From: Wei Li <liwei391@huawei.com>
To: <catalin.marinas@arm.com>, <will.deacon@arm.com>,
<marc.zyngier@arm.com>, <tglx@linutronix.de>,
<jason@lakedaemon.net>
Cc: <julien.thierry@arm.com>, <Suzuki.Poulose@arm.com>,
<sudeep.holla@arm.com>, <steve.capper@arm.com>,
<lorenzo.pieralisi@arm.com>, <daniel.thompson@linaro.org>,
<james.morse@arm.com>, <linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH 2/3] arm64: Add support for on-demand backtrace of other CPUs
Date: Mon, 6 May 2019 16:25:41 +0800 [thread overview]
Message-ID: <20190506082542.11357-3-liwei391@huawei.com> (raw)
In-Reply-To: <20190506082542.11357-1-liwei391@huawei.com>
To support backtracing of other CPUs in the system on lockups, add the
implementation of arch_trigger_cpumask_backtrace() for arm64.
In this patch, we add an arm64 NMI-like IPI based backtracer, referring
to the implementation on arm by Russell King and Chris Metcalf.
Signed-off-by: Wei Li <liwei391@huawei.com>
---
arch/arm64/include/asm/hardirq.h | 2 +-
arch/arm64/include/asm/irq.h | 6 ++++++
arch/arm64/kernel/smp.c | 22 +++++++++++++++++++++-
3 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/hardirq.h b/arch/arm64/include/asm/hardirq.h
index 89691c86640a..a5d94aa59c7c 100644
--- a/arch/arm64/include/asm/hardirq.h
+++ b/arch/arm64/include/asm/hardirq.h
@@ -24,7 +24,7 @@
#include <asm/kvm_arm.h>
#include <asm/sysreg.h>
-#define NR_IPI 7
+#define NR_IPI 8
typedef struct {
unsigned int __softirq_pending;
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h
index b2b0c6405eb0..28471df488c0 100644
--- a/arch/arm64/include/asm/irq.h
+++ b/arch/arm64/include/asm/irq.h
@@ -13,5 +13,11 @@ static inline int nr_legacy_irqs(void)
return 0;
}
+#ifdef CONFIG_SMP
+extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
+ bool exclude_self);
+#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
+#endif
+
#endif /* !__ASSEMBLER__ */
#endif
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index bd8fdf6fcd8e..7e862f9124f3 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -35,6 +35,7 @@
#include <linux/smp.h>
#include <linux/seq_file.h>
#include <linux/irq.h>
+#include <linux/nmi.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/percpu.h>
#include <linux/clockchips.h>
@@ -83,7 +84,8 @@ enum ipi_msg_type {
IPI_CPU_CRASH_STOP,
IPI_TIMER,
IPI_IRQ_WORK,
- IPI_WAKEUP
+ IPI_WAKEUP,
+ IPI_CPU_BACKTRACE
};
#ifdef CONFIG_HOTPLUG_CPU
@@ -787,6 +789,7 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = {
S(IPI_TIMER, "Timer broadcast interrupts"),
S(IPI_IRQ_WORK, "IRQ work interrupts"),
S(IPI_WAKEUP, "CPU wake-up interrupts"),
+ S(IPI_CPU_BACKTRACE, "Backtrace interrupts"),
};
static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
@@ -946,6 +949,12 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
break;
#endif
+ case IPI_CPU_BACKTRACE:
+ nmi_enter();
+ nmi_cpu_backtrace(regs);
+ nmi_exit();
+ break;
+
default:
pr_crit("CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr);
break;
@@ -1070,4 +1079,15 @@ bool cpus_are_stuck_in_kernel(void)
void ipi_gic_nmi_setup(void __iomem *base)
{
+ gic_sgi_set_prio(base, IPI_CPU_BACKTRACE, GICD_INT_NMI_PRI);
+}
+
+static void raise_nmi(cpumask_t *mask)
+{
+ smp_cross_call(mask, IPI_CPU_BACKTRACE);
+}
+
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
+{
+ nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_nmi);
}
--
2.17.1
next prev parent reply other threads:[~2019-05-06 8:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-06 8:25 [PATCH 0/3] arm64: Add support for on-demand backtrace by NMI-like IPI Wei Li
2019-05-06 8:25 ` [PATCH 1/3] arm64: Add pseudo NMI support of GICv3 SGIs Wei Li
2019-05-13 8:26 ` Julien Thierry
2019-05-06 8:25 ` Wei Li [this message]
2019-05-06 8:25 ` [PATCH 3/3] arm64: Avoid entering NMI context improperly Wei Li
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