linux/arch/arm/include/asm/irq.h
Chris Metcalf 9a01c3ed5c nmi_backtrace: add more trigger_*_cpu_backtrace() methods
Patch series "improvements to the nmi_backtrace code" v9.

This patch series modifies the trigger_xxx_backtrace() NMI-based remote
backtracing code to make it more flexible, and makes a few small
improvements along the way.

The motivation comes from the task isolation code, where there are
scenarios where we want to be able to diagnose a case where some cpu is
about to interrupt a task-isolated cpu.  It can be helpful to see both
where the interrupting cpu is, and also an approximation of where the
cpu that is being interrupted is.  The nmi_backtrace framework allows us
to discover the stack of the interrupted cpu.

I've tested that the change works as desired on tile, and build-tested
x86, arm, mips, and sparc64.  For x86 I confirmed that the generic
cpuidle stuff as well as the architecture-specific routines are in the
new cpuidle section.  For arm, mips, and sparc I just build-tested it
and made sure the generic cpuidle routines were in the new cpuidle
section, but I didn't attempt to figure out which the platform-specific
idle routines might be.  That might be more usefully done by someone
with platform experience in follow-up patches.

This patch (of 4):

Currently you can only request a backtrace of either all cpus, or all
cpus but yourself.  It can also be helpful to request a remote backtrace
of a single cpu, and since we want that, the logical extension is to
support a cpumask as the underlying primitive.

This change modifies the existing lib/nmi_backtrace.c code to take a
cpumask as its basic primitive, and modifies the linux/nmi.h code to use
the new "cpumask" method instead.

The existing clients of nmi_backtrace (arm and x86) are converted to
using the new cpumask approach in this change.

The other users of the backtracing API (sparc64 and mips) are converted
to use the cpumask approach rather than the all/allbutself approach.
The mips code ignored the "include_self" boolean but with this change it
will now also dump a local backtrace if requested.

Link: http://lkml.kernel.org/r/1472487169-14923-2-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-07 18:46:30 -07:00

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C

#ifndef __ASM_ARM_IRQ_H
#define __ASM_ARM_IRQ_H
#define NR_IRQS_LEGACY 16
#ifndef CONFIG_SPARSE_IRQ
#include <mach/irqs.h>
#else
#define NR_IRQS NR_IRQS_LEGACY
#endif
#ifndef irq_canonicalize
#define irq_canonicalize(i) (i)
#endif
/*
* Use this value to indicate lack of interrupt
* capability
*/
#ifndef NO_IRQ
#define NO_IRQ ((unsigned int)(-1))
#endif
#ifndef __ASSEMBLY__
struct irqaction;
struct pt_regs;
extern void migrate_irqs(void);
extern void asm_do_IRQ(unsigned int, struct pt_regs *);
void handle_IRQ(unsigned int, struct pt_regs *);
void init_IRQ(void);
#ifdef CONFIG_MULTI_IRQ_HANDLER
extern void (*handle_arch_irq)(struct pt_regs *);
extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
#endif
#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
static inline int nr_legacy_irqs(void)
{
return NR_IRQS_LEGACY;
}
#endif
#endif