scsi: ibmvfc: Define generic queue structure for CRQs

The primary and async CRQs are nearly identical outside of the format and
length of each message entry in the dma mapped page that represents the
queue data. These queues can be represented with a generic queue structure
that uses a union to differentiate between message format of the mapped
page.

This structure will further be leveraged in a followup patcheset that
introduces Sub-CRQs.

Link: https://lore.kernel.org/r/20210106201835.1053593-2-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 107 insertions, 62 deletions

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 42e4d35e0d35..c8e7c4701ac4 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -660,7 +660,7 @@ static void ibmvfc_init_host(struct ibmvfc_host *vhost)
 	}
 
 	if (!ibmvfc_set_host_state(vhost, IBMVFC_INITIALIZING)) {
-		memset(vhost->async_crq.msgs, 0, PAGE_SIZE);
+		memset(vhost->async_crq.msgs.async, 0, PAGE_SIZE);
 		vhost->async_crq.cur = 0;
 
 		list_for_each_entry(tgt, &vhost->targets, queue)
@@ -714,6 +714,23 @@ static int ibmvfc_send_crq_init_complete(struct ibmvfc_host *vhost)
 }
 
 /**
+ * ibmvfc_free_queue - Deallocate queue
+ * @vhost:	ibmvfc host struct
+ * @queue:	ibmvfc queue struct
+ *
+ * Unmaps dma and deallocates page for messages
+ **/
+static void ibmvfc_free_queue(struct ibmvfc_host *vhost,
+			      struct ibmvfc_queue *queue)
+{
+	struct device *dev = vhost->dev;
+
+	dma_unmap_single(dev, queue->msg_token, PAGE_SIZE, DMA_BIDIRECTIONAL);
+	free_page((unsigned long)queue->msgs.handle);
+	queue->msgs.handle = NULL;
+}
+
+/**
  * ibmvfc_release_crq_queue - Deallocates data and unregisters CRQ
  * @vhost:	ibmvfc host struct
  *
@@ -724,7 +741,7 @@ static void ibmvfc_release_crq_queue(struct ibmvfc_host *vhost)
 {
 	long rc = 0;
 	struct vio_dev *vdev = to_vio_dev(vhost->dev);
-	struct ibmvfc_crq_queue *crq = &vhost->crq;
+	struct ibmvfc_queue *crq = &vhost->crq;
 
 	ibmvfc_dbg(vhost, "Releasing CRQ\n");
 	free_irq(vdev->irq, vhost);
@@ -737,8 +754,8 @@ static void ibmvfc_release_crq_queue(struct ibmvfc_host *vhost)
 
 	vhost->state = IBMVFC_NO_CRQ;
 	vhost->logged_in = 0;
-	dma_unmap_single(vhost->dev, crq->msg_token, PAGE_SIZE, DMA_BIDIRECTIONAL);
-	free_page((unsigned long)crq->msgs);
+
+	ibmvfc_free_queue(vhost, crq);
 }
 
 /**
@@ -778,7 +795,7 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)
 	int rc = 0;
 	unsigned long flags;
 	struct vio_dev *vdev = to_vio_dev(vhost->dev);
-	struct ibmvfc_crq_queue *crq = &vhost->crq;
+	struct ibmvfc_queue *crq = &vhost->crq;
 
 	/* Close the CRQ */
 	do {
@@ -792,7 +809,7 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)
 	vhost->logged_in = 0;
 
 	/* Clean out the queue */
-	memset(crq->msgs, 0, PAGE_SIZE);
+	memset(crq->msgs.crq, 0, PAGE_SIZE);
 	crq->cur = 0;
 
 	/* And re-open it again */
@@ -1238,6 +1255,7 @@ static void ibmvfc_gather_partition_info(struct ibmvfc_host *vhost)
 static void ibmvfc_set_login_info(struct ibmvfc_host *vhost)
 {
 	struct ibmvfc_npiv_login *login_info = &vhost->login_info;
+	struct ibmvfc_queue *async_crq = &vhost->async_crq;
 	struct device_node *of_node = vhost->dev->of_node;
 	const char *location;
 
@@ -1257,7 +1275,8 @@ static void ibmvfc_set_login_info(struct ibmvfc_host *vhost)
 	login_info->max_cmds = cpu_to_be32(max_requests + IBMVFC_NUM_INTERNAL_REQ);
 	login_info->capabilities = cpu_to_be64(IBMVFC_CAN_MIGRATE | IBMVFC_CAN_SEND_VF_WWPN);
 	login_info->async.va = cpu_to_be64(vhost->async_crq.msg_token);
-	login_info->async.len = cpu_to_be32(vhost->async_crq.size * sizeof(*vhost->async_crq.msgs));
+	login_info->async.len = cpu_to_be32(async_crq->size *
+					    sizeof(*async_crq->msgs.async));
 	strncpy(login_info->partition_name, vhost->partition_name, IBMVFC_MAX_NAME);
 	strncpy(login_info->device_name,
 		dev_name(&vhost->host->shost_gendev), IBMVFC_MAX_NAME);
@@ -3230,10 +3249,10 @@ static struct scsi_host_template driver_template = {
  **/
 static struct ibmvfc_async_crq *ibmvfc_next_async_crq(struct ibmvfc_host *vhost)
 {
-	struct ibmvfc_async_crq_queue *async_crq = &vhost->async_crq;
+	struct ibmvfc_queue *async_crq = &vhost->async_crq;
 	struct ibmvfc_async_crq *crq;
 
-	crq = &async_crq->msgs[async_crq->cur];
+	crq = &async_crq->msgs.async[async_crq->cur];
 	if (crq->valid & 0x80) {
 		if (++async_crq->cur == async_crq->size)
 			async_crq->cur = 0;
@@ -3253,10 +3272,10 @@ static struct ibmvfc_async_crq *ibmvfc_next_async_crq(struct ibmvfc_host *vhost)
  **/
 static struct ibmvfc_crq *ibmvfc_next_crq(struct ibmvfc_host *vhost)
 {
-	struct ibmvfc_crq_queue *queue = &vhost->crq;
+	struct ibmvfc_queue *queue = &vhost->crq;
 	struct ibmvfc_crq *crq;
 
-	crq = &queue->msgs[queue->cur];
+	crq = &queue->msgs.crq[queue->cur];
 	if (crq->valid & 0x80) {
 		if (++queue->cur == queue->size)
 			queue->cur = 0;
@@ -4896,6 +4915,54 @@ static int ibmvfc_work(void *data)
 }
 
 /**
+ * ibmvfc_alloc_queue - Allocate queue
+ * @vhost:	ibmvfc host struct
+ * @queue:	ibmvfc queue to allocate
+ * @fmt:	queue format to allocate
+ *
+ * Returns:
+ *	0 on success / non-zero on failure
+ **/
+static int ibmvfc_alloc_queue(struct ibmvfc_host *vhost,
+			      struct ibmvfc_queue *queue,
+			      enum ibmvfc_msg_fmt fmt)
+{
+	struct device *dev = vhost->dev;
+	size_t fmt_size;
+
+	ENTER;
+	switch (fmt) {
+	case IBMVFC_CRQ_FMT:
+		fmt_size = sizeof(*queue->msgs.crq);
+		break;
+	case IBMVFC_ASYNC_FMT:
+		fmt_size = sizeof(*queue->msgs.async);
+		break;
+	default:
+		dev_warn(dev, "Unknown command/response queue message format: %d\n", fmt);
+		return -EINVAL;
+	}
+
+	queue->msgs.handle = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!queue->msgs.handle)
+		return -ENOMEM;
+
+	queue->msg_token = dma_map_single(dev, queue->msgs.handle, PAGE_SIZE,
+					  DMA_BIDIRECTIONAL);
+
+	if (dma_mapping_error(dev, queue->msg_token)) {
+		free_page((unsigned long)queue->msgs.handle);
+		queue->msgs.handle = NULL;
+		return -ENOMEM;
+	}
+
+	queue->cur = 0;
+	queue->fmt = fmt;
+	queue->size = PAGE_SIZE / fmt_size;
+	return 0;
+}
+
+/**
  * ibmvfc_init_crq - Initializes and registers CRQ with hypervisor
  * @vhost:	ibmvfc host struct
  *
@@ -4910,21 +4977,12 @@ static int ibmvfc_init_crq(struct ibmvfc_host *vhost)
 	int rc, retrc = -ENOMEM;
 	struct device *dev = vhost->dev;
 	struct vio_dev *vdev = to_vio_dev(dev);
-	struct ibmvfc_crq_queue *crq = &vhost->crq;
+	struct ibmvfc_queue *crq = &vhost->crq;
 
 	ENTER;
-	crq->msgs = (struct ibmvfc_crq *)get_zeroed_page(GFP_KERNEL);
-
-	if (!crq->msgs)
+	if (ibmvfc_alloc_queue(vhost, crq, IBMVFC_CRQ_FMT))
 		return -ENOMEM;
 
-	crq->size = PAGE_SIZE / sizeof(*crq->msgs);
-	crq->msg_token = dma_map_single(dev, crq->msgs,
-					PAGE_SIZE, DMA_BIDIRECTIONAL);
-
-	if (dma_mapping_error(dev, crq->msg_token))
-		goto map_failed;
-
 	retrc = rc = plpar_hcall_norets(H_REG_CRQ, vdev->unit_address,
 					crq->msg_token, PAGE_SIZE);
 
@@ -4953,7 +5011,6 @@ static int ibmvfc_init_crq(struct ibmvfc_host *vhost)
 		goto req_irq_failed;
 	}
 
-	crq->cur = 0;
 	LEAVE;
 	return retrc;
 
@@ -4963,9 +5020,7 @@ req_irq_failed:
 		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
 reg_crq_failed:
-	dma_unmap_single(dev, crq->msg_token, PAGE_SIZE, DMA_BIDIRECTIONAL);
-map_failed:
-	free_page((unsigned long)crq->msgs);
+	ibmvfc_free_queue(vhost, crq);
 	return retrc;
 }
 
@@ -4978,7 +5033,7 @@ map_failed:
  **/
 static void ibmvfc_free_mem(struct ibmvfc_host *vhost)
 {
-	struct ibmvfc_async_crq_queue *async_q = &vhost->async_crq;
+	struct ibmvfc_queue *async_q = &vhost->async_crq;
 
 	ENTER;
 	mempool_destroy(vhost->tgt_pool);
@@ -4988,9 +5043,7 @@ static void ibmvfc_free_mem(struct ibmvfc_host *vhost)
 	dma_free_coherent(vhost->dev, sizeof(*vhost->login_buf),
 			  vhost->login_buf, vhost->login_buf_dma);
 	dma_pool_destroy(vhost->sg_pool);
-	dma_unmap_single(vhost->dev, async_q->msg_token,
-			 async_q->size * sizeof(*async_q->msgs), DMA_BIDIRECTIONAL);
-	free_page((unsigned long)async_q->msgs);
+	ibmvfc_free_queue(vhost, async_q);
 	LEAVE;
 }
 
@@ -5003,26 +5056,15 @@ static void ibmvfc_free_mem(struct ibmvfc_host *vhost)
  **/
 static int ibmvfc_alloc_mem(struct ibmvfc_host *vhost)
 {
-	struct ibmvfc_async_crq_queue *async_q = &vhost->async_crq;
+	struct ibmvfc_queue *async_q = &vhost->async_crq;
 	struct device *dev = vhost->dev;
 
 	ENTER;
-	async_q->msgs = (struct ibmvfc_async_crq *)get_zeroed_page(GFP_KERNEL);
-	if (!async_q->msgs) {
-		dev_err(dev, "Couldn't allocate async queue.\n");
+	if (ibmvfc_alloc_queue(vhost, async_q, IBMVFC_ASYNC_FMT)) {
+		dev_err(dev, "Couldn't allocate/map async queue.\n");
 		goto nomem;
 	}
 
-	async_q->size = PAGE_SIZE / sizeof(struct ibmvfc_async_crq);
-	async_q->msg_token = dma_map_single(dev, async_q->msgs,
-					    async_q->size * sizeof(*async_q->msgs),
-					    DMA_BIDIRECTIONAL);
-
-	if (dma_mapping_error(dev, async_q->msg_token)) {
-		dev_err(dev, "Failed to map async queue\n");
-		goto free_async_crq;
-	}
-
 	vhost->sg_pool = dma_pool_create(IBMVFC_NAME, dev,
 					 SG_ALL * sizeof(struct srp_direct_buf),
 					 sizeof(struct srp_direct_buf), 0);
@@ -5077,10 +5119,7 @@ free_login_buffer:
 free_sg_pool:
 	dma_pool_destroy(vhost->sg_pool);
 unmap_async_crq:
-	dma_unmap_single(dev, async_q->msg_token,
-			 async_q->size * sizeof(*async_q->msgs), DMA_BIDIRECTIONAL);
-free_async_crq:
-	free_page((unsigned long)async_q->msgs);
+	ibmvfc_free_queue(vhost, async_q);
 nomem:
 	LEAVE;
 	return -ENOMEM;
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.h b/drivers/scsi/ibmvscsi/ibmvfc.h
index 9d58cfd774d3..5bf1621223d6 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.h
+++ b/drivers/scsi/ibmvscsi/ibmvfc.h
@@ -645,12 +645,6 @@ struct ibmvfc_crq {
 	volatile __be64 ioba;
 } __packed __aligned(8);
 
-struct ibmvfc_crq_queue {
-	struct ibmvfc_crq *msgs;
-	int size, cur;
-	dma_addr_t msg_token;
-};
-
 enum ibmvfc_ae_link_state {
 	IBMVFC_AE_LS_LINK_UP		= 0x01,
 	IBMVFC_AE_LS_LINK_BOUNCED	= 0x02,
@@ -678,12 +672,6 @@ struct ibmvfc_async_crq {
 	__be64 reserved;
 } __packed __aligned(8);
 
-struct ibmvfc_async_crq_queue {
-	struct ibmvfc_async_crq *msgs;
-	int size, cur;
-	dma_addr_t msg_token;
-};
-
 union ibmvfc_iu {
 	struct ibmvfc_mad_common mad_common;
 	struct ibmvfc_npiv_login_mad npiv_login;
@@ -763,6 +751,24 @@ struct ibmvfc_event_pool {
 	dma_addr_t iu_token;
 };
 
+enum ibmvfc_msg_fmt {
+	IBMVFC_CRQ_FMT = 0,
+	IBMVFC_ASYNC_FMT,
+};
+
+union ibmvfc_msgs {
+	void *handle;
+	struct ibmvfc_crq *crq;
+	struct ibmvfc_async_crq *async;
+};
+
+struct ibmvfc_queue {
+	union ibmvfc_msgs msgs;
+	dma_addr_t msg_token;
+	enum ibmvfc_msg_fmt fmt;
+	int size, cur;
+};
+
 enum ibmvfc_host_action {
 	IBMVFC_HOST_ACTION_NONE = 0,
 	IBMVFC_HOST_ACTION_RESET,
@@ -808,8 +814,8 @@ struct ibmvfc_host {
 	struct ibmvfc_event_pool pool;
 	struct dma_pool *sg_pool;
 	mempool_t *tgt_pool;
-	struct ibmvfc_crq_queue crq;
-	struct ibmvfc_async_crq_queue async_crq;
+	struct ibmvfc_queue crq;
+	struct ibmvfc_queue async_crq;
 	struct ibmvfc_npiv_login login_info;
 	union ibmvfc_npiv_login_data *login_buf;
 	dma_addr_t login_buf_dma;