linux/drivers/pci/pcie/portdrv_core.c
Gabriele Paoloni ae6dc7deac PCI/portdrv: Allocate MSI/MSI-X vector for Downstream Port Containment
Currently pcie_port_enable_irq_vec() only allocates MSI/MSI-X vectors for
PME, hotplug, and AER.

The Downstream Port Containment feature also supports MSI/MSI-X interrupts,
so allocate a vector for it, too.

Signed-off-by: Liudongdong <liudongdong3@huawei.com>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
[bhelgaas: changelog, comment]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-06-16 19:19:28 -05:00

546 lines
15 KiB
C

/*
* 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_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, entry, nvec = 0;
/*
* 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.
*/
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;
if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
u16 reg16;
/*
* Per PCIe r3.1, sec 6.1.6, "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".
*
* Per sec 7.8.2, "For MSI, the [Interrupt Message Number]
* indicates the offset between the base Message Data and
* the interrupt message that is generated."
*
* "For MSI-X, the [Interrupt Message Number] indicates
* which MSI-X Table entry is used to generate the
* interrupt message."
*/
pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);
entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
if (entry >= nr_entries)
goto out_free_irqs;
irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, entry);
irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, entry);
nvec = max(nvec, entry + 1);
}
if (mask & PCIE_PORT_SERVICE_AER) {
u32 reg32, pos;
/*
* Per PCIe r3.1, sec 7.10.10, the Advanced Error Interrupt
* Message Number in the Root Error Status register
* indicates which MSI/MSI-X vector is used for AER.
*
* "For MSI, the [Advanced Error Interrupt Message Number]
* indicates the offset between the base Message Data and
* the interrupt message that is generated."
*
* "For MSI-X, the [Advanced Error Interrupt Message
* Number] 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, &reg32);
entry = reg32 >> 27;
if (entry >= nr_entries)
goto out_free_irqs;
irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, entry);
nvec = max(nvec, entry + 1);
}
if (mask & PCIE_PORT_SERVICE_DPC) {
u16 reg16, pos;
/*
* Per PCIe r4.0 (v0.9), sec 7.9.15.2, the DPC Interrupt
* Message Number in the DPC Capability register indicates
* which MSI/MSI-X vector is used for DPC.
*
* "For MSI, the [DPC Interrupt Message Number] indicates
* the offset between the base Message Data and the
* interrupt message that is generated."
*
* "For MSI-X, the [DPC Interrupt Message Number] indicates
* which MSI-X Table entry is used to generate the
* interrupt message."
*/
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, &reg16);
entry = reg16 & 0x1f;
if (entry >= nr_entries)
goto out_free_irqs;
irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, entry);
nvec = max(nvec, entry + 1);
}
/*
* 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) {
/* Drop the temporary MSI-X setup */
pci_free_irq_vectors(dev);
/* Now allocate the MSI-X vectors for real */
nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec,
PCI_IRQ_MSIX | PCI_IRQ_MSI);
if (nr_entries < 0)
return nr_entries;
}
return 0;
out_free_irqs:
pci_free_irq_vectors(dev);
return -EIO;
}
/**
* 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 or hotplug, but we can't use MSI/MSI-X for
* them, 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;
if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_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++) {
if (i != PCIE_PORT_SERVICE_VC_SHIFT)
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)
{
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 = pcie_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:
pci_free_irq_vectors(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);
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);