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 } while (!ret); 47 48 return ret; 49 } 50 51 int __weak iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id) 52 { 53 return -1; 54 } 55 56 static 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 79 static struct msi_domain_ops its_pmsi_ops = { 80 .msi_prepare = its_pmsi_prepare, 81 }; 82 83 static 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 89 static const struct of_device_id its_device_id[] = { 90 { .compatible = "arm,gic-v3-its", }, 91 {}, 92 }; 93 94 static 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 116 static int __init 117 its_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); 135 136 out: 137 kfree(node_name); 138 return err; 139 } 140 141 static 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 147 static inline void its_pmsi_acpi_init(void) { } 148 #endif 149 150 static 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 } 162 163 static int __init its_pmsi_init(void) 164 { 165 its_pmsi_of_init(); 166 its_pmsi_acpi_init(); 167 return 0; 168 } 169 early_initcall(its_pmsi_init); 170