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
  24 static struct irq_chip its_pmsi_irq_chip = {
  25         .name                   = "ITS-pMSI",
  26 };
  27
  28 static 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                 index++;
  47         } while (!ret);
  48
  49         return ret;
  50 }
  51
  52 int __weak iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
  53 {
  54         return -1;
  55 }
  56
  57 static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
  58                             int nvec, msi_alloc_info_t *info)
  59 {
  60         struct msi_domain_info *msi_info;
  61         u32 dev_id;
  62         int ret;
  63
  64         msi_info = msi_get_domain_info(domain->parent);
  65
  66         if (dev->of_node)
  67                 ret = of_pmsi_get_dev_id(domain, dev, &dev_id);
  68         else
  69                 ret = iort_pmsi_get_dev_id(dev, &dev_id);
  70         if (ret)
  71                 return ret;
  72
  73         /* ITS specific DeviceID, as the core ITS ignores dev. */
  74         info->scratchpad[0].ul = dev_id;
  75
  76         return msi_info->ops->msi_prepare(domain->parent,
  77                                           dev, nvec, info);
  78 }
  79
  80 static struct msi_domain_ops its_pmsi_ops = {
  81         .msi_prepare    = its_pmsi_prepare,
  82 };
  83
  84 static struct msi_domain_info its_pmsi_domain_info = {
  85         .flags  = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
  86         .ops    = &its_pmsi_ops,
  87         .chip   = &its_pmsi_irq_chip,
  88 };
  89
  90 static const struct of_device_id its_device_id[] = {
  91         {       .compatible     = "arm,gic-v3-its",     },
  92         {},
  93 };
  94
  95 static int __init its_pmsi_init_one(struct fwnode_handle *fwnode,
  96                                 const char *name)
  97 {
  98         struct irq_domain *parent;
  99
 100         parent = irq_find_matching_fwnode(fwnode, DOMAIN_BUS_NEXUS);
 101         if (!parent || !msi_get_domain_info(parent)) {
 102                 pr_err("%s: unable to locate ITS domain\n", name);
 103                 return -ENXIO;
 104         }
 105
 106         if (!platform_msi_create_irq_domain(fwnode, &its_pmsi_domain_info,
 107                                             parent)) {
 108                 pr_err("%s: unable to create platform domain\n", name);
 109                 return -ENXIO;
 110         }
 111
 112         pr_info("Platform MSI: %s domain created\n", name);
 113         return 0;
 114 }
 115
 116 #ifdef CONFIG_ACPI
 117 static int __init
 118 its_pmsi_parse_madt(struct acpi_subtable_header *header,
 119                         const unsigned long end)
 120 {
 121         struct acpi_madt_generic_translator *its_entry;
 122         struct fwnode_handle *domain_handle;
 123         const char *node_name;
 124         int err = -ENXIO;
 125
 126         its_entry = (struct acpi_madt_generic_translator *)header;
 127         node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
 128                               (long)its_entry->base_address);
 129         domain_handle = iort_find_domain_token(its_entry->translation_id);
 130         if (!domain_handle) {
 131                 pr_err("%s: Unable to locate ITS domain handle\n", node_name);
 132                 goto out;
 133         }
 134
 135         err = its_pmsi_init_one(domain_handle, node_name);
 136
 137 out:
 138         kfree(node_name);
 139         return err;
 140 }
 141
 142 static void __init its_pmsi_acpi_init(void)
 143 {
 144         acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
 145                               its_pmsi_parse_madt, 0);
 146 }
 147 #else
 148 static inline void its_pmsi_acpi_init(void) { }
 149 #endif
 150
 151 static void __init its_pmsi_of_init(void)
 152 {
 153         struct device_node *np;
 154
 155         for (np = of_find_matching_node(NULL, its_device_id); np;
 156              np = of_find_matching_node(np, its_device_id)) {
 157                 if (!of_property_read_bool(np, "msi-controller"))
 158                         continue;
 159
 160                 its_pmsi_init_one(of_node_to_fwnode(np), np->full_name);
 161         }
 162 }
 163
 164 static int __init its_pmsi_init(void)
 165 {
 166         its_pmsi_of_init();
 167         its_pmsi_acpi_init();
 168         return 0;
 169 }
 170 early_initcall(its_pmsi_init);