In preparation for removing HANDLE_DOMAIN_IRQ, have arch/nds32 perform
all the necessary IRQ entry accounting in its entry code.

Currently arch/nds32 is tightly coupled with the ativic32 irqchip, and
while the entry code should logically live under arch/nds32/, moving the
entry logic there makes things more convoluted. So for now, place the
entry logic in the ativic32 irqchip, but separated into a separate
function to make the split of responsibility clear.

In future this should probably use GENERIC_IRQ_MULTI_HANDLER to cleanly
decouple this.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Greentime Hu <redacted>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Nick Hu <redacted>
Cc: Thomas Gleixner <redacted>
Cc: Vincent Chen <redacted>
---
 arch/nds32/Kconfig             |  1 -
 drivers/irqchip/irq-ativic32.c | 22 ++++++++++++++++++++--
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig
index aea26e739543..4d1421b18734 100644
--- a/arch/nds32/Kconfig
+++ b/arch/nds32/Kconfig

@@ -27,7 +27,6 @@ config NDS32
        select GENERIC_LIB_MULDI3
        select GENERIC_LIB_UCMPDI2
        select GENERIC_TIME_VSYSCALL
-       select HANDLE_DOMAIN_IRQ
        select HAVE_ARCH_TRACEHOOK
        select HAVE_DEBUG_KMEMLEAK
        select HAVE_EXIT_THREAD

diff --git a/drivers/irqchip/irq-ativic32.c b/drivers/irqchip/irq-ativic32.c
index 476d6024aaf2..223dd2f97d28 100644
--- a/drivers/irqchip/irq-ativic32.c
+++ b/drivers/irqchip/irq-ativic32.c

@@ -5,11 +5,14 @@
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
+#include <linux/hardirq.h>
 #include <linux/interrupt.h>
 #include <linux/irqdomain.h>
 #include <linux/irqchip.h>
 #include <nds32_intrinsic.h>

+#include <asm/irq_regs.h>
+
 unsigned long wake_mask;

 static void ativic32_ack_irq(struct irq_data *data)

@@ -103,10 +106,25 @@ static irq_hw_number_t get_intr_src(void)
                - NDS32_VECTOR_offINTERRUPT;
 }

-asmlinkage void asm_do_IRQ(struct pt_regs *regs)
+static void ativic32_handle_irq(struct pt_regs *regs)
 {
        irq_hw_number_t hwirq = get_intr_src();
-       handle_domain_irq(root_domain, hwirq, regs);
+       generic_handle_domain_irq(root_domain, hwirq);
+}
+
+/*
+ * TODO: convert nds32 to GENERIC_IRQ_MULTI_HANDLER so that this entry logic
+ * can live in arch code.
+ */
+asmlinkage void asm_do_IRQ(struct pt_regs *regs)
+{
+       struct pt_regs *old_regs;
+
+       irq_enter();
+       old_regs = set_irq_regs(regs);
+       ativic32_handle_irq(regs);
+       set_irq_regs(old_regs);
+       irq_exit();
 }

 int __init ativic32_init_irq(struct device_node *node, struct device_node *parent)
--

2.11.0