drivers/irqchip/irq-gic-v3-its-pci-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/msi.h>
  20 #include <linux/of.h>
  21 #include <linux/of_irq.h>
  22 #include <linux/of_pci.h>
  23
  24 static void its_mask_msi_irq(struct irq_data *d)
  25 {
  26         pci_msi_mask_irq(d);
  27         irq_chip_mask_parent(d);
  28 }
  29
  30 static void its_unmask_msi_irq(struct irq_data *d)
  31 {
  32         pci_msi_unmask_irq(d);
  33         irq_chip_unmask_parent(d);
  34 }
  35
  36 static struct irq_chip its_msi_irq_chip = {
  37         .name                   = "ITS-MSI",
  38         .irq_unmask             = its_unmask_msi_irq,
  39         .irq_mask               = its_mask_msi_irq,
  40         .irq_eoi                = irq_chip_eoi_parent,
  41         .irq_write_msi_msg      = pci_msi_domain_write_msg,
  42 };
  43
  44 struct its_pci_alias {
  45         struct pci_dev  *pdev;
  46         u32             count;
  47 };
  48
  49 static int its_pci_msi_vec_count(struct pci_dev *pdev)
  50 {
  51         int msi, msix;
  52
  53         msi = max(pci_msi_vec_count(pdev), 0);
  54         msix = max(pci_msix_vec_count(pdev), 0);
  55
  56         return max(msi, msix);
  57 }
  58
  59 static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
  60 {
  61         struct its_pci_alias *dev_alias = data;
  62
  63         if (pdev != dev_alias->pdev)
  64                 dev_alias->count += its_pci_msi_vec_count(pdev);
  65
  66         return 0;
  67 }
  68
  69 static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
  70                                int nvec, msi_alloc_info_t *info)
  71 {
  72         struct pci_dev *pdev;
  73         struct its_pci_alias dev_alias;
  74         struct msi_domain_info *msi_info;
  75
  76         if (!dev_is_pci(dev))
  77                 return -EINVAL;
  78
  79         msi_info = msi_get_domain_info(domain->parent);
  80
  81         pdev = to_pci_dev(dev);
  82         dev_alias.pdev = pdev;
  83         dev_alias.count = nvec;
  84
  85         pci_for_each_dma_alias(pdev, its_get_pci_alias, &dev_alias);
  86
  87         /* ITS specific DeviceID, as the core ITS ignores dev. */
  88         info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);
  89
  90         return msi_info->ops->msi_prepare(domain->parent,
  91                                           dev, dev_alias.count, info);
  92 }
  93
  94 static struct msi_domain_ops its_pci_msi_ops = {
  95         .msi_prepare    = its_pci_msi_prepare,
  96 };
  97
  98 static struct msi_domain_info its_pci_msi_domain_info = {
  99         .flags  = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
 100                    MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
 101         .ops    = &its_pci_msi_ops,
 102         .chip   = &its_msi_irq_chip,
 103 };
 104
 105 static struct of_device_id its_device_id[] = {
 106         {       .compatible     = "arm,gic-v3-its",     },
 107         {},
 108 };
 109
 110 static int __init its_pci_msi_init_one(struct fwnode_handle *handle,
 111                                        const char *name)
 112 {
 113         struct irq_domain *parent;
 114
 115         parent = irq_find_matching_fwnode(handle, DOMAIN_BUS_NEXUS);
 116         if (!parent || !msi_get_domain_info(parent)) {
 117                 pr_err("%s: Unable to locate ITS domain\n", name);
 118                 return -ENXIO;
 119         }
 120
 121         if (!pci_msi_create_irq_domain(handle, &its_pci_msi_domain_info,
 122                                        parent)) {
 123                 pr_err("%s: Unable to create PCI domain\n", name);
 124                 return -ENOMEM;
 125         }
 126
 127         return 0;
 128 }
 129
 130 static int __init its_pci_of_msi_init(void)
 131 {
 132         struct device_node *np;
 133
 134         for (np = of_find_matching_node(NULL, its_device_id); np;
 135              np = of_find_matching_node(np, its_device_id)) {
 136                 if (!of_device_is_available(np))
 137                         continue;
 138                 if (!of_property_read_bool(np, "msi-controller"))
 139                         continue;
 140
 141                 if (its_pci_msi_init_one(of_node_to_fwnode(np), np->full_name))
 142                         continue;
 143
 144                 pr_info("PCI/MSI: %s domain created\n", np->full_name);
 145         }
 146
 147         return 0;
 148 }
 149
 150 #ifdef CONFIG_ACPI
 151
 152 static int __init
 153 its_pci_msi_parse_madt(struct acpi_subtable_header *header,
 154                        const unsigned long end)
 155 {
 156         struct acpi_madt_generic_translator *its_entry;
 157         struct fwnode_handle *dom_handle;
 158         const char *node_name;
 159         int err = -ENXIO;
 160
 161         its_entry = (struct acpi_madt_generic_translator *)header;
 162         node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx",
 163                               (long)its_entry->base_address);
 164         dom_handle = iort_find_domain_token(its_entry->translation_id);
 165         if (!dom_handle) {
 166                 pr_err("%s: Unable to locate ITS domain handle\n", node_name);
 167                 goto out;
 168         }
 169
 170         err = its_pci_msi_init_one(dom_handle, node_name);
 171         if (!err)
 172                 pr_info("PCI/MSI: %s domain created\n", node_name);
 173
 174 out:
 175         kfree(node_name);
 176         return err;
 177 }
 178
 179 static int __init its_pci_acpi_msi_init(void)
 180 {
 181         acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
 182                               its_pci_msi_parse_madt, 0);
 183         return 0;
 184 }
 185 #else
 186 static int __init its_pci_acpi_msi_init(void)
 187 {
 188         return 0;
 189 }
 190 #endif
 191
 192 static int __init its_pci_msi_init(void)
 193 {
 194         its_pci_of_msi_init();
 195         its_pci_acpi_msi_init();
 196
 197         return 0;
 198 }
 199 early_initcall(its_pci_msi_init);