From a7b0872e964cf306fe26d9d49585a90486e32fdf Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 19 Oct 2021 18:17:17 +0100 Subject: [PATCH] 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 Reviewed-by: Marc Zyngier Tested-by: Vladimir Murzin # ARMv7M Cc: Russell King Cc: Thomas Gleixner --- arch/arm/Kconfig | 1 - arch/arm/kernel/entry-armv.S | 5 +---- arch/arm/kernel/irq.c | 14 ++++++++------ drivers/irqchip/irq-nvic.c | 17 ++++++++++++++++- 4 files changed, 25 insertions(+), 12 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index f18aff8..fc19642 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -65,7 +65,6 @@ config ARM select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD select HANDLE_DOMAIN_IRQ - select HANDLE_DOMAIN_IRQ_IRQENTRY select HARDIRQS_SW_RESEND select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6 diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 241b73d..3d0b616 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 diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 20ab1e6..b79975b 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -63,11 +63,8 @@ int arch_show_interrupts(struct seq_file *p, int prec) */ void handle_IRQ(unsigned int irq, struct pt_regs *regs) { - struct pt_regs *old_regs = set_irq_regs(regs); struct irq_desc *desc; - irq_enter(); - /* * Some hardware gives randomly wrong interrupts. Rather * than crashing, do something sensible. @@ -81,9 +78,6 @@ void handle_IRQ(unsigned int irq, struct pt_regs *regs) handle_irq_desc(desc); else ack_bad_irq(irq); - - irq_exit(); - set_irq_regs(old_regs); } /* @@ -92,7 +86,15 @@ void handle_IRQ(unsigned int irq, struct pt_regs *regs) asmlinkage void __exception_irq_entry asm_do_IRQ(unsigned int irq, struct pt_regs *regs) { + struct pt_regs *old_regs; + + irq_enter(); + old_regs = set_irq_regs(regs); + handle_IRQ(irq, regs); + + set_irq_regs(old_regs); + irq_exit(); } void __init init_IRQ(void) diff --git a/drivers/irqchip/irq-nvic.c b/drivers/irqchip/irq-nvic.c index b31c4cf..b2bd962 100644 --- a/drivers/irqchip/irq-nvic.c +++ b/drivers/irqchip/irq-nvic.c @@ -37,10 +37,25 @@ static struct irq_domain *nvic_irq_domain; +static void __nvic_handle_irq(irq_hw_number_t hwirq, struct pt_regs *regs) +{ + handle_domain_irq(nvic_irq_domain, hwirq, regs); +} + +/* + * TODO: restructure the ARMv7M entry logic so that this entry logic can live + * in arch code. + */ asmlinkage void __exception_irq_entry nvic_handle_irq(irq_hw_number_t hwirq, struct pt_regs *regs) { - handle_domain_irq(nvic_irq_domain, hwirq, regs); + struct pt_regs *old_regs; + + irq_enter(); + old_regs = set_irq_regs(regs); + __nvic_handle_irq(hwirq, regs); + set_irq_regs(old_regs); + irq_exit(); } static int nvic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, -- 2.7.4