IB/SA: Modify SA to implicitly cache Class Port info

SA will query and cache class port info as part of
its initialization. SA will also invalidate and
refresh the cache based on specific events. Callers such
as IPoIB and CM can query the SA to get the classportinfo
information. Apart from making the caller code much simpler,
this change puts the onus on the SA to query and maintain
classportinfo much like how it maitains the address handle to the SM.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 123 insertions, 52 deletions

diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index de2d586381cb..8a4b1f030e52 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -56,6 +56,8 @@
 #define IB_SA_LOCAL_SVC_TIMEOUT_MIN		100
 #define IB_SA_LOCAL_SVC_TIMEOUT_DEFAULT		2000
 #define IB_SA_LOCAL_SVC_TIMEOUT_MAX		200000
+#define IB_SA_CPI_MAX_RETRY_CNT			3
+#define IB_SA_CPI_RETRY_WAIT			1000 /*msecs */
 static int sa_local_svc_timeout_ms = IB_SA_LOCAL_SVC_TIMEOUT_DEFAULT;
 
 struct ib_sa_sm_ah {
@@ -67,6 +69,7 @@ struct ib_sa_sm_ah {
 
 struct ib_sa_classport_cache {
 	bool valid;
+	int retry_cnt;
 	struct ib_class_port_info data;
 };
 
@@ -75,6 +78,7 @@ struct ib_sa_port {
 	struct ib_sa_sm_ah  *sm_ah;
 	struct work_struct   update_task;
 	struct ib_sa_classport_cache classport_info;
+	struct delayed_work ib_cpi_work;
 	spinlock_t                   classport_lock; /* protects class port info set */
 	spinlock_t           ah_lock;
 	u8                   port_num;
@@ -123,7 +127,7 @@ struct ib_sa_guidinfo_query {
 };
 
 struct ib_sa_classport_info_query {
-	void (*callback)(int, struct ib_class_port_info *, void *);
+	void (*callback)(void *);
 	void *context;
 	struct ib_sa_query sa_query;
 };
@@ -1642,7 +1646,41 @@ err1:
 }
 EXPORT_SYMBOL(ib_sa_guid_info_rec_query);
 
-/* Support get SA ClassPortInfo */
+bool ib_sa_sendonly_fullmem_support(struct ib_sa_client *client,
+				    struct ib_device *device,
+				    u8 port_num)
+{
+	struct ib_sa_device *sa_dev = ib_get_client_data(device, &sa_client);
+	struct ib_sa_port *port;
+	bool ret = false;
+	unsigned long flags;
+
+	if (!sa_dev)
+		return ret;
+
+	port  = &sa_dev->port[port_num - sa_dev->start_port];
+
+	spin_lock_irqsave(&port->classport_lock, flags);
+	if (port->classport_info.valid)
+		ret = ib_get_cpi_capmask2(&port->classport_info.data) &
+			IB_SA_CAP_MASK2_SENDONLY_FULL_MEM_SUPPORT;
+	spin_unlock_irqrestore(&port->classport_lock, flags);
+	return ret;
+}
+EXPORT_SYMBOL(ib_sa_sendonly_fullmem_support);
+
+struct ib_classport_info_context {
+	struct completion	done;
+	struct ib_sa_query	*sa_query;
+};
+
+static void ib_classportinfo_cb(void *context)
+{
+	struct ib_classport_info_context *cb_ctx = context;
+
+	complete(&cb_ctx->done);
+}
+
 static void ib_sa_classport_info_rec_callback(struct ib_sa_query *sa_query,
 					      int status,
 					      struct ib_sa_mad *mad)
@@ -1666,54 +1704,30 @@ static void ib_sa_classport_info_rec_callback(struct ib_sa_query *sa_query,
 			sa_query->port->classport_info.valid = true;
 		}
 		spin_unlock_irqrestore(&sa_query->port->classport_lock, flags);
-
-		query->callback(status, &rec, query->context);
-	} else {
-		query->callback(status, NULL, query->context);
 	}
+	query->callback(query->context);
 }
 
-static void ib_sa_portclass_info_rec_release(struct ib_sa_query *sa_query)
+static void ib_sa_classport_info_rec_release(struct ib_sa_query *sa_query)
 {
 	kfree(container_of(sa_query, struct ib_sa_classport_info_query,
 			   sa_query));
 }
 
-int ib_sa_classport_info_rec_query(struct ib_sa_client *client,
-				   struct ib_device *device, u8 port_num,
-				   int timeout_ms, gfp_t gfp_mask,
-				   void (*callback)(int status,
-						    struct ib_class_port_info *resp,
-						    void *context),
-				   void *context,
-				   struct ib_sa_query **sa_query)
+static int ib_sa_classport_info_rec_query(struct ib_sa_port *port,
+					  int timeout_ms,
+					  void (*callback)(void *context),
+					  void *context,
+					  struct ib_sa_query **sa_query)
 {
-	struct ib_sa_classport_info_query *query;
-	struct ib_sa_device *sa_dev = ib_get_client_data(device, &sa_client);
-	struct ib_sa_port *port;
 	struct ib_mad_agent *agent;
+	struct ib_sa_classport_info_query *query;
 	struct ib_sa_mad *mad;
-	struct ib_class_port_info cached_class_port_info;
+	gfp_t gfp_mask = GFP_KERNEL;
 	int ret;
-	unsigned long flags;
 
-	if (!sa_dev)
-		return -ENODEV;
-
-	port  = &sa_dev->port[port_num - sa_dev->start_port];
 	agent = port->agent;
 
-	/* Use cached ClassPortInfo attribute if valid instead of sending mad */
-	spin_lock_irqsave(&port->classport_lock, flags);
-	if (port->classport_info.valid && callback) {
-		memcpy(&cached_class_port_info, &port->classport_info.data,
-		       sizeof(cached_class_port_info));
-		spin_unlock_irqrestore(&port->classport_lock, flags);
-		callback(0, &cached_class_port_info, context);
-		return 0;
-	}
-	spin_unlock_irqrestore(&port->classport_lock, flags);
-
 	query = kzalloc(sizeof(*query), gfp_mask);
 	if (!query)
 		return -ENOMEM;
@@ -1721,20 +1735,16 @@ int ib_sa_classport_info_rec_query(struct ib_sa_client *client,
 	query->sa_query.port = port;
 	ret = alloc_mad(&query->sa_query, gfp_mask);
 	if (ret)
-		goto err1;
+		goto err_free;
 
-	ib_sa_client_get(client);
-	query->sa_query.client = client;
-	query->callback        = callback;
-	query->context         = context;
+	query->callback = callback;
+	query->context = context;
 
 	mad = query->sa_query.mad_buf->mad;
 	init_mad(mad, agent);
 
-	query->sa_query.callback = callback ? ib_sa_classport_info_rec_callback : NULL;
-
-	query->sa_query.release  = ib_sa_portclass_info_rec_release;
-	/* support GET only */
+	query->sa_query.callback = ib_sa_classport_info_rec_callback;
+	query->sa_query.release  = ib_sa_classport_info_rec_release;
 	mad->mad_hdr.method	 = IB_MGMT_METHOD_GET;
 	mad->mad_hdr.attr_id	 = cpu_to_be16(IB_SA_ATTR_CLASS_PORTINFO);
 	mad->sa_hdr.comp_mask	 = 0;
@@ -1742,20 +1752,71 @@ int ib_sa_classport_info_rec_query(struct ib_sa_client *client,
 
 	ret = send_mad(&query->sa_query, timeout_ms, gfp_mask);
 	if (ret < 0)
-		goto err2;
+		goto err_free_mad;
 
 	return ret;
 
-err2:
+err_free_mad:
 	*sa_query = NULL;
-	ib_sa_client_put(query->sa_query.client);
 	free_mad(&query->sa_query);
 
-err1:
+err_free:
 	kfree(query);
 	return ret;
 }
-EXPORT_SYMBOL(ib_sa_classport_info_rec_query);
+
+static void update_ib_cpi(struct work_struct *work)
+{
+	struct ib_sa_port *port =
+		container_of(work, struct ib_sa_port, ib_cpi_work.work);
+	struct ib_classport_info_context *cb_context;
+	unsigned long flags;
+	int ret;
+
+	/* If the classport info is valid, nothing
+	 * to do here.
+	 */
+	spin_lock_irqsave(&port->classport_lock, flags);
+	if (port->classport_info.valid) {
+		spin_unlock_irqrestore(&port->classport_lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&port->classport_lock, flags);
+
+	cb_context = kmalloc(sizeof(*cb_context), GFP_KERNEL);
+	if (!cb_context)
+		goto err_nomem;
+
+	init_completion(&cb_context->done);
+
+	ret = ib_sa_classport_info_rec_query(port, 3000,
+					     ib_classportinfo_cb, cb_context,
+					     &cb_context->sa_query);
+	if (ret < 0)
+		goto free_cb_err;
+	wait_for_completion(&cb_context->done);
+free_cb_err:
+	kfree(cb_context);
+	spin_lock_irqsave(&port->classport_lock, flags);
+
+	/* If the classport info is still not valid, the query should have
+	 * failed for some reason. Retry issuing the query
+	 */
+	if (!port->classport_info.valid) {
+		port->classport_info.retry_cnt++;
+		if (port->classport_info.retry_cnt <=
+		    IB_SA_CPI_MAX_RETRY_CNT) {
+			unsigned long delay =
+				msecs_to_jiffies(IB_SA_CPI_RETRY_WAIT);
+
+			queue_delayed_work(ib_wq, &port->ib_cpi_work, delay);
+		}
+	}
+	spin_unlock_irqrestore(&port->classport_lock, flags);
+
+err_nomem:
+	return;
+}
 
 static void send_handler(struct ib_mad_agent *agent,
 			 struct ib_mad_send_wc *mad_send_wc)
@@ -1784,7 +1845,8 @@ static void send_handler(struct ib_mad_agent *agent,
 	spin_unlock_irqrestore(&idr_lock, flags);
 
 	free_mad(query);
-	ib_sa_client_put(query->client);
+	if (query->client)
+		ib_sa_client_put(query->client);
 	query->release(query);
 }
 
@@ -1888,10 +1950,17 @@ static void ib_sa_event(struct ib_event_handler *handler,
 
 		if (event->event == IB_EVENT_SM_CHANGE ||
 		    event->event == IB_EVENT_CLIENT_REREGISTER ||
-		    event->event == IB_EVENT_LID_CHANGE) {
+		    event->event == IB_EVENT_LID_CHANGE ||
+		    event->event == IB_EVENT_PORT_ACTIVE) {
+			unsigned long delay =
+				msecs_to_jiffies(IB_SA_CPI_RETRY_WAIT);
+
 			spin_lock_irqsave(&port->classport_lock, flags);
 			port->classport_info.valid = false;
+			port->classport_info.retry_cnt = 0;
 			spin_unlock_irqrestore(&port->classport_lock, flags);
+			queue_delayed_work(ib_wq,
+					   &port->ib_cpi_work, delay);
 		}
 		queue_work(ib_wq, &sa_dev->port[port_num].update_task);
 	}
@@ -1934,6 +2003,8 @@ static void ib_sa_add_one(struct ib_device *device)
 			goto err;
 
 		INIT_WORK(&sa_dev->port[i].update_task, update_sm_ah);
+		INIT_DELAYED_WORK(&sa_dev->port[i].ib_cpi_work,
+				  update_ib_cpi);
 
 		count++;
 	}
@@ -1980,11 +2051,11 @@ static void ib_sa_remove_one(struct ib_device *device, void *client_data)
 		return;
 
 	ib_unregister_event_handler(&sa_dev->event_handler);
-
 	flush_workqueue(ib_wq);
 
 	for (i = 0; i <= sa_dev->end_port - sa_dev->start_port; ++i) {
 		if (rdma_cap_ib_sa(device, i + 1)) {
+			cancel_delayed_work_sync(&sa_dev->port[i].ib_cpi_work);
 			ib_unregister_mad_agent(sa_dev->port[i].agent);
 			if (sa_dev->port[i].sm_ah)
 				kref_put(&sa_dev->port[i].sm_ah->ref, free_sm_ah);