4 files changed, 39 insertions, 13 deletions

diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 08b457c2d294..1645fba0d2d3 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -106,7 +106,10 @@ struct smc_link {
 	unsigned long		*wr_tx_mask;	/* bit mask of used indexes */
 	u32			wr_tx_cnt;	/* number of WR send buffers */
 	wait_queue_head_t	wr_tx_wait;	/* wait for free WR send buf */
-	atomic_t		wr_tx_refcnt;	/* tx refs to link */
+	struct {
+		struct percpu_ref	wr_tx_refs;
+	} ____cacheline_aligned_in_smp;
+	struct completion	tx_ref_comp;
 
 	struct smc_wr_buf	*wr_rx_bufs;	/* WR recv payload buffers */
 	struct ib_recv_wr	*wr_rx_ibs;	/* WR recv meta data */
@@ -122,7 +125,10 @@ struct smc_link {
 
 	struct ib_reg_wr	wr_reg;		/* WR register memory region */
 	wait_queue_head_t	wr_reg_wait;	/* wait for wr_reg result */
-	atomic_t		wr_reg_refcnt;	/* reg refs to link */
+	struct {
+		struct percpu_ref	wr_reg_refs;
+	} ____cacheline_aligned_in_smp;
+	struct completion	reg_ref_comp;
 	enum smc_wr_reg_state	wr_reg_state;	/* state of wr_reg request */
 
 	u8			gid[SMC_GID_SIZE];/* gid matching used vlan id*/
diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index 3b0b7710c6b0..fbee2493091f 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -429,7 +429,7 @@ static void smcd_register_dev(struct ism_dev *ism)
 		u8 *system_eid = NULL;
 
 		system_eid = smcd->ops->get_system_eid();
-		if (system_eid[24] != '0' || system_eid[28] != '0') {
+		if (smcd->ops->supports_v2()) {
 			smc_ism_v2_capable = true;
 			memcpy(smc_ism_v2_system_eid, system_eid,
 			       SMC_MAX_EID_LEN);
diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c
index b0678a417e09..0021065a600a 100644
--- a/net/smc/smc_wr.c
+++ b/net/smc/smc_wr.c
@@ -377,12 +377,11 @@ int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr)
 	if (rc)
 		return rc;
 
-	atomic_inc(&link->wr_reg_refcnt);
+	percpu_ref_get(&link->wr_reg_refs);
 	rc = wait_event_interruptible_timeout(link->wr_reg_wait,
 					      (link->wr_reg_state != POSTED),
 					      SMC_WR_REG_MR_WAIT_TIME);
-	if (atomic_dec_and_test(&link->wr_reg_refcnt))
-		wake_up_all(&link->wr_reg_wait);
+	percpu_ref_put(&link->wr_reg_refs);
 	if (!rc) {
 		/* timeout - terminate link */
 		smcr_link_down_cond_sched(link);
@@ -647,8 +646,10 @@ void smc_wr_free_link(struct smc_link *lnk)
 	smc_wr_wakeup_tx_wait(lnk);
 
 	smc_wr_tx_wait_no_pending_sends(lnk);
-	wait_event(lnk->wr_reg_wait, (!atomic_read(&lnk->wr_reg_refcnt)));
-	wait_event(lnk->wr_tx_wait, (!atomic_read(&lnk->wr_tx_refcnt)));
+	percpu_ref_kill(&lnk->wr_reg_refs);
+	wait_for_completion(&lnk->reg_ref_comp);
+	percpu_ref_kill(&lnk->wr_tx_refs);
+	wait_for_completion(&lnk->tx_ref_comp);
 
 	if (lnk->wr_rx_dma_addr) {
 		ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
@@ -847,6 +848,20 @@ void smc_wr_add_dev(struct smc_ib_device *smcibdev)
 	tasklet_setup(&smcibdev->send_tasklet, smc_wr_tx_tasklet_fn);
 }
 
+static void smcr_wr_tx_refs_free(struct percpu_ref *ref)
+{
+	struct smc_link *lnk = container_of(ref, struct smc_link, wr_tx_refs);
+
+	complete(&lnk->tx_ref_comp);
+}
+
+static void smcr_wr_reg_refs_free(struct percpu_ref *ref)
+{
+	struct smc_link *lnk = container_of(ref, struct smc_link, wr_reg_refs);
+
+	complete(&lnk->reg_ref_comp);
+}
+
 int smc_wr_create_link(struct smc_link *lnk)
 {
 	struct ib_device *ibdev = lnk->smcibdev->ibdev;
@@ -890,9 +905,15 @@ int smc_wr_create_link(struct smc_link *lnk)
 	smc_wr_init_sge(lnk);
 	bitmap_zero(lnk->wr_tx_mask, SMC_WR_BUF_CNT);
 	init_waitqueue_head(&lnk->wr_tx_wait);
-	atomic_set(&lnk->wr_tx_refcnt, 0);
+	rc = percpu_ref_init(&lnk->wr_tx_refs, smcr_wr_tx_refs_free, 0, GFP_KERNEL);
+	if (rc)
+		goto dma_unmap;
+	init_completion(&lnk->tx_ref_comp);
 	init_waitqueue_head(&lnk->wr_reg_wait);
-	atomic_set(&lnk->wr_reg_refcnt, 0);
+	rc = percpu_ref_init(&lnk->wr_reg_refs, smcr_wr_reg_refs_free, 0, GFP_KERNEL);
+	if (rc)
+		goto dma_unmap;
+	init_completion(&lnk->reg_ref_comp);
 	init_waitqueue_head(&lnk->wr_rx_empty_wait);
 	return rc;
 
diff --git a/net/smc/smc_wr.h b/net/smc/smc_wr.h
index 45e9b894d3f8..f3008dda222a 100644
--- a/net/smc/smc_wr.h
+++ b/net/smc/smc_wr.h
@@ -63,14 +63,13 @@ static inline bool smc_wr_tx_link_hold(struct smc_link *link)
 {
 	if (!smc_link_sendable(link))
 		return false;
-	atomic_inc(&link->wr_tx_refcnt);
+	percpu_ref_get(&link->wr_tx_refs);
 	return true;
 }
 
 static inline void smc_wr_tx_link_put(struct smc_link *link)
 {
-	if (atomic_dec_and_test(&link->wr_tx_refcnt))
-		wake_up_all(&link->wr_tx_wait);
+	percpu_ref_put(&link->wr_tx_refs);
 }
 
 static inline void smc_wr_drain_cq(struct smc_link *lnk)