1 // SPDX-License-Identifier: GPL-2.0
3  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
7  * information is available in Documentation/core-api/genericirq.rst
11 #include <linux/irq.h>
19 #include <trace/events/irq.h>
28  * handle_bad_irq - handle spurious and unhandled irqs
31  * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
35 	unsigned int irq = irq_desc_get_irq(desc);  in handle_bad_irq()  local
37 	print_irq_desc(irq, desc);  in handle_bad_irq()
39 	ack_bad_irq(irq);  in handle_bad_irq()
44  * Special, empty irq handler:
52 static void warn_no_thread(unsigned int irq, struct irqaction *action)  in warn_no_thread()  argument
54 	if (test_and_set_bit(IRQTF_WARNED, &action->thread_flags))  in warn_no_thread()
57 	printk(KERN_WARNING "IRQ %d device %s returned IRQ_WAKE_THREAD "  in warn_no_thread()
58 	       "but no thread function available.", irq, action->name);  in warn_no_thread()
66 	 * device interrupt, so no irq storm is lurking.  in __irq_wake_thread()
68 	if (action->thread->flags & PF_EXITING)  in __irq_wake_thread()
72 	 * Wake up the handler thread for this action. If the  in __irq_wake_thread()
75 	if (test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags))  in __irq_wake_thread()
81 	 * irq thread.  in __irq_wake_thread()
83 	 * This code is the hard irq context and can never run on two  in __irq_wake_thread()
87 	 * The irq threads of this irq which clear their "running" bit  in __irq_wake_thread()
88 	 * in threads_oneshot are serialized via desc->lock against  in __irq_wake_thread()
92 	 * Hard irq handler:  in __irq_wake_thread()
94 	 *	spin_lock(desc->lock);  in __irq_wake_thread()
95 	 *	desc->state |= IRQS_INPROGRESS;  in __irq_wake_thread()
96 	 *	spin_unlock(desc->lock);  in __irq_wake_thread()
97 	 *	set_bit(IRQTF_RUNTHREAD, &action->thread_flags);  in __irq_wake_thread()
98 	 *	desc->threads_oneshot |= mask;  in __irq_wake_thread()
99 	 *	spin_lock(desc->lock);  in __irq_wake_thread()
100 	 *	desc->state &= ~IRQS_INPROGRESS;  in __irq_wake_thread()
101 	 *	spin_unlock(desc->lock);  in __irq_wake_thread()
103 	 * irq thread:  in __irq_wake_thread()
106 	 *	spin_lock(desc->lock);  in __irq_wake_thread()
107 	 *	if (desc->state & IRQS_INPROGRESS) {  in __irq_wake_thread()
108 	 *		spin_unlock(desc->lock);  in __irq_wake_thread()
109 	 *		while(desc->state & IRQS_INPROGRESS)  in __irq_wake_thread()
113 	 *	if (!test_bit(IRQTF_RUNTHREAD, &action->thread_flags))  in __irq_wake_thread()
114 	 *		desc->threads_oneshot &= ~mask;  in __irq_wake_thread()
115 	 *	spin_unlock(desc->lock);  in __irq_wake_thread()
118 	 * or we are waiting in the flow handler for desc->lock to be  in __irq_wake_thread()
120 	 * IRQTF_RUNTHREAD under desc->lock. If set it leaves  in __irq_wake_thread()
123 	desc->threads_oneshot |= action->thread_mask;  in __irq_wake_thread()
126 	 * We increment the threads_active counter in case we wake up  in __irq_wake_thread()
127 	 * the irq thread. The irq thread decrements the counter when  in __irq_wake_thread()
131 	 * against this code (hard irq handler) via IRQS_INPROGRESS  in __irq_wake_thread()
134 	atomic_inc(&desc->threads_active);  in __irq_wake_thread()
136 	wake_up_process(action->thread);  in __irq_wake_thread()
142 	unsigned int irq = desc->irq_data.irq;  in __handle_irq_event_percpu()  local
151 		 * If this IRQ would be threaded under force_irqthreads, mark it so.  in __handle_irq_event_percpu()
154 		    !(action->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)))  in __handle_irq_event_percpu()
157 		trace_irq_handler_entry(irq, action);  in __handle_irq_event_percpu()
158 		res = action->handler(irq, action->dev_id);  in __handle_irq_event_percpu()
159 		trace_irq_handler_exit(irq, action, res);  in __handle_irq_event_percpu()
161 		if (WARN_ONCE(!irqs_disabled(),"irq %u handler %pS enabled interrupts\n",  in __handle_irq_event_percpu()
162 			      irq, action->handler))  in __handle_irq_event_percpu()
171 			if (unlikely(!action->thread_fn)) {  in __handle_irq_event_percpu()
172 				warn_no_thread(irq, action);  in __handle_irq_event_percpu()
195 	add_interrupt_randomness(desc->irq_data.irq);  in handle_irq_event_percpu()
206 	desc->istate &= ~IRQS_PENDING;  in handle_irq_event()
207 	irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);  in handle_irq_event()
208 	raw_spin_unlock(&desc->lock);  in handle_irq_event()
212 	raw_spin_lock(&desc->lock);  in handle_irq_event()
213 	irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);  in handle_irq_event()
221 		return -EBUSY;  in set_handle_irq()
228  * generic_handle_arch_irq - root irq handler for architectures which do no
230  * @regs:	Register file coming from the low-level handling code