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/of_device.h>
 13#include <linux/of_address.h>
 14#include <linux/irq.h>
 15#include <linux/msi.h>
 16#include <linux/of.h>
 17#include <linux/of_irq.h>
 18#include <linux/fsl/mc.h>
 19
 20static struct irq_chip its_msi_irq_chip = {
 21	.name = "ITS-fMSI",
 22	.irq_mask = irq_chip_mask_parent,
 23	.irq_unmask = irq_chip_unmask_parent,
 24	.irq_eoi = irq_chip_eoi_parent,
 25	.irq_set_affinity = msi_domain_set_affinity
 26};
 27
 28static u32 fsl_mc_msi_domain_get_msi_id(struct irq_domain *domain,
 29					struct fsl_mc_device *mc_dev)
 30{
 31	struct device_node *of_node;
 32	u32 out_id;
 33
 34	of_node = irq_domain_get_of_node(domain);
 35	out_id = of_node ? of_msi_map_id(&mc_dev->dev, of_node, mc_dev->icid) :
 36			iort_msi_map_id(&mc_dev->dev, mc_dev->icid);
 37
 38	return out_id;
 39}
 40
 41static int its_fsl_mc_msi_prepare(struct irq_domain *msi_domain,
 42				  struct device *dev,
 43				  int nvec, msi_alloc_info_t *info)
 44{
 45	struct fsl_mc_device *mc_bus_dev;
 46	struct msi_domain_info *msi_info;
 47
 48	if (!dev_is_fsl_mc(dev))
 49		return -EINVAL;
 50
 51	mc_bus_dev = to_fsl_mc_device(dev);
 52	if (!(mc_bus_dev->flags & FSL_MC_IS_DPRC))
 53		return -EINVAL;
 54
 55	/*
 56	 * Set the device Id to be passed to the GIC-ITS:
 57	 *
 58	 * NOTE: This device id corresponds to the IOMMU stream ID
 59	 * associated with the DPRC object (ICID).
 60	 */
 61	info->scratchpad[0].ul = fsl_mc_msi_domain_get_msi_id(msi_domain,
 62							      mc_bus_dev);
 63	msi_info = msi_get_domain_info(msi_domain->parent);
 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(msi_domain->parent, dev, nvec, info);
 68}
 69
 70static struct msi_domain_ops its_fsl_mc_msi_ops __ro_after_init = {
 71	.msi_prepare = its_fsl_mc_msi_prepare,
 72};
 73
 74static struct msi_domain_info its_fsl_mc_msi_domain_info = {
 75	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
 76	.ops	= &its_fsl_mc_msi_ops,
 77	.chip	= &its_msi_irq_chip,
 78};
 79
 80static const struct of_device_id its_device_id[] = {
 81	{	.compatible	= "arm,gic-v3-its",	},
 82	{},
 83};
 84
 85static void __init its_fsl_mc_msi_init_one(struct fwnode_handle *handle,
 86					  const char *name)
 87{
 88	struct irq_domain *parent;
 89	struct irq_domain *mc_msi_domain;
 90
 91	parent = irq_find_matching_fwnode(handle, DOMAIN_BUS_NEXUS);
 92	if (!parent || !msi_get_domain_info(parent)) {
 93		pr_err("%s: unable to locate ITS domain\n", name);
 94		return;
 95	}
 96
 97	mc_msi_domain = fsl_mc_msi_create_irq_domain(handle,
 98						&its_fsl_mc_msi_domain_info,
 99						parent);
100	if (!mc_msi_domain) {
101		pr_err("%s: unable to create fsl-mc domain\n", name);
102		return;
103	}
104
105	pr_info("fsl-mc MSI: %s domain created\n", name);
106}
107
108#ifdef CONFIG_ACPI
109static int __init
110its_fsl_mc_msi_parse_madt(union acpi_subtable_headers *header,
111			  const unsigned long end)
112{
113	struct acpi_madt_generic_translator *its_entry;
114	struct fwnode_handle *dom_handle;
115	const char *node_name;
116	int err = 0;
117
118	its_entry = (struct acpi_madt_generic_translator *)header;
119	node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
120			      (long)its_entry->base_address);
121
122	dom_handle = iort_find_domain_token(its_entry->translation_id);
123	if (!dom_handle) {
124		pr_err("%s: Unable to locate ITS domain handle\n", node_name);
125		err = -ENXIO;
126		goto out;
127	}
128
129	its_fsl_mc_msi_init_one(dom_handle, node_name);
130
131out:
132	kfree(node_name);
133	return err;
134}
135
136
137static void __init its_fsl_mc_acpi_msi_init(void)
138{
139	acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
140			      its_fsl_mc_msi_parse_madt, 0);
141}
142#else
143static inline void its_fsl_mc_acpi_msi_init(void) { }
144#endif
145
146static void __init its_fsl_mc_of_msi_init(void)
147{
148	struct device_node *np;
149
150	for (np = of_find_matching_node(NULL, its_device_id); np;
151	     np = of_find_matching_node(np, its_device_id)) {
152		if (!of_device_is_available(np))
153			continue;
154		if (!of_property_read_bool(np, "msi-controller"))
155			continue;
156
157		its_fsl_mc_msi_init_one(of_node_to_fwnode(np),
158					np->full_name);
159	}
160}
161
162static int __init its_fsl_mc_msi_init(void)
163{
164	its_fsl_mc_of_msi_init();
165	its_fsl_mc_acpi_msi_init();
166
167	return 0;
168}
169
170early_initcall(its_fsl_mc_msi_init);