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[RFC,net-next,10/10] net/smc: synchronize buffer usage with device

Message ID 20170720120946.67234-11-ubraun@linux.vnet.ibm.com (mailing list archive)
State RFC
Headers show

Commit Message

Ursula Braun July 20, 2017, 12:09 p.m. UTC
Usage of send buffer "sndbuf" is synced
(a) before filling sndbuf for cpu access
(b) after filling sndbuf for device access

Usage of receive buffer "RMB" is synced
(a) before reading RMB content for cpu access
(b) after reading RMB content for device access

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
---
 net/smc/af_smc.c   |  2 ++
 net/smc/smc_core.c | 32 ++++++++++++++++++++++++++++++++
 net/smc/smc_core.h |  4 ++++
 net/smc/smc_ib.c   | 41 +++++++++++++++++++++++++++++++++++++++++
 net/smc/smc_ib.h   |  6 ++++++
 net/smc/smc_rx.c   |  3 +++
 net/smc/smc_tx.c   |  3 +++
 7 files changed, 91 insertions(+)
diff mbox

Patch

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 75518879b68a..8c6d24b2995d 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -474,6 +474,7 @@  static int smc_connect_rdma(struct smc_sock *smc)
 			}
 		}
 	}
+	smc_rmb_sync_sg_for_device(&smc->conn);
 
 	rc = smc_clc_send_confirm(smc);
 	if (rc)
@@ -832,6 +833,7 @@  static void smc_listen_work(struct work_struct *work)
 			}
 		}
 	}
+	smc_rmb_sync_sg_for_device(&new_smc->conn);
 
 	rc = smc_clc_send_accept(new_smc, local_contact);
 	if (rc)
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 3232ae2d32e3..cec26ae73501 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -615,6 +615,38 @@  struct smc_link_group *lgr = conn->lgr;
 	return 0;
 }
 
+void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
+{
+	struct smc_link_group *lgr = conn->lgr;
+
+	smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
+			       conn->sndbuf_desc, DMA_TO_DEVICE);
+}
+
+void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
+{
+	struct smc_link_group *lgr = conn->lgr;
+
+	smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
+				  conn->sndbuf_desc, DMA_TO_DEVICE);
+}
+
+void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
+{
+	struct smc_link_group *lgr = conn->lgr;
+
+	smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
+			       conn->rmb_desc, DMA_FROM_DEVICE);
+}
+
+void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
+{
+	struct smc_link_group *lgr = conn->lgr;
+
+	smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
+				  conn->rmb_desc, DMA_FROM_DEVICE);
+}
+
 /* create the send and receive buffer for an SMC socket;
  * receive buffers are called RMBs;
  * (even though the SMC protocol allows more than one RMB-element per RMB,
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 1d713e8e067c..19c44bf4e391 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -189,4 +189,8 @@  void smc_lgr_terminate(struct smc_link_group *lgr);
 int smc_buf_create(struct smc_sock *smc);
 int smc_rmb_rtoken_handling(struct smc_connection *conn,
 			    struct smc_clc_msg_accept_confirm *clc);
+void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn);
+void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn);
+void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn);
+void smc_rmb_sync_sg_for_device(struct smc_connection *conn);
 #endif
diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
index dd75792f6d63..4d3ad41fb67c 100644
--- a/net/smc/smc_ib.c
+++ b/net/smc/smc_ib.c
@@ -13,6 +13,7 @@ 
 
 #include <linux/random.h>
 #include <linux/workqueue.h>
+#include <linux/scatterlist.h>
 #include <rdma/ib_verbs.h>
 
 #include "smc_pnet.h"
@@ -292,6 +293,46 @@  int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
 	return 0;
 }
 
+/* synchronize buffer usage for cpu access */
+void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
+			    struct smc_buf_desc *buf_slot,
+			    enum dma_data_direction data_direction)
+{
+	struct scatterlist *sg;
+	unsigned int i;
+
+	/* for now there is just one DMA address */
+	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
+		    buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
+		if (!sg_dma_len(sg))
+			break;
+		ib_dma_sync_single_for_cpu(smcibdev->ibdev,
+					   sg_dma_address(sg),
+					   sg_dma_len(sg),
+					   data_direction);
+	}
+}
+
+/* synchronize buffer usage for device access */
+void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
+			       struct smc_buf_desc *buf_slot,
+			       enum dma_data_direction data_direction)
+{
+	struct scatterlist *sg;
+	unsigned int i;
+
+	/* for now there is just one DMA address */
+	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
+		    buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
+		if (!sg_dma_len(sg))
+			break;
+		ib_dma_sync_single_for_device(smcibdev->ibdev,
+					      sg_dma_address(sg),
+					      sg_dma_len(sg),
+					      data_direction);
+	}
+}
+
 /* Map a new TX or RX buffer SG-table to DMA */
 int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
 		      struct smc_buf_desc *buf_slot,
diff --git a/net/smc/smc_ib.h b/net/smc/smc_ib.h
index 72acb19ffc67..9b927a33d5e6 100644
--- a/net/smc/smc_ib.h
+++ b/net/smc/smc_ib.h
@@ -68,4 +68,10 @@  long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev);
 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
 			     struct smc_buf_desc *buf_slot);
 void smc_ib_put_memory_region(struct ib_mr *mr);
+void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
+			    struct smc_buf_desc *buf_slot,
+			    enum dma_data_direction data_direction);
+void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
+			       struct smc_buf_desc *buf_slot,
+			       enum dma_data_direction data_direction);
 #endif
diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c
index f0c8b089f770..b17a333e9bb0 100644
--- a/net/smc/smc_rx.c
+++ b/net/smc/smc_rx.c
@@ -170,6 +170,7 @@  int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
 				  copylen, conn->rmbe_size - cons.count);
 		chunk_len_sum = chunk_len;
 		chunk_off = cons.count;
+		smc_rmb_sync_sg_for_cpu(conn);
 		for (chunk = 0; chunk < 2; chunk++) {
 			if (!(flags & MSG_TRUNC)) {
 				rc = memcpy_to_msg(msg, rcvbuf_base + chunk_off,
@@ -177,6 +178,7 @@  int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
 				if (rc) {
 					if (!read_done)
 						read_done = -EFAULT;
+					smc_rmb_sync_sg_for_device(conn);
 					goto out;
 				}
 			}
@@ -190,6 +192,7 @@  int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
 			chunk_len_sum += chunk_len;
 			chunk_off = 0; /* modulo offset in recv ring buffer */
 		}
+		smc_rmb_sync_sg_for_device(conn);
 
 		/* update cursors */
 		if (!(flags & MSG_PEEK)) {
diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c
index f4d58e2dd559..3c656beb8820 100644
--- a/net/smc/smc_tx.c
+++ b/net/smc/smc_tx.c
@@ -174,10 +174,12 @@  int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len)
 				  copylen, conn->sndbuf_size - tx_cnt_prep);
 		chunk_len_sum = chunk_len;
 		chunk_off = tx_cnt_prep;
+		smc_sndbuf_sync_sg_for_cpu(conn);
 		for (chunk = 0; chunk < 2; chunk++) {
 			rc = memcpy_from_msg(sndbuf_base + chunk_off,
 					     msg, chunk_len);
 			if (rc) {
+				smc_sndbuf_sync_sg_for_device(conn);
 				if (send_done)
 					return send_done;
 				goto out_err;
@@ -192,6 +194,7 @@  int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len)
 			chunk_len_sum += chunk_len;
 			chunk_off = 0; /* modulo offset in send ring buffer */
 		}
+		smc_sndbuf_sync_sg_for_device(conn);
 		/* update cursors */
 		smc_curs_add(conn->sndbuf_size, &prep, copylen);
 		smc_curs_write(&conn->tx_curs_prep,