[PATCH v3 2/5] RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handler

[Palmer Dabbelt]

The old mechanism for handling IRQs on RISC-V was pretty ugly: the arch
code looked at the Kconfig entry for our first-level irqchip driver and
called into it directly.

This patch uses the new generic IRQ handling infastructure, which
essentially just deletes a bunch of code.  This does add an additional
load to the interrupt latency, but there's a lot of tuning left to be
done there on RISC-V so I think it's OK for now.

Reviewed-by: Christoph Hellwig 
Acked-by: Stafford Horne 
Signed-off-by: Palmer Dabbelt 
---
 arch/riscv/Kconfig|  1 +
 arch/riscv/include/asm/Kbuild |  1 +
 arch/riscv/kernel/entry.S |  7 +++
 arch/riscv/kernel/irq.c   | 13 -
 4 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 04807c7f64cc..148865de1692 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -33,6 +33,7 @@ config RISCV
select MODULES_USE_ELF_RELA if MODULES
select THREAD_INFO_IN_TASK
select RISCV_TIMER
+   select GENERIC_IRQ_MULTI_HANDLER
 
 config MMU
def_bool y
diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index 4286a5f83876..1e5fd280fb4d 100644
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -15,6 +15,7 @@ generic-y += fcntl.h
 generic-y += futex.h
 generic-y += hardirq.h
 generic-y += hash.h
+generic-y += handle_irq.h
 generic-y += hw_irq.h
 generic-y += ioctl.h
 generic-y += ioctls.h
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 56fa592cfa34..9aaf6c986771 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -167,10 +167,9 @@ ENTRY(handle_exception)
bge s4, zero, 1f
 
/* Handle interrupts */
-   slli a0, s4, 1
-   srli a0, a0, 1
-   move a1, sp /* pt_regs */
-   tail do_IRQ
+   move a0, sp /* pt_regs */
+   REG_L a1, handle_arch_irq
+   jr a1
 1:
/* Exceptions run with interrupts enabled */
csrs sstatus, SR_SIE
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index 328718e8026e..b74cbfbce2d0 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -24,16 +24,3 @@ void __init init_IRQ(void)
 {
irqchip_init();
 }
-
-asmlinkage void __irq_entry do_IRQ(unsigned int cause, struct pt_regs *regs)
-{
-#ifdef CONFIG_RISCV_INTC
-   /*
-* FIXME: We don't want a direct call to riscv_intc_irq here.  The plan
-* is to put an IRQ domain here and let the interrupt controller
-* register with that, but I poked around the arm64 code a bit and
-* there might be a better way to do it (ie, something fully generic).
-*/
-   riscv_intc_irq(cause, regs);
-#endif
-}
-- 
2.16.1

[PATCH v3 2/5] RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handler

[Palmer Dabbelt]

The old mechanism for handling IRQs on RISC-V was pretty ugly: the arch
code looked at the Kconfig entry for our first-level irqchip driver and
called into it directly.

This patch uses the new generic IRQ handling infastructure, which
essentially just deletes a bunch of code.  This does add an additional
load to the interrupt latency, but there's a lot of tuning left to be
done there on RISC-V so I think it's OK for now.

Reviewed-by: Christoph Hellwig 
Acked-by: Stafford Horne 
Signed-off-by: Palmer Dabbelt 
---
 arch/riscv/Kconfig|  1 +
 arch/riscv/include/asm/Kbuild |  1 +
 arch/riscv/kernel/entry.S |  7 +++
 arch/riscv/kernel/irq.c   | 13 -
 4 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 04807c7f64cc..148865de1692 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -33,6 +33,7 @@ config RISCV
select MODULES_USE_ELF_RELA if MODULES
select THREAD_INFO_IN_TASK
select RISCV_TIMER
+   select GENERIC_IRQ_MULTI_HANDLER
 
 config MMU
def_bool y
diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index 4286a5f83876..1e5fd280fb4d 100644
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -15,6 +15,7 @@ generic-y += fcntl.h
 generic-y += futex.h
 generic-y += hardirq.h
 generic-y += hash.h
+generic-y += handle_irq.h
 generic-y += hw_irq.h
 generic-y += ioctl.h
 generic-y += ioctls.h
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 56fa592cfa34..9aaf6c986771 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -167,10 +167,9 @@ ENTRY(handle_exception)
bge s4, zero, 1f
 
/* Handle interrupts */
-   slli a0, s4, 1
-   srli a0, a0, 1
-   move a1, sp /* pt_regs */
-   tail do_IRQ
+   move a0, sp /* pt_regs */
+   REG_L a1, handle_arch_irq
+   jr a1
 1:
/* Exceptions run with interrupts enabled */
csrs sstatus, SR_SIE
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index 328718e8026e..b74cbfbce2d0 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -24,16 +24,3 @@ void __init init_IRQ(void)
 {
irqchip_init();
 }
-
-asmlinkage void __irq_entry do_IRQ(unsigned int cause, struct pt_regs *regs)
-{
-#ifdef CONFIG_RISCV_INTC
-   /*
-* FIXME: We don't want a direct call to riscv_intc_irq here.  The plan
-* is to put an IRQ domain here and let the interrupt controller
-* register with that, but I poked around the arm64 code a bit and
-* there might be a better way to do it (ie, something fully generic).
-*/
-   riscv_intc_irq(cause, regs);
-#endif
-}
-- 
2.16.1