scsi: ibmvfc: Make discovery buffer per protocol channel group

The target discovery buffer that the VIOS populates with targets is
currently a host adapter field. To facilitate the discovery of NVMe targets
as well as SCSI another discovery buffer is required. Move the discovery
buffer out of the host struct and into the ibmvfc_channels struct so that
each channels instance for a given protocol has its own discovery buffer.
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-11-tyreld@linux.ibm.comReviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ibmvscsi/ibmvfc.c

@@ -4935,7 +4935,7 @@ static int ibmvfc_alloc_targets(struct ibmvfc_host *vhost)
 	int i, rc;
 
 	for (i = 0, rc = 0; !rc && i < vhost->num_targets; i++)
-		rc = ibmvfc_alloc_target(vhost, &vhost->disc_buf[i]);
+		rc = ibmvfc_alloc_target(vhost, &vhost->scsi_scrqs.disc_buf[i]);
 
 	return rc;
 }
@@ -4999,9 +4999,9 @@ static void ibmvfc_discover_targets(struct ibmvfc_host *vhost)
 	mad->common.version = cpu_to_be32(1);
 	mad->common.opcode = cpu_to_be32(IBMVFC_DISC_TARGETS);
 	mad->common.length = cpu_to_be16(sizeof(*mad));
-	mad->bufflen = cpu_to_be32(vhost->disc_buf_sz);
-	mad->buffer.va = cpu_to_be64(vhost->disc_buf_dma);
-	mad->buffer.len = cpu_to_be32(vhost->disc_buf_sz);
+	mad->bufflen = cpu_to_be32(vhost->scsi_scrqs.disc_buf_sz);
+	mad->buffer.va = cpu_to_be64(vhost->scsi_scrqs.disc_buf_dma);
+	mad->buffer.len = cpu_to_be32(vhost->scsi_scrqs.disc_buf_sz);
 	mad->flags = cpu_to_be32(IBMVFC_DISC_TGT_PORT_ID_WWPN_LIST);
 	ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_INIT_WAIT);
 
@@ -6119,6 +6119,12 @@ static void ibmvfc_release_sub_crqs(struct ibmvfc_host *vhost)
 	LEAVE;
 }
 
+static void ibmvfc_free_disc_buf(struct device *dev, struct ibmvfc_channels *channels)
+{
+	dma_free_coherent(dev, channels->disc_buf_sz, channels->disc_buf,
+			  channels->disc_buf_dma);
+}
+
 /**
  * ibmvfc_free_mem - Free memory for vhost
  * @vhost:	ibmvfc host struct
@@ -6133,8 +6139,7 @@ static void ibmvfc_free_mem(struct ibmvfc_host *vhost)
 	ENTER;
 	mempool_destroy(vhost->tgt_pool);
 	kfree(vhost->trace);
-	dma_free_coherent(vhost->dev, vhost->disc_buf_sz, vhost->disc_buf,
-			  vhost->disc_buf_dma);
+	ibmvfc_free_disc_buf(vhost->dev, &vhost->scsi_scrqs);
 	dma_free_coherent(vhost->dev, sizeof(*vhost->login_buf),
 			  vhost->login_buf, vhost->login_buf_dma);
 	dma_free_coherent(vhost->dev, sizeof(*vhost->channel_setup_buf),
@@ -6144,6 +6149,21 @@ static void ibmvfc_free_mem(struct ibmvfc_host *vhost)
 	LEAVE;
 }
 
+static int ibmvfc_alloc_disc_buf(struct device *dev, struct ibmvfc_channels *channels)
+{
+	channels->disc_buf_sz = sizeof(*channels->disc_buf) * max_targets;
+	channels->disc_buf = dma_alloc_coherent(dev, channels->disc_buf_sz,
+					     &channels->disc_buf_dma, GFP_KERNEL);
+
+	if (!channels->disc_buf) {
+		dev_err(dev, "Couldn't allocate %s Discover Targets buffer\n",
+			(channels->protocol == IBMVFC_PROTO_SCSI) ? "SCSI" : "NVMe");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
 /**
  * ibmvfc_alloc_mem - Allocate memory for vhost
  * @vhost:	ibmvfc host struct
@@ -6179,21 +6199,15 @@ static int ibmvfc_alloc_mem(struct ibmvfc_host *vhost)
 		goto free_sg_pool;
 	}
 
-	vhost->disc_buf_sz = sizeof(*vhost->disc_buf) * max_targets;
-	vhost->disc_buf = dma_alloc_coherent(dev, vhost->disc_buf_sz,
-					     &vhost->disc_buf_dma, GFP_KERNEL);
-
-	if (!vhost->disc_buf) {
-		dev_err(dev, "Couldn't allocate Discover Targets buffer\n");
+	if (ibmvfc_alloc_disc_buf(dev, &vhost->scsi_scrqs))
 		goto free_login_buffer;
-	}
 
 	vhost->trace = kcalloc(IBMVFC_NUM_TRACE_ENTRIES,
 			       sizeof(struct ibmvfc_trace_entry), GFP_KERNEL);
 	atomic_set(&vhost->trace_index, -1);
 
 	if (!vhost->trace)
-		goto free_disc_buffer;
+		goto free_scsi_disc_buffer;
 
 	vhost->tgt_pool = mempool_create_kmalloc_pool(IBMVFC_TGT_MEMPOOL_SZ,
 						      sizeof(struct ibmvfc_target));
@@ -6219,9 +6233,8 @@ static int ibmvfc_alloc_mem(struct ibmvfc_host *vhost)
 	mempool_destroy(vhost->tgt_pool);
 free_trace:
 	kfree(vhost->trace);
-free_disc_buffer:
-	dma_free_coherent(dev, vhost->disc_buf_sz, vhost->disc_buf,
-			  vhost->disc_buf_dma);
+free_scsi_disc_buffer:
+	ibmvfc_free_disc_buf(dev, &vhost->scsi_scrqs);
 free_login_buffer:
 	dma_free_coherent(dev, sizeof(*vhost->login_buf),
 			  vhost->login_buf, vhost->login_buf_dma);

drivers/scsi/ibmvscsi/ibmvfc.h

@@ -827,6 +827,9 @@ struct ibmvfc_channels {
 	unsigned int active_queues;
 	unsigned int desired_queues;
 	unsigned int max_queues;
+	int disc_buf_sz;
+	struct ibmvfc_discover_targets_entry *disc_buf;
+	dma_addr_t disc_buf_dma;
 };
 
 enum ibmvfc_host_action {
@@ -881,9 +884,7 @@ struct ibmvfc_host {
 	dma_addr_t login_buf_dma;
 	struct ibmvfc_channel_setup *channel_setup_buf;
 	dma_addr_t channel_setup_dma;
-	int disc_buf_sz;
 	int log_level;
-	struct ibmvfc_discover_targets_entry *disc_buf;
 	struct mutex passthru_mutex;
 	unsigned int max_vios_scsi_channels;
 	int task_set;
@@ -904,7 +905,6 @@ struct ibmvfc_host {
 #define IBMVFC_AE_LINKUP	0x0001
 #define IBMVFC_AE_LINKDOWN	0x0002
 #define IBMVFC_AE_RSCN		0x0004
-	dma_addr_t disc_buf_dma;
 	unsigned int partition_number;
 	char partition_name[97];
 	void (*job_step) (struct ibmvfc_host *);