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[72.48.98.129]) by smtp.googlemail.com with ESMTPSA id v31sm680721ota.26.2017.01.25.12.23.45 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Jan 2017 12:23:46 -0800 (PST) From: Rob Herring To: Greg Kroah-Hartman , Marcel Holtmann , Jiri Slaby , Sebastian Reichel , Arnd Bergmann , "Dr . H . Nikolaus Schaller" , Peter Hurley , Andy Shevchenko , Alan Cox Cc: Loic Poulain , Pavel Machek , NeilBrown , Linus Walleij , linux-bluetooth@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/5] tty_port: Add port client functions Date: Wed, 25 Jan 2017 14:23:39 -0600 Message-Id: <20170125202343.30923-2-robh@kernel.org> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20170125202343.30923-1-robh@kernel.org> References: <20170125202343.30923-1-robh@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce a client (upward direction) operations struct for tty_port clients. Initially supported operations are for receiving data and write wake-up. This will allow for having clients other than an ldisc. Convert the calls to the ldisc to use the client ops as the default operations. Signed-off-by: Rob Herring Reviewed-By: Sebastian Reichel --- v3: - Restructured wakeup handling. We need to maintain the behavior of getting the tty ptr only once, otherwise the serial port can get in a bad state and stops responding. v2: - no change drivers/tty/tty_buffer.c | 17 +++-------------- drivers/tty/tty_port.c | 46 ++++++++++++++++++++++++++++++++++++++++------ include/linux/tty.h | 9 ++++++++- 3 files changed, 51 insertions(+), 21 deletions(-) -- 2.10.1 diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index f4dc3e296dd5..4e7a4e9dcf4d 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -437,7 +437,7 @@ int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p, EXPORT_SYMBOL_GPL(tty_ldisc_receive_buf); static int -receive_buf(struct tty_ldisc *ld, struct tty_buffer *head, int count) +receive_buf(struct tty_port *port, struct tty_buffer *head, int count) { unsigned char *p = char_buf_ptr(head, head->read); char *f = NULL; @@ -445,7 +445,7 @@ receive_buf(struct tty_ldisc *ld, struct tty_buffer *head, int count) if (~head->flags & TTYB_NORMAL) f = flag_buf_ptr(head, head->read); - return tty_ldisc_receive_buf(ld, p, f, count); + return port->client_ops->receive_buf(port, p, f, count); } /** @@ -465,16 +465,6 @@ static void flush_to_ldisc(struct work_struct *work) { struct tty_port *port = container_of(work, struct tty_port, buf.work); struct tty_bufhead *buf = &port->buf; - struct tty_struct *tty; - struct tty_ldisc *disc; - - tty = READ_ONCE(port->itty); - if (tty == NULL) - return; - - disc = tty_ldisc_ref(tty); - if (disc == NULL) - return; mutex_lock(&buf->lock); @@ -504,7 +494,7 @@ static void flush_to_ldisc(struct work_struct *work) continue; } - count = receive_buf(disc, head, count); + count = receive_buf(port, head, count); if (!count) break; head->read += count; @@ -512,7 +502,6 @@ static void flush_to_ldisc(struct work_struct *work) mutex_unlock(&buf->lock); - tty_ldisc_deref(disc); } /** diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c index 1d8804843103..8d9886b06037 100644 --- a/drivers/tty/tty_port.c +++ b/drivers/tty/tty_port.c @@ -17,6 +17,44 @@ #include #include +static int tty_port_default_receive_buf(struct tty_port *port, + const unsigned char *p, + const unsigned char *f, size_t count) +{ + int ret; + struct tty_struct *tty; + struct tty_ldisc *disc; + + tty = READ_ONCE(port->itty); + if (!tty) + return 0; + + disc = tty_ldisc_ref(tty); + if (!disc) + return 0; + + ret = tty_ldisc_receive_buf(disc, p, (char *)f, count); + + tty_ldisc_deref(disc); + + return ret; +} + +static void tty_port_default_wakeup(struct tty_port *port) +{ + struct tty_struct *tty = tty_port_tty_get(port); + + if (tty) { + tty_wakeup(tty); + tty_kref_put(tty); + } +} + +static const struct tty_port_client_operations default_client_ops = { + .receive_buf = tty_port_default_receive_buf, + .write_wakeup = tty_port_default_wakeup, +}; + void tty_port_init(struct tty_port *port) { memset(port, 0, sizeof(*port)); @@ -28,6 +66,7 @@ void tty_port_init(struct tty_port *port) spin_lock_init(&port->lock); port->close_delay = (50 * HZ) / 100; port->closing_wait = (3000 * HZ) / 100; + port->client_ops = &default_client_ops; kref_init(&port->kref); } EXPORT_SYMBOL(tty_port_init); @@ -272,12 +311,7 @@ EXPORT_SYMBOL_GPL(tty_port_tty_hangup); */ void tty_port_tty_wakeup(struct tty_port *port) { - struct tty_struct *tty = tty_port_tty_get(port); - - if (tty) { - tty_wakeup(tty); - tty_kref_put(tty); - } + port->client_ops->write_wakeup(port); } EXPORT_SYMBOL_GPL(tty_port_tty_wakeup); diff --git a/include/linux/tty.h b/include/linux/tty.h index 21c0fabfed60..1017e904c0a3 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -217,12 +217,18 @@ struct tty_port_operations { /* Called on the final put of a port */ void (*destruct)(struct tty_port *port); }; - + +struct tty_port_client_operations { + int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t); + void (*write_wakeup)(struct tty_port *port); +}; + struct tty_port { struct tty_bufhead buf; /* Locked internally */ struct tty_struct *tty; /* Back pointer */ struct tty_struct *itty; /* internal back ptr */ const struct tty_port_operations *ops; /* Port operations */ + const struct tty_port_client_operations *client_ops; /* Port client operations */ spinlock_t lock; /* Lock protecting tty field */ int blocked_open; /* Waiting to open */ int count; /* Usage count */ @@ -241,6 +247,7 @@ struct tty_port { based drain is needed else set to size of fifo */ struct kref kref; /* Ref counter */ + void *client_data; }; /* tty_port::iflags bits -- use atomic bit ops */