diff options
Diffstat (limited to 'drivers/pci/msi/irqdomain.c')
| -rw-r--r-- | drivers/pci/msi/irqdomain.c | 485 |
1 files changed, 485 insertions, 0 deletions
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c new file mode 100644 index 0000000000..c8be056c24 --- /dev/null +++ b/drivers/pci/msi/irqdomain.c @@ -0,0 +1,485 @@ +// 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_all_locked(&dev->dev, MSI_DEFAULT_DOMAIN, 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_all_locked(&dev->dev, MSI_DEFAULT_DOMAIN); + } 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 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, +}; + +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; + } +} + +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) +{ + 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); + + /* Let the core code free MSI descriptors when freeing interrupts */ + info->flags |= MSI_FLAG_FREE_MSI_DESCS; + + 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; + /* Let the core update the bus token */ + info->bus_token = DOMAIN_BUS_PCI_MSI; + + return msi_create_irq_domain(fwnode, info, parent); +} +EXPORT_SYMBOL_GPL(pci_msi_create_irq_domain); + +/* + * Per device MSI[-X] domain functionality + */ +static void pci_device_domain_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc) +{ + arg->desc = desc; + arg->hwirq = desc->msi_index; +} + +static void pci_irq_mask_msi(struct irq_data *data) +{ + struct msi_desc *desc = irq_data_get_msi_desc(data); + + pci_msi_mask(desc, BIT(data->irq - desc->irq)); +} + +static void pci_irq_unmask_msi(struct irq_data *data) +{ + struct msi_desc *desc = irq_data_get_msi_desc(data); + + pci_msi_unmask(desc, BIT(data->irq - desc->irq)); +} + +#ifdef CONFIG_GENERIC_IRQ_RESERVATION_MODE +# define MSI_REACTIVATE MSI_FLAG_MUST_REACTIVATE +#else +# define MSI_REACTIVATE 0 +#endif + +#define MSI_COMMON_FLAGS (MSI_FLAG_FREE_MSI_DESCS | \ + MSI_FLAG_ACTIVATE_EARLY | \ + MSI_FLAG_DEV_SYSFS | \ + MSI_REACTIVATE) + +static const struct msi_domain_template pci_msi_template = { + .chip = { + .name = "PCI-MSI", + .irq_mask = pci_irq_mask_msi, + .irq_unmask = pci_irq_unmask_msi, + .irq_write_msi_msg = pci_msi_domain_write_msg, + .flags = IRQCHIP_ONESHOT_SAFE, + }, + + .ops = { + .set_desc = pci_device_domain_set_desc, + }, + + .info = { + .flags = MSI_COMMON_FLAGS | MSI_FLAG_MULTI_PCI_MSI, + .bus_token = DOMAIN_BUS_PCI_DEVICE_MSI, + }, +}; + +static void pci_irq_mask_msix(struct irq_data *data) +{ + pci_msix_mask(irq_data_get_msi_desc(data)); +} + +static void pci_irq_unmask_msix(struct irq_data *data) +{ + pci_msix_unmask(irq_data_get_msi_desc(data)); +} + +static void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg, + struct msi_desc *desc) +{ + /* Don't fiddle with preallocated MSI descriptors */ + if (!desc->pci.mask_base) + msix_prepare_msi_desc(to_pci_dev(desc->dev), desc); +} + +static const struct msi_domain_template pci_msix_template = { + .chip = { + .name = "PCI-MSIX", + .irq_mask = pci_irq_mask_msix, + .irq_unmask = pci_irq_unmask_msix, + .irq_write_msi_msg = pci_msi_domain_write_msg, + .flags = IRQCHIP_ONESHOT_SAFE, + }, + + .ops = { + .prepare_desc = pci_msix_prepare_desc, + .set_desc = pci_device_domain_set_desc, + }, + + .info = { + .flags = MSI_COMMON_FLAGS | MSI_FLAG_PCI_MSIX | + MSI_FLAG_PCI_MSIX_ALLOC_DYN, + .bus_token = DOMAIN_BUS_PCI_DEVICE_MSIX, + }, +}; + +static bool pci_match_device_domain(struct pci_dev *pdev, enum irq_domain_bus_token bus_token) +{ + return msi_match_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN, bus_token); +} + +static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_domain_template *tmpl, + unsigned int hwsize) +{ + struct irq_domain *domain = dev_get_msi_domain(&pdev->dev); + + if (!domain || !irq_domain_is_msi_parent(domain)) + return true; + + return msi_create_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN, tmpl, + hwsize, NULL, NULL); +} + +/** + * pci_setup_msi_device_domain - Setup a device MSI interrupt domain + * @pdev: The PCI device to create the domain on + * + * Return: + * True when: + * - The device does not have a MSI parent irq domain associated, + * which keeps the legacy architecture specific and the global + * PCI/MSI domain models working + * - The MSI domain exists already + * - The MSI domain was successfully allocated + * False when: + * - MSI-X is enabled + * - The domain creation fails. + * + * The created MSI domain is preserved until: + * - The device is removed + * - MSI is disabled and a MSI-X domain is created + */ +bool pci_setup_msi_device_domain(struct pci_dev *pdev) +{ + if (WARN_ON_ONCE(pdev->msix_enabled)) + return false; + + if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSI)) + return true; + if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX)) + msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN); + + return pci_create_device_domain(pdev, &pci_msi_template, 1); +} + +/** + * pci_setup_msix_device_domain - Setup a device MSI-X interrupt domain + * @pdev: The PCI device to create the domain on + * @hwsize: The size of the MSI-X vector table + * + * Return: + * True when: + * - The device does not have a MSI parent irq domain associated, + * which keeps the legacy architecture specific and the global + * PCI/MSI domain models working + * - The MSI-X domain exists already + * - The MSI-X domain was successfully allocated + * False when: + * - MSI is enabled + * - The domain creation fails. + * + * The created MSI-X domain is preserved until: + * - The device is removed + * - MSI-X is disabled and a MSI domain is created + */ +bool pci_setup_msix_device_domain(struct pci_dev *pdev, unsigned int hwsize) +{ + if (WARN_ON_ONCE(pdev->msi_enabled)) + return false; + + if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX)) + return true; + if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSI)) + msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN); + + return pci_create_device_domain(pdev, &pci_msix_template, hwsize); +} + +/** + * pci_msi_domain_supports - Check for support of a particular feature flag + * @pdev: The PCI device to operate on + * @feature_mask: The feature mask to check for (full match) + * @mode: If ALLOW_LEGACY this grants the feature when there is no irq domain + * associated to the device. If DENY_LEGACY the lack of an irq domain + * makes the feature unsupported + */ +bool pci_msi_domain_supports(struct pci_dev *pdev, unsigned int feature_mask, + enum support_mode mode) +{ + struct msi_domain_info *info; + struct irq_domain *domain; + unsigned int supported; + + domain = dev_get_msi_domain(&pdev->dev); + + if (!domain || !irq_domain_is_hierarchy(domain)) + return mode == ALLOW_LEGACY; + + if (!irq_domain_is_msi_parent(domain)) { + /* + * For "global" PCI/MSI interrupt domains the associated + * msi_domain_info::flags is the authoritative source of + * information. + */ + info = domain->host_data; + supported = info->flags; + } else { + /* + * For MSI parent domains the supported feature set + * is available in the parent ops. This makes checks + * possible before actually instantiating the + * per device domain because the parent is never + * expanding the PCI/MSI functionality. + */ + supported = domain->msi_parent_ops->supported_flags; + } + + return (supported & feature_mask) == feature_mask; +} + +/** + * pci_create_ims_domain - Create a secondary IMS domain for a PCI device + * @pdev: The PCI device to operate on + * @template: The MSI info template which describes the domain + * @hwsize: The size of the hardware entry table or 0 if the domain + * is purely software managed + * @data: Optional pointer to domain specific data to be stored + * in msi_domain_info::data + * + * Return: True on success, false otherwise + * + * An IMS domain is expected to have the following constraints: + * - The index space is managed by the core code + * + * - There is no requirement for consecutive index ranges + * + * - The interrupt chip must provide the following callbacks: + * - irq_mask() + * - irq_unmask() + * - irq_write_msi_msg() + * + * - The interrupt chip must provide the following optional callbacks + * when the irq_mask(), irq_unmask() and irq_write_msi_msg() callbacks + * cannot operate directly on hardware, e.g. in the case that the + * interrupt message store is in queue memory: + * - irq_bus_lock() + * - irq_bus_unlock() + * + * These callbacks are invoked from preemptible task context and are + * allowed to sleep. In this case the mandatory callbacks above just + * store the information. The irq_bus_unlock() callback is supposed + * to make the change effective before returning. + * + * - Interrupt affinity setting is handled by the underlying parent + * interrupt domain and communicated to the IMS domain via + * irq_write_msi_msg(). + * + * The domain is automatically destroyed when the PCI device is removed. + */ +bool pci_create_ims_domain(struct pci_dev *pdev, const struct msi_domain_template *template, + unsigned int hwsize, void *data) +{ + struct irq_domain *domain = dev_get_msi_domain(&pdev->dev); + + if (!domain || !irq_domain_is_msi_parent(domain)) + return false; + + if (template->info.bus_token != DOMAIN_BUS_PCI_DEVICE_IMS || + !(template->info.flags & MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS) || + !(template->info.flags & MSI_FLAG_FREE_MSI_DESCS) || + !template->chip.irq_mask || !template->chip.irq_unmask || + !template->chip.irq_write_msi_msg || template->chip.irq_set_affinity) + return false; + + return msi_create_device_irq_domain(&pdev->dev, MSI_SECONDARY_DOMAIN, template, + hwsize, data, NULL); +} +EXPORT_SYMBOL_GPL(pci_create_ims_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; +} |