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_property_read_bool(np, "msi-controller")) 137 continue; 138 139 if (its_pci_msi_init_one(of_node_to_fwnode(np), np->full_name)) 140 continue; 141 142 pr_info("PCI/MSI: %s domain created\n", np->full_name); 143 } 144 145 return 0; 146 } 147 148 #ifdef CONFIG_ACPI 149 150 static int __init 151 its_pci_msi_parse_madt(struct acpi_subtable_header *header, 152 const unsigned long end) 153 { 154 struct acpi_madt_generic_translator *its_entry; 155 struct fwnode_handle *dom_handle; 156 const char *node_name; 157 int err = -ENXIO; 158 159 its_entry = (struct acpi_madt_generic_translator *)header; 160 node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx", 161 (long)its_entry->base_address); 162 dom_handle = iort_find_domain_token(its_entry->translation_id); 163 if (!dom_handle) { 164 pr_err("%s: Unable to locate ITS domain handle\n", node_name); 165 goto out; 166 } 167 168 err = its_pci_msi_init_one(dom_handle, node_name); 169 if (!err) 170 pr_info("PCI/MSI: %s domain created\n", node_name); 171 172 out: 173 kfree(node_name); 174 return err; 175 } 176 177 static int __init its_pci_acpi_msi_init(void) 178 { 179 acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR, 180 its_pci_msi_parse_madt, 0); 181 return 0; 182 } 183 #else 184 static int __init its_pci_acpi_msi_init(void) 185 { 186 return 0; 187 } 188 #endif 189 190 static int __init its_pci_msi_init(void) 191 { 192 its_pci_of_msi_init(); 193 its_pci_acpi_msi_init(); 194 195 return 0; 196 } 197 early_initcall(its_pci_msi_init); 198