Merge branch irq/remove-handle-domain-irq-20211026 into irq/irqchip-next

* irq/remove-handle-domain-irq-20211026:
  : Large rework of the architecture entry code from Mark Rutland.
  : From the cover letter:
  :
  : <quote>
  : The handle_domain_{irq,nmi}() functions were oringally intended as a
  : convenience, but recent rework to entry code across the kernel tree has
  : demonstrated that they cause more pain than they're worth and prevent
  : architectures from being able to write robust entry code.
  :
  : This series reworks the irq code to remove them, handling the necessary
  : entry work consistently in entry code (be it architectural or generic).
  : </quote>
  MIPS: irq: Avoid an unused-variable error
  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()
  irq: mips: stop (ab)using handle_domain_irq()
  irq: mips: simplify bcm6345_l1_irq_handle()
  irq: mips: avoid nested irq_enter()

Signed-off-by: Marc Zyngier <maz@kernel.org>

3 files changed, 35 insertions, 67 deletions

diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index fbc54c2a7f23..1b41078222f3 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -97,9 +97,6 @@ config GENERIC_MSI_IRQ_DOMAIN
 config IRQ_MSI_IOMMU
 	bool
 
-config HANDLE_DOMAIN_IRQ
-	bool
-
 config IRQ_TIMINGS
 	bool
 
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 221d80c31e94..27182003b879 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -14,6 +14,8 @@
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 
+#include <asm/irq_regs.h>
+
 #include <trace/events/irq.h>
 
 #include "internals.h"
@@ -226,4 +228,20 @@ int __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
 	handle_arch_irq = handle_irq;
 	return 0;
 }
+
+/**
+ * generic_handle_arch_irq - root irq handler for architectures which do no
+ *                           entry accounting themselves
+ * @regs:	Register file coming from the low-level handling code
+ */
+asmlinkage void noinstr generic_handle_arch_irq(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs;
+
+	irq_enter();
+	old_regs = set_irq_regs(regs);
+	handle_arch_irq(regs);
+	set_irq_regs(old_regs);
+	irq_exit();
+}
 #endif
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 4e3c29bb603c..2267e6527db3 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -646,13 +646,16 @@ int handle_irq_desc(struct irq_desc *desc)
 	generic_handle_irq_desc(desc);
 	return 0;
 }
-EXPORT_SYMBOL_GPL(handle_irq_desc);
 
 /**
  * generic_handle_irq - Invoke the handler for a particular irq
  * @irq:	The irq number to handle
  *
- */
+ * Returns:	0 on success, or -EINVAL if conversion has failed
+ *
+ * 		This function must be called from an IRQ context with irq regs
+ * 		initialized.
+  */
 int generic_handle_irq(unsigned int irq)
 {
 	return handle_irq_desc(irq_to_desc(irq));
@@ -662,89 +665,39 @@ EXPORT_SYMBOL_GPL(generic_handle_irq);
 #ifdef CONFIG_IRQ_DOMAIN
 /**
  * generic_handle_domain_irq - Invoke the handler for a HW irq belonging
- *                             to a domain, usually for a non-root interrupt
- *                             controller
+ *                             to a domain.
  * @domain:	The domain where to perform the lookup
  * @hwirq:	The HW irq number to convert to a logical one
  *
  * Returns:	0 on success, or -EINVAL if conversion has failed
  *
+ * 		This function must be called from an IRQ context with irq regs
+ * 		initialized.
  */
 int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq)
 {
+	WARN_ON_ONCE(!in_irq());
 	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 }
 EXPORT_SYMBOL_GPL(generic_handle_domain_irq);
 
-#ifdef CONFIG_HANDLE_DOMAIN_IRQ
 /**
- * handle_domain_irq - Invoke the handler for a HW irq belonging to a domain,
- *                     usually for a root interrupt controller
+ * generic_handle_domain_nmi - Invoke the handler for a HW nmi belonging
+ *                             to a domain.
  * @domain:	The domain where to perform the lookup
  * @hwirq:	The HW irq number to convert to a logical one
- * @regs:	Register file coming from the low-level handling code
  *
  * Returns:	0 on success, or -EINVAL if conversion has failed
- */
-int handle_domain_irq(struct irq_domain *domain,
-		      unsigned int hwirq, struct pt_regs *regs)
-{
-	struct pt_regs *old_regs = set_irq_regs(regs);
-	struct irq_desc *desc;
-	int ret = 0;
-
-	irq_enter();
-
-	/* The irqdomain code provides boundary checks */
-	desc = irq_resolve_mapping(domain, hwirq);
-	if (likely(desc))
-		handle_irq_desc(desc);
-	else
-		ret = -EINVAL;
-
-	irq_exit();
-	set_irq_regs(old_regs);
-	return ret;
-}
-
-/**
- * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain
- * @domain:	The domain where to perform the lookup
- * @hwirq:	The HW irq number to convert to a logical one
- * @regs:	Register file coming from the low-level handling code
  *
- *		This function must be called from an NMI context.
- *
- * Returns:	0 on success, or -EINVAL if conversion has failed
- */
-int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
-		      struct pt_regs *regs)
+ * 		This function must be called from an NMI context with irq regs
+ * 		initialized.
+ **/
+int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq)
 {
-	struct pt_regs *old_regs = set_irq_regs(regs);
-	struct irq_desc *desc;
-	int ret = 0;
-
-	/*
-	 * NMI context needs to be setup earlier in order to deal with tracing.
-	 */
-	WARN_ON(!in_nmi());
-
-	desc = irq_resolve_mapping(domain, hwirq);
-
-	/*
-	 * ack_bad_irq is not NMI-safe, just report
-	 * an invalid interrupt.
-	 */
-	if (likely(desc))
-		handle_irq_desc(desc);
-	else
-		ret = -EINVAL;
-
-	set_irq_regs(old_regs);
-	return ret;
+	WARN_ON_ONCE(!in_nmi());
+	return handle_irq_desc(irq_resolve_mapping(domain, hwirq));
 }
 #endif
-#endif
 
 /* Dynamic interrupt handling */