[PATCH v4 042/145] smb: smbdirect: introduce smbdirect_connection_grant_recv_credits()

[Stefan Metzmacher]

This is a copy of manage_credits_prior_sending() in the server.

It is very similar to manage_credits_prior_sending() in the
client, the only difference is that
atomic_add(new_credits, &sc->recv_io.credits.count) is done
in the caller there.

It will replace both versions in future.

Cc: Steve French <smfrench at gmail.com>
Cc: Tom Talpey <tom at talpey.com>
Cc: Long Li <longli at microsoft.com>
Cc: Namjae Jeon <linkinjeon at kernel.org>
Cc: linux-cifs at vger.kernel.org
Cc: samba-technical at lists.samba.org
Signed-off-by: Stefan Metzmacher <metze at samba.org>
Signed-off-by: Steve French <stfrench at microsoft.com>
---
 .../common/smbdirect/smbdirect_connection.c   | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/fs/smb/common/smbdirect/smbdirect_connection.c b/fs/smb/common/smbdirect/smbdirect_connection.c
index 71d2ee4030a2..6dce0f0c126a 100644
--- a/fs/smb/common/smbdirect/smbdirect_connection.c
+++ b/fs/smb/common/smbdirect/smbdirect_connection.c
@@ -704,6 +704,26 @@ static void smbdirect_connection_idle_timer_work(struct work_struct *work)
 	queue_work(sc->workqueue, &sc->idle.immediate_work);
 }
 
+__maybe_unused /* this is temporary while this file is included in others */
+static u16 smbdirect_connection_grant_recv_credits(struct smbdirect_socket *sc)
+{
+	u16 new_credits;
+
+	if (atomic_read(&sc->recv_io.credits.count) >= sc->recv_io.credits.target)
+		return 0;
+
+	new_credits = atomic_read(&sc->recv_io.posted.count);
+	if (new_credits == 0)
+		return 0;
+
+	new_credits -= atomic_read(&sc->recv_io.credits.count);
+	if (new_credits <= 0)
+		return 0;
+
+	atomic_add(new_credits, &sc->recv_io.credits.count);
+	return new_credits;
+}
+
 __maybe_unused /* this is temporary while this file is included in others */
 static void smbdirect_connection_send_io_done(struct ib_cq *cq, struct ib_wc *wc)
 {
-- 
2.43.0