// SPDX-License-Identifier: GPL-2.0 /* * Purpose: PCI Express Port Bus Driver * * 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 #include #include "../pci.h" #include "portdrv.h" /* * The PCIe Capability Interrupt Message Number (PCIe r3.1, sec 7.8.2) must * be one of the first 32 MSI-X entries. Per PCI r3.0, sec 6.8.3.1, MSI * supports a maximum of 32 vectors per function. */ #define PCIE_PORT_MAX_MSI_ENTRIES 32 #define get_descriptor_id(type, service) (((type - 4) << 8) | service) struct portdrv_service_data { struct pcie_port_service_driver *drv; struct device *dev; u32 service; }; /** * 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; 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_PORT_SERVICE_BWCTRL)) { pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16); *pme = FIELD_GET(PCI_EXP_FLAGS_IRQ, reg16); nvec = *pme + 1; } #ifdef CONFIG_PCIEAER if (mask & PCIE_PORT_SERVICE_AER) { u32 reg32; pos = dev->aer_cap; if (pos) { pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); *aer = FIELD_GET(PCI_ERR_ROOT_AER_IRQ, reg32); nvec = max(nvec, *aer + 1); } } #endif 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 = FIELD_GET(PCI_EXP_DPC_IRQ, reg16); 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, pcie_irq; 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, hotplug and bandwidth notification share an MSI/MSI-X vector */ if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP | PCIE_PORT_SERVICE_BWCTRL)) { pcie_irq = pci_irq_vector(dev, pme); irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pcie_irq; irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pcie_irq; irqs[PCIE_PORT_SERVICE_BWCTRL_SHIFT] = pcie_irq; } 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 but can't use MSI/MSI-X for it, 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 intx_irq; /* Try to use MSI-X or MSI if supported */ if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0) return 0; intx_irq: /* fall back to INTX IRQ */ ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_INTX); if (ret < 0) return -ENODEV; for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) 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) { struct pci_host_bridge *host = pci_find_host_bridge(dev->bus); int services = 0; if (dev->is_hotplug_bridge && (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT || pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) && (pcie_ports_native || host->native_pcie_hotplug)) { 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); } #ifdef CONFIG_PCIEAER if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT || pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC) && dev->aer_cap && pci_aer_available() && (pcie_ports_native || host->native_aer)) services |= PCIE_PORT_SERVICE_AER; #endif /* Root Ports and Root Complex Event Collectors may generate PMEs */ if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT || pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC) && (pcie_ports_native || host->native_pme)) { 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); } /* * With dpc-native, allow Linux to use DPC even if it doesn't have * permission to use AER. */ if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) && pci_aer_available() && (pcie_ports_dpc_native || (services & PCIE_PORT_SERVICE_AER))) services |= PCIE_PORT_SERVICE_DPC; if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM || pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { u32 linkcap; pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &linkcap); if (linkcap & PCI_EXP_LNKCAP_LBNC) services |= PCIE_PORT_SERVICE_BWCTRL; } 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. */ static 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_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; } typedef int (*pcie_callback_t)(struct pcie_device *); static int pcie_port_device_iter(struct device *dev, void *data) { struct pcie_port_service_driver *service_driver; size_t offset = *(size_t *)data; pcie_callback_t cb; if ((dev->bus == &pcie_port_bus_type) && dev->driver) { service_driver = to_service_driver(dev->driver); cb = *(pcie_callback_t *)((void *)service_driver + offset); if (cb) return cb(to_pcie_device(dev)); } return 0; } #ifdef CONFIG_PM /** * pcie_port_device_suspend - suspend port services associated with a PCIe port * @dev: PCI Express port to handle */ static int pcie_port_device_suspend(struct device *dev) { size_t off = offsetof(struct pcie_port_service_driver, suspend); return device_for_each_child(dev, &off, pcie_port_device_iter); } static int pcie_port_device_resume_noirq(struct device *dev) { size_t off = offsetof(struct pcie_port_service_driver, resume_noirq); return device_for_each_child(dev, &off, pcie_port_device_iter); } /** * pcie_port_device_resume - resume port services associated with a PCIe port * @dev: PCI Express port to handle */ static int pcie_port_device_resume(struct device *dev) { size_t off = offsetof(struct pcie_port_service_driver, resume); return device_for_each_child(dev, &off, pcie_port_device_iter); } /** * pcie_port_device_runtime_suspend - runtime suspend port services * @dev: PCI Express port to handle */ static int pcie_port_device_runtime_suspend(struct device *dev) { size_t off = offsetof(struct pcie_port_service_driver, runtime_suspend); return device_for_each_child(dev, &off, pcie_port_device_iter); } /** * pcie_port_device_runtime_resume - runtime resume port services * @dev: PCI Express port to handle */ static int pcie_port_device_runtime_resume(struct device *dev) { size_t off = offsetof(struct pcie_port_service_driver, runtime_resume); return device_for_each_child(dev, &off, pcie_port_device_iter); } #endif /* PM */ static int remove_iter(struct device *dev, void *data) { if (dev->bus == &pcie_port_bus_type) device_unregister(dev); return 0; } static int find_service_iter(struct device *device, void *data) { struct pcie_port_service_driver *service_driver; struct portdrv_service_data *pdrvs; u32 service; pdrvs = (struct portdrv_service_data *) data; service = pdrvs->service; if (device->bus == &pcie_port_bus_type && device->driver) { service_driver = to_service_driver(device->driver); if (service_driver->service == service) { pdrvs->drv = service_driver; pdrvs->dev = device; return 1; } } return 0; } /** * pcie_port_find_device - find the struct device * @dev: PCI Express port the service is associated with * @service: For the service to find * * Find the struct device associated with given service on a pci_dev */ struct device *pcie_port_find_device(struct pci_dev *dev, u32 service) { struct device *device; struct portdrv_service_data pdrvs; pdrvs.dev = NULL; pdrvs.service = service; device_for_each_child(&dev->dev, &pdrvs, find_service_iter); device = pdrvs.dev; return device; } EXPORT_SYMBOL_GPL(pcie_port_find_device); /** * 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. */ static void pcie_port_device_remove(struct pci_dev *dev) { device_for_each_child(&dev->dev, NULL, remove_iter); pci_free_irq_vectors(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); } /** * 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); } /* If this switch is set, PCIe port native services should not be enabled. */ bool pcie_ports_disabled; /* * If the user specified "pcie_ports=native", use the PCIe services regardless * of whether the platform has given us permission. On ACPI systems, this * means we ignore _OSC. */ bool pcie_ports_native; /* * If the user specified "pcie_ports=dpc-native", use the Linux DPC PCIe * service even if the platform hasn't given us permission. */ bool pcie_ports_dpc_native; static int __init pcie_port_setup(char *str) { if (!strncmp(str, "compat", 6)) pcie_ports_disabled = true; else if (!strncmp(str, "native", 6)) pcie_ports_native = true; else if (!strncmp(str, "dpc-native", 10)) pcie_ports_dpc_native = true; return 1; } __setup("pcie_ports=", pcie_port_setup); /* global data */ #ifdef CONFIG_PM static int pcie_port_runtime_suspend(struct device *dev) { if (!to_pci_dev(dev)->bridge_d3) return -EBUSY; return pcie_port_device_runtime_suspend(dev); } static int pcie_port_runtime_idle(struct device *dev) { /* * Assume the PCI core has set bridge_d3 whenever it thinks the port * should be good to go to D3. Everything else, including moving * the port to D3, is handled by the PCI core. */ return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY; } static const struct dev_pm_ops pcie_portdrv_pm_ops = { .suspend = pcie_port_device_suspend, .resume_noirq = pcie_port_device_resume_noirq, .resume = pcie_port_device_resume, .freeze = pcie_port_device_suspend, .thaw = pcie_port_device_resume, .poweroff = pcie_port_device_suspend, .restore_noirq = pcie_port_device_resume_noirq, .restore = pcie_port_device_resume, .runtime_suspend = pcie_port_runtime_suspend, .runtime_resume = pcie_port_device_runtime_resume, .runtime_idle = pcie_port_runtime_idle, }; #define PCIE_PORTDRV_PM_OPS (&pcie_portdrv_pm_ops) #else /* !PM */ #define PCIE_PORTDRV_PM_OPS NULL #endif /* !PM */ /* * pcie_portdrv_probe - Probe PCI-Express port devices * @dev: PCI-Express port device being probed * * If detected invokes the pcie_port_device_register() method for * this port device. * */ static int pcie_portdrv_probe(struct pci_dev *dev, const struct pci_device_id *id) { int type = pci_pcie_type(dev); int status; if (!pci_is_pcie(dev) || ((type != PCI_EXP_TYPE_ROOT_PORT) && (type != PCI_EXP_TYPE_UPSTREAM) && (type != PCI_EXP_TYPE_DOWNSTREAM) && (type != PCI_EXP_TYPE_RC_EC))) return -ENODEV; if (type == PCI_EXP_TYPE_RC_EC) pcie_link_rcec(dev); status = pcie_port_device_register(dev); if (status) return status; pci_save_state(dev); dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_NO_DIRECT_COMPLETE | DPM_FLAG_SMART_SUSPEND); if (pci_bridge_d3_possible(dev)) { /* * Keep the port resumed 100ms to make sure things like * config space accesses from userspace (lspci) will not * cause the port to repeatedly suspend and resume. */ pm_runtime_set_autosuspend_delay(&dev->dev, 100); pm_runtime_use_autosuspend(&dev->dev); pm_runtime_mark_last_busy(&dev->dev); pm_runtime_put_autosuspend(&dev->dev); pm_runtime_allow(&dev->dev); } return 0; } static void pcie_portdrv_remove(struct pci_dev *dev) { if (pci_bridge_d3_possible(dev)) { pm_runtime_forbid(&dev->dev); pm_runtime_get_noresume(&dev->dev); pm_runtime_dont_use_autosuspend(&dev->dev); } pcie_port_device_remove(dev); pci_disable_device(dev); } static void pcie_portdrv_shutdown(struct pci_dev *dev) { if (pci_bridge_d3_possible(dev)) { pm_runtime_forbid(&dev->dev); pm_runtime_get_noresume(&dev->dev); pm_runtime_dont_use_autosuspend(&dev->dev); } pcie_port_device_remove(dev); } static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, pci_channel_state_t error) { if (error == pci_channel_io_frozen) return PCI_ERS_RESULT_NEED_RESET; return PCI_ERS_RESULT_CAN_RECOVER; } static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev) { size_t off = offsetof(struct pcie_port_service_driver, slot_reset); device_for_each_child(&dev->dev, &off, pcie_port_device_iter); pci_restore_state(dev); pci_save_state(dev); return PCI_ERS_RESULT_RECOVERED; } static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev) { return PCI_ERS_RESULT_RECOVERED; } /* * LINUX Device Driver Model */ static const struct pci_device_id port_pci_ids[] = { /* handle any PCI-Express port */ { PCI_DEVICE_CLASS(PCI_CLASS_BRIDGE_PCI_NORMAL, ~0) }, /* subtractive decode PCI-to-PCI bridge, class type is 060401h */ { PCI_DEVICE_CLASS(PCI_CLASS_BRIDGE_PCI_SUBTRACTIVE, ~0) }, /* handle any Root Complex Event Collector */ { PCI_DEVICE_CLASS(((PCI_CLASS_SYSTEM_RCEC << 8) | 0x00), ~0) }, { }, }; static const struct pci_error_handlers pcie_portdrv_err_handler = { .error_detected = pcie_portdrv_error_detected, .slot_reset = pcie_portdrv_slot_reset, .mmio_enabled = pcie_portdrv_mmio_enabled, }; static struct pci_driver pcie_portdriver = { .name = "pcieport", .id_table = port_pci_ids, .probe = pcie_portdrv_probe, .remove = pcie_portdrv_remove, .shutdown = pcie_portdrv_shutdown, .err_handler = &pcie_portdrv_err_handler, .driver_managed_dma = true, .driver.pm = PCIE_PORTDRV_PM_OPS, }; static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d) { pr_notice("%s detected: will not use MSI for PCIe PME signaling\n", d->ident); pcie_pme_disable_msi(); return 0; } static const struct dmi_system_id pcie_portdrv_dmi_table[] __initconst = { /* * Boxes that should not use MSI for PCIe PME signaling. */ { .callback = dmi_pcie_pme_disable_msi, .ident = "MSI Wind U-100", .matches = { DMI_MATCH(DMI_SYS_VENDOR, "MICRO-STAR INTERNATIONAL CO., LTD"), DMI_MATCH(DMI_PRODUCT_NAME, "U-100"), }, }, {} }; static void __init pcie_init_services(void) { pcie_aer_init(); pcie_pme_init(); pcie_dpc_init(); pcie_bwctrl_init(); pcie_hp_init(); } static int __init pcie_portdrv_init(void) { if (pcie_ports_disabled) return -EACCES; pcie_init_services(); dmi_check_system(pcie_portdrv_dmi_table); return pci_register_driver(&pcie_portdriver); } device_initcall(pcie_portdrv_init);