LXR linux/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
  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);
 171