svn commit: r300605 - head/sys/dev/sfxge/common

[Andrew Rybchenko]

Author: arybchik
Date: Tue May 24 12:14:19 2016
New Revision: 300605
URL: https://svnweb.freebsd.org/changeset/base/300605

Log:
  sfxge(4): be ready to receive events immediately after event queues are created
  
  Submitted by:   Mark Spender <mspender at solarflare.com>
  Reviewed by:    gnn
  Sponsored by:   Solarflare Communications, Inc.
  MFC after:      1 week
  Differential Revision:  https://reviews.freebsd.org/D6507

Modified:
  head/sys/dev/sfxge/common/ef10_ev.c
  head/sys/dev/sfxge/common/efx_ev.c

Modified: head/sys/dev/sfxge/common/ef10_ev.c
==============================================================================
--- head/sys/dev/sfxge/common/ef10_ev.c	Tue May 24 12:06:56 2016	(r300604)
+++ head/sys/dev/sfxge/common/ef10_ev.c	Tue May 24 12:14:19 2016	(r300605)
@@ -275,6 +275,11 @@ ef10_ev_qcreate(
 
 	/* Set up the event queue */
 	irq = index;	/* INIT_EVQ expects function-relative vector number */
+
+	/*
+	 * Interrupts may be raised for events immediately after the queue is
+	 * created. See bug58606.
+	 */
 	if ((rc = efx_mcdi_init_evq(enp, index, esmp, n, irq)) != 0)
 		goto fail3;
 

Modified: head/sys/dev/sfxge/common/efx_ev.c
==============================================================================
--- head/sys/dev/sfxge/common/efx_ev.c	Tue May 24 12:06:56 2016	(r300604)
+++ head/sys/dev/sfxge/common/efx_ev.c	Tue May 24 12:14:19 2016	(r300605)
@@ -251,16 +251,27 @@ efx_ev_qcreate(
 	eep->ee_mask = n - 1;
 	eep->ee_esmp = esmp;
 
-	if ((rc = eevop->eevo_qcreate(enp, index, esmp, n, id, eep)) != 0)
-		goto fail2;
-
+	/*
+	 * Set outputs before the queue is created because interrupts may be
+	 * raised for events immediately after the queue is created, before the
+	 * function call below returns. See bug58606.
+	 *
+	 * The eepp pointer passed in by the client must therefore point to data
+	 * shared with the client's event processing context.
+	 */
 	enp->en_ev_qcount++;
 	*eepp = eep;
 
+	if ((rc = eevop->eevo_qcreate(enp, index, esmp, n, id, eep)) != 0)
+		goto fail2;
+
 	return (0);
 
 fail2:
 	EFSYS_PROBE(fail2);
+
+	*eepp = NULL;
+	enp->en_ev_qcount--;
 	EFSYS_KMEM_FREE(enp->en_esip, sizeof (efx_evq_t), eep);
 fail1:
 	EFSYS_PROBE1(fail1, efx_rc_t, rc);