linux/drivers/pci/pci-driver.c
Mika Westerberg ad9001f2f4 PCI/PM: Add missing link delays required by the PCIe spec
Currently Linux does not follow PCIe spec regarding the required delays
after reset. A concrete example is a Thunderbolt add-in-card that consists
of a PCIe switch and two PCIe endpoints:

  +-1b.0-[01-6b]----00.0-[02-6b]--+-00.0-[03]----00.0 TBT controller
                                  +-01.0-[04-36]-- DS hotplug port
                                  +-02.0-[37]----00.0 xHCI controller
                                  \-04.0-[38-6b]-- DS hotplug port

The root port (1b.0) and the PCIe switch downstream ports are all PCIe Gen3
so they support 8GT/s link speeds.

We wait for the PCIe hierarchy to enter D3cold (runtime):

  pcieport 0000:00:1b.0: power state changed by ACPI to D3cold

When it wakes up from D3cold, according to the PCIe 5.0 section 5.8 the
PCIe switch is put to reset and its power is re-applied. This means that we
must follow the rules in PCIe 5.0 section 6.6.1.

For the PCIe Gen3 ports we are dealing with here, the following applies:

  With a Downstream Port that supports Link speeds greater than 5.0 GT/s,
  software must wait a minimum of 100 ms after Link training completes
  before sending a Configuration Request to the device immediately below
  that Port. Software can determine when Link training completes by polling
  the Data Link Layer Link Active bit or by setting up an associated
  interrupt (see Section 6.7.3.3).

Translating this into the above topology we would need to do this (DLLLA
stands for Data Link Layer Link Active):

  0000:00:1b.0: wait for 100 ms after DLLLA is set before access to 0000:01:00.0
  0000:02:00.0: wait for 100 ms after DLLLA is set before access to 0000:03:00.0
  0000:02:02.0: wait for 100 ms after DLLLA is set before access to 0000:37:00.0

I've instrumented the kernel with some additional logging so we can see the
actual delays performed:

  pcieport 0000:00:1b.0: power state changed by ACPI to D0
  pcieport 0000:00:1b.0: waiting for D3cold delay of 100 ms
  pcieport 0000:00:1b.0: waiting for D3hot delay of 10 ms
  pcieport 0000:02:01.0: waiting for D3hot delay of 10 ms
  pcieport 0000:02:04.0: waiting for D3hot delay of 10 ms

For the switch upstream port (01:00.0 reachable through 00:1b.0 root port)
we wait for 100 ms but not taking into account the DLLLA requirement. We
then wait 10 ms for D3hot -> D0 transition of the root port and the two
downstream hotplug ports. This means that we deviate from what the spec
requires.

Performing the same check for system sleep (s2idle) transitions it turns
out to be even worse. None of the mandatory delays are performed. If this
would be S3 instead of s2idle then according to PCI FW spec 3.2 section
4.6.8. there is a specific _DSM that allows the OS to skip the delays but
this platform does not provide the _DSM and does not go to S3 anyway so no
firmware is involved that could already handle these delays.

On this particular platform these delays are not actually needed because
there is an additional delay as part of the ACPI power resource that is
used to turn on power to the hierarchy but since that additional delay is
not required by any of standards (PCIe, ACPI) it is not present in the
Intel Ice Lake, for example where missing the mandatory delays causes
pciehp to start tearing down the stack too early (links are not yet
trained). Below is an example how it looks like when this happens:

  pcieport 0000:83:04.0: pciehp: Slot(4): Card not present
  pcieport 0000:87:04.0: PME# disabled
  pcieport 0000:83:04.0: pciehp: pciehp_unconfigure_device: domain🚌dev = 0000:86:00
  pcieport 0000:86:00.0: Refused to change power state, currently in D3
  pcieport 0000:86:00.0: restoring config space at offset 0x3c (was 0xffffffff, writing 0x201ff)
  pcieport 0000:86:00.0: restoring config space at offset 0x38 (was 0xffffffff, writing 0x0)
  ...

There is also one reported case (see the bugzilla link below) where the
missing delay causes xHCI on a Titan Ridge controller fail to runtime
resume when USB-C dock is plugged. This does not involve pciehp but instead
the PCI core fails to runtime resume the xHCI device:

  pcieport 0000:04:02.0: restoring config space at offset 0xc (was 0x10000, writing 0x10020)
  pcieport 0000:04:02.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100406)
  xhci_hcd 0000:39:00.0: Refused to change power state, currently in D3
  xhci_hcd 0000:39:00.0: restoring config space at offset 0x3c (was 0xffffffff, writing 0x1ff)
  xhci_hcd 0000:39:00.0: restoring config space at offset 0x38 (was 0xffffffff, writing 0x0)
  ...

Add a new function pci_bridge_wait_for_secondary_bus() that is called on
PCI core resume and runtime resume paths accordingly if the bridge entered
D3cold (and thus went through reset).

This is second attempt to add the missing delays. The previous solution in
c2bf1fc212 ("PCI: Add missing link delays required by the PCIe spec") was
reverted because of two issues it caused:

  1. One system become unresponsive after S3 resume due to PME service
     spinning in pcie_pme_work_fn(). The root port in question reports that
     the xHCI sent PME but the xHCI device itself does not have PME status
     set. The PME status bit is never cleared in the root port resulting
     the indefinite loop in pcie_pme_work_fn().

  2. Slows down resume if the root/downstream port does not support Data
     Link Layer Active Reporting because pcie_wait_for_link_delay() waits
     1100 ms in that case.

This version should avoid the above issues because we restrict the delay to
happen only if the port went into D3cold.

Link: https://lore.kernel.org/linux-pci/SL2P216MB01878BBCD75F21D882AEEA2880C60@SL2P216MB0187.KORP216.PROD.OUTLOOK.COM/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203885
Link: https://lore.kernel.org/r/20191112091617.70282-3-mika.westerberg@linux.intel.com
Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-11-20 17:37:24 -06:00

1682 lines
42 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* (C) Copyright 2002-2004, 2007 Greg Kroah-Hartman <greg@kroah.com>
* (C) Copyright 2007 Novell Inc.
*/
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/mempolicy.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/cpu.h>
#include <linux/pm_runtime.h>
#include <linux/suspend.h>
#include <linux/kexec.h>
#include <linux/of_device.h>
#include <linux/acpi.h>
#include "pci.h"
#include "pcie/portdrv.h"
struct pci_dynid {
struct list_head node;
struct pci_device_id id;
};
/**
* pci_add_dynid - add a new PCI device ID to this driver and re-probe devices
* @drv: target pci driver
* @vendor: PCI vendor ID
* @device: PCI device ID
* @subvendor: PCI subvendor ID
* @subdevice: PCI subdevice ID
* @class: PCI class
* @class_mask: PCI class mask
* @driver_data: private driver data
*
* Adds a new dynamic pci device ID to this driver and causes the
* driver to probe for all devices again. @drv must have been
* registered prior to calling this function.
*
* CONTEXT:
* Does GFP_KERNEL allocation.
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int pci_add_dynid(struct pci_driver *drv,
unsigned int vendor, unsigned int device,
unsigned int subvendor, unsigned int subdevice,
unsigned int class, unsigned int class_mask,
unsigned long driver_data)
{
struct pci_dynid *dynid;
dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
if (!dynid)
return -ENOMEM;
dynid->id.vendor = vendor;
dynid->id.device = device;
dynid->id.subvendor = subvendor;
dynid->id.subdevice = subdevice;
dynid->id.class = class;
dynid->id.class_mask = class_mask;
dynid->id.driver_data = driver_data;
spin_lock(&drv->dynids.lock);
list_add_tail(&dynid->node, &drv->dynids.list);
spin_unlock(&drv->dynids.lock);
return driver_attach(&drv->driver);
}
EXPORT_SYMBOL_GPL(pci_add_dynid);
static void pci_free_dynids(struct pci_driver *drv)
{
struct pci_dynid *dynid, *n;
spin_lock(&drv->dynids.lock);
list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
list_del(&dynid->node);
kfree(dynid);
}
spin_unlock(&drv->dynids.lock);
}
/**
* store_new_id - sysfs frontend to pci_add_dynid()
* @driver: target device driver
* @buf: buffer for scanning device ID data
* @count: input size
*
* Allow PCI IDs to be added to an existing driver via sysfs.
*/
static ssize_t new_id_store(struct device_driver *driver, const char *buf,
size_t count)
{
struct pci_driver *pdrv = to_pci_driver(driver);
const struct pci_device_id *ids = pdrv->id_table;
u32 vendor, device, subvendor = PCI_ANY_ID,
subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
unsigned long driver_data = 0;
int fields = 0;
int retval = 0;
fields = sscanf(buf, "%x %x %x %x %x %x %lx",
&vendor, &device, &subvendor, &subdevice,
&class, &class_mask, &driver_data);
if (fields < 2)
return -EINVAL;
if (fields != 7) {
struct pci_dev *pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
if (!pdev)
return -ENOMEM;
pdev->vendor = vendor;
pdev->device = device;
pdev->subsystem_vendor = subvendor;
pdev->subsystem_device = subdevice;
pdev->class = class;
if (pci_match_id(pdrv->id_table, pdev))
retval = -EEXIST;
kfree(pdev);
if (retval)
return retval;
}
/* Only accept driver_data values that match an existing id_table
entry */
if (ids) {
retval = -EINVAL;
while (ids->vendor || ids->subvendor || ids->class_mask) {
if (driver_data == ids->driver_data) {
retval = 0;
break;
}
ids++;
}
if (retval) /* No match */
return retval;
}
retval = pci_add_dynid(pdrv, vendor, device, subvendor, subdevice,
class, class_mask, driver_data);
if (retval)
return retval;
return count;
}
static DRIVER_ATTR_WO(new_id);
/**
* store_remove_id - remove a PCI device ID from this driver
* @driver: target device driver
* @buf: buffer for scanning device ID data
* @count: input size
*
* Removes a dynamic pci device ID to this driver.
*/
static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
size_t count)
{
struct pci_dynid *dynid, *n;
struct pci_driver *pdrv = to_pci_driver(driver);
u32 vendor, device, subvendor = PCI_ANY_ID,
subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
int fields = 0;
size_t retval = -ENODEV;
fields = sscanf(buf, "%x %x %x %x %x %x",
&vendor, &device, &subvendor, &subdevice,
&class, &class_mask);
if (fields < 2)
return -EINVAL;
spin_lock(&pdrv->dynids.lock);
list_for_each_entry_safe(dynid, n, &pdrv->dynids.list, node) {
struct pci_device_id *id = &dynid->id;
if ((id->vendor == vendor) &&
(id->device == device) &&
(subvendor == PCI_ANY_ID || id->subvendor == subvendor) &&
(subdevice == PCI_ANY_ID || id->subdevice == subdevice) &&
!((id->class ^ class) & class_mask)) {
list_del(&dynid->node);
kfree(dynid);
retval = count;
break;
}
}
spin_unlock(&pdrv->dynids.lock);
return retval;
}
static DRIVER_ATTR_WO(remove_id);
static struct attribute *pci_drv_attrs[] = {
&driver_attr_new_id.attr,
&driver_attr_remove_id.attr,
NULL,
};
ATTRIBUTE_GROUPS(pci_drv);
/**
* pci_match_id - See if a pci device matches a given pci_id table
* @ids: array of PCI device id structures to search in
* @dev: the PCI device structure to match against.
*
* Used by a driver to check whether a PCI device present in the
* system is in its list of supported devices. Returns the matching
* pci_device_id structure or %NULL if there is no match.
*
* Deprecated, don't use this as it will not catch any dynamic ids
* that a driver might want to check for.
*/
const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
struct pci_dev *dev)
{
if (ids) {
while (ids->vendor || ids->subvendor || ids->class_mask) {
if (pci_match_one_device(ids, dev))
return ids;
ids++;
}
}
return NULL;
}
EXPORT_SYMBOL(pci_match_id);
static const struct pci_device_id pci_device_id_any = {
.vendor = PCI_ANY_ID,
.device = PCI_ANY_ID,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
};
/**
* pci_match_device - Tell if a PCI device structure has a matching PCI device id structure
* @drv: the PCI driver to match against
* @dev: the PCI device structure to match against
*
* Used by a driver to check whether a PCI device present in the
* system is in its list of supported devices. Returns the matching
* pci_device_id structure or %NULL if there is no match.
*/
static const struct pci_device_id *pci_match_device(struct pci_driver *drv,
struct pci_dev *dev)
{
struct pci_dynid *dynid;
const struct pci_device_id *found_id = NULL;
/* When driver_override is set, only bind to the matching driver */
if (dev->driver_override && strcmp(dev->driver_override, drv->name))
return NULL;
/* Look at the dynamic ids first, before the static ones */
spin_lock(&drv->dynids.lock);
list_for_each_entry(dynid, &drv->dynids.list, node) {
if (pci_match_one_device(&dynid->id, dev)) {
found_id = &dynid->id;
break;
}
}
spin_unlock(&drv->dynids.lock);
if (!found_id)
found_id = pci_match_id(drv->id_table, dev);
/* driver_override will always match, send a dummy id */
if (!found_id && dev->driver_override)
found_id = &pci_device_id_any;
return found_id;
}
struct drv_dev_and_id {
struct pci_driver *drv;
struct pci_dev *dev;
const struct pci_device_id *id;
};
static long local_pci_probe(void *_ddi)
{
struct drv_dev_and_id *ddi = _ddi;
struct pci_dev *pci_dev = ddi->dev;
struct pci_driver *pci_drv = ddi->drv;
struct device *dev = &pci_dev->dev;
int rc;
/*
* Unbound PCI devices are always put in D0, regardless of
* runtime PM status. During probe, the device is set to
* active and the usage count is incremented. If the driver
* supports runtime PM, it should call pm_runtime_put_noidle(),
* or any other runtime PM helper function decrementing the usage
* count, in its probe routine and pm_runtime_get_noresume() in
* its remove routine.
*/
pm_runtime_get_sync(dev);
pci_dev->driver = pci_drv;
rc = pci_drv->probe(pci_dev, ddi->id);
if (!rc)
return rc;
if (rc < 0) {
pci_dev->driver = NULL;
pm_runtime_put_sync(dev);
return rc;
}
/*
* Probe function should return < 0 for failure, 0 for success
* Treat values > 0 as success, but warn.
*/
pci_warn(pci_dev, "Driver probe function unexpectedly returned %d\n",
rc);
return 0;
}
static bool pci_physfn_is_probed(struct pci_dev *dev)
{
#ifdef CONFIG_PCI_IOV
return dev->is_virtfn && dev->physfn->is_probed;
#else
return false;
#endif
}
static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
const struct pci_device_id *id)
{
int error, node, cpu;
struct drv_dev_and_id ddi = { drv, dev, id };
/*
* Execute driver initialization on node where the device is
* attached. This way the driver likely allocates its local memory
* on the right node.
*/
node = dev_to_node(&dev->dev);
dev->is_probed = 1;
cpu_hotplug_disable();
/*
* Prevent nesting work_on_cpu() for the case where a Virtual Function
* device is probed from work_on_cpu() of the Physical device.
*/
if (node < 0 || node >= MAX_NUMNODES || !node_online(node) ||
pci_physfn_is_probed(dev))
cpu = nr_cpu_ids;
else
cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask);
if (cpu < nr_cpu_ids)
error = work_on_cpu(cpu, local_pci_probe, &ddi);
else
error = local_pci_probe(&ddi);
dev->is_probed = 0;
cpu_hotplug_enable();
return error;
}
/**
* __pci_device_probe - check if a driver wants to claim a specific PCI device
* @drv: driver to call to check if it wants the PCI device
* @pci_dev: PCI device being probed
*
* returns 0 on success, else error.
* side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
*/
static int __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
{
const struct pci_device_id *id;
int error = 0;
if (!pci_dev->driver && drv->probe) {
error = -ENODEV;
id = pci_match_device(drv, pci_dev);
if (id)
error = pci_call_probe(drv, pci_dev, id);
}
return error;
}
int __weak pcibios_alloc_irq(struct pci_dev *dev)
{
return 0;
}
void __weak pcibios_free_irq(struct pci_dev *dev)
{
}
#ifdef CONFIG_PCI_IOV
static inline bool pci_device_can_probe(struct pci_dev *pdev)
{
return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe ||
pdev->driver_override);
}
#else
static inline bool pci_device_can_probe(struct pci_dev *pdev)
{
return true;
}
#endif
static int pci_device_probe(struct device *dev)
{
int error;
struct pci_dev *pci_dev = to_pci_dev(dev);
struct pci_driver *drv = to_pci_driver(dev->driver);
if (!pci_device_can_probe(pci_dev))
return -ENODEV;
pci_assign_irq(pci_dev);
error = pcibios_alloc_irq(pci_dev);
if (error < 0)
return error;
pci_dev_get(pci_dev);
error = __pci_device_probe(drv, pci_dev);
if (error) {
pcibios_free_irq(pci_dev);
pci_dev_put(pci_dev);
}
return error;
}
static int pci_device_remove(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct pci_driver *drv = pci_dev->driver;
if (drv) {
if (drv->remove) {
pm_runtime_get_sync(dev);
drv->remove(pci_dev);
pm_runtime_put_noidle(dev);
}
pcibios_free_irq(pci_dev);
pci_dev->driver = NULL;
pci_iov_remove(pci_dev);
}
/* Undo the runtime PM settings in local_pci_probe() */
pm_runtime_put_sync(dev);
/*
* If the device is still on, set the power state as "unknown",
* since it might change by the next time we load the driver.
*/
if (pci_dev->current_state == PCI_D0)
pci_dev->current_state = PCI_UNKNOWN;
/*
* We would love to complain here if pci_dev->is_enabled is set, that
* the driver should have called pci_disable_device(), but the
* unfortunate fact is there are too many odd BIOS and bridge setups
* that don't like drivers doing that all of the time.
* Oh well, we can dream of sane hardware when we sleep, no matter how
* horrible the crap we have to deal with is when we are awake...
*/
pci_dev_put(pci_dev);
return 0;
}
static void pci_device_shutdown(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct pci_driver *drv = pci_dev->driver;
pm_runtime_resume(dev);
if (drv && drv->shutdown)
drv->shutdown(pci_dev);
/*
* If this is a kexec reboot, turn off Bus Master bit on the
* device to tell it to not continue to do DMA. Don't touch
* devices in D3cold or unknown states.
* If it is not a kexec reboot, firmware will hit the PCI
* devices with big hammer and stop their DMA any way.
*/
if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot))
pci_clear_master(pci_dev);
}
#ifdef CONFIG_PM
/* Auxiliary functions used for system resume and run-time resume. */
/**
* pci_restore_standard_config - restore standard config registers of PCI device
* @pci_dev: PCI device to handle
*/
static int pci_restore_standard_config(struct pci_dev *pci_dev)
{
pci_update_current_state(pci_dev, PCI_UNKNOWN);
if (pci_dev->current_state != PCI_D0) {
int error = pci_set_power_state(pci_dev, PCI_D0);
if (error)
return error;
}
pci_restore_state(pci_dev);
pci_pme_restore(pci_dev);
return 0;
}
static void pci_pm_default_resume(struct pci_dev *pci_dev)
{
pci_fixup_device(pci_fixup_resume, pci_dev);
pci_enable_wake(pci_dev, PCI_D0, false);
}
#endif
#ifdef CONFIG_PM_SLEEP
static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
{
pci_power_up(pci_dev);
pci_update_current_state(pci_dev, PCI_D0);
pci_restore_state(pci_dev);
pci_pme_restore(pci_dev);
}
/*
* Default "suspend" method for devices that have no driver provided suspend,
* or not even a driver at all (second part).
*/
static void pci_pm_set_unknown_state(struct pci_dev *pci_dev)
{
/*
* mark its power state as "unknown", since we don't know if
* e.g. the BIOS will change its device state when we suspend.
*/
if (pci_dev->current_state == PCI_D0)
pci_dev->current_state = PCI_UNKNOWN;
}
/*
* Default "resume" method for devices that have no driver provided resume,
* or not even a driver at all (second part).
*/
static int pci_pm_reenable_device(struct pci_dev *pci_dev)
{
int retval;
/* if the device was enabled before suspend, reenable */
retval = pci_reenable_device(pci_dev);
/*
* if the device was busmaster before the suspend, make it busmaster
* again
*/
if (pci_dev->is_busmaster)
pci_set_master(pci_dev);
return retval;
}
static int pci_legacy_suspend(struct device *dev, pm_message_t state)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct pci_driver *drv = pci_dev->driver;
if (drv && drv->suspend) {
pci_power_t prev = pci_dev->current_state;
int error;
error = drv->suspend(pci_dev, state);
suspend_report_result(drv->suspend, error);
if (error)
return error;
if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
&& pci_dev->current_state != PCI_UNKNOWN) {
pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
"PCI PM: Device state not saved by %pS\n",
drv->suspend);
}
}
pci_fixup_device(pci_fixup_suspend, pci_dev);
return 0;
}
static int pci_legacy_suspend_late(struct device *dev, pm_message_t state)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
if (!pci_dev->state_saved)
pci_save_state(pci_dev);
pci_pm_set_unknown_state(pci_dev);
pci_fixup_device(pci_fixup_suspend_late, pci_dev);
return 0;
}
static int pci_legacy_resume(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct pci_driver *drv = pci_dev->driver;
pci_fixup_device(pci_fixup_resume, pci_dev);
return drv && drv->resume ?
drv->resume(pci_dev) : pci_pm_reenable_device(pci_dev);
}
/* Auxiliary functions used by the new power management framework */
static void pci_pm_default_suspend(struct pci_dev *pci_dev)
{
/* Disable non-bridge devices without PM support */
if (!pci_has_subordinate(pci_dev))
pci_disable_enabled_device(pci_dev);
}
static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
{
struct pci_driver *drv = pci_dev->driver;
bool ret = drv && (drv->suspend || drv->resume);
/*
* Legacy PM support is used by default, so warn if the new framework is
* supported as well. Drivers are supposed to support either the
* former, or the latter, but not both at the same time.
*/
pci_WARN(pci_dev, ret && drv->driver.pm, "device %04x:%04x\n",
pci_dev->vendor, pci_dev->device);
return ret;
}
/* New power management framework */
static int pci_pm_prepare(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (pm && pm->prepare) {
int error = pm->prepare(dev);
if (error < 0)
return error;
if (!error && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
return 0;
}
if (pci_dev_need_resume(pci_dev))
return 0;
/*
* The PME setting needs to be adjusted here in case the direct-complete
* optimization is used with respect to this device.
*/
pci_dev_adjust_pme(pci_dev);
return 1;
}
static void pci_pm_complete(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
pci_dev_complete_resume(pci_dev);
pm_generic_complete(dev);
/* Resume device if platform firmware has put it in reset-power-on */
if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) {
pci_power_t pre_sleep_state = pci_dev->current_state;
pci_refresh_power_state(pci_dev);
/*
* On platforms with ACPI this check may also trigger for
* devices sharing power resources if one of those power
* resources has been activated as a result of a change of the
* power state of another device sharing it. However, in that
* case it is also better to resume the device, in general.
*/
if (pci_dev->current_state < pre_sleep_state)
pm_request_resume(dev);
}
}
#else /* !CONFIG_PM_SLEEP */
#define pci_pm_prepare NULL
#define pci_pm_complete NULL
#endif /* !CONFIG_PM_SLEEP */
#ifdef CONFIG_SUSPEND
static void pcie_pme_root_status_cleanup(struct pci_dev *pci_dev)
{
/*
* Some BIOSes forget to clear Root PME Status bits after system
* wakeup, which breaks ACPI-based runtime wakeup on PCI Express.
* Clear those bits now just in case (shouldn't hurt).
*/
if (pci_is_pcie(pci_dev) &&
(pci_pcie_type(pci_dev) == PCI_EXP_TYPE_ROOT_PORT ||
pci_pcie_type(pci_dev) == PCI_EXP_TYPE_RC_EC))
pcie_clear_root_pme_status(pci_dev);
}
static int pci_pm_suspend(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
pci_dev->skip_bus_pm = false;
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_suspend(dev, PMSG_SUSPEND);
if (!pm) {
pci_pm_default_suspend(pci_dev);
return 0;
}
/*
* PCI devices suspended at run time may need to be resumed at this
* point, because in general it may be necessary to reconfigure them for
* system suspend. Namely, if the device is expected to wake up the
* system from the sleep state, it may have to be reconfigured for this
* purpose, or if the device is not expected to wake up the system from
* the sleep state, it should be prevented from signaling wakeup events
* going forward.
*
* Also if the driver of the device does not indicate that its system
* suspend callbacks can cope with runtime-suspended devices, it is
* better to resume the device from runtime suspend here.
*/
if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
pci_dev_need_resume(pci_dev)) {
pm_runtime_resume(dev);
pci_dev->state_saved = false;
} else {
pci_dev_adjust_pme(pci_dev);
}
if (pm->suspend) {
pci_power_t prev = pci_dev->current_state;
int error;
error = pm->suspend(dev);
suspend_report_result(pm->suspend, error);
if (error)
return error;
if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
&& pci_dev->current_state != PCI_UNKNOWN) {
pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
"PCI PM: State of device not saved by %pS\n",
pm->suspend);
}
}
return 0;
}
static int pci_pm_suspend_late(struct device *dev)
{
if (dev_pm_smart_suspend_and_suspended(dev))
return 0;
pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
return pm_generic_suspend_late(dev);
}
static int pci_pm_suspend_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (dev_pm_smart_suspend_and_suspended(dev)) {
dev->power.may_skip_resume = true;
return 0;
}
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_suspend_late(dev, PMSG_SUSPEND);
if (!pm) {
pci_save_state(pci_dev);
goto Fixup;
}
if (pm->suspend_noirq) {
pci_power_t prev = pci_dev->current_state;
int error;
error = pm->suspend_noirq(dev);
suspend_report_result(pm->suspend_noirq, error);
if (error)
return error;
if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
&& pci_dev->current_state != PCI_UNKNOWN) {
pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
"PCI PM: State of device not saved by %pS\n",
pm->suspend_noirq);
goto Fixup;
}
}
if (pci_dev->skip_bus_pm) {
/*
* Either the device is a bridge with a child in D0 below it, or
* the function is running for the second time in a row without
* going through full resume, which is possible only during
* suspend-to-idle in a spurious wakeup case. The device should
* be in D0 at this point, but if it is a bridge, it may be
* necessary to save its state.
*/
if (!pci_dev->state_saved)
pci_save_state(pci_dev);
} else if (!pci_dev->state_saved) {
pci_save_state(pci_dev);
if (pci_power_manageable(pci_dev))
pci_prepare_to_sleep(pci_dev);
}
pci_dbg(pci_dev, "PCI PM: Suspend power state: %s\n",
pci_power_name(pci_dev->current_state));
if (pci_dev->current_state == PCI_D0) {
pci_dev->skip_bus_pm = true;
/*
* Per PCI PM r1.2, table 6-1, a bridge must be in D0 if any
* downstream device is in D0, so avoid changing the power state
* of the parent bridge by setting the skip_bus_pm flag for it.
*/
if (pci_dev->bus->self)
pci_dev->bus->self->skip_bus_pm = true;
}
if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
pci_dbg(pci_dev, "PCI PM: Skipped\n");
goto Fixup;
}
pci_pm_set_unknown_state(pci_dev);
/*
* Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
* PCI COMMAND register isn't 0, the BIOS assumes that the controller
* hasn't been quiesced and tries to turn it off. If the controller
* is already in D3, this can hang or cause memory corruption.
*
* Since the value of the COMMAND register doesn't matter once the
* device has been suspended, we can safely set it to 0 here.
*/
if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
pci_write_config_word(pci_dev, PCI_COMMAND, 0);
Fixup:
pci_fixup_device(pci_fixup_suspend_late, pci_dev);
/*
* If the target system sleep state is suspend-to-idle, it is sufficient
* to check whether or not the device's wakeup settings are good for
* runtime PM. Otherwise, the pm_resume_via_firmware() check will cause
* pci_pm_complete() to take care of fixing up the device's state
* anyway, if need be.
*/
dev->power.may_skip_resume = device_may_wakeup(dev) ||
!device_can_wakeup(dev);
return 0;
}
static int pci_pm_resume_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
pci_power_t prev_state = pci_dev->current_state;
bool skip_bus_pm = pci_dev->skip_bus_pm;
if (dev_pm_may_skip_resume(dev))
return 0;
/*
* Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend
* during system suspend, so update their runtime PM status to "active"
* as they are going to be put into D0 shortly.
*/
if (dev_pm_smart_suspend_and_suspended(dev))
pm_runtime_set_active(dev);
/*
* In the suspend-to-idle case, devices left in D0 during suspend will
* stay in D0, so it is not necessary to restore or update their
* configuration here and attempting to put them into D0 again is
* pointless, so avoid doing that.
*/
if (!(skip_bus_pm && pm_suspend_no_platform()))
pci_pm_default_resume_early(pci_dev);
pci_fixup_device(pci_fixup_resume_early, pci_dev);
pcie_pme_root_status_cleanup(pci_dev);
if (!skip_bus_pm && prev_state == PCI_D3cold)
pci_bridge_wait_for_secondary_bus(pci_dev);
if (pci_has_legacy_pm_support(pci_dev))
return 0;
if (pm && pm->resume_noirq)
return pm->resume_noirq(dev);
return 0;
}
static int pci_pm_resume(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
/*
* This is necessary for the suspend error path in which resume is
* called without restoring the standard config registers of the device.
*/
if (pci_dev->state_saved)
pci_restore_standard_config(pci_dev);
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_resume(dev);
pci_pm_default_resume(pci_dev);
if (pm) {
if (pm->resume)
return pm->resume(dev);
} else {
pci_pm_reenable_device(pci_dev);
}
return 0;
}
#else /* !CONFIG_SUSPEND */
#define pci_pm_suspend NULL
#define pci_pm_suspend_late NULL
#define pci_pm_suspend_noirq NULL
#define pci_pm_resume NULL
#define pci_pm_resume_noirq NULL
#endif /* !CONFIG_SUSPEND */
#ifdef CONFIG_HIBERNATE_CALLBACKS
/*
* pcibios_pm_ops - provide arch-specific hooks when a PCI device is doing
* a hibernate transition
*/
struct dev_pm_ops __weak pcibios_pm_ops;
static int pci_pm_freeze(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_suspend(dev, PMSG_FREEZE);
if (!pm) {
pci_pm_default_suspend(pci_dev);
return 0;
}
/*
* Resume all runtime-suspended devices before creating a snapshot
* image of system memory, because the restore kernel generally cannot
* be expected to always handle them consistently and they need to be
* put into the runtime-active metastate during system resume anyway,
* so it is better to ensure that the state saved in the image will be
* always consistent with that.
*/
pm_runtime_resume(dev);
pci_dev->state_saved = false;
if (pm->freeze) {
int error;
error = pm->freeze(dev);
suspend_report_result(pm->freeze, error);
if (error)
return error;
}
return 0;
}
static int pci_pm_freeze_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_suspend_late(dev, PMSG_FREEZE);
if (pm && pm->freeze_noirq) {
int error;
error = pm->freeze_noirq(dev);
suspend_report_result(pm->freeze_noirq, error);
if (error)
return error;
}
if (!pci_dev->state_saved)
pci_save_state(pci_dev);
pci_pm_set_unknown_state(pci_dev);
if (pcibios_pm_ops.freeze_noirq)
return pcibios_pm_ops.freeze_noirq(dev);
return 0;
}
static int pci_pm_thaw_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int error;
if (pcibios_pm_ops.thaw_noirq) {
error = pcibios_pm_ops.thaw_noirq(dev);
if (error)
return error;
}
/*
* The pm->thaw_noirq() callback assumes the device has been
* returned to D0 and its config state has been restored.
*
* In addition, pci_restore_state() restores MSI-X state in MMIO
* space, which requires the device to be in D0, so return it to D0
* in case the driver's "freeze" callbacks put it into a low-power
* state.
*/
pci_set_power_state(pci_dev, PCI_D0);
pci_restore_state(pci_dev);
if (pci_has_legacy_pm_support(pci_dev))
return 0;
if (pm && pm->thaw_noirq)
return pm->thaw_noirq(dev);
return 0;
}
static int pci_pm_thaw(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int error = 0;
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_resume(dev);
if (pm) {
if (pm->thaw)
error = pm->thaw(dev);
} else {
pci_pm_reenable_device(pci_dev);
}
pci_dev->state_saved = false;
return error;
}
static int pci_pm_poweroff(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_suspend(dev, PMSG_HIBERNATE);
if (!pm) {
pci_pm_default_suspend(pci_dev);
return 0;
}
/* The reason to do that is the same as in pci_pm_suspend(). */
if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
pci_dev_need_resume(pci_dev)) {
pm_runtime_resume(dev);
pci_dev->state_saved = false;
} else {
pci_dev_adjust_pme(pci_dev);
}
if (pm->poweroff) {
int error;
error = pm->poweroff(dev);
suspend_report_result(pm->poweroff, error);
if (error)
return error;
}
return 0;
}
static int pci_pm_poweroff_late(struct device *dev)
{
if (dev_pm_smart_suspend_and_suspended(dev))
return 0;
pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
return pm_generic_poweroff_late(dev);
}
static int pci_pm_poweroff_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (dev_pm_smart_suspend_and_suspended(dev))
return 0;
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_suspend_late(dev, PMSG_HIBERNATE);
if (!pm) {
pci_fixup_device(pci_fixup_suspend_late, pci_dev);
return 0;
}
if (pm->poweroff_noirq) {
int error;
error = pm->poweroff_noirq(dev);
suspend_report_result(pm->poweroff_noirq, error);
if (error)
return error;
}
if (!pci_dev->state_saved && !pci_has_subordinate(pci_dev))
pci_prepare_to_sleep(pci_dev);
/*
* The reason for doing this here is the same as for the analogous code
* in pci_pm_suspend_noirq().
*/
if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
pci_write_config_word(pci_dev, PCI_COMMAND, 0);
pci_fixup_device(pci_fixup_suspend_late, pci_dev);
if (pcibios_pm_ops.poweroff_noirq)
return pcibios_pm_ops.poweroff_noirq(dev);
return 0;
}
static int pci_pm_restore_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int error;
if (pcibios_pm_ops.restore_noirq) {
error = pcibios_pm_ops.restore_noirq(dev);
if (error)
return error;
}
pci_pm_default_resume_early(pci_dev);
pci_fixup_device(pci_fixup_resume_early, pci_dev);
if (pci_has_legacy_pm_support(pci_dev))
return 0;
if (pm && pm->restore_noirq)
return pm->restore_noirq(dev);
return 0;
}
static int pci_pm_restore(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
/*
* This is necessary for the hibernation error path in which restore is
* called without restoring the standard config registers of the device.
*/
if (pci_dev->state_saved)
pci_restore_standard_config(pci_dev);
if (pci_has_legacy_pm_support(pci_dev))
return pci_legacy_resume(dev);
pci_pm_default_resume(pci_dev);
if (pm) {
if (pm->restore)
return pm->restore(dev);
} else {
pci_pm_reenable_device(pci_dev);
}
return 0;
}
#else /* !CONFIG_HIBERNATE_CALLBACKS */
#define pci_pm_freeze NULL
#define pci_pm_freeze_noirq NULL
#define pci_pm_thaw NULL
#define pci_pm_thaw_noirq NULL
#define pci_pm_poweroff NULL
#define pci_pm_poweroff_late NULL
#define pci_pm_poweroff_noirq NULL
#define pci_pm_restore NULL
#define pci_pm_restore_noirq NULL
#endif /* !CONFIG_HIBERNATE_CALLBACKS */
#ifdef CONFIG_PM
static int pci_pm_runtime_suspend(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
pci_power_t prev = pci_dev->current_state;
int error;
/*
* If pci_dev->driver is not set (unbound), we leave the device in D0,
* but it may go to D3cold when the bridge above it runtime suspends.
* Save its config space in case that happens.
*/
if (!pci_dev->driver) {
pci_save_state(pci_dev);
return 0;
}
pci_dev->state_saved = false;
if (pm && pm->runtime_suspend) {
error = pm->runtime_suspend(dev);
/*
* -EBUSY and -EAGAIN is used to request the runtime PM core
* to schedule a new suspend, so log the event only with debug
* log level.
*/
if (error == -EBUSY || error == -EAGAIN) {
pci_dbg(pci_dev, "can't suspend now (%ps returned %d)\n",
pm->runtime_suspend, error);
return error;
} else if (error) {
pci_err(pci_dev, "can't suspend (%ps returned %d)\n",
pm->runtime_suspend, error);
return error;
}
}
pci_fixup_device(pci_fixup_suspend, pci_dev);
if (pm && pm->runtime_suspend
&& !pci_dev->state_saved && pci_dev->current_state != PCI_D0
&& pci_dev->current_state != PCI_UNKNOWN) {
pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
"PCI PM: State of device not saved by %pS\n",
pm->runtime_suspend);
return 0;
}
if (!pci_dev->state_saved) {
pci_save_state(pci_dev);
pci_finish_runtime_suspend(pci_dev);
}
return 0;
}
static int pci_pm_runtime_resume(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
pci_power_t prev_state = pci_dev->current_state;
int error = 0;
/*
* Restoring config space is necessary even if the device is not bound
* to a driver because although we left it in D0, it may have gone to
* D3cold when the bridge above it runtime suspended.
*/
pci_restore_standard_config(pci_dev);
if (!pci_dev->driver)
return 0;
pci_fixup_device(pci_fixup_resume_early, pci_dev);
pci_pm_default_resume(pci_dev);
if (prev_state == PCI_D3cold)
pci_bridge_wait_for_secondary_bus(pci_dev);
if (pm && pm->runtime_resume)
error = pm->runtime_resume(dev);
pci_dev->runtime_d3cold = false;
return error;
}
static int pci_pm_runtime_idle(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
/*
* If pci_dev->driver is not set (unbound), the device should
* always remain in D0 regardless of the runtime PM status
*/
if (!pci_dev->driver)
return 0;
if (!pm)
return -ENOSYS;
if (pm->runtime_idle)
return pm->runtime_idle(dev);
return 0;
}
static const struct dev_pm_ops pci_dev_pm_ops = {
.prepare = pci_pm_prepare,
.complete = pci_pm_complete,
.suspend = pci_pm_suspend,
.suspend_late = pci_pm_suspend_late,
.resume = pci_pm_resume,
.freeze = pci_pm_freeze,
.thaw = pci_pm_thaw,
.poweroff = pci_pm_poweroff,
.poweroff_late = pci_pm_poweroff_late,
.restore = pci_pm_restore,
.suspend_noirq = pci_pm_suspend_noirq,
.resume_noirq = pci_pm_resume_noirq,
.freeze_noirq = pci_pm_freeze_noirq,
.thaw_noirq = pci_pm_thaw_noirq,
.poweroff_noirq = pci_pm_poweroff_noirq,
.restore_noirq = pci_pm_restore_noirq,
.runtime_suspend = pci_pm_runtime_suspend,
.runtime_resume = pci_pm_runtime_resume,
.runtime_idle = pci_pm_runtime_idle,
};
#define PCI_PM_OPS_PTR (&pci_dev_pm_ops)
#else /* !CONFIG_PM */
#define pci_pm_runtime_suspend NULL
#define pci_pm_runtime_resume NULL
#define pci_pm_runtime_idle NULL
#define PCI_PM_OPS_PTR NULL
#endif /* !CONFIG_PM */
/**
* __pci_register_driver - register a new pci driver
* @drv: the driver structure to register
* @owner: owner module of drv
* @mod_name: module name string
*
* Adds the driver structure to the list of registered drivers.
* Returns a negative value on error, otherwise 0.
* If no error occurred, the driver remains registered even if
* no device was claimed during registration.
*/
int __pci_register_driver(struct pci_driver *drv, struct module *owner,
const char *mod_name)
{
/* initialize common driver fields */
drv->driver.name = drv->name;
drv->driver.bus = &pci_bus_type;
drv->driver.owner = owner;
drv->driver.mod_name = mod_name;
drv->driver.groups = drv->groups;
spin_lock_init(&drv->dynids.lock);
INIT_LIST_HEAD(&drv->dynids.list);
/* register with core */
return driver_register(&drv->driver);
}
EXPORT_SYMBOL(__pci_register_driver);
/**
* pci_unregister_driver - unregister a pci driver
* @drv: the driver structure to unregister
*
* Deletes the driver structure from the list of registered PCI drivers,
* gives it a chance to clean up by calling its remove() function for
* each device it was responsible for, and marks those devices as
* driverless.
*/
void pci_unregister_driver(struct pci_driver *drv)
{
driver_unregister(&drv->driver);
pci_free_dynids(drv);
}
EXPORT_SYMBOL(pci_unregister_driver);
static struct pci_driver pci_compat_driver = {
.name = "compat"
};
/**
* pci_dev_driver - get the pci_driver of a device
* @dev: the device to query
*
* Returns the appropriate pci_driver structure or %NULL if there is no
* registered driver for the device.
*/
struct pci_driver *pci_dev_driver(const struct pci_dev *dev)
{
if (dev->driver)
return dev->driver;
else {
int i;
for (i = 0; i <= PCI_ROM_RESOURCE; i++)
if (dev->resource[i].flags & IORESOURCE_BUSY)
return &pci_compat_driver;
}
return NULL;
}
EXPORT_SYMBOL(pci_dev_driver);
/**
* pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
* @dev: the PCI device structure to match against
* @drv: the device driver to search for matching PCI device id structures
*
* Used by a driver to check whether a PCI device present in the
* system is in its list of supported devices. Returns the matching
* pci_device_id structure or %NULL if there is no match.
*/
static int pci_bus_match(struct device *dev, struct device_driver *drv)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct pci_driver *pci_drv;
const struct pci_device_id *found_id;
if (!pci_dev->match_driver)
return 0;
pci_drv = to_pci_driver(drv);
found_id = pci_match_device(pci_drv, pci_dev);
if (found_id)
return 1;
return 0;
}
/**
* pci_dev_get - increments the reference count of the pci device structure
* @dev: the device being referenced
*
* Each live reference to a device should be refcounted.
*
* Drivers for PCI devices should normally record such references in
* their probe() methods, when they bind to a device, and release
* them by calling pci_dev_put(), in their disconnect() methods.
*
* A pointer to the device with the incremented reference counter is returned.
*/
struct pci_dev *pci_dev_get(struct pci_dev *dev)
{
if (dev)
get_device(&dev->dev);
return dev;
}
EXPORT_SYMBOL(pci_dev_get);
/**
* pci_dev_put - release a use of the pci device structure
* @dev: device that's been disconnected
*
* Must be called when a user of a device is finished with it. When the last
* user of the device calls this function, the memory of the device is freed.
*/
void pci_dev_put(struct pci_dev *dev)
{
if (dev)
put_device(&dev->dev);
}
EXPORT_SYMBOL(pci_dev_put);
static int pci_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct pci_dev *pdev;
if (!dev)
return -ENODEV;
pdev = to_pci_dev(dev);
if (add_uevent_var(env, "PCI_CLASS=%04X", pdev->class))
return -ENOMEM;
if (add_uevent_var(env, "PCI_ID=%04X:%04X", pdev->vendor, pdev->device))
return -ENOMEM;
if (add_uevent_var(env, "PCI_SUBSYS_ID=%04X:%04X", pdev->subsystem_vendor,
pdev->subsystem_device))
return -ENOMEM;
if (add_uevent_var(env, "PCI_SLOT_NAME=%s", pci_name(pdev)))
return -ENOMEM;
if (add_uevent_var(env, "MODALIAS=pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02X",
pdev->vendor, pdev->device,
pdev->subsystem_vendor, pdev->subsystem_device,
(u8)(pdev->class >> 16), (u8)(pdev->class >> 8),
(u8)(pdev->class)))
return -ENOMEM;
return 0;
}
#if defined(CONFIG_PCIEPORTBUS) || defined(CONFIG_EEH)
/**
* pci_uevent_ers - emit a uevent during recovery path of PCI device
* @pdev: PCI device undergoing error recovery
* @err_type: type of error event
*/
void pci_uevent_ers(struct pci_dev *pdev, enum pci_ers_result err_type)
{
int idx = 0;
char *envp[3];
switch (err_type) {
case PCI_ERS_RESULT_NONE:
case PCI_ERS_RESULT_CAN_RECOVER:
envp[idx++] = "ERROR_EVENT=BEGIN_RECOVERY";
envp[idx++] = "DEVICE_ONLINE=0";
break;
case PCI_ERS_RESULT_RECOVERED:
envp[idx++] = "ERROR_EVENT=SUCCESSFUL_RECOVERY";
envp[idx++] = "DEVICE_ONLINE=1";
break;
case PCI_ERS_RESULT_DISCONNECT:
envp[idx++] = "ERROR_EVENT=FAILED_RECOVERY";
envp[idx++] = "DEVICE_ONLINE=0";
break;
default:
break;
}
if (idx > 0) {
envp[idx++] = NULL;
kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, envp);
}
}
#endif
static int pci_bus_num_vf(struct device *dev)
{
return pci_num_vf(to_pci_dev(dev));
}
/**
* pci_dma_configure - Setup DMA configuration
* @dev: ptr to dev structure
*
* Function to update PCI devices's DMA configuration using the same
* info from the OF node or ACPI node of host bridge's parent (if any).
*/
static int pci_dma_configure(struct device *dev)
{
struct device *bridge;
int ret = 0;
bridge = pci_get_host_bridge_device(to_pci_dev(dev));
if (IS_ENABLED(CONFIG_OF) && bridge->parent &&
bridge->parent->of_node) {
ret = of_dma_configure(dev, bridge->parent->of_node, true);
} else if (has_acpi_companion(bridge)) {
struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
ret = acpi_dma_configure(dev, acpi_get_dma_attr(adev));
}
pci_put_host_bridge_device(bridge);
return ret;
}
struct bus_type pci_bus_type = {
.name = "pci",
.match = pci_bus_match,
.uevent = pci_uevent,
.probe = pci_device_probe,
.remove = pci_device_remove,
.shutdown = pci_device_shutdown,
.dev_groups = pci_dev_groups,
.bus_groups = pci_bus_groups,
.drv_groups = pci_drv_groups,
.pm = PCI_PM_OPS_PTR,
.num_vf = pci_bus_num_vf,
.dma_configure = pci_dma_configure,
};
EXPORT_SYMBOL(pci_bus_type);
#ifdef CONFIG_PCIEPORTBUS
static int pcie_port_bus_match(struct device *dev, struct device_driver *drv)
{
struct pcie_device *pciedev;
struct pcie_port_service_driver *driver;
if (drv->bus != &pcie_port_bus_type || dev->bus != &pcie_port_bus_type)
return 0;
pciedev = to_pcie_device(dev);
driver = to_service_driver(drv);
if (driver->service != pciedev->service)
return 0;
if (driver->port_type != PCIE_ANY_PORT &&
driver->port_type != pci_pcie_type(pciedev->port))
return 0;
return 1;
}
struct bus_type pcie_port_bus_type = {
.name = "pci_express",
.match = pcie_port_bus_match,
};
EXPORT_SYMBOL_GPL(pcie_port_bus_type);
#endif
static int __init pci_driver_init(void)
{
int ret;
ret = bus_register(&pci_bus_type);
if (ret)
return ret;
#ifdef CONFIG_PCIEPORTBUS
ret = bus_register(&pcie_port_bus_type);
if (ret)
return ret;
#endif
dma_debug_add_bus(&pci_bus_type);
return 0;
}
postcore_initcall(pci_driver_init);