/* * File: portdrv_core.c * 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/pcieport_if.h> #include <linux/aer.h> #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)); } /** * pcie_port_msix_add_entry - add entry to given array of MSI-X entries * @entries: Array of MSI-X entries * @new_entry: Index of the entry to add to the array * @nr_entries: Number of entries already in the array * * Return value: Position of the added entry in the array */ static int pcie_port_msix_add_entry( struct msix_entry *entries, int new_entry, int nr_entries) { int j; for (j = 0; j < nr_entries; j++) if (entries[j].entry == new_entry) return j; entries[j].entry = new_entry; return j; } /** * pcie_port_enable_msix - try to set up MSI-X as interrupt mode for given port * @dev: PCI Express port to handle * @vectors: 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_msix(struct pci_dev *dev, int *vectors, int mask) { struct msix_entry *msix_entries; int idx[PCIE_PORT_DEVICE_MAXSERVICES]; int nr_entries, status, pos, i, nvec; u16 reg16; u32 reg32; nr_entries = pci_msix_vec_count(dev); if (nr_entries < 0) return nr_entries; BUG_ON(!nr_entries); if (nr_entries > PCIE_PORT_MAX_MSIX_ENTRIES) nr_entries = PCIE_PORT_MAX_MSIX_ENTRIES; msix_entries = kzalloc(sizeof(*msix_entries) * nr_entries, GFP_KERNEL); if (!msix_entries) return -ENOMEM; /* * Allocate as many entries as the port wants, so that we can check * which of them will be useful. Moreover, if nr_entries is correctly * equal to the number of entries this port actually uses, we'll happily * go through without any tricks. */ for (i = 0; i < nr_entries; i++) msix_entries[i].entry = i; status = pci_enable_msix_exact(dev, msix_entries, nr_entries); if (status) goto Exit; for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) idx[i] = -1; status = -EIO; nvec = 0; if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) { int entry; /* * The code below follows the PCI Express Base Specification 2.0 * stating in Section 6.1.6 that "PME and Hot-Plug Event * interrupts (when both are implemented) always share the same * MSI or MSI-X vector, as indicated by the Interrupt Message * Number field in the PCI Express Capabilities register", where * according to Section 7.8.2 of the specification "For MSI-X, * the value in this field indicates which MSI-X Table entry is * used to generate the interrupt message." */ pcie_capability_read_word(dev, PCI_EXP_FLAGS, ®16); entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9; if (entry >= nr_entries) goto Error; i = pcie_port_msix_add_entry(msix_entries, entry, nvec); if (i == nvec) nvec++; idx[PCIE_PORT_SERVICE_PME_SHIFT] = i; idx[PCIE_PORT_SERVICE_HP_SHIFT] = i; } if (mask & PCIE_PORT_SERVICE_AER) { int entry; /* * The code below follows Section 7.10.10 of the PCI Express * Base Specification 2.0 stating that bits 31-27 of the Root * Error Status Register contain a value indicating which of the * MSI/MSI-X vectors assigned to the port is going to be used * for AER, where "For MSI-X, the value in this register * indicates which MSI-X Table entry is used to generate the * interrupt message." */ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); entry = reg32 >> 27; if (entry >= nr_entries) goto Error; i = pcie_port_msix_add_entry(msix_entries, entry, nvec); if (i == nvec) nvec++; idx[PCIE_PORT_SERVICE_AER_SHIFT] = i; } /* * If nvec is equal to the allocated number of entries, we can just use * what we have. Otherwise, the port has some extra entries not for the * services we know and we need to work around that. */ if (nvec == nr_entries) { status = 0; } else { /* Drop the temporary MSI-X setup */ pci_disable_msix(dev); /* Now allocate the MSI-X vectors for real */ status = pci_enable_msix_exact(dev, msix_entries, nvec); if (status) goto Exit; } for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) vectors[i] = idx[i] >= 0 ? msix_entries[idx[i]].vector : -1; Exit: kfree(msix_entries); return status; Error: pci_disable_msix(dev); goto Exit; } /** * 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 init_service_irqs(struct pci_dev *dev, int *irqs, int mask) { int i, irq = -1; /* * If MSI cannot be used for PCIe PME or hotplug, we have to use * INTx or other interrupts, e.g. system shared interrupt. */ if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) || ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) { if (dev->irq) irq = dev->irq; goto no_msi; } /* Try to use MSI-X if supported */ if (!pcie_port_enable_msix(dev, irqs, mask)) return 0; /* * We're not going to use MSI-X, so try MSI and fall back to INTx. * If neither MSI/MSI-X nor INTx available, try other interrupt. On * some platforms, root port doesn't support MSI/MSI-X/INTx in RC mode. */ if (!pci_enable_msi(dev) || dev->irq) irq = dev->irq; no_msi: for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) irqs[i] = irq; irqs[PCIE_PORT_SERVICE_VC_SHIFT] = -1; if (irq < 0) return -ENODEV; return 0; } static void cleanup_service_irqs(struct pci_dev *dev) { if (dev->msix_enabled) pci_disable_msix(dev); else if (dev->msi_enabled) pci_disable_msi(dev); } /** * 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 | PCIE_PORT_SERVICE_DPC; if (pci_aer_available()) cap_mask |= PCIE_PORT_SERVICE_AER; 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 = 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: cleanup_service_irqs(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); cleanup_service_irqs(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; dev_printk(KERN_DEBUG, dev, "service driver %s loaded\n", driver->name); 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) { dev_printk(KERN_DEBUG, dev, "unloading service driver %s\n", driver->name); 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);