[v15,17/20] arm64: kdump: implement machine_crash_shutdown()

Message ID	8f53a31cf8bbfdd73eb289e078addc31c5a19fcf.1457977403.git.geoff@infradead.org
State	New
Headers	show Delivered-To: patch@linaro.org Received-SPF: pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) client-ip=2001:1868:205::9; Message-Id: <8f53a31cf8bbfdd73eb289e078addc31c5a19fcf.1457977403.git.geoff@infradead.org> In-Reply-To: <cover.1457977401.git.geoff@infradead.org> References: <cover.1457977401.git.geoff@infradead.org> From: Geoff Levand <geoff@infradead.org> Patch-Date: Wed, 19 Aug 2015 16:42:23 +0900 Subject: [PATCH v15 17/20] arm64: kdump: implement machine_crash_shutdown() To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will.deacon@arm.com> Date: Mon, 14 Mar 2016 17:48:01 +0000 Precedence: list Cc: Mark Rutland <mark.rutland@arm.com>, marc.zyngier@arm.com, kexec@lists.infradead.org, AKASHI Takahiro <takahiro.akashi@linaro.org>, James Morse <james.morse@arm.com>, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org

diff --git a/arch/arm64/include/asm/hardirq.h b/arch/arm64/include/asm/hardirq.h index a57601f..8740297 100644 --- a/arch/arm64/include/asm/hardirq.h +++ b/arch/arm64/include/asm/hardirq.h @@ -20,7 +20,7 @@ #include <linux/threads.h> #include <asm/irq.h> -#define NR_IPI 5 +#define NR_IPI 6 typedef struct { unsigned int __softirq_pending; diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index 04744dc..2f089b3 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -30,6 +30,10 @@ #ifndef __ASSEMBLY__ +#ifndef CONFIG_KEXEC_CORE +#define crash_save_cpu(regs, cpu) +#endif + /** * crash_setup_regs() - save registers for the panic kernel * @@ -40,7 +44,37 @@ 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/include/asm/smp.h b/arch/arm64/include/asm/smp.h index d9c3d6a..0e42ece 100644 --- a/arch/arm64/include/asm/smp.h +++ b/arch/arm64/include/asm/smp.h @@ -69,4 +69,9 @@ extern int __cpu_disable(void); extern void __cpu_die(unsigned int cpu); extern void cpu_die(void); +/* + * for crash dump + */ +extern void smp_send_crash_stop(void); + #endif /* ifndef __ASM_SMP_H */ diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index 75f6696..8651b27 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -10,6 +10,9 @@ */ #include <linux/highmem.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel.h> #include <linux/kexec.h> #include <linux/libfdt_env.h> #include <linux/of_fdt.h> @@ -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; /** @@ -150,7 +154,7 @@ void machine_kexec(struct kimage *kimage) phys_addr_t reboot_code_buffer_phys; void *reboot_code_buffer; - BUG_ON(num_online_cpus() > 1); + BUG_ON((num_online_cpus() > 1) && !WARN_ON(in_crash_kexec)); reboot_code_buffer_phys = page_to_phys(kimage->control_code_page); reboot_code_buffer = kmap(kimage->control_code_page); @@ -209,13 +213,58 @@ 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. */ + local_irq_disable(); + + in_crash_kexec = true; + + /* shutdown non-crashing cpus */ + smp_send_crash_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..76402c6cd 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -37,6 +37,7 @@ #include <linux/completion.h> #include <linux/of.h> #include <linux/irq_work.h> +#include <linux/kexec.h> #include <asm/alternative.h> #include <asm/atomic.h> @@ -44,6 +45,7 @@ #include <asm/cpu.h> #include <asm/cputype.h> #include <asm/cpu_ops.h> +#include <asm/kexec.h> #include <asm/mmu_context.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> @@ -68,6 +70,7 @@ enum ipi_msg_type { IPI_RESCHEDULE, IPI_CALL_FUNC, IPI_CPU_STOP, + IPI_CPU_CRASH_STOP, IPI_TIMER, IPI_IRQ_WORK, }; @@ -625,6 +628,7 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = { S(IPI_RESCHEDULE, "Rescheduling interrupts"), S(IPI_CALL_FUNC, "Function call interrupts"), S(IPI_CPU_STOP, "CPU stop interrupts"), + S(IPI_CPU_CRASH_STOP, "CPU stop (for crash dump) interrupts"), S(IPI_TIMER, "Timer broadcast interrupts"), S(IPI_IRQ_WORK, "IRQ work interrupts"), }; @@ -701,6 +705,28 @@ static void ipi_cpu_stop(unsigned int cpu) cpu_relax(); } +static atomic_t waiting_for_crash_ipi; + +static void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs) +{ + crash_save_cpu(regs, cpu); + + raw_spin_lock(&stop_lock); + pr_debug("CPU%u: stopping\n", cpu); + raw_spin_unlock(&stop_lock); + + atomic_dec(&waiting_for_crash_ipi); + + local_irq_disable(); + + if (cpu_ops[cpu]->cpu_die) + cpu_ops[cpu]->cpu_die(cpu); + + /* just in case */ + while (1) + wfi(); +} + /* * Main handler for inter-processor interrupts */ @@ -731,6 +757,12 @@ void handle_IPI(int ipinr, struct pt_regs *regs) irq_exit(); break; + case IPI_CPU_CRASH_STOP: + irq_enter(); + ipi_cpu_crash_stop(cpu, regs); + irq_exit(); + break; + #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST case IPI_TIMER: irq_enter(); @@ -791,6 +823,30 @@ void smp_send_stop(void) pr_warning("SMP: failed to stop secondary CPUs\n"); } +void smp_send_crash_stop(void) +{ + cpumask_t mask; + unsigned long timeout; + + if (num_online_cpus() == 1) + return; + + cpumask_copy(&mask, cpu_online_mask); + cpumask_clear_cpu(smp_processor_id(), &mask); + + atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); + + smp_cross_call(&mask, IPI_CPU_CRASH_STOP); + + /* Wait up to one second for other CPUs to stop */ + timeout = USEC_PER_SEC; + while ((atomic_read(&waiting_for_crash_ipi) > 0) && timeout--) + udelay(1); + + if (atomic_read(&waiting_for_crash_ipi) > 0) + pr_warn("SMP: failed to stop secondary CPUs\n"); +} + /* * not supported here */

[v15,17/20] arm64: kdump: implement machine_crash_shutdown()

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