From patchwork Thu Feb 13 09:15:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 214304 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 786ADC2BA83 for ; Thu, 13 Feb 2020 09:16:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A171217F4 for ; Thu, 13 Feb 2020 09:16:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729781AbgBMJQQ (ORCPT ); Thu, 13 Feb 2020 04:16:16 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:36009 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729747AbgBMJQQ (ORCPT ); Thu, 13 Feb 2020 04:16:16 -0500 Received: from pty.hi.pengutronix.de ([2001:67c:670:100:1d::c5]) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j2AbR-00080R-9Y; Thu, 13 Feb 2020 10:16:09 +0100 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1j2AbQ-0005r0-Ud; Thu, 13 Feb 2020 10:16:08 +0100 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Jacek Anaszewski , Pavel Machek , Dan Murphy , Greg Kroah-Hartman , Jiri Slaby Cc: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, linux-serial@vger.kernel.org Subject: [PATCH v6 2/4] tty: rename tty_kopen() and add new function tty_kopen_shared() Date: Thu, 13 Feb 2020 10:15:58 +0100 Message-Id: <20200213091600.554-3-uwe@kleine-koenig.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200213091600.554-1-uwe@kleine-koenig.org> References: <20200213091600.554-1-uwe@kleine-koenig.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c5 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-serial@vger.kernel.org Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Uwe Kleine-König Introduce a new function tty_kopen_shared() that yields a struct tty_struct. The semantic difference to tty_kopen() is that the tty is expected to be used already. So rename tty_kopen() to tty_kopen_exclusive() for clearness, adapt the single user and put the common code in a new static helper function. tty_kopen_shared is to be used to implement an LED trigger for tty devices in one of the next patches. Signed-off-by: Uwe Kleine-König --- drivers/staging/speakup/spk_ttyio.c | 2 +- drivers/tty/tty_io.c | 58 ++++++++++++++++++++--------- include/linux/tty.h | 5 ++- 3 files changed, 44 insertions(+), 21 deletions(-) diff --git a/drivers/staging/speakup/spk_ttyio.c b/drivers/staging/speakup/spk_ttyio.c index 5a9eff08cb96..e9db06eae875 100644 --- a/drivers/staging/speakup/spk_ttyio.c +++ b/drivers/staging/speakup/spk_ttyio.c @@ -147,7 +147,7 @@ static int spk_ttyio_initialise_ldisc(struct spk_synth *synth) if (ret) return ret; - tty = tty_kopen(dev); + tty = tty_kopen_exclusive(dev); if (IS_ERR(tty)) return PTR_ERR(tty); diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index a1453fe10862..b718666ce73c 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1875,22 +1875,7 @@ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, return driver; } -/** - * tty_kopen - open a tty device for kernel - * @device: dev_t of device to open - * - * Opens tty exclusively for kernel. Performs the driver lookup, - * makes sure it's not already opened and performs the first-time - * tty initialization. - * - * Returns the locked initialized &tty_struct - * - * Claims the global tty_mutex to serialize: - * - concurrent first-time tty initialization - * - concurrent tty driver removal w/ lookup - * - concurrent tty removal from driver table - */ -struct tty_struct *tty_kopen(dev_t device) +static struct tty_struct *tty_kopen(dev_t device, int shared) { struct tty_struct *tty; struct tty_driver *driver; @@ -1905,7 +1890,7 @@ struct tty_struct *tty_kopen(dev_t device) /* check whether we're reopening an existing tty */ tty = tty_driver_lookup_tty(driver, NULL, index); - if (IS_ERR(tty)) + if (IS_ERR(tty) || shared) goto out; if (tty) { @@ -1923,7 +1908,44 @@ struct tty_struct *tty_kopen(dev_t device) tty_driver_kref_put(driver); return tty; } -EXPORT_SYMBOL_GPL(tty_kopen); + +/** + * tty_kopen_exclusive - open a tty device for kernel + * @device: dev_t of device to open + * + * Opens tty exclusively for kernel. Performs the driver lookup, + * makes sure it's not already opened and performs the first-time + * tty initialization. + * + * Returns the locked initialized &tty_struct + * + * Claims the global tty_mutex to serialize: + * - concurrent first-time tty initialization + * - concurrent tty driver removal w/ lookup + * - concurrent tty removal from driver table + */ +struct tty_struct *tty_kopen_exclusive(dev_t device) +{ + return tty_kopen(device, 0); +} +EXPORT_SYMBOL_GPL(tty_kopen_exclusive); + +/** + * tty_kopen_shared - open a tty device for shared in-kernel use + * @device: dev_t of device to open + * + * Opens an already existing tty + * rnel. Performs the driver lookup, + * makes sure it's not already opened and performs the first-time + * tty initialization. + * + * Locking is identical to tty_kopen() above. + */ +struct tty_struct *tty_kopen_shared(dev_t device) +{ + return tty_kopen(device, 1); +} +EXPORT_SYMBOL_GPL(tty_kopen_shared); /** * tty_open_by_driver - open a tty device diff --git a/include/linux/tty.h b/include/linux/tty.h index bfa4e2ee94a9..d0bcf3226fb2 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -411,7 +411,8 @@ extern struct tty_struct *get_current_tty(void); /* tty_io.c */ extern int __init tty_init(void); extern const char *tty_name(const struct tty_struct *tty); -extern struct tty_struct *tty_kopen(dev_t device); +extern struct tty_struct *tty_kopen_exclusive(dev_t device); +extern struct tty_struct *tty_kopen_shared(dev_t device); extern void tty_kclose(struct tty_struct *tty); extern int tty_dev_name_to_number(const char *name, dev_t *number); extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout); @@ -436,7 +437,7 @@ static inline int __init tty_init(void) { return 0; } static inline const char *tty_name(const struct tty_struct *tty) { return "(none)"; } -static inline struct tty_struct *tty_kopen(dev_t device) +static inline struct tty_struct *tty_kopen_exclusive(dev_t device) { return ERR_PTR(-ENODEV); } static inline void tty_kclose(struct tty_struct *tty) { }