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- // 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_PORT_SERVICE_BWNOTIF)) {
- 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, 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_BWNOTIF)) {
- 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_BWNOTIF_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 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);
- }
- /*
- * 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_BWNOTIF;
- }
- 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);
- }
- /**
- * pcie_port_device_runtime_suspend - runtime suspend port services
- * @dev: PCI Express port to handle
- */
- 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, pm_iter);
- }
- /**
- * pcie_port_device_runtime_resume - runtime resume port services
- * @dev: PCI Express port to handle
- */
- 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, 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_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.
- */
- 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);
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