IB/iser: New receive buffer posting logic
Currently, the recv buffer posting logic is based on the transactional
nature of iSER which allows for posting a buffer before sending a PDU.
Change this to post only when the number of outstanding recv buffers
is below a water mark and in a batched manner, thus simplifying and
optimizing the data path. Use a pre-allocated ring of recv buffers
instead of allocating from kmem cache. A special treatment is given
to the login response buffer whose size must be 8K unlike the size of
buffers used for any other purpose which is 128 bytes.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h
index e8dfdcf..83effb6 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.h
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
@@ -102,9 +102,9 @@
#define ISER_MAX_TX_MISC_PDUS 6 /* NOOP_OUT(2), TEXT(1), *
* SCSI_TMFUNC(2), LOGOUT(1) */
-#define ISER_QP_MAX_RECV_DTOS (ISCSI_DEF_XMIT_CMDS_MAX + \
- ISER_MAX_RX_MISC_PDUS + \
- ISER_MAX_TX_MISC_PDUS)
+#define ISER_QP_MAX_RECV_DTOS (ISCSI_DEF_XMIT_CMDS_MAX)
+
+#define ISER_MIN_POSTED_RX (ISCSI_DEF_XMIT_CMDS_MAX >> 2)
/* the max TX (send) WR supported by the iSER QP is defined by *
* max_send_wr = T * (1 + D) + C ; D is how many inflight dataouts we expect *
@@ -132,6 +132,12 @@
__be64 read_va;
} __attribute__((packed));
+/* Constant PDU lengths calculations */
+#define ISER_HEADERS_LEN (sizeof(struct iser_hdr) + sizeof(struct iscsi_hdr))
+
+#define ISER_RECV_DATA_SEG_LEN 128
+#define ISER_RX_PAYLOAD_SIZE (ISER_HEADERS_LEN + ISER_RECV_DATA_SEG_LEN)
+#define ISER_RX_LOGIN_SIZE (ISER_HEADERS_LEN + ISCSI_DEF_MAX_RECV_SEG_LEN)
/* Length of an object name string */
#define ISER_OBJECT_NAME_SIZE 64
@@ -212,7 +218,6 @@
};
enum iser_desc_type {
- ISCSI_RX,
ISCSI_TX_CONTROL ,
ISCSI_TX_SCSI_COMMAND,
ISCSI_TX_DATAOUT
@@ -228,6 +233,17 @@
struct iser_dto dto;
};
+#define ISER_RX_PAD_SIZE (256 - (ISER_RX_PAYLOAD_SIZE + \
+ sizeof(u64) + sizeof(struct ib_sge)))
+struct iser_rx_desc {
+ struct iser_hdr iser_header;
+ struct iscsi_hdr iscsi_header;
+ char data[ISER_RECV_DATA_SEG_LEN];
+ u64 dma_addr;
+ struct ib_sge rx_sg;
+ char pad[ISER_RX_PAD_SIZE];
+} __attribute__((packed));
+
struct iser_device {
struct ib_device *ib_device;
struct ib_pd *pd;
@@ -256,6 +272,12 @@
struct iser_page_vec *page_vec; /* represents SG to fmr maps*
* maps serialized as tx is*/
struct list_head conn_list; /* entry in ig conn list */
+
+ char *login_buf;
+ u64 login_dma;
+ unsigned int rx_desc_head;
+ struct iser_rx_desc *rx_descs;
+ struct ib_recv_wr rx_wr[ISER_MIN_POSTED_RX];
};
struct iscsi_iser_conn {
@@ -319,8 +341,9 @@
void iser_conn_terminate(struct iser_conn *ib_conn);
-void iser_rcv_completion(struct iser_desc *desc,
- unsigned long dto_xfer_len);
+void iser_rcv_completion(struct iser_rx_desc *desc,
+ unsigned long dto_xfer_len,
+ struct iser_conn *ib_conn);
void iser_snd_completion(struct iser_desc *desc);
@@ -332,6 +355,8 @@
int iser_regd_buff_release(struct iser_regd_buf *regd_buf);
+void iser_free_rx_descriptors(struct iser_conn *ib_conn);
+
void iser_reg_single(struct iser_device *device,
struct iser_regd_buf *regd_buf,
enum dma_data_direction direction);
@@ -353,7 +378,8 @@
void iser_unreg_mem(struct iser_mem_reg *mem_reg);
-int iser_post_recv(struct iser_desc *rx_desc);
+int iser_post_recvl(struct iser_conn *ib_conn);
+int iser_post_recvm(struct iser_conn *ib_conn, int count);
int iser_post_send(struct iser_desc *tx_desc);
int iser_conn_state_comp(struct iser_conn *ib_conn,