diff options
Diffstat (limited to 'drivers/irqchip/irq-gic-v3-its-pci-msi.c')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3-its-pci-msi.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c new file mode 100644 index 000000000..93f77a819 --- /dev/null +++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c @@ -0,0 +1,202 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved. + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <linux/acpi_iort.h> +#include <linux/pci.h> +#include <linux/msi.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_pci.h> + +static void its_mask_msi_irq(struct irq_data *d) +{ + pci_msi_mask_irq(d); + irq_chip_mask_parent(d); +} + +static void its_unmask_msi_irq(struct irq_data *d) +{ + pci_msi_unmask_irq(d); + irq_chip_unmask_parent(d); +} + +static struct irq_chip its_msi_irq_chip = { + .name = "ITS-MSI", + .irq_unmask = its_unmask_msi_irq, + .irq_mask = its_mask_msi_irq, + .irq_eoi = irq_chip_eoi_parent, +}; + +static int its_pci_msi_vec_count(struct pci_dev *pdev, void *data) +{ + int msi, msix, *count = data; + + msi = max(pci_msi_vec_count(pdev), 0); + msix = max(pci_msix_vec_count(pdev), 0); + *count += max(msi, msix); + + return 0; +} + +static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data) +{ + struct pci_dev **alias_dev = data; + + *alias_dev = pdev; + + return 0; +} + +static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev, + int nvec, msi_alloc_info_t *info) +{ + struct pci_dev *pdev, *alias_dev; + struct msi_domain_info *msi_info; + int alias_count = 0, minnvec = 1; + + if (!dev_is_pci(dev)) + return -EINVAL; + + msi_info = msi_get_domain_info(domain->parent); + + pdev = to_pci_dev(dev); + /* + * If pdev is downstream of any aliasing bridges, take an upper + * bound of how many other vectors could map to the same DevID. + * Also tell the ITS that the signalling will come from a proxy + * device, and that special allocation rules apply. + */ + pci_for_each_dma_alias(pdev, its_get_pci_alias, &alias_dev); + if (alias_dev != pdev) { + if (alias_dev->subordinate) + pci_walk_bus(alias_dev->subordinate, + its_pci_msi_vec_count, &alias_count); + info->flags |= MSI_ALLOC_FLAGS_PROXY_DEVICE; + } + + /* ITS specific DeviceID, as the core ITS ignores dev. */ + info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev); + + /* + * Always allocate a power of 2, and special case device 0 for + * broken systems where the DevID is not wired (and all devices + * appear as DevID 0). For that reason, we generously allocate a + * minimum of 32 MSIs for DevID 0. If you want more because all + * your devices are aliasing to DevID 0, consider fixing your HW. + */ + nvec = max(nvec, alias_count); + if (!info->scratchpad[0].ul) + minnvec = 32; + nvec = max_t(int, minnvec, roundup_pow_of_two(nvec)); + return msi_info->ops->msi_prepare(domain->parent, dev, nvec, info); +} + +static struct msi_domain_ops its_pci_msi_ops = { + .msi_prepare = its_pci_msi_prepare, +}; + +static struct msi_domain_info its_pci_msi_domain_info = { + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | + MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX), + .ops = &its_pci_msi_ops, + .chip = &its_msi_irq_chip, +}; + +static struct of_device_id its_device_id[] = { + { .compatible = "arm,gic-v3-its", }, + {}, +}; + +static int __init its_pci_msi_init_one(struct fwnode_handle *handle, + const char *name) +{ + struct irq_domain *parent; + + parent = irq_find_matching_fwnode(handle, DOMAIN_BUS_NEXUS); + if (!parent || !msi_get_domain_info(parent)) { + pr_err("%s: Unable to locate ITS domain\n", name); + return -ENXIO; + } + + if (!pci_msi_create_irq_domain(handle, &its_pci_msi_domain_info, + parent)) { + pr_err("%s: Unable to create PCI domain\n", name); + return -ENOMEM; + } + + return 0; +} + +static int __init its_pci_of_msi_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; + + if (its_pci_msi_init_one(of_node_to_fwnode(np), np->full_name)) + continue; + + pr_info("PCI/MSI: %pOF domain created\n", np); + } + + return 0; +} + +#ifdef CONFIG_ACPI + +static int __init +its_pci_msi_parse_madt(union acpi_subtable_headers *header, + const unsigned long end) +{ + struct acpi_madt_generic_translator *its_entry; + struct fwnode_handle *dom_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); + dom_handle = iort_find_domain_token(its_entry->translation_id); + if (!dom_handle) { + pr_err("%s: Unable to locate ITS domain handle\n", node_name); + goto out; + } + + err = its_pci_msi_init_one(dom_handle, node_name); + if (!err) + pr_info("PCI/MSI: %s domain created\n", node_name); + +out: + kfree(node_name); + return err; +} + +static int __init its_pci_acpi_msi_init(void) +{ + acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR, + its_pci_msi_parse_madt, 0); + return 0; +} +#else +static int __init its_pci_acpi_msi_init(void) +{ + return 0; +} +#endif + +static int __init its_pci_msi_init(void) +{ + its_pci_of_msi_init(); + its_pci_acpi_msi_init(); + + return 0; +} +early_initcall(its_pci_msi_init); |