Merge tag 'irq-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "Updates for the interrupt subsystem:

  Core changes:

   - Prevent a potential deadlock when initial priority is assigned to a
     newly created interrupt thread. A recent change to plug a race
     between cpuset and __sched_setscheduler() introduced a new lock
     dependency which is now triggered. Break the lock dependency chain
     by moving the priority assignment to the thread function.

   - A couple of small updates to make the irq core RT safe.

   - Confine the irq_cpu_online/offline() API to the only left unfixable
     user Cavium Octeon so that it does not grow new usage.

   - A small documentation update

  Driver changes:

   - A large cross architecture rework to move irq_enter/exit() into the
     architecture code to make addressing the NOHZ_FULL/RCU issues
     simpler.

   - The obligatory new irq chip driver for Microchip EIC

   - Modularize a few irq chip drivers

   - Expand usage of devm_*() helpers throughout the driver code

   - The usual small fixes and improvements all over the place"

* tag 'irq-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  h8300: Fix linux/irqchip.h include mess
  dt-bindings: irqchip: renesas-irqc: Document r8a774e1 bindings
  MIPS: irq: Avoid an unused-variable error
  genirq: Hide irq_cpu_{on,off}line() behind a deprecated option
  irqchip/mips-gic: Get rid of the reliance on irq_cpu_online()
  MIPS: loongson64: Drop call to irq_cpu_offline()
  irq: remove handle_domain_{irq,nmi}()
  irq: remove CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY
  irq: riscv: perform irqentry in entry code
  irq: openrisc: perform irqentry in entry code
  irq: csky: perform irqentry in entry code
  irq: arm64: perform irqentry in entry code
  irq: arm: perform irqentry in entry code
  irq: add a (temporary) CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY
  irq: nds32: avoid CONFIG_HANDLE_DOMAIN_IRQ
  irq: arc: avoid CONFIG_HANDLE_DOMAIN_IRQ
  irq: add generic_handle_arch_irq()
  irq: unexport handle_irq_desc()
  irq: simplify handle_domain_{irq,nmi}()
  irq: mips: simplify do_domain_IRQ()
  ...

2 files changed, 9 insertions, 10 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
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 20ab1e607522..b79975bd988c 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)