Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934399AbZLKXeL (ORCPT ); Fri, 11 Dec 2009 18:34:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934814AbZLKXeG (ORCPT ); Fri, 11 Dec 2009 18:34:06 -0500 Received: from kroah.org ([198.145.64.141]:50479 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933562AbZLKX3Y (ORCPT ); Fri, 11 Dec 2009 18:29:24 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Alan Cox , Greg Kroah-Hartman Subject: [PATCH 41/58] tty: tty_port: Add a kref object to the tty port Date: Fri, 11 Dec 2009 15:28:25 -0800 Message-Id: <1260574122-10676-41-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.6.5.3 In-Reply-To: <20091211232805.GA10652@kroah.com> References: <20091211232805.GA10652@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2915 Lines: 93 From: Alan Cox Users of tty port need a way to refcount ports when hotplugging is involved. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/char/tty_port.c | 18 ++++++++++++++++++ include/linux/tty.h | 12 ++++++++++++ 2 files changed, 30 insertions(+), 0 deletions(-) diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index 84006de..be492dd 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -29,6 +29,7 @@ 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; + kref_init(&port->kref); } EXPORT_SYMBOL(tty_port_init); @@ -56,6 +57,23 @@ void tty_port_free_xmit_buf(struct tty_port *port) } EXPORT_SYMBOL(tty_port_free_xmit_buf); +static void tty_port_destructor(struct kref *kref) +{ + struct tty_port *port = container_of(kref, struct tty_port, kref); + if (port->xmit_buf) + free_page((unsigned long)port->xmit_buf); + if (port->ops->destruct) + port->ops->destruct(port); + else + kfree(port); +} + +void tty_port_put(struct tty_port *port) +{ + if (port) + kref_put(&port->kref, tty_port_destructor); +} +EXPORT_SYMBOL(tty_port_put); /** * tty_port_tty_get - get a tty reference diff --git a/include/linux/tty.h b/include/linux/tty.h index e9269ca..e6da667 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -199,6 +199,8 @@ struct tty_port_operations { /* FIXME: long term getting the tty argument *out* of this would be good for consoles */ int (*activate)(struct tty_port *port, struct tty_struct *tty); + /* Called on the final put of a port */ + void (*destruct)(struct tty_port *port); }; struct tty_port { @@ -219,6 +221,7 @@ struct tty_port { int drain_delay; /* Set to zero if no pure time based drain is needed else set to size of fifo */ + struct kref kref; /* Ref counter */ }; /* @@ -461,6 +464,15 @@ extern int tty_write_lock(struct tty_struct *tty, int ndelay); extern void tty_port_init(struct tty_port *port); extern int tty_port_alloc_xmit_buf(struct tty_port *port); extern void tty_port_free_xmit_buf(struct tty_port *port); +extern void tty_port_put(struct tty_port *port); + +extern inline struct tty_port *tty_port_get(struct tty_port *port) +{ + if (port) + kref_get(&port->kref); + return port; +} + extern struct tty_struct *tty_port_tty_get(struct tty_port *port); extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty); extern int tty_port_carrier_raised(struct tty_port *port); -- 1.6.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/