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