From patchwork Tue Sep 2 13:00:38 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Thompson X-Patchwork-Id: 4825341 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id A69869F3FA for ; Tue, 2 Sep 2014 13:06:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E547D201C8 for ; Tue, 2 Sep 2014 13:06:51 +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 B01C0201BC for ; Tue, 2 Sep 2014 13:06:50 +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 1XOniq-0008IY-EQ; Tue, 02 Sep 2014 13:02:08 +0000 Received: from mail-wi0-f178.google.com ([209.85.212.178]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XOniV-000853-OI for linux-arm-kernel@lists.infradead.org; Tue, 02 Sep 2014 13:01:48 +0000 Received: by mail-wi0-f178.google.com with SMTP id r20so7796746wiv.11 for ; Tue, 02 Sep 2014 06:01:25 -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=NtAK8ee2NZ+Egd87Ctu/l49MwdcjN8Il06KgihpDG8U=; b=SeebFK8YHb24S7LoAxZbcF36ePtRM1fr0uOIrqj+fgeoovrDHKM1qbimqOF25znIhK NanKcfeFJrwXGjDZEEHrJIcpax0XvlimcOffnqrZ9h01Q1wcGQLS0dfmRP4FiUrYfWUu f4xZraTyZ9STvJQcLqiphmIhaSttJcQWwVVMhG84COk6mYD7v7JcCyditR/3lwjnKViI me/ic1JrgPVgzGQnCq036gPCoG8Dscxvck1b/TJ580MrvyfJqYZ6GTUKbxtD+FnWYIAi 0ZuUU8kTKXnToBWCQ/ZCtUfNTHBtD18QUGKxFSx6MEWMmbwx5iKmRnEiU5qVmpD4pfPv sasg== X-Gm-Message-State: ALoCoQmdONaFWR2YOhWEuiY2DXUJ9n6IuAYZqyOcVUON5KI3d6Q6OrLDF0ltomknXmQ4KGv2TmfL X-Received: by 10.194.6.195 with SMTP id d3mr2986546wja.107.1409662885032; Tue, 02 Sep 2014 06:01:25 -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 ec2sm34928892wib.19.2014.09.02.06.01.23 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Sep 2014 06:01:24 -0700 (PDT) From: Daniel Thompson To: Russell King Subject: [PATCH v11 04/19] arm: smp: Introduce a special IPI signalled using FIQ Date: Tue, 2 Sep 2014 14:00:38 +0100 Message-Id: <1409662853-29313-5-git-send-email-daniel.thompson@linaro.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1409662853-29313-1-git-send-email-daniel.thompson@linaro.org> References: <1408466769-20004-1-git-send-email-daniel.thompson@linaro.org> <1409662853-29313-1-git-send-email-daniel.thompson@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140902_060147_938703_11829D89 X-CRM114-Status: GOOD ( 14.88 ) X-Spam-Score: -0.7 (/) Cc: Daniel Thompson , linaro-kernel@lists.linaro.org, Catalin Marinas , patches@linaro.org, kgdb-bugreport@lists.sourceforge.net, Linus Walleij , Nicolas Pitre , linux-kernel@vger.kernel.org, Frederic Weisbecker , Anton Vorontsov , Ben Dooks , John Stultz , Fabio Estevam , Colin Cross , kernel-team@android.com, Dave Martin , linux-arm-kernel@lists.infradead.org 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=-3.6 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 Cross CPU signalling based on FIQ is especially useful for kgdb since it makes stopping all the CPUs during breakpointing more robust (some of the other architectures already roundup the CPUs using NMIs). The approach taken provides infrastructure that can be called (or not) by the driver's FIQ handler depending upon it requirements. In other words nothing is added here that prevents the driver from accessing "bare metal" performance. Signed-off-by: Daniel Thompson --- arch/arm/include/asm/hardirq.h | 2 +- arch/arm/include/asm/smp.h | 7 +++++++ arch/arm/kernel/smp.c | 15 +++++++++++++++ 3 files changed, 23 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/hardirq.h b/arch/arm/include/asm/hardirq.h index fe3ea77..5df33e3 100644 --- a/arch/arm/include/asm/hardirq.h +++ b/arch/arm/include/asm/hardirq.h @@ -5,7 +5,7 @@ #include #include -#define NR_IPI 8 +#define NR_IPI 9 typedef struct { unsigned int __softirq_pending; diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index 2ec765c..215c927 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -20,6 +20,9 @@ #define raw_smp_processor_id() (current_thread_info()->cpu) +/* bitmap of IPIs that must be signalled using FIQ */ +#define SMP_IPI_FIQ_MASK 0x0100 + struct seq_file; /* @@ -87,6 +90,10 @@ extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask); extern int register_ipi_completion(struct completion *completion, int cpu); +#ifdef CONFIG_FIQ +extern void send_fiq_ipi_mask(const struct cpumask *); +#endif + struct smp_operations { #ifdef CONFIG_SMP /* diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 9388a3d..d386c32 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -72,6 +72,7 @@ enum ipi_msg_type { IPI_CPU_STOP, IPI_IRQ_WORK, IPI_COMPLETION, + IPI_FIQ, }; static DECLARE_COMPLETION(cpu_running); @@ -451,6 +452,7 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = { S(IPI_CPU_STOP, "CPU stop interrupts"), S(IPI_IRQ_WORK, "IRQ work interrupts"), S(IPI_COMPLETION, "completion interrupts"), + S(IPI_FIQ, "FIQ interrupts"), }; static void smp_cross_call(const struct cpumask *target, unsigned int ipinr) @@ -552,6 +554,13 @@ static void ipi_complete(unsigned int cpu) complete(per_cpu(cpu_completion, cpu)); } +#ifdef CONFIG_FIQ +void send_fiq_ipi_mask(const struct cpumask *mask) +{ + smp_cross_call(mask, IPI_FIQ); +} +#endif + /* * Main handler for inter-processor interrupts */ @@ -618,6 +627,12 @@ void handle_IPI(int ipinr, struct pt_regs *regs) irq_exit(); break; +#ifdef CONFIG_FIQ + case IPI_FIQ: + pr_crit("CPU%u: IPI FIQ delivered via IRQ vector\n", cpu); + break; +#endif + default: printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr);