// 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);
}
if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
pci_aer_available() && 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)
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_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;
}
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);
