s390/ism: Introduce struct ism_dmb

Conceptually, a DMB is a structure that belongs to ISM devices. However,
SMC currently 'owns' this structure. So future exploiters of ISM devices
would be forced to include SMC headers to work - which is just weird.
Therefore, we switch ISM to struct ism_dmb, introduce a new public header
with the definition (will be populated with further API calls later on),
and, add a thin wrapper to please SMC. Since structs smcd_dmb and ism_dmb
are identical, we can simply convert between the two for now.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/s390/net/ism.h

@@ -5,6 +5,7 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 #include <linux/pci.h>
+#include <linux/ism.h>
 #include <net/smc.h>
 #include <asm/pci_insn.h>
 

drivers/s390/net/ism_drv.c

@@ -215,14 +215,14 @@ static int ism_query_rgid(struct smcd_dev *smcd, u64 rgid, u32 vid_valid,
 	return ism_cmd(ism, &cmd);
 }
 
-static void ism_free_dmb(struct ism_dev *ism, struct smcd_dmb *dmb)
+static void ism_free_dmb(struct ism_dev *ism, struct ism_dmb *dmb)
 {
 	clear_bit(dmb->sba_idx, ism->sba_bitmap);
 	dma_free_coherent(&ism->pdev->dev, dmb->dmb_len,
 			  dmb->cpu_addr, dmb->dma_addr);
 }
 
-static int ism_alloc_dmb(struct ism_dev *ism, struct smcd_dmb *dmb)
+static int ism_alloc_dmb(struct ism_dev *ism, struct ism_dmb *dmb)
 {
 	unsigned long bit;
 
@@ -251,7 +251,7 @@ static int ism_alloc_dmb(struct ism_dev *ism, struct smcd_dmb *dmb)
 	return dmb->cpu_addr ? 0 : -ENOMEM;
 }
 
-static int ism_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
+static int ism_register_dmb(struct smcd_dev *smcd, struct ism_dmb *dmb)
 {
 	struct ism_dev *ism = smcd->priv;
 	union ism_reg_dmb cmd;
@@ -282,7 +282,12 @@ static int ism_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
 	return ret;
 }
 
-static int ism_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
+static int smcd_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
+{
+	return ism_register_dmb(smcd, (struct ism_dmb *)dmb);
+}
+
+static int ism_unregister_dmb(struct smcd_dev *smcd, struct ism_dmb *dmb)
 {
 	struct ism_dev *ism = smcd->priv;
 	union ism_unreg_dmb cmd;
@@ -303,6 +308,11 @@ static int ism_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
 	return ret;
 }
 
+static int smcd_unregister_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb)
+{
+	return ism_unregister_dmb(smcd, (struct ism_dmb *)dmb);
+}
+
 static int ism_add_vlan_id(struct smcd_dev *smcd, u64 vlan_id)
 {
 	struct ism_dev *ism = smcd->priv;
@@ -475,8 +485,8 @@ static irqreturn_t ism_handle_irq(int irq, void *data)
 
 static const struct smcd_ops ism_ops = {
 	.query_remote_gid = ism_query_rgid,
-	.register_dmb = ism_register_dmb,
-	.unregister_dmb = ism_unregister_dmb,
+	.register_dmb = smcd_register_dmb,
+	.unregister_dmb = smcd_unregister_dmb,
 	.add_vlan_id = ism_add_vlan_id,
 	.del_vlan_id = ism_del_vlan_id,
 	.set_vlan_required = ism_set_vlan_required,

include/linux/ism.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  Internal Shared Memory
+ *
+ *  Definitions for the ISM module
+ *
+ *  Copyright IBM Corp. 2022
+ */
+#ifndef _ISM_H
+#define _ISM_H
+
+struct ism_dmb {
+	u64 dmb_tok;
+	u64 rgid;
+	u32 dmb_len;
+	u32 sba_idx;
+	u32 vlan_valid;
+	u32 vlan_id;
+	void *cpu_addr;
+	dma_addr_t dma_addr;
+};
+
+#endif	/* _ISM_H */