IB/ipath: Use S_ABORT not cancel and abort on exit freeze mode after recovery

This centralizes the use of the abort functionality, removes the
unneeded buffer cancel (abort does the same thing), sets up to ignore
launch errors after abort, same as cancel.  We need abort on exit from
freeze mode to avoid having buffers stuck in the busy state, if a user
process happened to complete the send while we were in freeze mode
doing the recovery.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 36 insertions, 21 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index e9639860b48d..8b611796f33e 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -706,9 +706,9 @@ void ipath_disarm_piobufs(struct ipath_devdata *dd, unsigned first,
 	u64 sendctrl, sendorig;
 
 	ipath_cdbg(PKT, "disarm %u PIObufs first=%u\n", cnt, first);
-	sendorig = dd->ipath_sendctrl | INFINIPATH_S_DISARM;
+	sendorig = dd->ipath_sendctrl;
 	for (i = first; i < last; i++) {
-		sendctrl = sendorig |
+		sendctrl = sendorig  | INFINIPATH_S_DISARM |
 			(i << INFINIPATH_S_DISARMPIOBUF_SHIFT);
 		ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
 				 sendctrl);
@@ -719,12 +719,12 @@ void ipath_disarm_piobufs(struct ipath_devdata *dd, unsigned first,
 	 * while we were looping; no critical bits that would require
 	 * locking.
 	 *
-	 * Write a 0, and then the original value, reading scratch in
+	 * disable PIOAVAILUPD, then re-enable, reading scratch in
 	 * between.  This seems to avoid a chip timing race that causes
 	 * pioavail updates to memory to stop.
 	 */
 	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
-			 0);
+			 sendorig & ~IPATH_S_PIOBUFAVAILUPD);
 	sendorig = ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
 	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
 			 dd->ipath_sendctrl);
@@ -1596,6 +1596,35 @@ int ipath_waitfor_mdio_cmdready(struct ipath_devdata *dd)
 	return ret;
 }
 
+
+/*
+ * Flush all sends that might be in the ready to send state, as well as any
+ * that are in the process of being sent.   Used whenever we need to be
+ * sure the send side is idle.  Cleans up all buffer state by canceling
+ * all pio buffers, and issuing an abort, which cleans up anything in the
+ * launch fifo.  The cancel is superfluous on some chip versions, but
+ * it's safer to always do it.
+ * PIOAvail bits are updated by the chip as if normal send had happened.
+ */
+void ipath_cancel_sends(struct ipath_devdata *dd)
+{
+	ipath_dbg("Cancelling all in-progress send buffers\n");
+	dd->ipath_lastcancel = jiffies+HZ/2; /* skip armlaunch errs a bit */
+	/*
+	 * the abort bit is auto-clearing.  We read scratch to be sure
+	 * that cancels and the abort have taken effect in the chip.
+	 */
+	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
+		INFINIPATH_S_ABORT);
+	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+	ipath_disarm_piobufs(dd, 0,
+		(unsigned)(dd->ipath_piobcnt2k + dd->ipath_piobcnt4k));
+
+	/* and again, be sure all have hit the chip */
+	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+}
+
+
 static void ipath_set_ib_lstate(struct ipath_devdata *dd, int which)
 {
 	static const char *what[4] = {
@@ -1617,14 +1646,8 @@ static void ipath_set_ib_lstate(struct ipath_devdata *dd, int which)
 			   INFINIPATH_IBCS_LINKTRAININGSTATE_MASK]);
 	/* flush all queued sends when going to DOWN or INIT, to be sure that
 	 * they don't block MAD packets */
-	if (!linkcmd || linkcmd == INFINIPATH_IBCC_LINKCMD_INIT) {
-		ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
-				 INFINIPATH_S_ABORT);
-		ipath_disarm_piobufs(dd, dd->ipath_lastport_piobuf,
-		                    (unsigned)(dd->ipath_piobcnt2k +
-				    dd->ipath_piobcnt4k) -
-				    dd->ipath_lastport_piobuf);
-	}
+	if (!linkcmd || linkcmd == INFINIPATH_IBCC_LINKCMD_INIT)
+		ipath_cancel_sends(dd);
 
 	ipath_write_kreg(dd, dd->ipath_kregs->kr_ibcctrl,
 			 dd->ipath_ibcctrl | which);
@@ -1967,17 +1990,9 @@ void ipath_shutdown_device(struct ipath_devdata *dd)
 	 */
 	udelay(5);
 
-	/*
-	 * abort any armed or launched PIO buffers that didn't go. (self
-	 * clearing).  Will cause any packet currently being transmitted to
-	 * go out with an EBP, and may also cause a short packet error on
-	 * the receiver.
-	 */
-	ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
-			 INFINIPATH_S_ABORT);
-
 	ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKINITCMD_DISABLE <<
 			    INFINIPATH_IBCC_LINKINITCMD_SHIFT);
+	ipath_cancel_sends(dd);
 
 	/* disable IBC */
 	dd->ipath_control &= ~INFINIPATH_C_LINKENABLE;