From patchwork Fri Jan 15 19:18:38 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geoff Levand X-Patchwork-Id: 8044361 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 [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 74A8B9F744 for ; Fri, 15 Jan 2016 19:30:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 693212037E for ; Fri, 15 Jan 2016 19:30:13 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5FE1C200D9 for ; Fri, 15 Jan 2016 19:30:12 +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 1aKA35-0003MV-Lv; Fri, 15 Jan 2016 19:28:39 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aK9tV-0000Bu-Ls; Fri, 15 Jan 2016 19:18:45 +0000 Received: from geoff by merlin.infradead.org with local (Exim 4.85 #2 (Red Hat Linux)) id 1aK9tO-0000nW-Ed; Fri, 15 Jan 2016 19:18:38 +0000 Message-Id: In-Reply-To: References: From: Geoff Levand Patch-Date: Wed, 19 Aug 2015 16:42:23 +0900 Subject: [PATCH 15/19] arm64: kdump: implement machine_crash_shutdown() To: Catalin Marinas , Will Deacon Date: Fri, 15 Jan 2016 19:18:38 +0000 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , marc.zyngier@arm.com, kexec@lists.infradead.org, AKASHI Takahiro , James Morse , linux-arm-kernel@lists.infradead.org, christoffer.dall@linaro.org 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=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 From: AKASHI Takahiro kdump calls machine_crash_shutdown() to shut down non-boot cpus and save registers' status in per-cpu ELF notes before starting the crash dump kernel. See kernel_kexec(). ipi_cpu_stop() is a bit modified and used to support this behavior. Signed-off-by: AKASHI Takahiro --- arch/arm64/include/asm/kexec.h | 47 +++++++++++++++++++++++++++- arch/arm64/kernel/machine_kexec.c | 65 +++++++++++++++++++++++++++++++++++++-- arch/arm64/kernel/smp.c | 18 ++++++++--- 3 files changed, 123 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index 04744dc..3dffb1d 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -30,6 +30,21 @@ #ifndef __ASSEMBLY__ +extern bool in_crash_kexec; + +static inline bool is_in_crash_kexec(void) +{ +#ifdef CONFIG_KEXEC_CORE + return in_crash_kexec; +#else + return false; +#endif +} + +#ifndef CONFIG_KEXEC_CORE +#define crash_save_cpu(regs, cpu) +#endif + /** * crash_setup_regs() - save registers for the panic kernel * @@ -40,7 +55,37 @@ static inline void crash_setup_regs(struct pt_regs *newregs, struct pt_regs *oldregs) { - /* Empty routine needed to avoid build errors. */ + if (oldregs) { + memcpy(newregs, oldregs, sizeof(*newregs)); + } else { + __asm__ __volatile__ ( + "stp x0, x1, [%3, #16 * 0]\n" + "stp x2, x3, [%3, #16 * 1]\n" + "stp x4, x5, [%3, #16 * 2]\n" + "stp x6, x7, [%3, #16 * 3]\n" + "stp x8, x9, [%3, #16 * 4]\n" + "stp x10, x11, [%3, #16 * 5]\n" + "stp x12, x13, [%3, #16 * 6]\n" + "stp x14, x15, [%3, #16 * 7]\n" + "stp x16, x17, [%3, #16 * 8]\n" + "stp x18, x19, [%3, #16 * 9]\n" + "stp x20, x21, [%3, #16 * 10]\n" + "stp x22, x23, [%3, #16 * 11]\n" + "stp x24, x25, [%3, #16 * 12]\n" + "stp x26, x27, [%3, #16 * 13]\n" + "stp x28, x29, [%3, #16 * 14]\n" + "str x30, [%3, #16 * 15]\n" + "mov %0, sp\n" + "adr %1, 1f\n" + "mrs %2, spsr_el1\n" + "1:" + : "=r" (newregs->sp), + "=r" (newregs->pc), + "=r" (newregs->pstate) + : "r" (&newregs->regs) + : "memory" + ); + } } #endif /* __ASSEMBLY__ */ diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index a375268..0ba2ae4 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -10,6 +10,9 @@ */ #include +#include +#include +#include #include #include #include @@ -25,6 +28,7 @@ extern const unsigned char arm64_relocate_new_kernel[]; extern const unsigned long arm64_relocate_new_kernel_size; +bool in_crash_kexec; static unsigned long kimage_start; /** @@ -212,13 +216,70 @@ void machine_kexec(struct kimage *kimage) * relocation is complete. */ - cpu_soft_restart(is_hyp_mode_available(), + cpu_soft_restart(in_crash_kexec ? 0 : is_hyp_mode_available(), reboot_code_buffer_phys, kimage->head, kimage_start, 0); BUG(); /* Should never get here. */ } +static void machine_kexec_mask_interrupts(void) +{ + unsigned int i; + struct irq_desc *desc; + + for_each_irq_desc(i, desc) { + struct irq_chip *chip; + int ret; + + chip = irq_desc_get_chip(desc); + if (!chip) + continue; + + /* + * First try to remove the active state. If this + * fails, try to EOI the interrupt. + */ + ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false); + + if (ret && irqd_irq_inprogress(&desc->irq_data) && + chip->irq_eoi) + chip->irq_eoi(&desc->irq_data); + + if (chip->irq_mask) + chip->irq_mask(&desc->irq_data); + + if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) + chip->irq_disable(&desc->irq_data); + } +} + +/** + * machine_crash_shutdown - shutdown non-crashing cpus and save registers + */ void machine_crash_shutdown(struct pt_regs *regs) { - /* Empty routine needed to avoid build errors. */ + struct pt_regs dummy_regs; + int cpu; + + local_irq_disable(); + + in_crash_kexec = true; + + /* + * clear and initialize the per-cpu info. This is necessary + * because, otherwise, slots for offline cpus would never be + * filled up. See smp_send_stop(). + */ + memset(&dummy_regs, 0, sizeof(dummy_regs)); + for_each_possible_cpu(cpu) + crash_save_cpu(&dummy_regs, cpu); + + /* shutdown non-crashing cpus */ + smp_send_stop(); + + /* for crashing cpu */ + crash_save_cpu(regs, smp_processor_id()); + machine_kexec_mask_interrupts(); + + pr_info("Starting crashdump kernel...\n"); } diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index b1adc51..aa45c21 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -44,6 +45,7 @@ #include #include #include +#include #include #include #include @@ -54,6 +56,8 @@ #include #include +#include "cpu-reset.h" + #define CREATE_TRACE_POINTS #include @@ -683,10 +687,16 @@ static DEFINE_RAW_SPINLOCK(stop_lock); /* * ipi_cpu_stop - handle IPI from smp_send_stop() */ -static void ipi_cpu_stop(unsigned int cpu) +static void ipi_cpu_stop(unsigned int cpu, struct pt_regs *regs) { - if (system_state == SYSTEM_BOOTING || - system_state == SYSTEM_RUNNING) { + if (is_in_crash_kexec()) { + crash_save_cpu(regs, cpu); + /* + * printing messages at panic may slow down the shutdown. + * So don't fall through dump_stack(). + */ + } else if (system_state == SYSTEM_BOOTING || + system_state == SYSTEM_RUNNING) { raw_spin_lock(&stop_lock); pr_crit("CPU%u: stopping\n", cpu); dump_stack(); @@ -727,7 +737,7 @@ void handle_IPI(int ipinr, struct pt_regs *regs) case IPI_CPU_STOP: irq_enter(); - ipi_cpu_stop(cpu); + ipi_cpu_stop(cpu, regs); irq_exit(); break;