irq: remove handle_domain_{irq,nmi}()

Now that entry code handles IRQ entry (including setting the IRQ regs)
before calling irqchip code, irqchip code can safely call
generic_handle_domain_irq(), and there's no functional reason for it to
call handle_domain_irq().

Let's cement this split of responsibility and remove handle_domain_irq()
entirely, updating irqchip drivers to call generic_handle_domain_irq().

For consistency, handle_domain_nmi() is similarly removed and replaced
with a generic_handle_domain_nmi() function which also does not perform
any entry logic.

Previously handle_domain_{irq,nmi}() had a WARN_ON() which would fire
when they were called in an inappropriate context. So that we can
identify similar issues going forward, similar WARN_ON_ONCE() logic is
added to the generic_handle_*() functions, and comments are updated for
clarity and consistency.

Signed-off-by: Mark Rutland <[email protected]>
Reviewed-by: Marc Zyngier <[email protected]>
Cc: Thomas Gleixner <[email protected]>

Author: mrutland-arm

Documentation/core-api/irq/irq-domain.rst

@@ -67,9 +67,6 @@ variety of methods:
   deprecated
 - generic_handle_domain_irq() handles an interrupt described by a
   domain and a hwirq number
-- handle_domain_irq() does the same thing for root interrupt
-  controllers and deals with the set_irq_reg()/irq_enter() sequences
-  that most architecture requires
 
 Note that irq domain lookups must happen in contexts that are
 compatible with a RCU read-side critical section.

arch/arm/Kconfig

@@ -64,7 +64,6 @@ config ARM
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
-	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
 	select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6

arch/arm/mach-imx/avic.c

@@ -154,7 +154,7 @@ static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
 		if (nivector == 0xffff)
 			break;
 
-		handle_domain_irq(domain, nivector, regs);
+		generic_handle_domain_irq(domain, nivector);
 	} while (1);
 }
 

arch/arm/mach-imx/tzic.c

@@ -134,7 +134,7 @@ static void __exception_irq_entry tzic_handle_irq(struct pt_regs *regs)
 			while (stat) {
 				handled = 1;
 				irqofs = fls(stat) - 1;
-				handle_domain_irq(domain, irqofs + i * 32, regs);
+				generic_handle_domain_irq(domain, irqofs + i * 32);
 				stat &= ~(1 << irqofs);
 			}
 		}

arch/arm/mach-omap1/irq.c

@@ -165,7 +165,7 @@ asmlinkage void __exception_irq_entry omap1_handle_irq(struct pt_regs *regs)
 		}
 irq:
 		if (irqnr)
-			handle_domain_irq(domain, irqnr, regs);
+			generic_handle_domain_irq(domain, irqnr);
 		else
 			break;
 	} while (irqnr);

arch/arm/mach-s3c/irq-s3c24xx.c

@@ -354,7 +354,7 @@ static inline int s3c24xx_handle_intc(struct s3c_irq_intc *intc,
 	if (!(pnd & (1 << offset)))
 		offset =  __ffs(pnd);
 
-	handle_domain_irq(intc->domain, intc_offset + offset, regs);
+	generic_handle_domain_irq(intc->domain, intc_offset + offset);
 	return true;
 }
 

arch/arm64/Kconfig

@@ -133,7 +133,6 @@ config ARM64
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
 	select GENERIC_VDSO_TIME_NS
-	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_MOVE_PMD
 	select HAVE_MOVE_PUD

arch/csky/Kconfig

@@ -17,7 +17,6 @@ config CSKY
 	select CSKY_APB_INTC
 	select DMA_DIRECT_REMAP
 	select IRQ_DOMAIN
-	select HANDLE_DOMAIN_IRQ
 	select DW_APB_TIMER_OF
 	select GENERIC_IOREMAP
 	select GENERIC_LIB_ASHLDI3

arch/openrisc/Kconfig

@@ -13,7 +13,6 @@ config OPENRISC
 	select OF
 	select OF_EARLY_FLATTREE
 	select IRQ_DOMAIN
-	select HANDLE_DOMAIN_IRQ
 	select GPIOLIB
 	select HAVE_ARCH_TRACEHOOK
 	select SPARSE_IRQ

arch/riscv/Kconfig

@@ -62,7 +62,6 @@ config RISCV
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL if MMU && 64BIT
-	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
 	select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL