Rounding up the other CPUs using FIQ improves debugger robustness.
Signed-off-by: Daniel Thompson daniel.thompson@linaro.org --- arch/arm/include/asm/kgdb.h | 1 + arch/arm/kernel/kgdb.c | 20 ++++++++++++++++---- arch/arm/kernel/kgdb_fiq.c | 7 ++++++- 3 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/arch/arm/include/asm/kgdb.h b/arch/arm/include/asm/kgdb.h index 5de21f01..ceb466f 100644 --- a/arch/arm/include/asm/kgdb.h +++ b/arch/arm/include/asm/kgdb.h @@ -50,6 +50,7 @@ static inline void arch_kgdb_breakpoint(void) extern void kgdb_handle_bus_error(void); extern int kgdb_fault_expected;
+extern int kgdb_fiq_enabled; extern char kgdb_fiq_handler; extern char kgdb_fiq_handler_end; asmlinkage void __exception_irq_entry kgdb_fiq_do_handle(struct pt_regs *regs); diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c index a74b53c..e5c3ec0 100644 --- a/arch/arm/kernel/kgdb.c +++ b/arch/arm/kernel/kgdb.c @@ -175,14 +175,26 @@ static struct undef_hook kgdb_compiled_brkpt_hook = {
static void kgdb_call_nmi_hook(void *ignored) { - kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); + kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); }
void kgdb_roundup_cpus(unsigned long flags) { - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); +#ifdef CONFIG_FIQ + struct cpumask mask; + + if (kgdb_fiq_enabled) { + cpumask_copy(&mask, cpu_online_mask); + cpumask_clear_cpu(raw_smp_processor_id(), &mask); + if (!cpumask_empty(&mask)) + send_fiq_ipi_mask(&mask); + return; + } +#endif + + local_irq_enable(); + smp_call_function(kgdb_call_nmi_hook, NULL, 0); + local_irq_disable(); }
static int __kgdb_notify(struct die_args *args, unsigned long cmd) diff --git a/arch/arm/kernel/kgdb_fiq.c b/arch/arm/kernel/kgdb_fiq.c index a894dde..f7a2c3d 100644 --- a/arch/arm/kernel/kgdb_fiq.c +++ b/arch/arm/kernel/kgdb_fiq.c @@ -24,7 +24,7 @@ #include <asm/fiq.h> #include <asm/exception.h>
-static int kgdb_fiq_enabled; +int kgdb_fiq_enabled; module_param_named(enable, kgdb_fiq_enabled, int, 0600); MODULE_PARM_DESC(enable, "set to 1 to enable FIQ KGDB");
@@ -40,6 +40,11 @@ asmlinkage void __exception_irq_entry kgdb_fiq_do_handle(struct pt_regs *regs) { int actual;
+ if (!kgdb_nmicallback(raw_smp_processor_id(), regs)) { + handle_IPI_FIQ(regs); + return; + } + nmi_enter(); actual = ack_fiq(kgdb_fiq); WARN_ON(actual != kgdb_fiq);