[PATCH v3 1/3] ARC: SMP: Register IPI handler using virq but not hwirq

From: Yuriy Kolerov
Date: Thu Nov 03 2016 - 08:24:54 EST

smp_ipi_irq_setup takes a cpu number and a hwirq number for the per core
local interrupt line in the root interrupt controller and registers an
appropriate IPI handler per cpu. However this function tries to bind a
handler to the hwirq as virtual IRQ number and it is a wrong behavior.
It is necessary to find a mapping of hwirq in the root IRQ domain to
the actual virq using irq_find_mapping.

Also a declaration of smp_ipi_irq_setup is corrected to denote that
this function takes a hardware IRQ number but not a virtual IRQ number.

Signed-off-by: Yuriy Kolerov <yuriy.kolerov@xxxxxxxxxxxx>
arch/arc/include/asm/smp.h | 4 ++--
arch/arc/kernel/smp.c | 13 +++++++++----
2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/arc/include/asm/smp.h b/arch/arc/include/asm/smp.h
index 89fdd1b..0861007 100644
--- a/arch/arc/include/asm/smp.h
+++ b/arch/arc/include/asm/smp.h
@@ -37,9 +37,9 @@ extern const char *arc_platform_smp_cpuinfo(void);
* API expected BY platform smp code (FROM arch smp code)
* smp_ipi_irq_setup:
- * Takes @cpu and @irq to which the arch-common ISR is hooked up
+ * Takes @cpu and @hwirq to which the arch-common ISR is hooked up
-extern int smp_ipi_irq_setup(int cpu, int irq);
+extern int smp_ipi_irq_setup(int cpu, irq_hw_number_t hwirq);

* struct plat_smp_ops - SMP callbacks provided by platform to ARC SMP
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index f183cc6..692ca51 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -22,6 +22,7 @@
#include <linux/atomic.h>
#include <linux/cpumask.h>
#include <linux/reboot.h>
+#include <linux/irqdomain.h>
#include <asm/processor.h>
#include <asm/setup.h>
#include <asm/mach_desc.h>
@@ -351,20 +352,24 @@ irqreturn_t do_IPI(int irq, void *dev_id)
static DEFINE_PER_CPU(int, ipi_dev);

-int smp_ipi_irq_setup(int cpu, int irq)
+int smp_ipi_irq_setup(int cpu, irq_hw_number_t hwirq)
int *dev = per_cpu_ptr(&ipi_dev, cpu);
+ unsigned int virq = irq_find_mapping(NULL, hwirq);
+ if (!virq)
+ panic("Cannot find virq for root domain and hwirq=%lu", hwirq);

/* Boot cpu calls request, all call enable */
if (!cpu) {
int rc;

- rc = request_percpu_irq(irq, do_IPI, "IPI Interrupt", dev);
+ rc = request_percpu_irq(virq, do_IPI, "IPI Interrupt", dev);
if (rc)
- panic("Percpu IRQ request failed for %d\n", irq);
+ panic("Percpu IRQ request failed for %u\n", virq);

- enable_percpu_irq(irq, 0);
+ enable_percpu_irq(virq, 0);

return 0;