Previous changes have introduced a replacement default FIQ handler and an implementation of arch_trigger_all_cpu_backtrace for ARM but these are currently independant.
This patch plumbs together these features making it possible, on platforms that support it, to trigger backtrace using FIQ.
Signed-off-by: Daniel Thompson daniel.thompson@linaro.org --- arch/arm/include/asm/smp.h | 3 +++ arch/arm/kernel/fiq.c | 8 ++++---- arch/arm/kernel/smp.c | 4 +++- arch/arm/kernel/traps.c | 3 +++ 4 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index 2ec765c..0580270 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -18,6 +18,8 @@ # error "<asm/smp.h> included in non-SMP build" #endif
+#define SMP_IPI_FIQ_MASK 0x0100 + #define raw_smp_processor_id() (current_thread_info()->cpu)
struct seq_file; @@ -85,6 +87,7 @@ extern void arch_send_call_function_single_ipi(int cpu); extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
+extern void ipi_cpu_backtrace(struct pt_regs *regs); extern int register_ipi_completion(struct completion *completion, int cpu);
struct smp_operations { diff --git a/arch/arm/kernel/fiq.c b/arch/arm/kernel/fiq.c index 1743049..b37752a 100644 --- a/arch/arm/kernel/fiq.c +++ b/arch/arm/kernel/fiq.c @@ -52,8 +52,8 @@ (unsigned)&vector_fiq_offset; \ })
-static unsigned long no_fiq_insn; -static struct pt_regs def_fiq_regs; +static unsigned long dfl_fiq_insn; +static struct pt_regs dfl_fiq_regs;
/* Default reacquire function * - we always relinquish FIQ control @@ -65,7 +65,7 @@ static int fiq_def_op(void *ref, int relinquish) /* Restore default handler and registers */ local_fiq_disable(); set_fiq_regs(&dfl_fiq_regs); - set_fiq_handler(&no_fiq_insn, sizeof(no_fiq_insn)); + set_fiq_handler(&dfl_fiq_insn, sizeof(dfl_fiq_insn)); local_fiq_enable();
/* FIXME: notify irq controller to standard enable FIQs */ @@ -158,7 +158,7 @@ EXPORT_SYMBOL(disable_fiq); void __init init_FIQ(int start) { unsigned offset = FIQ_OFFSET; - no_fiq_insn = *(unsigned long *)(0xffff0000 + offset); + dfl_fiq_insn = *(unsigned long *)(0xffff0000 + offset); get_fiq_regs(&dfl_fiq_regs); fiq_start = start; } diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 94959f9..7a79d11 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -543,7 +543,7 @@ static void ipi_cpu_stop(unsigned int cpu) cpu_relax(); }
-static void ipi_cpu_backtrace(struct pt_regs *regs) +void ipi_cpu_backtrace(struct pt_regs *regs) { int cpu = smp_processor_id();
@@ -584,6 +584,8 @@ void handle_IPI(int ipinr, struct pt_regs *regs) unsigned int cpu = smp_processor_id(); struct pt_regs *old_regs = set_irq_regs(regs);
+ BUILD_BUG_ON(SMP_IPI_FIQ_MASK != BIT(IPI_CPU_BACKTRACE)); + if ((unsigned)ipinr < NR_IPI) { trace_ipi_entry(ipi_types[ipinr]); __inc_irq_stat(cpu, ipi_irqs[ipinr]); diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 92c4ea1..40b1de7 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -483,6 +483,9 @@ asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs) #ifdef CONFIG_ARM_GIC gic_handle_fiq_ipi(); #endif +#ifdef CONFIG_SMP + ipi_cpu_backtrace(regs); +#endif
nmi_exit();