| // 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 <linux/module.h> |
| #include <linux/pci.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/pm.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/string.h> |
| #include <linux/slab.h> |
| #include <linux/aer.h> |
| |
| #include "../pci.h" |
| #include "portdrv.h" |
| |
| 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_capability_read_word(dev, PCI_EXP_FLAGS, ®16); |
| *pme = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9; |
| 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 = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27; |
| 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 = 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 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 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++) |
| 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 && |
| (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 (dev->aer_cap && pci_aer_available() && |
| (pcie_ports_native || host->native_aer)) { |
| 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); |
| } |
| #endif |
| |
| /* |
| * Root ports are capable of generating PME too. Root Complex |
| * Event Collectors can also generate PMEs, but we don't handle |
| * those yet. |
| */ |
| if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT && |
| (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); |
| } |
| |
| if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) && |
| pci_aer_available() && services & PCIE_PORT_SERVICE_AER) |
| 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_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 |
| typedef int (*pcie_pm_callback_t)(struct pcie_device *); |
| |
| static int pm_iter(struct device *dev, void *data) |
| { |
| struct pcie_port_service_driver *service_driver; |
| size_t offset = *(size_t *)data; |
| pcie_pm_callback_t cb; |
| |
| if ((dev->bus == &pcie_port_bus_type) && dev->driver) { |
| service_driver = to_service_driver(dev->driver); |
| cb = *(pcie_pm_callback_t *)((void *)service_driver + offset); |
| if (cb) |
| return cb(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) |
| { |
| size_t off = offsetof(struct pcie_port_service_driver, suspend); |
| return device_for_each_child(dev, &off, pm_iter); |
| } |
| |
| 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, pm_iter); |
| } |
| |
| /** |
| * 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) |
| { |
| size_t off = offsetof(struct pcie_port_service_driver, resume); |
| return device_for_each_child(dev, &off, pm_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_service - find the service driver |
| * @dev: PCI Express port the service is associated with |
| * @service: Service to find |
| * |
| * Find PCI Express port service driver associated with given service |
| */ |
| struct pcie_port_service_driver *pcie_port_find_service(struct pci_dev *dev, |
| u32 service) |
| { |
| struct pcie_port_service_driver *drv; |
| struct portdrv_service_data pdrvs; |
| |
| pdrvs.drv = NULL; |
| pdrvs.service = service; |
| device_for_each_child(&dev->dev, &pdrvs, find_service_iter); |
| |
| drv = pdrvs.drv; |
| return drv; |
| } |
| |
| /** |
| * 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; |
| } |
| |
| /** |
| * 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); |