1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved. |
4 | * Author: Marc Zyngier <marc.zyngier@arm.com> |
5 | */ |
6 | |
7 | #include <linux/acpi_iort.h> |
8 | #include <linux/device.h> |
9 | #include <linux/msi.h> |
10 | #include <linux/of.h> |
11 | #include <linux/of_irq.h> |
12 | |
13 | static struct irq_chip its_pmsi_irq_chip = { |
14 | .name = "ITS-pMSI" , |
15 | }; |
16 | |
17 | static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev, |
18 | u32 *dev_id) |
19 | { |
20 | int ret, index = 0; |
21 | |
22 | /* Suck the DeviceID out of the msi-parent property */ |
23 | do { |
24 | struct of_phandle_args args; |
25 | |
26 | ret = of_parse_phandle_with_args(np: dev->of_node, |
27 | list_name: "msi-parent" , cells_name: "#msi-cells" , |
28 | index, out_args: &args); |
29 | if (args.np == irq_domain_get_of_node(d: domain)) { |
30 | if (WARN_ON(args.args_count != 1)) |
31 | return -EINVAL; |
32 | *dev_id = args.args[0]; |
33 | break; |
34 | } |
35 | index++; |
36 | } while (!ret); |
37 | |
38 | return ret; |
39 | } |
40 | |
41 | int __weak iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id) |
42 | { |
43 | return -1; |
44 | } |
45 | |
46 | static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev, |
47 | int nvec, msi_alloc_info_t *info) |
48 | { |
49 | struct msi_domain_info *msi_info; |
50 | u32 dev_id; |
51 | int ret; |
52 | |
53 | msi_info = msi_get_domain_info(domain: domain->parent); |
54 | |
55 | if (dev->of_node) |
56 | ret = of_pmsi_get_dev_id(domain, dev, dev_id: &dev_id); |
57 | else |
58 | ret = iort_pmsi_get_dev_id(dev, dev_id: &dev_id); |
59 | if (ret) |
60 | return ret; |
61 | |
62 | /* ITS specific DeviceID, as the core ITS ignores dev. */ |
63 | info->scratchpad[0].ul = dev_id; |
64 | |
65 | /* Allocate at least 32 MSIs, and always as a power of 2 */ |
66 | nvec = max_t(int, 32, roundup_pow_of_two(nvec)); |
67 | return msi_info->ops->msi_prepare(domain->parent, |
68 | dev, nvec, info); |
69 | } |
70 | |
71 | static struct msi_domain_ops its_pmsi_ops = { |
72 | .msi_prepare = its_pmsi_prepare, |
73 | }; |
74 | |
75 | static struct msi_domain_info its_pmsi_domain_info = { |
76 | .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS), |
77 | .ops = &its_pmsi_ops, |
78 | .chip = &its_pmsi_irq_chip, |
79 | }; |
80 | |
81 | static const struct of_device_id its_device_id[] = { |
82 | { .compatible = "arm,gic-v3-its" , }, |
83 | {}, |
84 | }; |
85 | |
86 | static int __init its_pmsi_init_one(struct fwnode_handle *fwnode, |
87 | const char *name) |
88 | { |
89 | struct irq_domain *parent; |
90 | |
91 | parent = irq_find_matching_fwnode(fwnode, bus_token: DOMAIN_BUS_NEXUS); |
92 | if (!parent || !msi_get_domain_info(domain: parent)) { |
93 | pr_err("%s: unable to locate ITS domain\n" , name); |
94 | return -ENXIO; |
95 | } |
96 | |
97 | if (!platform_msi_create_irq_domain(fwnode, info: &its_pmsi_domain_info, |
98 | parent)) { |
99 | pr_err("%s: unable to create platform domain\n" , name); |
100 | return -ENXIO; |
101 | } |
102 | |
103 | pr_info("Platform MSI: %s domain created\n" , name); |
104 | return 0; |
105 | } |
106 | |
107 | #ifdef CONFIG_ACPI |
108 | static int __init |
109 | its_pmsi_parse_madt(union acpi_subtable_headers *, |
110 | const unsigned long end) |
111 | { |
112 | struct acpi_madt_generic_translator *its_entry; |
113 | struct fwnode_handle *domain_handle; |
114 | const char *node_name; |
115 | int err = -ENXIO; |
116 | |
117 | its_entry = (struct acpi_madt_generic_translator *)header; |
118 | node_name = kasprintf(GFP_KERNEL, fmt: "ITS@0x%lx" , |
119 | (long)its_entry->base_address); |
120 | domain_handle = iort_find_domain_token(trans_id: its_entry->translation_id); |
121 | if (!domain_handle) { |
122 | pr_err("%s: Unable to locate ITS domain handle\n" , node_name); |
123 | goto out; |
124 | } |
125 | |
126 | err = its_pmsi_init_one(fwnode: domain_handle, name: node_name); |
127 | |
128 | out: |
129 | kfree(objp: node_name); |
130 | return err; |
131 | } |
132 | |
133 | static void __init its_pmsi_acpi_init(void) |
134 | { |
135 | acpi_table_parse_madt(id: ACPI_MADT_TYPE_GENERIC_TRANSLATOR, |
136 | handler: its_pmsi_parse_madt, max_entries: 0); |
137 | } |
138 | #else |
139 | static inline void its_pmsi_acpi_init(void) { } |
140 | #endif |
141 | |
142 | static void __init its_pmsi_of_init(void) |
143 | { |
144 | struct device_node *np; |
145 | |
146 | for (np = of_find_matching_node(NULL, matches: its_device_id); np; |
147 | np = of_find_matching_node(from: np, matches: its_device_id)) { |
148 | if (!of_device_is_available(device: np)) |
149 | continue; |
150 | if (!of_property_read_bool(np, propname: "msi-controller" )) |
151 | continue; |
152 | |
153 | its_pmsi_init_one(fwnode: of_node_to_fwnode(node: np), name: np->full_name); |
154 | } |
155 | } |
156 | |
157 | static int __init its_pmsi_init(void) |
158 | { |
159 | its_pmsi_of_init(); |
160 | its_pmsi_acpi_init(); |
161 | return 0; |
162 | } |
163 | early_initcall(its_pmsi_init); |
164 | |