soc: fsl: qbman: allow registering a device link for the portal user

Introduce the API required to make sure that the devices that use
the QMan portal are unbound when the portal is unbound.

Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/soc/fsl/qbman/qman.c

@@ -1749,6 +1749,19 @@ struct qman_portal *qman_get_affine_portal(int cpu)
 }
 EXPORT_SYMBOL(qman_get_affine_portal);
 
+int qman_start_using_portal(struct qman_portal *p, struct device *dev)
+{
+	return (!device_link_add(dev, p->config->dev,
+				 DL_FLAG_AUTOREMOVE_CONSUMER)) ? -EINVAL : 0;
+}
+EXPORT_SYMBOL(qman_start_using_portal);
+
+void qman_stop_using_portal(struct qman_portal *p, struct device *dev)
+{
+	device_link_remove(dev, p->config->dev);
+}
+EXPORT_SYMBOL(qman_stop_using_portal);
+
 int qman_p_poll_dqrr(struct qman_portal *p, unsigned int limit)
 {
 	return __poll_portal_fast(p, limit);

include/soc/fsl/qman.h

@@ -32,6 +32,7 @@
 #define __FSL_QMAN_H
 
 #include <linux/bitops.h>
+#include <linux/device.h>
 
 /* Hardware constants */
 #define QM_CHANNEL_SWPORTAL0 0
@@ -914,6 +915,23 @@ u16 qman_affine_channel(int cpu);
  */
 struct qman_portal *qman_get_affine_portal(int cpu);
 
+/**
+ * qman_start_using_portal - register a device link for the portal user
+ * @p: the portal that will be in use
+ * @dev: the device that will use the portal
+ *
+ * Makes sure that the devices that use the portal are unbound when the
+ * portal is unbound
+ */
+int qman_start_using_portal(struct qman_portal *p, struct device *dev);
+
+/**
+ * qman_stop_using_portal - deregister a device link for the portal user
+ * @p: the portal that will no longer be in use
+ * @dev: the device that uses the portal
+ */
+void qman_stop_using_portal(struct qman_portal *p, struct device *dev);
+
 /**
  * qman_p_poll_dqrr - process DQRR (fast-path) entries
  * @limit: the maximum number of DQRR entries to process