linux-stable/drivers/pci/pcie/portdrv_pci.c
Alexandru Gagniuc e8303bb7a7 PCI/LINK: Report degraded links via link bandwidth notification
A warning is generated when a PCIe device is probed with a degraded link,
but there was no similar mechanism to warn when the link becomes degraded
after probing.  The Link Bandwidth Notification provides this mechanism.

Use the Link Bandwidth Management Interrupt to detect bandwidth changes,
and rescan the bandwidth, looking for the weakest point.  This is the same
logic used in probe().

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
2019-03-05 15:04:13 -06:00

256 lines
6.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Purpose: PCI Express Port Bus Driver
* Author: Tom Nguyen <tom.l.nguyen@intel.com>
*
* Copyright (C) 2004 Intel
* Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
*/
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/init.h>
#include <linux/aer.h>
#include <linux/dmi.h>
#include "../pci.h"
#include "portdrv.h"
/* If this switch is set, PCIe port native services should not be enabled. */
bool pcie_ports_disabled;
/*
* If the user specified "pcie_ports=native", use the PCIe services regardless
* of whether the platform has given us permission. On ACPI systems, this
* means we ignore _OSC.
*/
bool pcie_ports_native;
static int __init pcie_port_setup(char *str)
{
if (!strncmp(str, "compat", 6))
pcie_ports_disabled = true;
else if (!strncmp(str, "native", 6))
pcie_ports_native = true;
return 1;
}
__setup("pcie_ports=", pcie_port_setup);
/* global data */
#ifdef CONFIG_PM
static int pcie_port_runtime_suspend(struct device *dev)
{
if (!to_pci_dev(dev)->bridge_d3)
return -EBUSY;
return pcie_port_device_runtime_suspend(dev);
}
static int pcie_port_runtime_idle(struct device *dev)
{
/*
* Assume the PCI core has set bridge_d3 whenever it thinks the port
* should be good to go to D3. Everything else, including moving
* the port to D3, is handled by the PCI core.
*/
return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
}
static const struct dev_pm_ops pcie_portdrv_pm_ops = {
.suspend = pcie_port_device_suspend,
.resume_noirq = pcie_port_device_resume_noirq,
.resume = pcie_port_device_resume,
.freeze = pcie_port_device_suspend,
.thaw = pcie_port_device_resume,
.poweroff = pcie_port_device_suspend,
.restore_noirq = pcie_port_device_resume_noirq,
.restore = pcie_port_device_resume,
.runtime_suspend = pcie_port_runtime_suspend,
.runtime_resume = pcie_port_device_runtime_resume,
.runtime_idle = pcie_port_runtime_idle,
};
#define PCIE_PORTDRV_PM_OPS (&pcie_portdrv_pm_ops)
#else /* !PM */
#define PCIE_PORTDRV_PM_OPS NULL
#endif /* !PM */
/*
* pcie_portdrv_probe - Probe PCI-Express port devices
* @dev: PCI-Express port device being probed
*
* If detected invokes the pcie_port_device_register() method for
* this port device.
*
*/
static int pcie_portdrv_probe(struct pci_dev *dev,
const struct pci_device_id *id)
{
int status;
if (!pci_is_pcie(dev) ||
((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) &&
(pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM) &&
(pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)))
return -ENODEV;
status = pcie_port_device_register(dev);
if (status)
return status;
pci_save_state(dev);
dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_NEVER_SKIP |
DPM_FLAG_SMART_SUSPEND);
if (pci_bridge_d3_possible(dev)) {
/*
* Keep the port resumed 100ms to make sure things like
* config space accesses from userspace (lspci) will not
* cause the port to repeatedly suspend and resume.
*/
pm_runtime_set_autosuspend_delay(&dev->dev, 100);
pm_runtime_use_autosuspend(&dev->dev);
pm_runtime_mark_last_busy(&dev->dev);
pm_runtime_put_autosuspend(&dev->dev);
pm_runtime_allow(&dev->dev);
}
return 0;
}
static void pcie_portdrv_remove(struct pci_dev *dev)
{
if (pci_bridge_d3_possible(dev)) {
pm_runtime_forbid(&dev->dev);
pm_runtime_get_noresume(&dev->dev);
pm_runtime_dont_use_autosuspend(&dev->dev);
}
pcie_port_device_remove(dev);
}
static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
enum pci_channel_state error)
{
/* Root Port has no impact. Always recovers. */
return PCI_ERS_RESULT_CAN_RECOVER;
}
static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
{
pci_restore_state(dev);
pci_save_state(dev);
return PCI_ERS_RESULT_RECOVERED;
}
static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
{
return PCI_ERS_RESULT_RECOVERED;
}
static int resume_iter(struct device *device, void *data)
{
struct pcie_device *pcie_device;
struct pcie_port_service_driver *driver;
if (device->bus == &pcie_port_bus_type && device->driver) {
driver = to_service_driver(device->driver);
if (driver && driver->error_resume) {
pcie_device = to_pcie_device(device);
/* Forward error message to service drivers */
driver->error_resume(pcie_device->port);
}
}
return 0;
}
static void pcie_portdrv_err_resume(struct pci_dev *dev)
{
device_for_each_child(&dev->dev, NULL, resume_iter);
}
/*
* LINUX Device Driver Model
*/
static const struct pci_device_id port_pci_ids[] = {
/* handle any PCI-Express port */
{ PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0) },
/* subtractive decode PCI-to-PCI bridge, class type is 060401h */
{ PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x01), ~0) },
{ },
};
static const struct pci_error_handlers pcie_portdrv_err_handler = {
.error_detected = pcie_portdrv_error_detected,
.slot_reset = pcie_portdrv_slot_reset,
.mmio_enabled = pcie_portdrv_mmio_enabled,
.resume = pcie_portdrv_err_resume,
};
static struct pci_driver pcie_portdriver = {
.name = "pcieport",
.id_table = &port_pci_ids[0],
.probe = pcie_portdrv_probe,
.remove = pcie_portdrv_remove,
.shutdown = pcie_portdrv_remove,
.err_handler = &pcie_portdrv_err_handler,
.driver.pm = PCIE_PORTDRV_PM_OPS,
};
static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d)
{
pr_notice("%s detected: will not use MSI for PCIe PME signaling\n",
d->ident);
pcie_pme_disable_msi();
return 0;
}
static const struct dmi_system_id pcie_portdrv_dmi_table[] __initconst = {
/*
* Boxes that should not use MSI for PCIe PME signaling.
*/
{
.callback = dmi_pcie_pme_disable_msi,
.ident = "MSI Wind U-100",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"MICRO-STAR INTERNATIONAL CO., LTD"),
DMI_MATCH(DMI_PRODUCT_NAME, "U-100"),
},
},
{}
};
static void __init pcie_init_services(void)
{
pcie_aer_init();
pcie_pme_init();
pcie_dpc_init();
pcie_hp_init();
pcie_bandwidth_notification_init();
}
static int __init pcie_portdrv_init(void)
{
if (pcie_ports_disabled)
return -EACCES;
pcie_init_services();
dmi_check_system(pcie_portdrv_dmi_table);
return pci_register_driver(&pcie_portdriver);
}
device_initcall(pcie_portdrv_init);