irq: arm: perform irqentry in entry code

In preparation for removing HANDLE_DOMAIN_IRQ_IRQENTRY, have arch/arm
perform all the irqentry accounting in its entry code.

For configurations with CONFIG_GENERIC_IRQ_MULTI_HANDLER, we can use
generic_handle_arch_irq(). Other than asm_do_IRQ(), all C calls to
handle_IRQ() are from irqchip handlers which will be called from
generic_handle_arch_irq(), so to avoid double accounting IRQ entry, the
entry logic is moved from handle_IRQ() into asm_do_IRQ().

For ARMv7M the entry assembly is tightly coupled with the NVIC irqchip, and
while the entry code should logically live under arch/arm/, moving the
entry logic there makes things more convoluted. So for now, place the
entry logic in the NVIC irqchip, but separated into a separate
function to make the split of responsibility clear.

For all other configurations without CONFIG_GENERIC_IRQ_MULTI_HANDLER,
IRQ entry is already handled in arch code, and requires no changes.

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

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 1 insertions, 4 deletions

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 241b73d64df7..3d0b6169ab86 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -38,14 +38,11 @@
  */
 	.macro	irq_handler
 #ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER
-	ldr	r1, =handle_arch_irq
 	mov	r0, sp
-	badr	lr, 9997f
-	ldr	pc, [r1]
+	bl	generic_handle_arch_irq
 #else
 	arch_irq_handler_default
 #endif
-9997:
 	.endm
 
 	.macro	pabt_helper