1 files changed, 60 insertions, 0 deletions

diff --git a/drivers/scsi/libfc/fc_libfc.c b/drivers/scsi/libfc/fc_libfc.c
index 6a48c28e4420..ae3abef6523e 100644
--- a/drivers/scsi/libfc/fc_libfc.c
+++ b/drivers/scsi/libfc/fc_libfc.c
@@ -35,6 +35,23 @@ unsigned int fc_debug_logging;
 module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
 
+DEFINE_MUTEX(fc_prov_mutex);
+
+/*
+ * Providers which primarily send requests and PRLIs.
+ */
+struct fc4_prov *fc_active_prov[FC_FC4_PROV_SIZE] = {
+	[0] = &fc_rport_t0_prov,
+	[FC_TYPE_FCP] = &fc_rport_fcp_init,
+};
+
+/*
+ * Providers which receive requests.
+ */
+struct fc4_prov *fc_passive_prov[FC_FC4_PROV_SIZE] = {
+	[FC_TYPE_ELS] = &fc_lport_els_prov,
+};
+
 /**
  * libfc_init() - Initialize libfc.ko
  */
@@ -210,3 +227,46 @@ void fc_fill_reply_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
 	fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset);
 }
 EXPORT_SYMBOL(fc_fill_reply_hdr);
+
+/**
+ * fc_fc4_register_provider() - register FC-4 upper-level provider.
+ * @type: FC-4 type, such as FC_TYPE_FCP
+ * @prov: structure describing provider including ops vector.
+ *
+ * Returns 0 on success, negative error otherwise.
+ */
+int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov)
+{
+	struct fc4_prov **prov_entry;
+	int ret = 0;
+
+	if (type >= FC_FC4_PROV_SIZE)
+		return -EINVAL;
+	mutex_lock(&fc_prov_mutex);
+	prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type;
+	if (*prov_entry)
+		ret = -EBUSY;
+	else
+		*prov_entry = prov;
+	mutex_unlock(&fc_prov_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(fc_fc4_register_provider);
+
+/**
+ * fc_fc4_deregister_provider() - deregister FC-4 upper-level provider.
+ * @type: FC-4 type, such as FC_TYPE_FCP
+ * @prov: structure describing provider including ops vector.
+ */
+void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
+{
+	BUG_ON(type >= FC_FC4_PROV_SIZE);
+	mutex_lock(&fc_prov_mutex);
+	if (prov->recv)
+		rcu_assign_pointer(fc_passive_prov[type], NULL);
+	else
+		rcu_assign_pointer(fc_active_prov[type], NULL);
+	mutex_unlock(&fc_prov_mutex);
+	synchronize_rcu();
+}
+EXPORT_SYMBOL(fc_fc4_deregister_provider);