1 files changed, 129 insertions, 28 deletions

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 131ca176b497..786f5570a640 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -1,12 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
- * linux/kernel/irq/handle.c
- *
  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
  *
- * This file contains the core interrupt handling code.
- *
- * Detailed information is available in Documentation/DocBook/genericirq
+ * This file contains the core interrupt handling code. Detailed
+ * information is available in Documentation/core-api/genericirq.rst
  *
  */
 
@@ -16,23 +14,31 @@
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 
+#include <asm/irq_regs.h>
+
 #include <trace/events/irq.h>
 
 #include "internals.h"
 
+#ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER
+void (*handle_arch_irq)(struct pt_regs *) __ro_after_init;
+#endif
+
 /**
  * handle_bad_irq - handle spurious and unhandled irqs
- * @irq:       the interrupt number
  * @desc:      description of the interrupt
  *
  * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
  */
-void handle_bad_irq(unsigned int irq, struct irq_desc *desc)
+void handle_bad_irq(struct irq_desc *desc)
 {
+	unsigned int irq = irq_desc_get_irq(desc);
+
 	print_irq_desc(irq, desc);
-	kstat_incr_irqs_this_cpu(irq, desc);
+	kstat_incr_irqs_this_cpu(desc);
 	ack_bad_irq(irq);
 }
+EXPORT_SYMBOL_GPL(handle_bad_irq);
 
 /*
  * Special, empty irq handler:
@@ -41,6 +47,7 @@ irqreturn_t no_action(int cpl, void *dev_id)
 {
 	return IRQ_NONE;
 }
+EXPORT_SYMBOL_GPL(no_action);
 
 static void warn_no_thread(unsigned int irq, struct irqaction *action)
 {
@@ -51,7 +58,7 @@ static void warn_no_thread(unsigned int irq, struct irqaction *action)
 	       "but no thread function available.", irq, action->name);
 }
 
-static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
+void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
 {
 	/*
 	 * In case the thread crashed and was killed we just pretend that
@@ -126,23 +133,87 @@ static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
 	 */
 	atomic_inc(&desc->threads_active);
 
-	wake_up_process(action->thread);
+	/*
+	 * This might be a premature wakeup before the thread reached the
+	 * thread function and set the IRQTF_READY bit. It's waiting in
+	 * kthread code with state UNINTERRUPTIBLE. Once it reaches the
+	 * thread function it waits with INTERRUPTIBLE. The wakeup is not
+	 * lost in that case because the thread is guaranteed to observe
+	 * the RUN flag before it goes to sleep in wait_for_interrupt().
+	 */
+	wake_up_state(action->thread, TASK_INTERRUPTIBLE);
 }
 
-irqreturn_t
-handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
+static DEFINE_STATIC_KEY_FALSE(irqhandler_duration_check_enabled);
+static u64 irqhandler_duration_threshold_ns __ro_after_init;
+
+static int __init irqhandler_duration_check_setup(char *arg)
+{
+	unsigned long val;
+	int ret;
+
+	ret = kstrtoul(arg, 0, &val);
+	if (ret) {
+		pr_err("Unable to parse irqhandler.duration_warn_us setting: ret=%d\n", ret);
+		return 0;
+	}
+
+	if (!val) {
+		pr_err("Invalid irqhandler.duration_warn_us setting, must be > 0\n");
+		return 0;
+	}
+
+	irqhandler_duration_threshold_ns = val * 1000;
+	static_branch_enable(&irqhandler_duration_check_enabled);
+
+	return 1;
+}
+__setup("irqhandler.duration_warn_us=", irqhandler_duration_check_setup);
+
+static inline void irqhandler_duration_check(u64 ts_start, unsigned int irq,
+					     const struct irqaction *action)
+{
+	u64 delta_ns = local_clock() - ts_start;
+
+	if (unlikely(delta_ns > irqhandler_duration_threshold_ns)) {
+		pr_warn_ratelimited("[CPU%u] long duration of IRQ[%u:%ps], took: %llu us\n",
+				    smp_processor_id(), irq, action->handler,
+				    div_u64(delta_ns, NSEC_PER_USEC));
+	}
+}
+
+irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc)
 {
 	irqreturn_t retval = IRQ_NONE;
-	unsigned int flags = 0, irq = desc->irq_data.irq;
+	unsigned int irq = desc->irq_data.irq;
+	struct irqaction *action;
 
-	do {
+	record_irq_time(desc);
+
+	for_each_action_of_desc(desc, action) {
 		irqreturn_t res;
 
+		/*
+		 * If this IRQ would be threaded under force_irqthreads, mark it so.
+		 */
+		if (irq_settings_can_thread(desc) &&
+		    !(action->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)))
+			lockdep_hardirq_threaded();
+
 		trace_irq_handler_entry(irq, action);
-		res = action->handler(irq, action->dev_id);
+
+		if (static_branch_unlikely(&irqhandler_duration_check_enabled)) {
+			u64 ts_start = local_clock();
+
+			res = action->handler(irq, action->dev_id);
+			irqhandler_duration_check(ts_start, irq, action);
+		} else {
+			res = action->handler(irq, action->dev_id);
+		}
+
 		trace_irq_handler_exit(irq, action, res);
 
-		if (WARN_ONCE(!irqs_disabled(),"irq %u handler %pF enabled interrupts\n",
+		if (WARN_ONCE(!irqs_disabled(),"irq %u handler %pS enabled interrupts\n",
 			      irq, action->handler))
 			local_irq_disable();
 
@@ -157,11 +228,7 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
 				break;
 			}
 
-			irq_wake_thread(desc, action);
-
-			/* Fall through to add to randomness */
-		case IRQ_HANDLED:
-			flags |= action->flags;
+			__irq_wake_thread(desc, action);
 			break;
 
 		default:
@@ -169,28 +236,62 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
 		}
 
 		retval |= res;
-		action = action->next;
-	} while (action);
+	}
+
+	return retval;
+}
+
+irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
+{
+	irqreturn_t retval;
+
+	retval = __handle_irq_event_percpu(desc);
 
-	add_interrupt_randomness(irq, flags);
+	add_interrupt_randomness(desc->irq_data.irq);
 
-	if (!noirqdebug)
-		note_interrupt(irq, desc, retval);
+	if (!irq_settings_no_debug(desc))
+		note_interrupt(desc, retval);
 	return retval;
 }
 
 irqreturn_t handle_irq_event(struct irq_desc *desc)
 {
-	struct irqaction *action = desc->action;
 	irqreturn_t ret;
 
 	desc->istate &= ~IRQS_PENDING;
 	irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
 	raw_spin_unlock(&desc->lock);
 
-	ret = handle_irq_event_percpu(desc, action);
+	ret = handle_irq_event_percpu(desc);
 
 	raw_spin_lock(&desc->lock);
 	irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
 	return ret;
 }
+
+#ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER
+int __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
+{
+	if (handle_arch_irq)
+		return -EBUSY;
+
+	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