s390/ism: ism driver implies smc protocol

Since commit a72178cfe855 ("net/smc: Fix dependency of SMC on ISM")
you can build the ism code without selecting the SMC network protocol.
That leaves some ism functions be reported as unused. Move these
functions under the conditional compile with CONFIG_SMC.

Also codify the suggestion to also configure the SMC protocol in ism's
Kconfig - but with an "imply" rather than a "select" as SMC depends on
other config options and allow for a deliberate decision not to build
SMC. Also, mention that in ISM's help.

Fixes: a72178cfe855 ("net/smc: Fix dependency of SMC on ISM")
Reported-by: Randy Dunlap <[e-mail]>
Closes: https://lore.kernel.org/netdev/[e-mail]/
Signed-off-by: Gerd Bayer <[e-mail]>
Reviewed-by: Wenjia Zhang <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Acked-by: Randy Dunlap <[e-mail]>
Tested-by: Randy Dunlap <[e-mail]> # build-tested
Signed-off-by: David S. Miller <[e-mail]>

drivers/s390/net/Kconfig

···
 config ISM
 	tristate "Support for ISM vPCI Adapter"
 	depends on PCI
+	imply SMC
 	default n
 	help
 	  Select this option if you want to use the Internal Shared Memory
-	  vPCI Adapter.
+	  vPCI Adapter. The adapter can be used with the SMC network protocol.
 
 	  To compile as a module choose M. The module name is ism.
 	  If unsure, choose N.

drivers/s390/net/ism_drv.c

···
 MODULE_DEVICE_TABLE(pci, ism_device_table);
 
 static debug_info_t *ism_debug_info;
-static const struct smcd_ops ism_ops;
 
 #define NO_CLIENT		0xff		/* must be >= MAX_CLIENTS */
 static struct ism_client *clients[MAX_CLIENTS];	/* use an array rather than */
···
 	return ret;
 }
 
-static int ism_query_rgid(struct ism_dev *ism, u64 rgid, u32 vid_valid,
-			  u32 vid)
-{
-	union ism_query_rgid cmd;
-
-	memset(&cmd, 0, sizeof(cmd));
-	cmd.request.hdr.cmd = ISM_QUERY_RGID;
-	cmd.request.hdr.len = sizeof(cmd.request);
-
-	cmd.request.rgid = rgid;
-	cmd.request.vlan_valid = vid_valid;
-	cmd.request.vlan_id = vid;
-
-	return ism_cmd(ism, &cmd);
-}
-
 static void ism_free_dmb(struct ism_dev *ism, struct ism_dmb *dmb)
 {
 	clear_bit(dmb->sba_idx, ism->sba_bitmap);
···
 	return ism_cmd(ism, &cmd);
 }
 
-static int ism_signal_ieq(struct ism_dev *ism, u64 rgid, u32 trigger_irq,
-			  u32 event_code, u64 info)
-{
-	union ism_sig_ieq cmd;
-
-	memset(&cmd, 0, sizeof(cmd));
-	cmd.request.hdr.cmd = ISM_SIGNAL_IEQ;
-	cmd.request.hdr.len = sizeof(cmd.request);
-
-	cmd.request.rgid = rgid;
-	cmd.request.trigger_irq = trigger_irq;
-	cmd.request.event_code = event_code;
-	cmd.request.info = info;
-
-	return ism_cmd(ism, &cmd);
-}
-
 static unsigned int max_bytes(unsigned int start, unsigned int len,
 			      unsigned int boundary)
 {
···
 }
 EXPORT_SYMBOL_GPL(ism_get_seid);
 
-static u16 ism_get_chid(struct ism_dev *ism)
-{
-	if (!ism || !ism->pdev)
-		return 0;
-
-	return to_zpci(ism->pdev)->pchid;
-}
-
 static void ism_handle_event(struct ism_dev *ism)
 {
 	struct ism_event *entry;
···
 	}
 	spin_unlock(&ism->lock);
 	return IRQ_HANDLED;
-}
-
-static u64 ism_get_local_gid(struct ism_dev *ism)
-{
-	return ism->local_gid;
 }
 
 static int ism_dev_init(struct ism_dev *ism)
···
 /*************************** SMC-D Implementation *****************************/
 
 #if IS_ENABLED(CONFIG_SMC)
+static int ism_query_rgid(struct ism_dev *ism, u64 rgid, u32 vid_valid,
+			  u32 vid)
+{
+	union ism_query_rgid cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_QUERY_RGID;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	cmd.request.rgid = rgid;
+	cmd.request.vlan_valid = vid_valid;
+	cmd.request.vlan_id = vid;
+
+	return ism_cmd(ism, &cmd);
+}
+
 static int smcd_query_rgid(struct smcd_dev *smcd, u64 rgid, u32 vid_valid,
 			   u32 vid)
 {
···
 	return ism_cmd_simple(smcd->priv, ISM_RESET_VLAN);
 }
 
+static int ism_signal_ieq(struct ism_dev *ism, u64 rgid, u32 trigger_irq,
+			  u32 event_code, u64 info)
+{
+	union ism_sig_ieq cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.request.hdr.cmd = ISM_SIGNAL_IEQ;
+	cmd.request.hdr.len = sizeof(cmd.request);
+
+	cmd.request.rgid = rgid;
+	cmd.request.trigger_irq = trigger_irq;
+	cmd.request.event_code = event_code;
+	cmd.request.info = info;
+
+	return ism_cmd(ism, &cmd);
+}
+
 static int smcd_signal_ieq(struct smcd_dev *smcd, u64 rgid, u32 trigger_irq,
 			   u32 event_code, u64 info)
 {
···
 		SYSTEM_EID.type[0] != '0';
 }
 
+static u64 ism_get_local_gid(struct ism_dev *ism)
+{
+	return ism->local_gid;
+}
+
 static u64 smcd_get_local_gid(struct smcd_dev *smcd)
 {
 	return ism_get_local_gid(smcd->priv);
+}
+
+static u16 ism_get_chid(struct ism_dev *ism)
+{
+	if (!ism || !ism->pdev)
+		return 0;
+
+	return to_zpci(ism->pdev)->pchid;
 }
 
 static u16 smcd_get_chid(struct smcd_dev *smcd)