// SPDX-License-Identifier: GPL-2.0 /* * Purpose: PCI Express Port Bus Driver's Core Functions * * Copyright (C) 2004 Intel * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com) */ #include #include #include #include #include #include #include #include #include #include #include "../pci.h" #include "portdrv.h" bool pciehp_msi_disabled; static int __init pciehp_setup(char *str) { if (!strncmp(str, "nomsi", 5)) pciehp_msi_disabled = true; return 1; } __setup("pcie_hp=", pciehp_setup); /** * release_pcie_device - free PCI Express port service device structure * @dev: Port service device to release * * Invoked automatically when device is being removed in response to * device_unregister(dev). Release all resources being claimed. */ static void release_pcie_device(struct device *dev) { kfree(to_pcie_device(dev)); } /* * Fill in *pme, *aer, *dpc with the relevant Interrupt Message Numbers if * services are enabled in "mask". Return the number of MSI/MSI-X vectors * required to accommodate the largest Message Number. */ static int pcie_message_numbers(struct pci_dev *dev, int mask, u32 *pme, u32 *aer, u32 *dpc) { u32 nvec = 0, pos, reg32; u16 reg16; /* * The Interrupt Message Number indicates which vector is used, i.e., * the MSI-X table entry or the MSI offset between the base Message * Data and the generated interrupt message. See PCIe r3.1, sec * 7.8.2, 7.10.10, 7.31.2. */ if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) { pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16); *pme = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9; nvec = *pme + 1; } if (mask & PCIE_PORT_SERVICE_AER) { pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); if (pos) { pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); *aer = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27; nvec = max(nvec, *aer + 1); } } if (mask & PCIE_PORT_SERVICE_DPC) { pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC); if (pos) { pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, ®16); *dpc = reg16 & PCI_EXP_DPC_IRQ; nvec = max(nvec, *dpc + 1); } } return nvec; } /** * pcie_port_enable_irq_vec - try to set up MSI-X or MSI as interrupt mode * for given port * @dev: PCI Express port to handle * @irqs: Array of interrupt vectors to populate * @mask: Bitmask of port capabilities returned by get_port_device_capability() * * Return value: 0 on success, error code on failure */ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) { int nr_entries, nvec; u32 pme = 0, aer = 0, dpc = 0; /* Allocate the maximum possible number of MSI/MSI-X vectors */ nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES, PCI_IRQ_MSIX | PCI_IRQ_MSI); if (nr_entries < 0) return nr_entries; /* See how many and which Interrupt Message Numbers we actually use */ nvec = pcie_message_numbers(dev, mask, &pme, &aer, &dpc); if (nvec > nr_entries) { pci_free_irq_vectors(dev); return -EIO; } /* * If we allocated more than we need, free them and reallocate fewer. * * Reallocating may change the specific vectors we get, so * pci_irq_vector() must be done *after* the reallocation. * * If we're using MSI, hardware is *allowed* to change the Interrupt * Message Numbers when we free and reallocate the vectors, but we * assume it won't because we allocate enough vectors for the * biggest Message Number we found. */ if (nvec != nr_entries) { pci_free_irq_vectors(dev); nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec, PCI_IRQ_MSIX | PCI_IRQ_MSI); if (nr_entries < 0) return nr_entries; } /* PME and hotplug share an MSI/MSI-X vector */ if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) { irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, pme); irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, pme); } if (mask & PCIE_PORT_SERVICE_AER) irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, aer); if (mask & PCIE_PORT_SERVICE_DPC) irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, dpc); return 0; } /** * pcie_init_service_irqs - initialize irqs for PCI Express port services * @dev: PCI Express port to handle * @irqs: Array of irqs to populate * @mask: Bitmask of port capabilities returned by get_port_device_capability() * * Return value: Interrupt mode associated with the port */ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask) { int ret, i; for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) irqs[i] = -1; /* * If we support PME or hotplug, but we can't use MSI/MSI-X for * them, we have to fall back to INTx or other interrupts, e.g., a * system shared interrupt. */ if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) goto legacy_irq; if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi()) goto legacy_irq; /* Try to use MSI-X or MSI if supported */ if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0) return 0; legacy_irq: /* fall back to legacy IRQ */ ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY); if (ret < 0) return -ENODEV; for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) { if (i != PCIE_PORT_SERVICE_VC_SHIFT) irqs[i] = pci_irq_vector(dev, 0); } return 0; } /** * get_port_device_capability - discover capabilities of a PCI Express port * @dev: PCI Express port to examine * * The capabilities are read from the port's PCI Express configuration registers * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and * 7.9 - 7.11. * * Return value: Bitmask of discovered port capabilities */ static int get_port_device_capability(struct pci_dev *dev) { int services = 0; int cap_mask = 0; if (pcie_ports_disabled) return 0; cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP | PCIE_PORT_SERVICE_VC; if (pci_aer_available()) cap_mask |= PCIE_PORT_SERVICE_AER | PCIE_PORT_SERVICE_DPC; if (pcie_ports_auto) pcie_port_platform_notify(dev, &cap_mask); /* Hot-Plug Capable */ if ((cap_mask & PCIE_PORT_SERVICE_HP) && dev->is_hotplug_bridge) { services |= PCIE_PORT_SERVICE_HP; /* * Disable hot-plug interrupts in case they have been enabled * by the BIOS and the hot-plug service driver is not loaded. */ pcie_capability_clear_word(dev, PCI_EXP_SLTCTL, PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE); } /* AER capable */ if ((cap_mask & PCIE_PORT_SERVICE_AER) && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) { services |= PCIE_PORT_SERVICE_AER; /* * Disable AER on this port in case it's been enabled by the * BIOS (the AER service driver will enable it when necessary). */ pci_disable_pcie_error_reporting(dev); } /* VC support */ if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC)) services |= PCIE_PORT_SERVICE_VC; /* Root ports are capable of generating PME too */ if ((cap_mask & PCIE_PORT_SERVICE_PME) && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { services |= PCIE_PORT_SERVICE_PME; /* * Disable PME interrupt on this port in case it's been enabled * by the BIOS (the PME service driver will enable it when * necessary). */ pcie_pme_interrupt_enable(dev, false); } if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC)) services |= PCIE_PORT_SERVICE_DPC; return services; } /** * pcie_device_init - allocate and initialize PCI Express port service device * @pdev: PCI Express port to associate the service device with * @service: Type of service to associate with the service device * @irq: Interrupt vector to associate with the service device */ static int pcie_device_init(struct pci_dev *pdev, int service, int irq) { int retval; struct pcie_device *pcie; struct device *device; pcie = kzalloc(sizeof(*pcie), GFP_KERNEL); if (!pcie) return -ENOMEM; pcie->port = pdev; pcie->irq = irq; pcie->service = service; /* Initialize generic device interface */ device = &pcie->device; device->bus = &pcie_port_bus_type; device->release = release_pcie_device; /* callback to free pcie dev */ dev_set_name(device, "%s:pcie%03x", pci_name(pdev), get_descriptor_id(pci_pcie_type(pdev), service)); device->parent = &pdev->dev; device_enable_async_suspend(device); retval = device_register(device); if (retval) { put_device(device); return retval; } pm_runtime_no_callbacks(device); return 0; } /** * pcie_port_device_register - register PCI Express port * @dev: PCI Express port to register * * Allocate the port extension structure and register services associated with * the port. */ int pcie_port_device_register(struct pci_dev *dev) { int status, capabilities, i, nr_service; int irqs[PCIE_PORT_DEVICE_MAXSERVICES]; /* Enable PCI Express port device */ status = pci_enable_device(dev); if (status) return status; /* Get and check PCI Express port services */ capabilities = get_port_device_capability(dev); if (!capabilities) return 0; pci_set_master(dev); /* * Initialize service irqs. Don't use service devices that * require interrupts if there is no way to generate them. * However, some drivers may have a polling mode (e.g. pciehp_poll_mode) * that can be used in the absence of irqs. Allow them to determine * if that is to be used. */ status = pcie_init_service_irqs(dev, irqs, capabilities); if (status) { capabilities &= PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_HP; if (!capabilities) goto error_disable; } /* Allocate child services if any */ status = -ENODEV; nr_service = 0; for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) { int service = 1 << i; if (!(capabilities & service)) continue; if (!pcie_device_init(dev, service, irqs[i])) nr_service++; } if (!nr_service) goto error_cleanup_irqs; return 0; error_cleanup_irqs: pci_free_irq_vectors(dev); error_disable: pci_disable_device(dev); return status; } #ifdef CONFIG_PM static int suspend_iter(struct device *dev, void *data) { struct pcie_port_service_driver *service_driver; if ((dev->bus == &pcie_port_bus_type) && dev->driver) { service_driver = to_service_driver(dev->driver); if (service_driver->suspend) service_driver->suspend(to_pcie_device(dev)); } return 0; } /** * pcie_port_device_suspend - suspend port services associated with a PCIe port * @dev: PCI Express port to handle */ int pcie_port_device_suspend(struct device *dev) { return device_for_each_child(dev, NULL, suspend_iter); } static int resume_iter(struct device *dev, void *data) { struct pcie_port_service_driver *service_driver; if ((dev->bus == &pcie_port_bus_type) && (dev->driver)) { service_driver = to_service_driver(dev->driver); if (service_driver->resume) service_driver->resume(to_pcie_device(dev)); } return 0; } /** * pcie_port_device_resume - resume port services associated with a PCIe port * @dev: PCI Express port to handle */ int pcie_port_device_resume(struct device *dev) { return device_for_each_child(dev, NULL, resume_iter); } #endif /* PM */ static int remove_iter(struct device *dev, void *data) { if (dev->bus == &pcie_port_bus_type) device_unregister(dev); return 0; } /** * pcie_port_device_remove - unregister PCI Express port service devices * @dev: PCI Express port the service devices to unregister are associated with * * Remove PCI Express port service devices associated with given port and * disable MSI-X or MSI for the port. */ void pcie_port_device_remove(struct pci_dev *dev) { device_for_each_child(&dev->dev, NULL, remove_iter); pci_free_irq_vectors(dev); pci_disable_device(dev); } /** * pcie_port_probe_service - probe driver for given PCI Express port service * @dev: PCI Express port service device to probe against * * If PCI Express port service driver is registered with * pcie_port_service_register(), this function will be called by the driver core * whenever match is found between the driver and a port service device. */ static int pcie_port_probe_service(struct device *dev) { struct pcie_device *pciedev; struct pcie_port_service_driver *driver; int status; if (!dev || !dev->driver) return -ENODEV; driver = to_service_driver(dev->driver); if (!driver || !driver->probe) return -ENODEV; pciedev = to_pcie_device(dev); status = driver->probe(pciedev); if (status) return status; get_device(dev); return 0; } /** * pcie_port_remove_service - detach driver from given PCI Express port service * @dev: PCI Express port service device to handle * * If PCI Express port service driver is registered with * pcie_port_service_register(), this function will be called by the driver core * when device_unregister() is called for the port service device associated * with the driver. */ static int pcie_port_remove_service(struct device *dev) { struct pcie_device *pciedev; struct pcie_port_service_driver *driver; if (!dev || !dev->driver) return 0; pciedev = to_pcie_device(dev); driver = to_service_driver(dev->driver); if (driver && driver->remove) { driver->remove(pciedev); put_device(dev); } return 0; } /** * pcie_port_shutdown_service - shut down given PCI Express port service * @dev: PCI Express port service device to handle * * If PCI Express port service driver is registered with * pcie_port_service_register(), this function will be called by the driver core * when device_shutdown() is called for the port service device associated * with the driver. */ static void pcie_port_shutdown_service(struct device *dev) {} /** * pcie_port_service_register - register PCI Express port service driver * @new: PCI Express port service driver to register */ int pcie_port_service_register(struct pcie_port_service_driver *new) { if (pcie_ports_disabled) return -ENODEV; new->driver.name = new->name; new->driver.bus = &pcie_port_bus_type; new->driver.probe = pcie_port_probe_service; new->driver.remove = pcie_port_remove_service; new->driver.shutdown = pcie_port_shutdown_service; return driver_register(&new->driver); } EXPORT_SYMBOL(pcie_port_service_register); /** * pcie_port_service_unregister - unregister PCI Express port service driver * @drv: PCI Express port service driver to unregister */ void pcie_port_service_unregister(struct pcie_port_service_driver *drv) { driver_unregister(&drv->driver); } EXPORT_SYMBOL(pcie_port_service_unregister);