1 /*
2  * Dynamic IRQ management
3  *
4  * Copyright (C) 2010  Paul Mundt
5  *
6  * Modelled after arch/x86/kernel/apic/io_apic.c
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12 #define pr_fmt(fmt) "intc: " fmt
13 
14 #include <linux/irq.h>
15 #include <linux/bitmap.h>
16 #include <linux/spinlock.h>
17 #include <linux/module.h>
18 #include "internals.h" /* only for activate_irq() damage.. */
19 
20 /*
21  * The IRQ bitmap provides a global map of bound IRQ vectors for a
22  * given platform. Allocation of IRQs are either static through the CPU
23  * vector map, or dynamic in the case of board mux vectors or MSI.
24  *
25  * As this is a central point for all IRQ controllers on the system,
26  * each of the available sources are mapped out here. This combined with
27  * sparseirq makes it quite trivial to keep the vector map tightly packed
28  * when dynamically creating IRQs, as well as tying in to otherwise
29  * unused irq_desc positions in the sparse array.
30  */
31 
32 /*
33  * Dynamic IRQ allocation and deallocation
34  */
create_irq_nr(unsigned int irq_want,int node)35 unsigned int create_irq_nr(unsigned int irq_want, int node)
36 {
37 	int irq = irq_alloc_desc_at(irq_want, node);
38 	if (irq < 0)
39 		return 0;
40 
41 	activate_irq(irq);
42 	return irq;
43 }
44 
create_irq(void)45 int create_irq(void)
46 {
47 	int irq = irq_alloc_desc(numa_node_id());
48 	if (irq >= 0)
49 		activate_irq(irq);
50 
51 	return irq;
52 }
53 
destroy_irq(unsigned int irq)54 void destroy_irq(unsigned int irq)
55 {
56 	irq_free_desc(irq);
57 }
58 
reserve_intc_vectors(struct intc_vect * vectors,unsigned int nr_vecs)59 void reserve_intc_vectors(struct intc_vect *vectors, unsigned int nr_vecs)
60 {
61 	int i;
62 
63 	for (i = 0; i < nr_vecs; i++)
64 		irq_reserve_irq(evt2irq(vectors[i].vect));
65 }
66