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/msi.h> 19 #include <linux/of.h> 20 #include <linux/of_irq.h> 21 #include <linux/of_pci.h> 22 23 static void its_mask_msi_irq(struct irq_data *d) 24 { 25 pci_msi_mask_irq(d); 26 irq_chip_mask_parent(d); 27 } 28 29 static void its_unmask_msi_irq(struct irq_data *d) 30 { 31 pci_msi_unmask_irq(d); 32 irq_chip_unmask_parent(d); 33 } 34 35 static struct irq_chip its_msi_irq_chip = { 36 .name = "ITS-MSI", 37 .irq_unmask = its_unmask_msi_irq, 38 .irq_mask = its_mask_msi_irq, 39 .irq_eoi = irq_chip_eoi_parent, 40 .irq_write_msi_msg = pci_msi_domain_write_msg, 41 }; 42 43 struct its_pci_alias { 44 struct pci_dev *pdev; 45 u32 count; 46 }; 47 48 static int its_pci_msi_vec_count(struct pci_dev *pdev) 49 { 50 int msi, msix; 51 52 msi = max(pci_msi_vec_count(pdev), 0); 53 msix = max(pci_msix_vec_count(pdev), 0); 54 55 return max(msi, msix); 56 } 57 58 static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data) 59 { 60 struct its_pci_alias *dev_alias = data; 61 62 if (pdev != dev_alias->pdev) 63 dev_alias->count += its_pci_msi_vec_count(pdev); 64 65 return 0; 66 } 67 68 static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev, 69 int nvec, msi_alloc_info_t *info) 70 { 71 struct pci_dev *pdev; 72 struct its_pci_alias dev_alias; 73 struct msi_domain_info *msi_info; 74 75 if (!dev_is_pci(dev)) 76 return -EINVAL; 77 78 msi_info = msi_get_domain_info(domain->parent); 79 80 pdev = to_pci_dev(dev); 81 dev_alias.pdev = pdev; 82 dev_alias.count = nvec; 83 84 pci_for_each_dma_alias(pdev, its_get_pci_alias, &dev_alias); 85 86 /* ITS specific DeviceID, as the core ITS ignores dev. */ 87 info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev); 88 89 return msi_info->ops->msi_prepare(domain->parent, 90 dev, dev_alias.count, info); 91 } 92 93 static struct msi_domain_ops its_pci_msi_ops = { 94 .msi_prepare = its_pci_msi_prepare, 95 }; 96 97 static struct msi_domain_info its_pci_msi_domain_info = { 98 .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | 99 MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX), 100 .ops = &its_pci_msi_ops, 101 .chip = &its_msi_irq_chip, 102 }; 103 104 static struct of_device_id its_device_id[] = { 105 { .compatible = "arm,gic-v3-its", }, 106 {}, 107 }; 108 109 static int __init its_pci_msi_init(void) 110 { 111 struct device_node *np; 112 struct irq_domain *parent; 113 114 for (np = of_find_matching_node(NULL, its_device_id); np; 115 np = of_find_matching_node(np, its_device_id)) { 116 if (!of_property_read_bool(np, "msi-controller")) 117 continue; 118 119 parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS); 120 if (!parent || !msi_get_domain_info(parent)) { 121 pr_err("%s: unable to locate ITS domain\n", 122 np->full_name); 123 continue; 124 } 125 126 if (!pci_msi_create_irq_domain(of_node_to_fwnode(np), 127 &its_pci_msi_domain_info, 128 parent)) { 129 pr_err("%s: unable to create PCI domain\n", 130 np->full_name); 131 continue; 132 } 133 134 pr_info("PCI/MSI: %s domain created\n", np->full_name); 135 } 136 137 return 0; 138 } 139 early_initcall(its_pci_msi_init); 140