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authorRussell King <rmk+kernel@arm.linux.org.uk>2014-09-03 23:57:13 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-07-17 12:23:30 +0100
commit96f0e00378d4a1fc1b79933ef84e1595015de808 (patch)
treeede21e674c04e85d4bd322d83541c10f4e3ae6d5 /arch/arm/kernel
parent4d7489ffba0aef4d2c708b6ff1428efd6ccf41df (diff)
downloadlinux-linaro-stable-96f0e00378d4a1fc1b79933ef84e1595015de808.tar.gz
ARM: add basic support for on-demand backtrace of other CPUs
As we now have generic infrastructure to support backtracing of other CPUs in the system on lockups, we can start to implement this for ARM. Initially, we add an IPI based implementation, as the GIC code needs modification to support the generation of FIQ IPIs, and not all ARM platforms have the ability to raise a FIQ in the non-secure world. This provides us with a "best efforts" implementation in the absence of FIQs. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/smp.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 90dfbedfbfb8..3a20c386fd33 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -21,6 +21,7 @@
#include <linux/cpu.h>
#include <linux/seq_file.h>
#include <linux/irq.h>
+#include <linux/nmi.h>
#include <linux/percpu.h>
#include <linux/clockchips.h>
#include <linux/completion.h>
@@ -72,6 +73,7 @@ enum ipi_msg_type {
IPI_CPU_STOP,
IPI_IRQ_WORK,
IPI_COMPLETION,
+ IPI_CPU_BACKTRACE = 15,
};
static DECLARE_COMPLETION(cpu_running);
@@ -630,6 +632,12 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
irq_exit();
break;
+ case IPI_CPU_BACKTRACE:
+ irq_enter();
+ nmi_cpu_backtrace(regs);
+ irq_exit();
+ break;
+
default:
pr_crit("CPU%u: Unknown IPI message 0x%x\n",
cpu, ipinr);
@@ -724,3 +732,13 @@ static int __init register_cpufreq_notifier(void)
core_initcall(register_cpufreq_notifier);
#endif
+
+static void raise_nmi(cpumask_t *mask)
+{
+ smp_cross_call(mask, IPI_CPU_BACKTRACE);
+}
+
+void arch_trigger_all_cpu_backtrace(bool include_self)
+{
+ nmi_trigger_all_cpu_backtrace(include_self, raise_nmi);
+}