diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/pci/msi/irqdomain.c | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c new file mode 100644 index 000000000..e9cf318e6 --- /dev/null +++ b/drivers/pci/msi/irqdomain.c @@ -0,0 +1,280 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Message Signaled Interrupt (MSI) - irqdomain support + */ +#include <linux/acpi_iort.h> +#include <linux/irqdomain.h> +#include <linux/of_irq.h> + +#include "msi.h" + +int pci_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) +{ + struct irq_domain *domain; + + domain = dev_get_msi_domain(&dev->dev); + if (domain && irq_domain_is_hierarchy(domain)) + return msi_domain_alloc_irqs_descs_locked(domain, &dev->dev, nvec); + + return pci_msi_legacy_setup_msi_irqs(dev, nvec, type); +} + +void pci_msi_teardown_msi_irqs(struct pci_dev *dev) +{ + struct irq_domain *domain; + + domain = dev_get_msi_domain(&dev->dev); + if (domain && irq_domain_is_hierarchy(domain)) + msi_domain_free_irqs_descs_locked(domain, &dev->dev); + else + pci_msi_legacy_teardown_msi_irqs(dev); + msi_free_msi_descs(&dev->dev); +} + +/** + * pci_msi_domain_write_msg - Helper to write MSI message to PCI config space + * @irq_data: Pointer to interrupt data of the MSI interrupt + * @msg: Pointer to the message + */ +static void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg) +{ + struct msi_desc *desc = irq_data_get_msi_desc(irq_data); + + /* + * For MSI-X desc->irq is always equal to irq_data->irq. For + * MSI only the first interrupt of MULTI MSI passes the test. + */ + if (desc->irq == irq_data->irq) + __pci_write_msi_msg(desc, msg); +} + +/** + * pci_msi_domain_calc_hwirq - Generate a unique ID for an MSI source + * @desc: Pointer to the MSI descriptor + * + * The ID number is only used within the irqdomain. + */ +static irq_hw_number_t pci_msi_domain_calc_hwirq(struct msi_desc *desc) +{ + struct pci_dev *dev = msi_desc_to_pci_dev(desc); + + return (irq_hw_number_t)desc->msi_index | + pci_dev_id(dev) << 11 | + (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27; +} + +static inline bool pci_msi_desc_is_multi_msi(struct msi_desc *desc) +{ + return !desc->pci.msi_attrib.is_msix && desc->nvec_used > 1; +} + +/** + * pci_msi_domain_check_cap - Verify that @domain supports the capabilities + * for @dev + * @domain: The interrupt domain to check + * @info: The domain info for verification + * @dev: The device to check + * + * Returns: + * 0 if the functionality is supported + * 1 if Multi MSI is requested, but the domain does not support it + * -ENOTSUPP otherwise + */ +static int pci_msi_domain_check_cap(struct irq_domain *domain, + struct msi_domain_info *info, + struct device *dev) +{ + struct msi_desc *desc = msi_first_desc(dev, MSI_DESC_ALL); + + /* Special handling to support __pci_enable_msi_range() */ + if (pci_msi_desc_is_multi_msi(desc) && + !(info->flags & MSI_FLAG_MULTI_PCI_MSI)) + return 1; + + if (desc->pci.msi_attrib.is_msix) { + if (!(info->flags & MSI_FLAG_PCI_MSIX)) + return -ENOTSUPP; + + if (info->flags & MSI_FLAG_MSIX_CONTIGUOUS) { + unsigned int idx = 0; + + /* Check for gaps in the entry indices */ + msi_for_each_desc(desc, dev, MSI_DESC_ALL) { + if (desc->msi_index != idx++) + return -ENOTSUPP; + } + } + } + return 0; +} + +static void pci_msi_domain_set_desc(msi_alloc_info_t *arg, + struct msi_desc *desc) +{ + arg->desc = desc; + arg->hwirq = pci_msi_domain_calc_hwirq(desc); +} + +static struct msi_domain_ops pci_msi_domain_ops_default = { + .set_desc = pci_msi_domain_set_desc, + .msi_check = pci_msi_domain_check_cap, +}; + +static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info) +{ + struct msi_domain_ops *ops = info->ops; + + if (ops == NULL) { + info->ops = &pci_msi_domain_ops_default; + } else { + if (ops->set_desc == NULL) + ops->set_desc = pci_msi_domain_set_desc; + if (ops->msi_check == NULL) + ops->msi_check = pci_msi_domain_check_cap; + } +} + +static void pci_msi_domain_update_chip_ops(struct msi_domain_info *info) +{ + struct irq_chip *chip = info->chip; + + BUG_ON(!chip); + if (!chip->irq_write_msi_msg) + chip->irq_write_msi_msg = pci_msi_domain_write_msg; + if (!chip->irq_mask) + chip->irq_mask = pci_msi_mask_irq; + if (!chip->irq_unmask) + chip->irq_unmask = pci_msi_unmask_irq; +} + +/** + * pci_msi_create_irq_domain - Create a MSI interrupt domain + * @fwnode: Optional fwnode of the interrupt controller + * @info: MSI domain info + * @parent: Parent irq domain + * + * Updates the domain and chip ops and creates a MSI interrupt domain. + * + * Returns: + * A domain pointer or NULL in case of failure. + */ +struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode, + struct msi_domain_info *info, + struct irq_domain *parent) +{ + struct irq_domain *domain; + + if (WARN_ON(info->flags & MSI_FLAG_LEVEL_CAPABLE)) + info->flags &= ~MSI_FLAG_LEVEL_CAPABLE; + + if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS) + pci_msi_domain_update_dom_ops(info); + if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) + pci_msi_domain_update_chip_ops(info); + + info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS; + if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE)) + info->flags |= MSI_FLAG_MUST_REACTIVATE; + + /* PCI-MSI is oneshot-safe */ + info->chip->flags |= IRQCHIP_ONESHOT_SAFE; + + domain = msi_create_irq_domain(fwnode, info, parent); + if (!domain) + return NULL; + + irq_domain_update_bus_token(domain, DOMAIN_BUS_PCI_MSI); + return domain; +} +EXPORT_SYMBOL_GPL(pci_msi_create_irq_domain); + +/* + * Users of the generic MSI infrastructure expect a device to have a single ID, + * so with DMA aliases we have to pick the least-worst compromise. Devices with + * DMA phantom functions tend to still emit MSIs from the real function number, + * so we ignore those and only consider topological aliases where either the + * alias device or RID appears on a different bus number. We also make the + * reasonable assumption that bridges are walked in an upstream direction (so + * the last one seen wins), and the much braver assumption that the most likely + * case is that of PCI->PCIe so we should always use the alias RID. This echoes + * the logic from intel_irq_remapping's set_msi_sid(), which presumably works + * well enough in practice; in the face of the horrible PCIe<->PCI-X conditions + * for taking ownership all we can really do is close our eyes and hope... + */ +static int get_msi_id_cb(struct pci_dev *pdev, u16 alias, void *data) +{ + u32 *pa = data; + u8 bus = PCI_BUS_NUM(*pa); + + if (pdev->bus->number != bus || PCI_BUS_NUM(alias) != bus) + *pa = alias; + + return 0; +} + +/** + * pci_msi_domain_get_msi_rid - Get the MSI requester id (RID) + * @domain: The interrupt domain + * @pdev: The PCI device. + * + * The RID for a device is formed from the alias, with a firmware + * supplied mapping applied + * + * Returns: The RID. + */ +u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev) +{ + struct device_node *of_node; + u32 rid = pci_dev_id(pdev); + + pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid); + + of_node = irq_domain_get_of_node(domain); + rid = of_node ? of_msi_map_id(&pdev->dev, of_node, rid) : + iort_msi_map_id(&pdev->dev, rid); + + return rid; +} + +/** + * pci_msi_get_device_domain - Get the MSI domain for a given PCI device + * @pdev: The PCI device + * + * Use the firmware data to find a device-specific MSI domain + * (i.e. not one that is set as a default). + * + * Returns: The corresponding MSI domain or NULL if none has been found. + */ +struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev) +{ + struct irq_domain *dom; + u32 rid = pci_dev_id(pdev); + + pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid); + dom = of_msi_map_get_device_domain(&pdev->dev, rid, DOMAIN_BUS_PCI_MSI); + if (!dom) + dom = iort_get_device_domain(&pdev->dev, rid, + DOMAIN_BUS_PCI_MSI); + return dom; +} + +/** + * pci_dev_has_special_msi_domain - Check whether the device is handled by + * a non-standard PCI-MSI domain + * @pdev: The PCI device to check. + * + * Returns: True if the device irqdomain or the bus irqdomain is + * non-standard PCI/MSI. + */ +bool pci_dev_has_special_msi_domain(struct pci_dev *pdev) +{ + struct irq_domain *dom = dev_get_msi_domain(&pdev->dev); + + if (!dom) + dom = dev_get_msi_domain(&pdev->bus->dev); + + if (!dom) + return true; + + return dom->bus_token != DOMAIN_BUS_PCI_MSI; +} |