diff options
Diffstat (limited to 'drivers/irqchip/irq-gic-v3-its-platform-msi.c')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3-its-platform-msi.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its-platform-msi.c b/drivers/irqchip/irq-gic-v3-its-platform-msi.c new file mode 100644 index 000000000..7b8e87b49 --- /dev/null +++ b/drivers/irqchip/irq-gic-v3-its-platform-msi.c @@ -0,0 +1,174 @@ +/* + * 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); |