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
 18static 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
 26static 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
 39static 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
 68static struct msi_domain_ops its_fsl_mc_msi_ops __ro_after_init = {
 69	.msi_prepare = its_fsl_mc_msi_prepare,
 70};
 71
 72static 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
 78static const struct of_device_id its_device_id[] = {
 79	{	.compatible	= "arm,gic-v3-its",	},
 80	{},
 81};
 82
 83static 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
107static int __init
108its_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
129out:
130	kfree(node_name);
131	return err;
132}
133
134
135static 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
141static inline void its_fsl_mc_acpi_msi_init(void) { }
142#endif
143
144static 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
160static 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
168early_initcall(its_fsl_mc_msi_init);