[PATCH 2/5] ARC: SMP: Pass virq to smp_ipi_irq_setup instead of hwirq

From: Yuriy Kolerov
Date: Fri Oct 21 2016 - 18:17:03 EST

This function takes a cpu number and a virq number and registers an
appropriate handler per cpu. However smp_ipi_irq_setup is incorrectly
used in several places of ARC platform code - hwirq is passed instead of
virq. There is a code with an example of inccorect usage of smp_ipi_irq_setup:

smp_ipi_irq_setup(cpu, IPI_IRQ);
smp_ipi_irq_setup(cpu, SOFTIRQ_IRQ);

where IPI_IRQ and SOFTIRQ_IRQ are hwirq numbers for per cpu interrupts.
Since smp_ipi_irq_setup must be taken a virq number insdead of a hwirq
number then it is necessary to fix usage of this function this way:

smp_ipi_irq_setup(cpu, irq_find_mapping(NULL, IPI_IRQ));
smp_ipi_irq_setup(cpu, irq_find_mapping(NULL, SOFTIRQ_IRQ));

The idea is to find an appropriate mapping of <domain, hwirq> to virq
by using irq_find_mapping function. NULL value is used as a domain
argument (a default domain) since smp_ipi_irq_setup is used for
registering an IRQ handler for a root interrupt controller (a default
IRQ domain must be used).

Signed-off-by: Yuriy Kolerov <yuriy.kolerov@xxxxxxxxxxxx>
arch/arc/kernel/mcip.c | 5 +++--
arch/arc/plat-eznps/smp.c | 2 +-
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arc/kernel/mcip.c b/arch/arc/kernel/mcip.c
index 72f9179..28ff766 100644
--- a/arch/arc/kernel/mcip.c
+++ b/arch/arc/kernel/mcip.c
@@ -11,6 +11,7 @@
#include <linux/smp.h>
#include <linux/irq.h>
#include <linux/spinlock.h>
+#include <linux/irqdomain.h>
#include <asm/irqflags-arcv2.h>
#include <asm/mcip.h>
#include <asm/setup.h>
@@ -22,8 +23,8 @@ static DEFINE_RAW_SPINLOCK(mcip_lock);

static void mcip_setup_per_cpu(int cpu)
- smp_ipi_irq_setup(cpu, IPI_IRQ);
- smp_ipi_irq_setup(cpu, SOFTIRQ_IRQ);
+ smp_ipi_irq_setup(cpu, irq_find_mapping(NULL, IPI_IRQ));
+ smp_ipi_irq_setup(cpu, irq_find_mapping(NULL, SOFTIRQ_IRQ));

static void mcip_ipi_send(int cpu)
diff --git a/arch/arc/plat-eznps/smp.c b/arch/arc/plat-eznps/smp.c
index 5e901f8..dd996e0 100644
--- a/arch/arc/plat-eznps/smp.c
+++ b/arch/arc/plat-eznps/smp.c
@@ -134,7 +134,7 @@ static void eznps_ipi_send(int cpu)

static void eznps_init_per_cpu(int cpu)
- smp_ipi_irq_setup(cpu, NPS_IPI_IRQ);
+ smp_ipi_irq_setup(cpu, irq_find_mapping(NULL, NPS_IPI_IRQ));