESTALE to report this.
+ */
+ timediff_adj = reftime - host_ts.ref_time;
+ if (timediff_adj * 100 > HOST_TIMESYNC_DELAY_THRESH) {
+ pr_warn_once("TIMESYNC IC: Stale time stamp, %llu nsecs old\n",
+ (timediff_adj * 100));
+ ret = -ESTALE;
+ }
+
+ newtime = host_ts.host_time + timediff_adj;
+ *ts = ns_to_timespec64(reftime_to_ns(newtime));
spin_unlock_irqrestore(&host_ts.lock, flags);
- return ts;
+ return ret;
}
static void hv_set_host_time(struct work_struct *work)
{
- struct timespec64 ts = hv_get_adj_host_time();
- do_settimeofday64(&ts);
+ struct timespec64 ts;
+
+ if (!hv_get_adj_host_time(&ts))
+ do_settimeofday64(&ts);
}
/*
@@ -361,10 +387,23 @@ static void timesync_onchannelcallback(void *context)
struct ictimesync_ref_data *refdata;
u8 *time_txf_buf = util_timesynch.recv_buffer;
- vmbus_recvpacket(channel, time_txf_buf,
- HV_HYP_PAGE_SIZE, &recvlen, &requestid);
+ /*
+ * Drain the ring buffer and use the last packet to update
+ * host_ts
+ */
+ while (1) {
+ int ret = vmbus_recvpacket(channel, time_txf_buf,
+ HV_HYP_PAGE_SIZE, &recvlen,
+ &requestid);
+ if (ret) {
+ pr_warn_once("TimeSync IC pkt recv failed (Err: %d)\n",
+ ret);
+ break;
+ }
+
+ if (!recvlen)
+ break;
- if (recvlen > 0) {
icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
sizeof(struct vmbuspipe_hdr)];
@@ -622,9 +661,7 @@ 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)
{
- *ts = hv_get_adj_host_time();
-
- return 0;
+ return hv_get_adj_host_time(ts);
}
static struct ptp_clock_info ptp_hyperv_info = {