ixgbe: extend PTP gettime function to read system clock

This adds support for the PTP_SYS_OFFSET_EXTENDED ioctl.

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c

@@ -443,22 +443,52 @@ static int ixgbe_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 }
 
 /**
- * ixgbe_ptp_gettime
+ * ixgbe_ptp_gettimex
  * @ptp: the ptp clock structure
- * @ts: timespec structure to hold the current time value
+ * @ts: timespec to hold the PHC timestamp
+ * @sts: structure to hold the system time before and after reading the PHC
  *
  * read the timecounter and return the correct value on ns,
  * after converting it into a struct timespec.
  */
-static int ixgbe_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
+static int ixgbe_ptp_gettimex(struct ptp_clock_info *ptp,
+			      struct timespec64 *ts,
+			      struct ptp_system_timestamp *sts)
 {
 	struct ixgbe_adapter *adapter =
 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
+	struct ixgbe_hw *hw = &adapter->hw;
 	unsigned long flags;
-	u64 ns;
+	u64 ns, stamp;
 
 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
-	ns = timecounter_read(&adapter->hw_tc);
+
+	switch (adapter->hw.mac.type) {
+	case ixgbe_mac_X550:
+	case ixgbe_mac_X550EM_x:
+	case ixgbe_mac_x550em_a:
+		/* Upper 32 bits represent billions of cycles, lower 32 bits
+		 * represent cycles. However, we use timespec64_to_ns for the
+		 * correct math even though the units haven't been corrected
+		 * yet.
+		 */
+		ptp_read_system_prets(sts);
+		IXGBE_READ_REG(hw, IXGBE_SYSTIMR);
+		ptp_read_system_postts(sts);
+		ts->tv_nsec = IXGBE_READ_REG(hw, IXGBE_SYSTIML);
+		ts->tv_sec = IXGBE_READ_REG(hw, IXGBE_SYSTIMH);
+		stamp = timespec64_to_ns(ts);
+		break;
+	default:
+		ptp_read_system_prets(sts);
+		stamp = IXGBE_READ_REG(hw, IXGBE_SYSTIML);
+		ptp_read_system_postts(sts);
+		stamp |= (u64)IXGBE_READ_REG(hw, IXGBE_SYSTIMH) << 32;
+		break;
+	}
+
+	ns = timecounter_cyc2time(&adapter->hw_tc, stamp);
+
 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
 
 	*ts = ns_to_timespec64(ns);
@@ -567,10 +597,14 @@ void ixgbe_ptp_overflow_check(struct ixgbe_adapter *adapter)
 {
 	bool timeout = time_is_before_jiffies(adapter->last_overflow_check +
 					     IXGBE_OVERFLOW_PERIOD);
-	struct timespec64 ts;
+	unsigned long flags;
 
 	if (timeout) {
-		ixgbe_ptp_gettime(&adapter->ptp_caps, &ts);
+		/* Update the timecounter */
+		spin_lock_irqsave(&adapter->tmreg_lock, flags);
+		timecounter_read(&adapter->hw_tc);
+		spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
+
 		adapter->last_overflow_check = jiffies;
 	}
 }
@@ -1216,7 +1250,7 @@ static long ixgbe_ptp_create_clock(struct ixgbe_adapter *adapter)
 		adapter->ptp_caps.pps = 1;
 		adapter->ptp_caps.adjfreq = ixgbe_ptp_adjfreq_82599;
 		adapter->ptp_caps.adjtime = ixgbe_ptp_adjtime;
-		adapter->ptp_caps.gettime64 = ixgbe_ptp_gettime;
+		adapter->ptp_caps.gettimex64 = ixgbe_ptp_gettimex;
 		adapter->ptp_caps.settime64 = ixgbe_ptp_settime;
 		adapter->ptp_caps.enable = ixgbe_ptp_feature_enable;
 		adapter->ptp_setup_sdp = ixgbe_ptp_setup_sdp_x540;
@@ -1233,7 +1267,7 @@ static long ixgbe_ptp_create_clock(struct ixgbe_adapter *adapter)
 		adapter->ptp_caps.pps = 0;
 		adapter->ptp_caps.adjfreq = ixgbe_ptp_adjfreq_82599;
 		adapter->ptp_caps.adjtime = ixgbe_ptp_adjtime;
-		adapter->ptp_caps.gettime64 = ixgbe_ptp_gettime;
+		adapter->ptp_caps.gettimex64 = ixgbe_ptp_gettimex;
 		adapter->ptp_caps.settime64 = ixgbe_ptp_settime;
 		adapter->ptp_caps.enable = ixgbe_ptp_feature_enable;
 		break;
@@ -1249,7 +1283,7 @@ static long ixgbe_ptp_create_clock(struct ixgbe_adapter *adapter)
 		adapter->ptp_caps.pps = 0;
 		adapter->ptp_caps.adjfreq = ixgbe_ptp_adjfreq_X550;
 		adapter->ptp_caps.adjtime = ixgbe_ptp_adjtime;
-		adapter->ptp_caps.gettime64 = ixgbe_ptp_gettime;
+		adapter->ptp_caps.gettimex64 = ixgbe_ptp_gettimex;
 		adapter->ptp_caps.settime64 = ixgbe_ptp_settime;
 		adapter->ptp_caps.enable = ixgbe_ptp_feature_enable;
 		adapter->ptp_setup_sdp = NULL;