From patchwork Mon Aug 18 14:28:08 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Thompson X-Patchwork-Id: 4737081 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0B18BC0338 for ; Mon, 18 Aug 2014 14:32:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5453120131 for ; Mon, 18 Aug 2014 14:32:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 297272011D for ; Mon, 18 Aug 2014 14:32:38 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XJNvp-0005XC-00; Mon, 18 Aug 2014 14:29:09 +0000 Received: from mail-wi0-f171.google.com ([209.85.212.171]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XJNvV-0004yK-Ah for linux-arm-kernel@lists.infradead.org; Mon, 18 Aug 2014 14:28:50 +0000 Received: by mail-wi0-f171.google.com with SMTP id hi2so3810092wib.16 for ; Mon, 18 Aug 2014 07:28:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=H/OVumPYHu57WxdFIo4QtoQh8hH1r+NiM0qdefaYdVU=; b=di7xcISdbav5+GzTRQ9odn/wjinpJ6nIF/sLipEdYJU0A7klGlScmGPpH5EhBR+LxE cwYHgceGhmTCvomv0pDTI50DQDGCswI30wm74YnyvQr2b1urVy6KhoHD8sVcGUQpllsg E8mpi0qyb8wsXHzi/0c7mGnVcGMcQRQAXAXVrpv6kFOuh0EJug3aAhVQDKH6cJpoXQNH Oz0ANWmwLrNyaw17qmFAxH58U+GYgHoNwImfwaWcac4+IG+X7O1ueGS0+YMz7OIDc3aM 2qN5OuWSz+MTS7uERRZFNn7bHoWr9DVV+VAjNUmL3NlS0G7cybJLsZOvpxrgdpbrrUmp eJFw== X-Gm-Message-State: ALoCoQnX52SV9t/+djtgGDjyB/5XHiH9z9bwP0W4yvoEuxR4YjdJv/Vggqn71VSn3pxHBsI0apDi X-Received: by 10.180.37.16 with SMTP id u16mr17668785wij.72.1408372107171; Mon, 18 Aug 2014 07:28:27 -0700 (PDT) Received: from sundance.lan (cpc4-aztw19-0-0-cust157.18-1.cable.virginm.net. [82.33.25.158]) by mx.google.com with ESMTPSA id pe6sm42668080wjb.38.2014.08.18.07.28.25 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 18 Aug 2014 07:28:26 -0700 (PDT) From: Daniel Thompson To: Russell King Subject: [PATCH v9 13/16] serial: asc: Add support for KGDB's FIQ/NMI mode Date: Mon, 18 Aug 2014 15:28:08 +0100 Message-Id: <1408372091-12689-14-git-send-email-daniel.thompson@linaro.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1404979427-12943-1-git-send-email-daniel.thompson@linaro.org> References: <1404979427-12943-1-git-send-email-daniel.thompson@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140818_072849_523442_698A9B1B X-CRM114-Status: GOOD ( 16.47 ) X-Spam-Score: -0.7 (/) Cc: kernel@stlinux.com, Catalin Marinas , Linus Walleij , Patrice Chotard , Fabio Estevam , Daniel Thompson , Nicolas Pitre , Jiri Slaby , Anton Vorontsov , Ben Dooks , linux-serial@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net, kernel-team@android.com, Dave Martin , linaro-kernel@lists.linaro.org, patches@linaro.org, John Stultz , linux-arm-kernel@lists.infradead.org, Maxime Coquelin , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Colin Cross , Frederic Weisbecker , Srinivas Kandagatla X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add a .poll_init() function that enables UART RX and registers the UART's irq with KGDB. By providing this information to KGDB the serial driver offers "permission" for KGDB to route the UART interrupt signal from the drivers own handler to KGDBs FIQ handler (which will eventually use the UART's polled I/O callbacks to interact with the user). Note that the RX is not only enabled but also unmasked. This is required because otherwise the FIQ handler could never trigger. This unmask is copied from similar code in amba-pl011.c . Signed-off-by: Daniel Thompson Cc: Srinivas Kandagatla Cc: Maxime Coquelin Cc: Patrice Chotard Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: kernel@stlinux.com Cc: linux-serial@vger.kernel.org --- drivers/tty/serial/st-asc.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c index 8b2d735..2b5eb6e 100644 --- a/drivers/tty/serial/st-asc.c +++ b/drivers/tty/serial/st-asc.c @@ -30,6 +30,7 @@ #include #include #include +#include #define DRIVER_NAME "st-asc" #define ASC_SERIAL_NAME "ttyAS" @@ -607,6 +608,25 @@ asc_verify_port(struct uart_port *port, struct serial_struct *ser) } #ifdef CONFIG_CONSOLE_POLL + +#ifdef CONFIG_KGDB_FIQ +/* + * Prepare the UART to be used from kgdb's NMI support. + */ +static int asc_poll_init(struct uart_port *port) +{ + struct asc_port *ascport = container_of(port, struct asc_port, port); + + /* register the FIQ with kgdb */ + kgdb_register_fiq(ascport->port.irq); + + /* enable RX interrupts in case the interrupt is used for NMI entry. */ + asc_enable_rx_interrupts(port); + + return 0; +} +#endif /* CONFIG_KGDB_FIQ */ + /* * Console polling routines for writing and reading from the uart while * in an interrupt or debug context (i.e. kgdb). @@ -649,6 +669,9 @@ static struct uart_ops asc_uart_ops = { .verify_port = asc_verify_port, .pm = asc_pm, #ifdef CONFIG_CONSOLE_POLL +#ifdef CONFIG_KGDB_FIQ + .poll_init = asc_poll_init, +#endif /* CONFIG_KGDB_FIQ */ .poll_get_char = asc_get_poll_char, .poll_put_char = asc_put_poll_char, #endif /* CONFIG_CONSOLE_POLL */