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 /* Allocate at least 32 MSIs, and always as a power of 2 */ 77 nvec = max_t(int, 32, roundup_pow_of_two(nvec)); 78 return msi_info->ops->msi_prepare(domain->parent, 79 dev, nvec, info); 80 } 81 82 static struct msi_domain_ops its_pmsi_ops = { 83 .msi_prepare = its_pmsi_prepare, 84 }; 85 86 static struct msi_domain_info its_pmsi_domain_info = { 87 .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS), 88 .ops = &its_pmsi_ops, 89 .chip = &its_pmsi_irq_chip, 90 }; 91 92 static const struct of_device_id its_device_id[] = { 93 { .compatible = "arm,gic-v3-its", }, 94 {}, 95 }; 96 97 static int __init its_pmsi_init_one(struct fwnode_handle *fwnode, 98 const char *name) 99 { 100 struct irq_domain *parent; 101 102 parent = irq_find_matching_fwnode(fwnode, DOMAIN_BUS_NEXUS); 103 if (!parent || !msi_get_domain_info(parent)) { 104 pr_err("%s: unable to locate ITS domain\n", name); 105 return -ENXIO; 106 } 107 108 if (!platform_msi_create_irq_domain(fwnode, &its_pmsi_domain_info, 109 parent)) { 110 pr_err("%s: unable to create platform domain\n", name); 111 return -ENXIO; 112 } 113 114 pr_info("Platform MSI: %s domain created\n", name); 115 return 0; 116 } 117 118 #ifdef CONFIG_ACPI 119 static int __init 120 its_pmsi_parse_madt(union acpi_subtable_headers *header, 121 const unsigned long end) 122 { 123 struct acpi_madt_generic_translator *its_entry; 124 struct fwnode_handle *domain_handle; 125 const char *node_name; 126 int err = -ENXIO; 127 128 its_entry = (struct acpi_madt_generic_translator *)header; 129 node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx", 130 (long)its_entry->base_address); 131 domain_handle = iort_find_domain_token(its_entry->translation_id); 132 if (!domain_handle) { 133 pr_err("%s: Unable to locate ITS domain handle\n", node_name); 134 goto out; 135 } 136 137 err = its_pmsi_init_one(domain_handle, node_name); 138 139 out: 140 kfree(node_name); 141 return err; 142 } 143 144 static void __init its_pmsi_acpi_init(void) 145 { 146 acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR, 147 its_pmsi_parse_madt, 0); 148 } 149 #else 150 static inline void its_pmsi_acpi_init(void) { } 151 #endif 152 153 static void __init its_pmsi_of_init(void) 154 { 155 struct device_node *np; 156 157 for (np = of_find_matching_node(NULL, its_device_id); np; 158 np = of_find_matching_node(np, its_device_id)) { 159 if (!of_device_is_available(np)) 160 continue; 161 if (!of_property_read_bool(np, "msi-controller")) 162 continue; 163 164 its_pmsi_init_one(of_node_to_fwnode(np), np->full_name); 165 } 166 } 167 168 static int __init its_pmsi_init(void) 169 { 170 its_pmsi_of_init(); 171 its_pmsi_acpi_init(); 172 return 0; 173 } 174 early_initcall(its_pmsi_init); 175