IB/hfi1: IB/hfi1: Add an API to handle special case drop

This patch pushes special case drop logic into an API to be shared by all
interrupt handlers.

Additionally, convert do_drop to a bool.

Link: https://lore.kernel.org/r/20200106134203.119356.36962.stgit@awfm-01.aw.intel.com
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hfi1/driver.c

@@ -1004,11 +1004,7 @@ int handle_receive_interrupt(struct hfi1_ctxtdata *rcd, int thread)
 	prescan_rxq(rcd, &packet);
 
 	while (last == RCV_PKT_OK) {
-		if (unlikely(dd->do_drop &&
-			     atomic_xchg(&dd->drop_packet, DROP_PACKET_OFF) ==
-			     DROP_PACKET_ON)) {
-			dd->do_drop = 0;
-
+		if (hfi1_need_drop(dd)) {
 			/* On to the next packet */
 			packet.rhqoff += packet.rsize;
 			packet.rhf_addr = (__le32 *)rcd->rcvhdrq +

drivers/infiniband/hw/hfi1/hfi.h

@@ -1316,7 +1316,7 @@ struct hfi1_devdata {
 	struct err_info_constraint err_info_xmit_constraint;
 
 	atomic_t drop_packet;
-	u8 do_drop;
+	bool do_drop;
 	u8 err_info_uncorrectable;
 	u8 err_info_fmconfig;
 
@@ -2462,6 +2462,25 @@ static inline bool is_integrated(struct hfi1_devdata *dd)
 	return dd->pcidev->device == PCI_DEVICE_ID_INTEL1;
 }
 
+/**
+ * hfi1_need_drop - detect need for drop
+ * @dd: - the device
+ *
+ * In some cases, the first packet needs to be dropped.
+ *
+ * Return true is the current packet needs to be dropped and false otherwise.
+ */
+static inline bool hfi1_need_drop(struct hfi1_devdata *dd)
+{
+	if (unlikely(dd->do_drop &&
+		     atomic_xchg(&dd->drop_packet, DROP_PACKET_OFF) ==
+		     DROP_PACKET_ON)) {
+		dd->do_drop = false;
+		return true;
+	}
+	return false;
+}
+
 int hfi1_tempsense_rd(struct hfi1_devdata *dd, struct hfi1_temp *temp);
 
 #define DD_DEV_ENTRY(dd)       __string(dev, dev_name(&(dd)->pcidev->dev))

drivers/infiniband/hw/hfi1/init.c

@@ -876,10 +876,10 @@ int hfi1_init(struct hfi1_devdata *dd, int reinit)
 
 	if (is_ax(dd)) {
 		atomic_set(&dd->drop_packet, DROP_PACKET_ON);
-		dd->do_drop = 1;
+		dd->do_drop = true;
 	} else {
 		atomic_set(&dd->drop_packet, DROP_PACKET_OFF);
-		dd->do_drop = 0;
+		dd->do_drop = false;
 	}
 
 	/* make sure the link is not "up" */