diff options
Diffstat (limited to 'drivers/pci/pcie/portdrv_core.c')
| -rw-r--r-- | drivers/pci/pcie/portdrv_core.c | 578 |
1 files changed, 578 insertions, 0 deletions
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c new file mode 100644 index 000000000..2f0ce668a --- /dev/null +++ b/drivers/pci/pcie/portdrv_core.c @@ -0,0 +1,578 @@ +/* + * 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/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; + u32 reg32; + int cap_mask = 0; + int err; + + 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; + + if (pcie_ports_auto) { + err = pcie_port_platform_notify(dev, &cap_mask); + if (err) + return 0; + } + + /* Hot-Plug Capable */ + if ((cap_mask & PCIE_PORT_SERVICE_HP) && + pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT) { + pcie_capability_read_dword(dev, PCI_EXP_SLTCAP, ®32); + if (reg32 & PCI_EXP_SLTCAP_HPC) { + 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); + } + + 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%02x", + 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; + } + + 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_suspend - 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); |