Merge tag 'irq-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

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

  Core:

   - Prevent a deadlock of nested interrupt threads vs.
     synchronize_hard()

   - Removal of a stale extern declaration

  Drivers:

   - The first new driver since v6.2 for Amlogic-C3 SoCs

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

* tag 'irq-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: Add support for Amlogic-C3 SoCs
  dt-bindings: interrupt-controller: Add support for Amlogic-C3 SoCs
  irqchip/irq-mvebu-sei: Use devm_platform_get_and_ioremap_resource()
  irqchip/ls-scfg-msi: Use devm_platform_get_and_ioremap_resource()
  irqchip: Explicitly include correct DT includes
  irqchip/orion: Use of_address_count() helper
  irqchip/irq-pruss-intc: Do not check for 0 return after calling platform_get_irq()
  irqchip/imx-mu-msi: Do not check for 0 return after calling platform_get_irq()
  irqchipr/i8259: Mark i8259_of_init() static
  irqchip/mips-gic: Mark gic_irq_domain_free() static
  irqchip/xtensa-pic: Include header for xtensa_pic_init_legacy()
  irqchip/loongson-eiointc: Fix return value checking of eiointc_index
  genirq: Remove unused extern declaration
  genirq: Prevent nested thread vs synchronize_hardirq() deadlock

3 files changed, 20 insertions, 21 deletions

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index ee8c0acf39df..dc94e0bf2c94 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -473,11 +473,12 @@ void handle_nested_irq(unsigned int irq)
 	action = desc->action;
 	if (unlikely(!action || irqd_irq_disabled(&desc->irq_data))) {
 		desc->istate |= IRQS_PENDING;
-		goto out_unlock;
+		raw_spin_unlock_irq(&desc->lock);
+		return;
 	}
 
 	kstat_incr_irqs_this_cpu(desc);
-	irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
+	atomic_inc(&desc->threads_active);
 	raw_spin_unlock_irq(&desc->lock);
 
 	action_ret = IRQ_NONE;
@@ -487,11 +488,7 @@ void handle_nested_irq(unsigned int irq)
 	if (!irq_settings_no_debug(desc))
 		note_interrupt(desc, action_ret);
 
-	raw_spin_lock_irq(&desc->lock);
-	irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
-
-out_unlock:
-	raw_spin_unlock_irq(&desc->lock);
+	wake_threads_waitq(desc);
 }
 EXPORT_SYMBOL_GPL(handle_nested_irq);
 
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index bdd35bb9c735..bcc7f21db9ee 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -108,8 +108,6 @@ extern int __irq_get_irqchip_state(struct irq_data *data,
 				   enum irqchip_irq_state which,
 				   bool *state);
 
-extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);
-
 irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc);
 irqreturn_t handle_irq_event_percpu(struct irq_desc *desc);
 irqreturn_t handle_irq_event(struct irq_desc *desc);
@@ -121,6 +119,8 @@ void irq_resend_init(struct irq_desc *desc);
 bool irq_wait_for_poll(struct irq_desc *desc);
 void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action);
 
+void wake_threads_waitq(struct irq_desc *desc);
+
 #ifdef CONFIG_PROC_FS
 extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
 extern void unregister_irq_proc(unsigned int irq, struct irq_desc *desc);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d2742af0f0fd..d309ba84e08a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -108,6 +108,16 @@ bool synchronize_hardirq(unsigned int irq)
 }
 EXPORT_SYMBOL(synchronize_hardirq);
 
+static void __synchronize_irq(struct irq_desc *desc)
+{
+	__synchronize_hardirq(desc, true);
+	/*
+	 * We made sure that no hardirq handler is running. Now verify that no
+	 * threaded handlers are active.
+	 */
+	wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
+}
+
 /**
  *	synchronize_irq - wait for pending IRQ handlers (on other CPUs)
  *	@irq: interrupt number to wait for
@@ -127,16 +137,8 @@ void synchronize_irq(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
-	if (desc) {
-		__synchronize_hardirq(desc, true);
-		/*
-		 * We made sure that no hardirq handler is
-		 * running. Now verify that no threaded handlers are
-		 * active.
-		 */
-		wait_event(desc->wait_for_threads,
-			   !atomic_read(&desc->threads_active));
-	}
+	if (desc)
+		__synchronize_irq(desc);
 }
 EXPORT_SYMBOL(synchronize_irq);
 
@@ -1216,7 +1218,7 @@ static irqreturn_t irq_thread_fn(struct irq_desc *desc,
 	return ret;
 }
 
-static void wake_threads_waitq(struct irq_desc *desc)
+void wake_threads_waitq(struct irq_desc *desc)
 {
 	if (atomic_dec_and_test(&desc->threads_active))
 		wake_up(&desc->wait_for_threads);
@@ -1944,7 +1946,7 @@ static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id)
 	 * supports it also make sure that there is no (not yet serviced)
 	 * interrupt in flight at the hardware level.
 	 */
-	__synchronize_hardirq(desc, true);
+	__synchronize_irq(desc);
 
 #ifdef CONFIG_DEBUG_SHIRQ
 	/*