drivers/irqchip/irq-gic-v3-its-platform-msi.c

   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(dev->of_node,
  27                                                  "msi-parent", "#msi-cells",
  28                                                  index, &args);
  29                 if (args.np == irq_domain_get_of_node(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->parent);
  54
  55         if (dev->of_node)
  56                 ret = of_pmsi_get_dev_id(domain, dev, &dev_id);
  57         else
  58                 ret = iort_pmsi_get_dev_id(dev, &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, DOMAIN_BUS_NEXUS);
  92         if (!parent || !msi_get_domain_info(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, &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 *header,
 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, "ITS@0x%lx",
 119                               (long)its_entry->base_address);
 120         domain_handle = iort_find_domain_token(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(domain_handle, node_name);
 127
 128 out:
 129         kfree(node_name);
 130         return err;
 131 }
 132
 133 static void __init its_pmsi_acpi_init(void)
 134 {
 135         acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
 136                               its_pmsi_parse_madt, 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, its_device_id); np;
 147              np = of_find_matching_node(np, its_device_id)) {
 148                 if (!of_device_is_available(np))
 149                         continue;
 150                 if (!of_property_read_bool(np, "msi-controller"))
 151                         continue;
 152
 153                 its_pmsi_init_one(of_node_to_fwnode(np), 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);