From: Stefan Raspl <raspl@linux.ibm.com>
Subject: net/smc: add common buffer size in send and receive buffer descriptors
Patch-mainline: v4.18-rc1
Git-commit: 69cb7dc0218b2c54416722eddf181e720f24c305
References: FATE#325694, LTC#167874, bsc#1113480

Summary:     net/smc: SMC-R MVP
Description: Add latest upstream patches to push SMC-R to the MVP level

Upstream-Description:

             net/smc: add common buffer size in send and receive buffer descriptors

             In addition to the buffer references, SMC currently stores the sizes of
             the receive and send buffers in each connection as separate variables.
             This patch introduces a buffer length variable in the common buffer
             descriptor and uses this length instead.

             Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
             Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
             Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 net/smc/af_smc.c   |    2 +-
 net/smc/smc.h      |    2 --
 net/smc/smc_cdc.c  |    8 ++++----
 net/smc/smc_core.c |    8 ++------
 net/smc/smc_core.h |    1 +
 net/smc/smc_diag.c |    5 +++--
 net/smc/smc_rx.c   |   10 +++++-----
 net/smc/smc_tx.c   |   28 ++++++++++++++--------------
 net/smc/smc_tx.h   |    2 +-
 9 files changed, 31 insertions(+), 35 deletions(-)

--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1419,7 +1419,7 @@ static int smc_ioctl(struct socket *sock
 		/* output queue size (not send + not acked) */
 		if (smc->sk.sk_state == SMC_LISTEN)
 			return -EINVAL;
-		answ = smc->conn.sndbuf_size -
+		answ = smc->conn.sndbuf_desc->len -
 					atomic_read(&smc->conn.sndbuf_space);
 		break;
 	case SIOCOUTQNSD:
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -125,9 +125,7 @@ struct smc_connection {
 	int			rtoken_idx;	/* idx to peer RMB rkey/addr */
 
 	struct smc_buf_desc	*sndbuf_desc;	/* send buffer descriptor */
-	int			sndbuf_size;	/* sndbuf size <== sock wmem */
 	struct smc_buf_desc	*rmb_desc;	/* RMBE descriptor */
-	int			rmbe_size;	/* RMBE size <== sock rmem */
 	int			rmbe_size_short;/* compressed notation */
 	int			rmbe_update_limit;
 						/* lower limit for consumer
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -43,13 +43,13 @@ static void smc_cdc_tx_handler(struct sm
 	smc = container_of(cdcpend->conn, struct smc_sock, conn);
 	bh_lock_sock(&smc->sk);
 	if (!wc_status) {
-		diff = smc_curs_diff(cdcpend->conn->sndbuf_size,
+		diff = smc_curs_diff(cdcpend->conn->sndbuf_desc->len,
 				     &cdcpend->conn->tx_curs_fin,
 				     &cdcpend->cursor);
 		/* sndbuf_space is decreased in smc_sendmsg */
 		smp_mb__before_atomic();
 		atomic_add(diff, &cdcpend->conn->sndbuf_space);
-		/* guarantee 0 <= sndbuf_space <= sndbuf_size */
+		/* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
 		smp_mb__after_atomic();
 		smc_curs_write(&cdcpend->conn->tx_curs_fin,
 			       smc_curs_read(&cdcpend->cursor, cdcpend->conn),
@@ -197,13 +197,13 @@ static void smc_cdc_msg_recv_action(stru
 		smp_mb__after_atomic();
 	}
 
-	diff_prod = smc_curs_diff(conn->rmbe_size, &prod_old,
+	diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,
 				  &conn->local_rx_ctrl.prod);
 	if (diff_prod) {
 		/* bytes_to_rcv is decreased in smc_recvmsg */
 		smp_mb__before_atomic();
 		atomic_add(diff_prod, &conn->bytes_to_rcv);
-		/* guarantee 0 <= bytes_to_rcv <= rmbe_size */
+		/* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */
 		smp_mb__after_atomic();
 		smc->sk.sk_data_ready(&smc->sk);
 	} else if ((conn->local_rx_ctrl.prod_flags.write_blocked) ||
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -235,15 +235,12 @@ out:
 
 static void smc_buf_unuse(struct smc_connection *conn)
 {
-	if (conn->sndbuf_desc) {
+	if (conn->sndbuf_desc)
 		conn->sndbuf_desc->used = 0;
-		conn->sndbuf_size = 0;
-	}
 	if (conn->rmb_desc) {
 		if (!conn->rmb_desc->regerr) {
 			conn->rmb_desc->reused = 1;
 			conn->rmb_desc->used = 0;
-			conn->rmbe_size = 0;
 		} else {
 			/* buf registration failed, reuse not possible */
 			struct smc_link_group *lgr = conn->lgr;
@@ -615,6 +612,7 @@ static struct smc_buf_desc *smc_new_buf_
 		}
 	}
 
+	buf_desc->len = bufsize;
 	return buf_desc;
 }
 
@@ -674,14 +672,12 @@ static int __smc_buf_create(struct smc_s
 
 	if (is_rmb) {
 		conn->rmb_desc = buf_desc;
-		conn->rmbe_size = bufsize;
 		conn->rmbe_size_short = bufsize_short;
 		smc->sk.sk_rcvbuf = bufsize * 2;
 		atomic_set(&conn->bytes_to_rcv, 0);
 		conn->rmbe_update_limit = smc_rmb_wnd_update_limit(bufsize);
 	} else {
 		conn->sndbuf_desc = buf_desc;
-		conn->sndbuf_size = bufsize;
 		smc->sk.sk_sndbuf = bufsize * 2;
 		atomic_set(&conn->sndbuf_space, bufsize);
 	}
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -123,6 +123,7 @@ struct smc_buf_desc {
 	struct list_head	list;
 	void			*cpu_addr;	/* virtual address of buffer */
 	struct page		*pages;
+	int			len;		/* length of buffer */
 	struct sg_table		sgt[SMC_LINKS_PER_LGR_MAX];/* virtual buffer */
 	struct ib_mr		*mr_rx[SMC_LINKS_PER_LGR_MAX];
 						/* for rmb only: memory region
--- a/net/smc/smc_diag.c
+++ b/net/smc/smc_diag.c
@@ -101,8 +101,9 @@ static int __smc_diag_dump(struct sock *
 		struct smc_connection *conn = &smc->conn;
 		struct smc_diag_conninfo cinfo = {
 			.token = conn->alert_token_local,
-			.sndbuf_size = conn->sndbuf_size,
-			.rmbe_size = conn->rmbe_size,
+			.sndbuf_size = conn->sndbuf_desc ?
+				conn->sndbuf_desc->len : 0,
+			.rmbe_size = conn->rmb_desc ? conn->rmb_desc->len : 0,
 			.peer_rmbe_size = conn->peer_rmbe_size,
 
 			.rx_prod.wrap = conn->local_rx_ctrl.prod.wrap,
--- a/net/smc/smc_rx.c
+++ b/net/smc/smc_rx.c
@@ -50,7 +50,7 @@ static void smc_rx_wake_up(struct sock *
 static void smc_rx_update_consumer(struct smc_connection *conn,
 				   union smc_host_cursor cons, size_t len)
 {
-	smc_curs_add(conn->rmbe_size, &cons, len);
+	smc_curs_add(conn->rmb_desc->len, &cons, len);
 	smc_curs_write(&conn->local_tx_ctrl.cons, smc_curs_read(&cons, conn),
 		       conn);
 	/* send consumer cursor update if required */
@@ -287,11 +287,11 @@ copy:
 			       conn);
 		/* subsequent splice() calls pick up where previous left */
 		if (splbytes)
-			smc_curs_add(conn->rmbe_size, &cons, splbytes);
+			smc_curs_add(conn->rmb_desc->len, &cons, splbytes);
 		/* determine chunks where to read from rcvbuf */
 		/* either unwrapped case, or 1st chunk of wrapped case */
-		chunk_len = min_t(size_t,
-				  copylen, conn->rmbe_size - cons.count);
+		chunk_len = min_t(size_t, copylen, conn->rmb_desc->len -
+				  cons.count);
 		chunk_len_sum = chunk_len;
 		chunk_off = cons.count;
 		smc_rmb_sync_sg_for_cpu(conn);
@@ -330,7 +330,7 @@ copy:
 			/* increased in recv tasklet smc_cdc_msg_rcv() */
 			smp_mb__before_atomic();
 			atomic_sub(copylen, &conn->bytes_to_rcv);
-			/* guarantee 0 <= bytes_to_rcv <= rmbe_size */
+			/* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */
 			smp_mb__after_atomic();
 			if (msg)
 				smc_rx_update_consumer(conn, cons, copylen);
--- a/net/smc/smc_tx.c
+++ b/net/smc/smc_tx.c
@@ -179,8 +179,8 @@ int smc_tx_sendmsg(struct smc_sock *smc,
 		tx_cnt_prep = prep.count;
 		/* determine chunks where to write into sndbuf */
 		/* either unwrapped case, or 1st chunk of wrapped case */
-		chunk_len = min_t(size_t,
-				  copylen, conn->sndbuf_size - tx_cnt_prep);
+		chunk_len = min_t(size_t, copylen, conn->sndbuf_desc->len -
+				  tx_cnt_prep);
 		chunk_len_sum = chunk_len;
 		chunk_off = tx_cnt_prep;
 		smc_sndbuf_sync_sg_for_cpu(conn);
@@ -205,21 +205,21 @@ int smc_tx_sendmsg(struct smc_sock *smc,
 		}
 		smc_sndbuf_sync_sg_for_device(conn);
 		/* update cursors */
-		smc_curs_add(conn->sndbuf_size, &prep, copylen);
+		smc_curs_add(conn->sndbuf_desc->len, &prep, copylen);
 		smc_curs_write(&conn->tx_curs_prep,
 			       smc_curs_read(&prep, conn),
 			       conn);
 		/* increased in send tasklet smc_cdc_tx_handler() */
 		smp_mb__before_atomic();
 		atomic_sub(copylen, &conn->sndbuf_space);
-		/* guarantee 0 <= sndbuf_space <= sndbuf_size */
+		/* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
 		smp_mb__after_atomic();
 		/* since we just produced more new data into sndbuf,
 		 * trigger sndbuf consumer: RDMA write into peer RMBE and CDC
 		 */
 		if ((msg->msg_flags & MSG_MORE || smc_tx_is_corked(smc)) &&
 		    (atomic_read(&conn->sndbuf_space) >
-						(conn->sndbuf_size >> 1)))
+						(conn->sndbuf_desc->len >> 1)))
 			/* for a corked socket defer the RDMA writes if there
 			 * is still sufficient sndbuf_space available
 			 */
@@ -285,7 +285,7 @@ static inline void smc_tx_advance_cursor
 	atomic_sub(len, &conn->peer_rmbe_space);
 	/* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */
 	smp_mb__after_atomic();
-	smc_curs_add(conn->sndbuf_size, sent, len);
+	smc_curs_add(conn->sndbuf_desc->len, sent, len);
 }
 
 /* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit;
@@ -308,7 +308,7 @@ static int smc_tx_rdma_writes(struct smc
 	smc_curs_write(&sent, smc_curs_read(&conn->tx_curs_sent, conn), conn);
 	smc_curs_write(&prep, smc_curs_read(&conn->tx_curs_prep, conn), conn);
 	/* cf. wmem_alloc - (snd_max - snd_una) */
-	to_send = smc_curs_diff(conn->sndbuf_size, &sent, &prep);
+	to_send = smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep);
 	if (to_send <= 0)
 		return 0;
 
@@ -350,12 +350,12 @@ static int smc_tx_rdma_writes(struct smc
 	dst_len_sum = dst_len;
 	src_off = sent.count;
 	/* dst_len determines the maximum src_len */
-	if (sent.count + dst_len <= conn->sndbuf_size) {
+	if (sent.count + dst_len <= conn->sndbuf_desc->len) {
 		/* unwrapped src case: single chunk of entire dst_len */
 		src_len = dst_len;
 	} else {
 		/* wrapped src case: 2 chunks of sum dst_len; start with 1st: */
-		src_len = conn->sndbuf_size - sent.count;
+		src_len = conn->sndbuf_desc->len - sent.count;
 	}
 	src_len_sum = src_len;
 	dma_addr = sg_dma_address(conn->sndbuf_desc->sgt[SMC_SINGLE_LINK].sgl);
@@ -367,8 +367,8 @@ static int smc_tx_rdma_writes(struct smc
 			sges[srcchunk].lkey = link->roce_pd->local_dma_lkey;
 			num_sges++;
 			src_off += src_len;
-			if (src_off >= conn->sndbuf_size)
-				src_off -= conn->sndbuf_size;
+			if (src_off >= conn->sndbuf_desc->len)
+				src_off -= conn->sndbuf_desc->len;
 						/* modulo in send ring */
 			if (src_len_sum == dst_len)
 				break; /* either on 1st or 2nd iteration */
@@ -386,7 +386,7 @@ static int smc_tx_rdma_writes(struct smc
 		dst_len = len - dst_len; /* remainder */
 		dst_len_sum += dst_len;
 		src_len = min_t(int,
-				dst_len, conn->sndbuf_size - sent.count);
+				dst_len, conn->sndbuf_desc->len - sent.count);
 		src_len_sum = src_len;
 	}
 
@@ -483,11 +483,11 @@ void smc_tx_consumer_update(struct smc_c
 	smc_curs_write(&cfed,
 		       smc_curs_read(&conn->rx_curs_confirmed, conn),
 		       conn);
-	to_confirm = smc_curs_diff(conn->rmbe_size, &cfed, &cons);
+	to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons);
 
 	if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
 	    ((to_confirm > conn->rmbe_update_limit) &&
-	     ((to_confirm > (conn->rmbe_size / 2)) ||
+	     ((to_confirm > (conn->rmb_desc->len / 2)) ||
 	      conn->local_rx_ctrl.prod_flags.write_blocked))) {
 		if ((smc_cdc_get_slot_and_msg_send(conn) < 0) &&
 		    conn->alert_token_local) { /* connection healthy */
--- a/net/smc/smc_tx.h
+++ b/net/smc/smc_tx.h
@@ -23,7 +23,7 @@ static inline int smc_tx_prepared_sends(
 
 	smc_curs_write(&sent, smc_curs_read(&conn->tx_curs_sent, conn), conn);
 	smc_curs_write(&prep, smc_curs_read(&conn->tx_curs_prep, conn), conn);
-	return smc_curs_diff(conn->sndbuf_size, &sent, &prep);
+	return smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep);
 }
 
 void smc_tx_work(struct work_struct *work);