1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Freescale Management Complex (MC) bus driver MSI support
4 *
5 * Copyright (C) 2015-2016 Freescale Semiconductor, Inc.
6 * Author: German Rivera <German.Rivera@freescale.com>
7 *
8 */
9
10 #include <linux/acpi.h>
11 #include <linux/acpi_iort.h>
12 #include <linux/irq.h>
13 #include <linux/msi.h>
14 #include <linux/of.h>
15 #include <linux/of_irq.h>
16 #include <linux/fsl/mc.h>
17
18 static struct irq_chip its_msi_irq_chip = {
19 .name = "ITS-fMSI",
20 .irq_mask = irq_chip_mask_parent,
21 .irq_unmask = irq_chip_unmask_parent,
22 .irq_eoi = irq_chip_eoi_parent,
23 .irq_set_affinity = msi_domain_set_affinity
24 };
25
fsl_mc_msi_domain_get_msi_id(struct irq_domain * domain,struct fsl_mc_device * mc_dev)26 static u32 fsl_mc_msi_domain_get_msi_id(struct irq_domain *domain,
27 struct fsl_mc_device *mc_dev)
28 {
29 struct device_node *of_node;
30 u32 out_id;
31
32 of_node = irq_domain_get_of_node(domain);
33 out_id = of_node ? of_msi_map_id(&mc_dev->dev, of_node, mc_dev->icid) :
34 iort_msi_map_id(&mc_dev->dev, mc_dev->icid);
35
36 return out_id;
37 }
38
its_fsl_mc_msi_prepare(struct irq_domain * msi_domain,struct device * dev,int nvec,msi_alloc_info_t * info)39 static int its_fsl_mc_msi_prepare(struct irq_domain *msi_domain,
40 struct device *dev,
41 int nvec, msi_alloc_info_t *info)
42 {
43 struct fsl_mc_device *mc_bus_dev;
44 struct msi_domain_info *msi_info;
45
46 if (!dev_is_fsl_mc(dev))
47 return -EINVAL;
48
49 mc_bus_dev = to_fsl_mc_device(dev);
50 if (!(mc_bus_dev->flags & FSL_MC_IS_DPRC))
51 return -EINVAL;
52
53 /*
54 * Set the device Id to be passed to the GIC-ITS:
55 *
56 * NOTE: This device id corresponds to the IOMMU stream ID
57 * associated with the DPRC object (ICID).
58 */
59 info->scratchpad[0].ul = fsl_mc_msi_domain_get_msi_id(msi_domain,
60 mc_bus_dev);
61 msi_info = msi_get_domain_info(msi_domain->parent);
62
63 /* Allocate at least 32 MSIs, and always as a power of 2 */
64 nvec = max_t(int, 32, roundup_pow_of_two(nvec));
65 return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);
66 }
67
68 static struct msi_domain_ops its_fsl_mc_msi_ops __ro_after_init = {
69 .msi_prepare = its_fsl_mc_msi_prepare,
70 };
71
72 static struct msi_domain_info its_fsl_mc_msi_domain_info = {
73 .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
74 .ops = &its_fsl_mc_msi_ops,
75 .chip = &its_msi_irq_chip,
76 };
77
78 static const struct of_device_id its_device_id[] = {
79 { .compatible = "arm,gic-v3-its", },
80 {},
81 };
82
its_fsl_mc_msi_init_one(struct fwnode_handle * handle,const char * name)83 static void __init its_fsl_mc_msi_init_one(struct fwnode_handle *handle,
84 const char *name)
85 {
86 struct irq_domain *parent;
87 struct irq_domain *mc_msi_domain;
88
89 parent = irq_find_matching_fwnode(handle, DOMAIN_BUS_NEXUS);
90 if (!parent || !msi_get_domain_info(parent)) {
91 pr_err("%s: unable to locate ITS domain\n", name);
92 return;
93 }
94
95 mc_msi_domain = fsl_mc_msi_create_irq_domain(handle,
96 &its_fsl_mc_msi_domain_info,
97 parent);
98 if (!mc_msi_domain) {
99 pr_err("%s: unable to create fsl-mc domain\n", name);
100 return;
101 }
102
103 pr_info("fsl-mc MSI: %s domain created\n", name);
104 }
105
106 #ifdef CONFIG_ACPI
107 static int __init
its_fsl_mc_msi_parse_madt(union acpi_subtable_headers * header,const unsigned long end)108 its_fsl_mc_msi_parse_madt(union acpi_subtable_headers *header,
109 const unsigned long end)
110 {
111 struct acpi_madt_generic_translator *its_entry;
112 struct fwnode_handle *dom_handle;
113 const char *node_name;
114 int err = 0;
115
116 its_entry = (struct acpi_madt_generic_translator *)header;
117 node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
118 (long)its_entry->base_address);
119
120 dom_handle = iort_find_domain_token(its_entry->translation_id);
121 if (!dom_handle) {
122 pr_err("%s: Unable to locate ITS domain handle\n", node_name);
123 err = -ENXIO;
124 goto out;
125 }
126
127 its_fsl_mc_msi_init_one(dom_handle, node_name);
128
129 out:
130 kfree(node_name);
131 return err;
132 }
133
134
its_fsl_mc_acpi_msi_init(void)135 static void __init its_fsl_mc_acpi_msi_init(void)
136 {
137 acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
138 its_fsl_mc_msi_parse_madt, 0);
139 }
140 #else
its_fsl_mc_acpi_msi_init(void)141 static inline void its_fsl_mc_acpi_msi_init(void) { }
142 #endif
143
its_fsl_mc_of_msi_init(void)144 static void __init its_fsl_mc_of_msi_init(void)
145 {
146 struct device_node *np;
147
148 for (np = of_find_matching_node(NULL, its_device_id); np;
149 np = of_find_matching_node(np, its_device_id)) {
150 if (!of_device_is_available(np))
151 continue;
152 if (!of_property_read_bool(np, "msi-controller"))
153 continue;
154
155 its_fsl_mc_msi_init_one(of_node_to_fwnode(np),
156 np->full_name);
157 }
158 }
159
its_fsl_mc_msi_init(void)160 static int __init its_fsl_mc_msi_init(void)
161 {
162 its_fsl_mc_of_msi_init();
163 its_fsl_mc_acpi_msi_init();
164
165 return 0;
166 }
167
168 early_initcall(its_fsl_mc_msi_init);
169