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/of_device.h>
11 #include <linux/of_address.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
its_fsl_mc_msi_prepare(struct irq_domain * msi_domain,struct device * dev,int nvec,msi_alloc_info_t * info)26 static int its_fsl_mc_msi_prepare(struct irq_domain *msi_domain,
27 struct device *dev,
28 int nvec, msi_alloc_info_t *info)
29 {
30 struct fsl_mc_device *mc_bus_dev;
31 struct msi_domain_info *msi_info;
32
33 if (!dev_is_fsl_mc(dev))
34 return -EINVAL;
35
36 mc_bus_dev = to_fsl_mc_device(dev);
37 if (!(mc_bus_dev->flags & FSL_MC_IS_DPRC))
38 return -EINVAL;
39
40 /*
41 * Set the device Id to be passed to the GIC-ITS:
42 *
43 * NOTE: This device id corresponds to the IOMMU stream ID
44 * associated with the DPRC object (ICID).
45 */
46 info->scratchpad[0].ul = mc_bus_dev->icid;
47 msi_info = msi_get_domain_info(msi_domain->parent);
48
49 /* Allocate at least 32 MSIs, and always as a power of 2 */
50 nvec = max_t(int, 32, roundup_pow_of_two(nvec));
51 return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);
52 }
53
54 static struct msi_domain_ops its_fsl_mc_msi_ops __ro_after_init = {
55 .msi_prepare = its_fsl_mc_msi_prepare,
56 };
57
58 static struct msi_domain_info its_fsl_mc_msi_domain_info = {
59 .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
60 .ops = &its_fsl_mc_msi_ops,
61 .chip = &its_msi_irq_chip,
62 };
63
64 static const struct of_device_id its_device_id[] = {
65 { .compatible = "arm,gic-v3-its", },
66 {},
67 };
68
its_fsl_mc_msi_init(void)69 static int __init its_fsl_mc_msi_init(void)
70 {
71 struct device_node *np;
72 struct irq_domain *parent;
73 struct irq_domain *mc_msi_domain;
74
75 for (np = of_find_matching_node(NULL, its_device_id); np;
76 np = of_find_matching_node(np, its_device_id)) {
77 if (!of_device_is_available(np))
78 continue;
79 if (!of_property_read_bool(np, "msi-controller"))
80 continue;
81
82 parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS);
83 if (!parent || !msi_get_domain_info(parent)) {
84 pr_err("%pOF: unable to locate ITS domain\n", np);
85 continue;
86 }
87
88 mc_msi_domain = fsl_mc_msi_create_irq_domain(
89 of_node_to_fwnode(np),
90 &its_fsl_mc_msi_domain_info,
91 parent);
92 if (!mc_msi_domain) {
93 pr_err("%pOF: unable to create fsl-mc domain\n", np);
94 continue;
95 }
96
97 pr_info("fsl-mc MSI: %pOF domain created\n", np);
98 }
99
100 return 0;
101 }
102
103 early_initcall(its_fsl_mc_msi_init);
104
