arm64: kdump: implement machine_crash_shutdown() (78fd584c) · Commits · 戴 / test

arch/arm64/include/asm/hardirq.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -20,7 +20,7 @@
		#include <linux/threads.h>
		#include <asm/irq.h>

		#define NR_IPI 6
		#define NR_IPI 7

		typedef struct {
		unsigned int __softirq_pending;

arch/arm64/include/asm/kexec.h

+41 −1

Original line number	Diff line number	Diff line
		@@ -40,7 +40,47 @@
		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 {
		u64 tmp1, tmp2;

		__asm__ __volatile__ (
		"stp x0, x1, [%2, #16 * 0]\n"
		"stp x2, x3, [%2, #16 * 1]\n"
		"stp x4, x5, [%2, #16 * 2]\n"
		"stp x6, x7, [%2, #16 * 3]\n"
		"stp x8, x9, [%2, #16 * 4]\n"
		"stp x10, x11, [%2, #16 * 5]\n"
		"stp x12, x13, [%2, #16 * 6]\n"
		"stp x14, x15, [%2, #16 * 7]\n"
		"stp x16, x17, [%2, #16 * 8]\n"
		"stp x18, x19, [%2, #16 * 9]\n"
		"stp x20, x21, [%2, #16 * 10]\n"
		"stp x22, x23, [%2, #16 * 11]\n"
		"stp x24, x25, [%2, #16 * 12]\n"
		"stp x26, x27, [%2, #16 * 13]\n"
		"stp x28, x29, [%2, #16 * 14]\n"
		"mov %0, sp\n"
		"stp x30, %0, [%2, #16 * 15]\n"

		"/* faked current PSTATE */\n"
		"mrs %0, CurrentEL\n"
		"mrs %1, SPSEL\n"
		"orr %0, %0, %1\n"
		"mrs %1, DAIF\n"
		"orr %0, %0, %1\n"
		"mrs %1, NZCV\n"
		"orr %0, %0, %1\n"
		/* pc */
		"adr %1, 1f\n"
		"1:\n"
		"stp %1, %0, [%2, #16 * 16]\n"
		: "=&r" (tmp1), "=&r" (tmp2)
		: "r" (newregs)
		: "memory"
		);
		}
		}

		#if defined(CONFIG_KEXEC_CORE) && defined(CONFIG_HIBERNATION)

arch/arm64/include/asm/smp.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -148,6 +148,9 @@ static inline void cpu_panic_kernel(void)
		*/
		bool cpus_are_stuck_in_kernel(void);

		extern void smp_send_crash_stop(void);
		extern bool smp_crash_stop_failed(void);

		#endif /* ifndef __ASSEMBLY__ */

		#endif /* ifndef __ASM_SMP_H */

arch/arm64/kernel/machine_kexec.c

+54 −4

Original line number	Diff line number	Diff line
		@@ -9,6 +9,9 @@
		* published by the Free Software Foundation.
		*/

		#include <linux/interrupt.h>
		#include <linux/irq.h>
		#include <linux/kernel.h>
		#include <linux/kexec.h>
		#include <linux/page-flags.h>
		#include <linux/smp.h>
		@@ -143,11 +146,15 @@ void machine_kexec(struct kimage *kimage)
		{
		phys_addr_t reboot_code_buffer_phys;
		void *reboot_code_buffer;
		bool in_kexec_crash = (kimage == kexec_crash_image);
		bool stuck_cpus = cpus_are_stuck_in_kernel();

		/*
		* New cpus may have become stuck_in_kernel after we loaded the image.
		*/
		BUG_ON(cpus_are_stuck_in_kernel() \|\| (num_online_cpus() > 1));
		BUG_ON(!in_kexec_crash && (stuck_cpus \|\| (num_online_cpus() > 1)));
		WARN(in_kexec_crash && (stuck_cpus \|\| smp_crash_stop_failed()),
		"Some CPUs may be stale, kdump will be unreliable.\n");

		reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
		reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys);
		@@ -199,15 +206,58 @@ void machine_kexec(struct kimage *kimage)
		* relocation is complete.
		*/

		cpu_soft_restart(1, reboot_code_buffer_phys, kimage->head,
		kimage->start, 0);
		cpu_soft_restart(kimage != kexec_crash_image,
		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();

		/* 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");
		}

		void arch_kexec_protect_crashkres(void)

arch/arm64/kernel/smp.c

+68 −0

Original line number	Diff line number	Diff line
		@@ -39,6 +39,7 @@
		#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>
		@@ -76,6 +77,7 @@ enum ipi_msg_type {
		IPI_RESCHEDULE,
		IPI_CALL_FUNC,
		IPI_CPU_STOP,
		IPI_CPU_CRASH_STOP,
		IPI_TIMER,
		IPI_IRQ_WORK,
		IPI_WAKEUP
		@@ -756,6 +758,7 @@ 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"),
		S(IPI_WAKEUP, "CPU wake-up interrupts"),
		@@ -830,6 +833,29 @@ static void ipi_cpu_stop(unsigned int cpu)
		cpu_relax();
		}

		#ifdef CONFIG_KEXEC_CORE
		static atomic_t waiting_for_crash_ipi = ATOMIC_INIT(0);
		#endif

		static void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs)
		{
		#ifdef CONFIG_KEXEC_CORE
		crash_save_cpu(regs, cpu);

		atomic_dec(&waiting_for_crash_ipi);

		local_irq_disable();

		#ifdef CONFIG_HOTPLUG_CPU
		if (cpu_ops[cpu]->cpu_die)
		cpu_ops[cpu]->cpu_die(cpu);
		#endif

		/* just in case */
		cpu_park_loop();
		#endif
		}

		/*
		* Main handler for inter-processor interrupts
		*/
		@@ -860,6 +886,15 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
		irq_exit();
		break;

		case IPI_CPU_CRASH_STOP:
		if (IS_ENABLED(CONFIG_KEXEC_CORE)) {
		irq_enter();
		ipi_cpu_crash_stop(cpu, regs);

		unreachable();
		}
		break;

		#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
		case IPI_TIMER:
		irq_enter();
		@@ -932,6 +967,39 @@ void smp_send_stop(void)
		cpumask_pr_args(cpu_online_mask));
		}

		#ifdef CONFIG_KEXEC_CORE
		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);

		pr_crit("SMP: stopping secondary CPUs\n");
		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_warning("SMP: failed to stop secondary CPUs %*pbl\n",
		cpumask_pr_args(&mask));
		}

		bool smp_crash_stop_failed(void)
		{
		return (atomic_read(&waiting_for_crash_ipi) > 0);
		}
		#endif

		/*
		* not supported here
		*/

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