ptp: Introduce strict checking of external time stamp options.

User space may request time stamps on rising edges, falling edges, or
both.  However, the particular mode may or may not be supported in the
hardware or in the driver.  This patch adds a "strict" flag that tells
drivers to ensure that the requested mode will be honored.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/ptp.c

@@ -276,7 +276,8 @@ static int mv88e6352_ptp_enable_extts(struct mv88e6xxx_chip *chip,
 	/* Reject requests with unsupported flags */
 	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
 				PTP_RISING_EDGE |
-				PTP_FALLING_EDGE))
+				PTP_FALLING_EDGE |
+				PTP_STRICT_FLAGS))
 		return -EOPNOTSUPP;
 
 	pin = ptp_find_pin(chip->ptp_clock, PTP_PF_EXTTS, rq->extts.index);

drivers/net/ethernet/intel/igb/igb_ptp.c

@@ -524,7 +524,8 @@ static int igb_ptp_feature_enable_i210(struct ptp_clock_info *ptp,
 		/* Reject requests with unsupported flags */
 		if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
 					PTP_RISING_EDGE |
-					PTP_FALLING_EDGE))
+					PTP_FALLING_EDGE |
+					PTP_STRICT_FLAGS))
 			return -EOPNOTSUPP;
 
 		if (on) {

drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c

@@ -239,7 +239,8 @@ static int mlx5_extts_configure(struct ptp_clock_info *ptp,
 	/* Reject requests with unsupported flags */
 	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
 				PTP_RISING_EDGE |
-				PTP_FALLING_EDGE))
+				PTP_FALLING_EDGE |
+				PTP_STRICT_FLAGS))
 		return -EOPNOTSUPP;
 
 	if (rq->extts.index >= clock->ptp_info.n_pins)

drivers/net/ethernet/renesas/ravb_ptp.c

@@ -185,7 +185,8 @@ static int ravb_ptp_extts(struct ptp_clock_info *ptp,
 	/* Reject requests with unsupported flags */
 	if (req->flags & ~(PTP_ENABLE_FEATURE |
 			   PTP_RISING_EDGE |
-			   PTP_FALLING_EDGE))
+			   PTP_FALLING_EDGE |
+			   PTP_STRICT_FLAGS))
 		return -EOPNOTSUPP;
 
 	if (req->index)

drivers/net/phy/dp83640.c

@@ -472,7 +472,8 @@ static int ptp_dp83640_enable(struct ptp_clock_info *ptp,
 		/* Reject requests with unsupported flags */
 		if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
 					PTP_RISING_EDGE |
-					PTP_FALLING_EDGE))
+					PTP_FALLING_EDGE |
+					PTP_STRICT_FLAGS))
 			return -EOPNOTSUPP;
 		index = rq->extts.index;
 		if (index >= N_EXT_TS)

drivers/ptp/ptp_chardev.c

@@ -150,6 +150,8 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 			break;
 		}
 		if (cmd == PTP_EXTTS_REQUEST2) {
+			/* Tell the drivers to check the flags carefully. */
+			req.extts.flags |= PTP_STRICT_FLAGS;
 			/* Make sure no reserved bit is set. */
 			if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
 			    req.extts.rsv[0] || req.extts.rsv[1]) {

include/uapi/linux/ptp_clock.h

@@ -31,6 +31,7 @@
 #define PTP_ENABLE_FEATURE (1<<0)
 #define PTP_RISING_EDGE    (1<<1)
 #define PTP_FALLING_EDGE   (1<<2)
+#define PTP_STRICT_FLAGS   (1<<3)
 #define PTP_EXTTS_EDGES    (PTP_RISING_EDGE | PTP_FALLING_EDGE)
 
 /*
@@ -38,7 +39,8 @@
  */
 #define PTP_EXTTS_VALID_FLAGS	(PTP_ENABLE_FEATURE |	\
 				 PTP_RISING_EDGE |	\
-				 PTP_FALLING_EDGE)
+				 PTP_FALLING_EDGE |	\
+				 PTP_STRICT_FLAGS)
 
 /*
  * flag fields valid for the original PTP_EXTTS_REQUEST ioctl.