genirq: Add generic msi irq domain support
[deliverable/linux.git] / kernel / irq / msi.c
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1/*
2 * linux/kernel/irq/msi.c
3 *
4 * Copyright (C) 2014 Intel Corp.
5 * Author: Jiang Liu <jiang.liu@linux.intel.com>
6 *
7 * This file is licensed under GPLv2.
8 *
9 * This file contains common code to support Message Signalled Interrupt for
10 * PCI compatible and non PCI compatible devices.
11 */
12#include <linux/irq.h>
13#include <linux/irqdomain.h>
14#include <linux/msi.h>
15
16#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
17/**
18 * msi_domain_set_affinity - Generic affinity setter function for MSI domains
19 * @irq_data: The irq data associated to the interrupt
20 * @mask: The affinity mask to set
21 * @force: Flag to enforce setting (disable online checks)
22 *
23 * Intended to be used by MSI interrupt controllers which are
24 * implemented with hierarchical domains.
25 */
26int msi_domain_set_affinity(struct irq_data *irq_data,
27 const struct cpumask *mask, bool force)
28{
29 struct irq_data *parent = irq_data->parent_data;
30 struct msi_msg msg;
31 int ret;
32
33 ret = parent->chip->irq_set_affinity(parent, mask, force);
34 if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
35 BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
36 irq_chip_write_msi_msg(irq_data, &msg);
37 }
38
39 return ret;
40}
41
42static void msi_domain_activate(struct irq_domain *domain,
43 struct irq_data *irq_data)
44{
45 struct msi_msg msg;
46
47 BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg));
48 irq_chip_write_msi_msg(irq_data, &msg);
49}
50
51static void msi_domain_deactivate(struct irq_domain *domain,
52 struct irq_data *irq_data)
53{
54 struct msi_msg msg;
55
56 memset(&msg, 0, sizeof(msg));
57 irq_chip_write_msi_msg(irq_data, &msg);
58}
59
60static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
61 unsigned int nr_irqs, void *arg)
62{
63 struct msi_domain_info *info = domain->host_data;
64 struct msi_domain_ops *ops = info->ops;
65 irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
66 int i, ret;
67
68 if (irq_find_mapping(domain, hwirq) > 0)
69 return -EEXIST;
70
71 ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
72 if (ret < 0)
73 return ret;
74
75 for (i = 0; i < nr_irqs; i++) {
76 ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
77 if (ret < 0) {
78 if (ops->msi_free) {
79 for (i--; i > 0; i--)
80 ops->msi_free(domain, info, virq + i);
81 }
82 irq_domain_free_irqs_top(domain, virq, nr_irqs);
83 return ret;
84 }
85 }
86
87 return 0;
88}
89
90static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
91 unsigned int nr_irqs)
92{
93 struct msi_domain_info *info = domain->host_data;
94 int i;
95
96 if (info->ops->msi_free) {
97 for (i = 0; i < nr_irqs; i++)
98 info->ops->msi_free(domain, info, virq + i);
99 }
100 irq_domain_free_irqs_top(domain, virq, nr_irqs);
101}
102
103static struct irq_domain_ops msi_domain_ops = {
104 .alloc = msi_domain_alloc,
105 .free = msi_domain_free,
106 .activate = msi_domain_activate,
107 .deactivate = msi_domain_deactivate,
108};
109
110/**
111 * msi_create_irq_domain - Create a MSI interrupt domain
112 * @of_node: Optional device-tree node of the interrupt controller
113 * @info: MSI domain info
114 * @parent: Parent irq domain
115 */
116struct irq_domain *msi_create_irq_domain(struct device_node *of_node,
117 struct msi_domain_info *info,
118 struct irq_domain *parent)
119{
120 struct irq_domain *domain;
121
122 domain = irq_domain_add_tree(of_node, &msi_domain_ops, info);
123 if (domain)
124 domain->parent = parent;
125
126 return domain;
127}
128
129/**
130 * msi_get_domain_info - Get the MSI interrupt domain info for @domain
131 * @domain: The interrupt domain to retrieve data from
132 *
133 * Returns the pointer to the msi_domain_info stored in
134 * @domain->host_data.
135 */
136struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
137{
138 return (struct msi_domain_info *)domain->host_data;
139}
140
141#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
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