diff options
Diffstat (limited to 'drivers/pci/pcie/portdrv_core.c')
| -rw-r--r-- | drivers/pci/pcie/portdrv_core.c | 586 |
1 files changed, 586 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..1ac7fec47 --- /dev/null +++ b/drivers/pci/pcie/portdrv_core.c @@ -0,0 +1,586 @@ +// 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; +#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_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; +} + +typedef int (*pcie_callback_t)(struct pcie_device *); + +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 + */ +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); +} + +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 + */ +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 + */ +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 + */ +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. + */ +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); |