From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754584AbaIDQEB (ORCPT ); Thu, 4 Sep 2014 12:04:01 -0400 Received: from mail-we0-f176.google.com ([74.125.82.176]:48914 "EHLO mail-we0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754479AbaIDQD7 (ORCPT ); Thu, 4 Sep 2014 12:03:59 -0400 From: Daniel Thompson To: Russell King Cc: Daniel Thompson , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, patches@linaro.org, linaro-kernel@lists.linaro.org, John Stultz , Thomas Gleixner , Sumit Semwal Subject: [PATCH v1 2/6] arm: smp: Introduce a non-maskable IPI Date: Thu, 4 Sep 2014 17:03:36 +0100 Message-Id: <1409846620-14542-3-git-send-email-daniel.thompson@linaro.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1409846620-14542-1-git-send-email-daniel.thompson@linaro.org> References: <1409662853-29313-1-git-send-email-daniel.thompson@linaro.org> <1409846620-14542-1-git-send-email-daniel.thompson@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces a new IPI intended to be routed to FIQ rather than IRQ. An IPI based upon FIQ can be used to implement debug features that require non-maskable interrupts. Signed-off-by: Daniel Thompson Cc: Russell King --- arch/arm/include/asm/hardirq.h | 2 +- arch/arm/include/asm/smp.h | 3 +++ arch/arm/kernel/smp.c | 7 +++++++ 3 files changed, 11 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..0e23384 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; /* diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 9388a3d..b2404d0 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) @@ -618,6 +620,11 @@ void handle_IPI(int ipinr, struct pt_regs *regs) irq_exit(); break; + case IPI_FIQ: + BUILD_BUG_ON(SMP_IPI_FIQ_MASK != BIT(IPI_FIQ)); + pr_warn("CPU%u: IPI FIQ delivered via IRQ vector\n", cpu); + break; + default: printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr); -- 1.9.3