IB/iser: Restructure allocation/deallocation of connection resources

This is a preparation step to a patch that accepts the number of max
SCSI commands to be supported a session from user space iSCSI tools.

Move the allocation of the login buffer, FMR pool and its associated
page vector from iser_create_ib_conn_res() (which is called prior when
we actually know how many commands should be supported) to
iser_alloc_rx_descriptors() (which is called during the iscsi
connection bind step where this quantity is known).

Also do small refactoring around the deallocation to make that path
similar to the allocation one.

Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 89 insertions, 3 deletions

diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c
index b6d81a86c976..626d950b64a8 100644
--- a/drivers/infiniband/ulp/iser/iser_initiator.c
+++ b/drivers/infiniband/ulp/iser/iser_initiator.c
@@ -170,6 +170,76 @@ static void iser_create_send_desc(struct iser_conn	*ib_conn,
 	}
 }
 
+static void iser_free_login_buf(struct iser_conn *ib_conn)
+{
+	if (!ib_conn->login_buf)
+		return;
+
+	if (ib_conn->login_req_dma)
+		ib_dma_unmap_single(ib_conn->device->ib_device,
+				    ib_conn->login_req_dma,
+				    ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
+
+	if (ib_conn->login_resp_dma)
+		ib_dma_unmap_single(ib_conn->device->ib_device,
+				    ib_conn->login_resp_dma,
+				    ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
+
+	kfree(ib_conn->login_buf);
+
+	/* make sure we never redo any unmapping */
+	ib_conn->login_req_dma = 0;
+	ib_conn->login_resp_dma = 0;
+	ib_conn->login_buf = NULL;
+}
+
+static int iser_alloc_login_buf(struct iser_conn *ib_conn)
+{
+	struct iser_device	*device;
+	int			req_err, resp_err;
+
+	BUG_ON(ib_conn->device == NULL);
+
+	device = ib_conn->device;
+
+	ib_conn->login_buf = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN +
+				     ISER_RX_LOGIN_SIZE, GFP_KERNEL);
+	if (!ib_conn->login_buf)
+		goto out_err;
+
+	ib_conn->login_req_buf  = ib_conn->login_buf;
+	ib_conn->login_resp_buf = ib_conn->login_buf +
+						ISCSI_DEF_MAX_RECV_SEG_LEN;
+
+	ib_conn->login_req_dma = ib_dma_map_single(ib_conn->device->ib_device,
+				(void *)ib_conn->login_req_buf,
+				ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
+
+	ib_conn->login_resp_dma = ib_dma_map_single(ib_conn->device->ib_device,
+				(void *)ib_conn->login_resp_buf,
+				ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
+
+	req_err  = ib_dma_mapping_error(device->ib_device,
+					ib_conn->login_req_dma);
+	resp_err = ib_dma_mapping_error(device->ib_device,
+					ib_conn->login_resp_dma);
+
+	if (req_err || resp_err) {
+		if (req_err)
+			ib_conn->login_req_dma = 0;
+		if (resp_err)
+			ib_conn->login_resp_dma = 0;
+		goto free_login_buf;
+	}
+	return 0;
+
+free_login_buf:
+	iser_free_login_buf(ib_conn);
+
+out_err:
+	iser_err("unable to alloc or map login buf\n");
+	return -ENOMEM;
+}
 
 int iser_alloc_rx_descriptors(struct iser_conn *ib_conn)
 {
@@ -179,6 +249,12 @@ int iser_alloc_rx_descriptors(struct iser_conn *ib_conn)
 	struct ib_sge       *rx_sg;
 	struct iser_device  *device = ib_conn->device;
 
+	if (iser_create_fmr_pool(ib_conn))
+		goto create_fmr_pool_failed;
+
+	if (iser_alloc_login_buf(ib_conn))
+		goto alloc_login_buf_fail;
+
 	ib_conn->rx_descs = kmalloc(ISER_QP_MAX_RECV_DTOS *
 				sizeof(struct iser_rx_desc), GFP_KERNEL);
 	if (!ib_conn->rx_descs)
@@ -207,10 +283,14 @@ rx_desc_dma_map_failed:
 	rx_desc = ib_conn->rx_descs;
 	for (j = 0; j < i; j++, rx_desc++)
 		ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
-			ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
+				    ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 	kfree(ib_conn->rx_descs);
 	ib_conn->rx_descs = NULL;
 rx_desc_alloc_fail:
+	iser_free_login_buf(ib_conn);
+alloc_login_buf_fail:
+	iser_free_fmr_pool(ib_conn);
+create_fmr_pool_failed:
 	iser_err("failed allocating rx descriptors / data buffers\n");
 	return -ENOMEM;
 }
@@ -222,13 +302,19 @@ void iser_free_rx_descriptors(struct iser_conn *ib_conn)
 	struct iser_device *device = ib_conn->device;
 
 	if (!ib_conn->rx_descs)
-		return;
+		goto free_login_buf;
 
 	rx_desc = ib_conn->rx_descs;
 	for (i = 0; i < ISER_QP_MAX_RECV_DTOS; i++, rx_desc++)
 		ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
-			ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
+				    ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 	kfree(ib_conn->rx_descs);
+	/* make sure we never redo any unmapping */
+	ib_conn->rx_descs = NULL;
+
+free_login_buf:
+	iser_free_login_buf(ib_conn);
+	iser_free_fmr_pool(ib_conn);
 }
 
 static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req)