/* * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved. * Author: Marc Zyngier <marc.zyngier@arm.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <linux/acpi_iort.h> #include <linux/device.h> #include <linux/msi.h> #include <linux/of.h> #include <linux/of_irq.h> static struct irq_chip its_pmsi_irq_chip = { .name = "ITS-pMSI", }; static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev, u32 *dev_id) { int ret, index = 0; /* Suck the DeviceID out of the msi-parent property */ do { struct of_phandle_args args; ret = of_parse_phandle_with_args(dev->of_node, "msi-parent", "#msi-cells", index, &args); if (args.np == irq_domain_get_of_node(domain)) { if (WARN_ON(args.args_count != 1)) return -EINVAL; *dev_id = args.args[0]; break; } index++; } while (!ret); return ret; } int __weak iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id) { return -1; } static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev, int nvec, msi_alloc_info_t *info) { struct msi_domain_info *msi_info; u32 dev_id; int ret; msi_info = msi_get_domain_info(domain->parent); if (dev->of_node) ret = of_pmsi_get_dev_id(domain, dev, &dev_id); else ret = iort_pmsi_get_dev_id(dev, &dev_id); if (ret) return ret; /* ITS specific DeviceID, as the core ITS ignores dev. */ info->scratchpad[0].ul = dev_id; /* Allocate at least 32 MSIs, and always as a power of 2 */ nvec = max_t(int, 32, roundup_pow_of_two(nvec)); return msi_info->ops->msi_prepare(domain->parent, dev, nvec, info); } static struct msi_domain_ops its_pmsi_ops = { .msi_prepare = its_pmsi_prepare, }; static struct msi_domain_info its_pmsi_domain_info = { .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS), .ops = &its_pmsi_ops, .chip = &its_pmsi_irq_chip, }; static const struct of_device_id its_device_id[] = { { .compatible = "arm,gic-v3-its", }, {}, }; static int __init its_pmsi_init_one(struct fwnode_handle *fwnode, const char *name) { struct irq_domain *parent; parent = irq_find_matching_fwnode(fwnode, DOMAIN_BUS_NEXUS); if (!parent || !msi_get_domain_info(parent)) { pr_err("%s: unable to locate ITS domain\n", name); return -ENXIO; } if (!platform_msi_create_irq_domain(fwnode, &its_pmsi_domain_info, parent)) { pr_err("%s: unable to create platform domain\n", name); return -ENXIO; } pr_info("Platform MSI: %s domain created\n", name); return 0; } #ifdef CONFIG_ACPI static int __init its_pmsi_parse_madt(struct acpi_subtable_header *header, const unsigned long end) { struct acpi_madt_generic_translator *its_entry; struct fwnode_handle *domain_handle; const char *node_name; int err = -ENXIO; its_entry = (struct acpi_madt_generic_translator *)header; node_name = kasprintf(GFP_KERNEL, "ITS@0x%lx", (long)its_entry->base_address); domain_handle = iort_find_domain_token(its_entry->translation_id); if (!domain_handle) { pr_err("%s: Unable to locate ITS domain handle\n", node_name); goto out; } err = its_pmsi_init_one(domain_handle, node_name); out: kfree(node_name); return err; } static void __init its_pmsi_acpi_init(void) { acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR, its_pmsi_parse_madt, 0); } #else static inline void its_pmsi_acpi_init(void) { } #endif static void __init its_pmsi_of_init(void) { struct device_node *np; for (np = of_find_matching_node(NULL, its_device_id); np; np = of_find_matching_node(np, its_device_id)) { if (!of_device_is_available(np)) continue; if (!of_property_read_bool(np, "msi-controller")) continue; its_pmsi_init_one(of_node_to_fwnode(np), np->full_name); } } static int __init its_pmsi_init(void) { its_pmsi_of_init(); its_pmsi_acpi_init(); return 0; } early_initcall(its_pmsi_init);