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

   1/*
   2 * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved.
   3 * Author: Marc Zyngier <marc.zyngier@arm.com>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18#include <linux/acpi_iort.h>
  19#include <linux/device.h>
  20#include <linux/msi.h>
  21#include <linux/of.h>
  22#include <linux/of_irq.h>
  23
  24static struct irq_chip its_pmsi_irq_chip = {
  25        .name                   = "ITS-pMSI",
  26};
  27
  28static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev,
  29                                  u32 *dev_id)
  30{
  31        int ret, index = 0;
  32
  33        /* Suck the DeviceID out of the msi-parent property */
  34        do {
  35                struct of_phandle_args args;
  36
  37                ret = of_parse_phandle_with_args(dev->of_node,
  38                                                 "msi-parent", "#msi-cells",
  39                                                 index, &args);
  40                if (args.np == irq_domain_get_of_node(domain)) {
  41                        if (WARN_ON(args.args_count != 1))
  42                                return -EINVAL;
  43                        *dev_id = args.args[0];
  44                        break;
  45                }
  46        } while (!ret);
  47
  48        return ret;
  49}
  50
  51int __weak iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
  52{
  53        return -1;
  54}
  55
  56static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
  57                            int nvec, msi_alloc_info_t *info)
  58{
  59        struct msi_domain_info *msi_info;
  60        u32 dev_id;
  61        int ret;
  62
  63        msi_info = msi_get_domain_info(domain->parent);
  64
  65        if (dev->of_node)
  66                ret = of_pmsi_get_dev_id(domain, dev, &dev_id);
  67        else
  68                ret = iort_pmsi_get_dev_id(dev, &dev_id);
  69        if (ret)
  70                return ret;
  71
  72        /* ITS specific DeviceID, as the core ITS ignores dev. */
  73        info->scratchpad[0].ul = dev_id;
  74
  75        return msi_info->ops->msi_prepare(domain->parent,
  76                                          dev, nvec, info);
  77}
  78
  79static struct msi_domain_ops its_pmsi_ops = {
  80        .msi_prepare    = its_pmsi_prepare,
  81};
  82
  83static struct msi_domain_info its_pmsi_domain_info = {
  84        .flags  = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
  85        .ops    = &its_pmsi_ops,
  86        .chip   = &its_pmsi_irq_chip,
  87};
  88
  89static struct of_device_id its_device_id[] = {
  90        {       .compatible     = "arm,gic-v3-its",     },
  91        {},
  92};
  93
  94static int __init its_pmsi_init_one(struct fwnode_handle *fwnode,
  95                                const char *name)
  96{
  97        struct irq_domain *parent;
  98
  99        parent = irq_find_matching_fwnode(fwnode, DOMAIN_BUS_NEXUS);
 100        if (!parent || !msi_get_domain_info(parent)) {
 101                pr_err("%s: unable to locate ITS domain\n", name);
 102                return -ENXIO;
 103        }
 104
 105        if (!platform_msi_create_irq_domain(fwnode, &its_pmsi_domain_info,
 106                                            parent)) {
 107                pr_err("%s: unable to create platform domain\n", name);
 108                return -ENXIO;
 109        }
 110
 111        pr_info("Platform MSI: %s domain created\n", name);
 112        return 0;
 113}
 114
 115#ifdef CONFIG_ACPI
 116static int __init
 117its_pmsi_parse_madt(struct acpi_subtable_header *header,
 118                        const unsigned long end)
 119{
 120        struct acpi_madt_generic_translator *its_entry;
 121        struct fwnode_handle *domain_handle;
 122        const char *node_name;
 123        int err = -ENXIO;
 124
 125        its_entry = (struct acpi_madt_generic_translator *)header;
 126        node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
 127                              (long)its_entry->base_address);
 128        domain_handle = iort_find_domain_token(its_entry->translation_id);
 129        if (!domain_handle) {
 130                pr_err("%s: Unable to locate ITS domain handle\n", node_name);
 131                goto out;
 132        }
 133
 134        err = its_pmsi_init_one(domain_handle, node_name);
 135
 136out:
 137        kfree(node_name);
 138        return err;
 139}
 140
 141static void __init its_pmsi_acpi_init(void)
 142{
 143        acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
 144                              its_pmsi_parse_madt, 0);
 145}
 146#else
 147static inline void its_pmsi_acpi_init(void) { }
 148#endif
 149
 150static void __init its_pmsi_of_init(void)
 151{
 152        struct device_node *np;
 153
 154        for (np = of_find_matching_node(NULL, its_device_id); np;
 155             np = of_find_matching_node(np, its_device_id)) {
 156                if (!of_property_read_bool(np, "msi-controller"))
 157                        continue;
 158
 159                its_pmsi_init_one(of_node_to_fwnode(np), np->full_name);
 160        }
 161}
 162
 163static int __init its_pmsi_init(void)
 164{
 165        its_pmsi_of_init();
 166        its_pmsi_acpi_init();
 167        return 0;
 168}
 169early_initcall(its_pmsi_init);
 170