drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c

   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
  20 static 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
  28 static 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
  41 static 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
  70 static struct msi_domain_ops its_fsl_mc_msi_ops __ro_after_init = {
  71         .msi_prepare = its_fsl_mc_msi_prepare,
  72 };
  73
  74 static 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
  80 static const struct of_device_id its_device_id[] = {
  81         {       .compatible     = "arm,gic-v3-its",     },
  82         {},
  83 };
  84
  85 static 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
 109 static int __init
 110 its_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
 131 out:
 132         kfree(node_name);
 133         return err;
 134 }
 135
 136
 137 static 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
 143 static inline void its_fsl_mc_acpi_msi_init(void) { }
 144 #endif
 145
 146 static 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
 162 static 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
 170 early_initcall(its_fsl_mc_msi_init);