PCI: Add pci_reset_bus_function() Secondary Bus Reset interface

pci_parent_bus_reset() resets a device by performing a Secondary Bus Reset
on a PCI-to-PCI bridge leading to the device.

pci_dev_reset_slot_function() does the same, except that it uses a hotplug
driver to keep the reset from looking like a hot-remove followed by a
hot-add.

Add a pci_reset_bus_function() wrapper, which attempts the hotplug driver
slot reset and falls back to the parent bus reset if that fails.  This
provides a single interface for performing a Secondary Bus Reset.

[bhelgaas: commit log, don't expose yet]
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20210323100625.0021a943@omen.home.shazbot.org/
Link: https://lore.kernel.org/r/20210408182328.12323-1-raphael.norwitz@nutanix.com
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
This commit is contained in:
Raphael Norwitz 2021-04-08 18:23:40 +00:00 committed by Bjorn Helgaas
parent 6efb943b86
commit 0dad3ce523
1 changed files with 12 additions and 8 deletions

View File

@ -5020,6 +5020,16 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
}
static int pci_reset_bus_function(struct pci_dev *dev, int probe)
{
int rc;
rc = pci_dev_reset_slot_function(dev, probe);
if (rc != -ENOTTY)
return rc;
return pci_parent_bus_reset(dev, probe);
}
static void pci_dev_lock(struct pci_dev *dev)
{
pci_cfg_access_lock(dev);
@ -5140,10 +5150,7 @@ int __pci_reset_function_locked(struct pci_dev *dev)
rc = pci_pm_reset(dev, 0);
if (rc != -ENOTTY)
return rc;
rc = pci_dev_reset_slot_function(dev, 0);
if (rc != -ENOTTY)
return rc;
return pci_parent_bus_reset(dev, 0);
return pci_reset_bus_function(dev, 0);
}
EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
@ -5173,13 +5180,10 @@ int pci_probe_reset_function(struct pci_dev *dev)
if (rc != -ENOTTY)
return rc;
rc = pci_pm_reset(dev, 1);
if (rc != -ENOTTY)
return rc;
rc = pci_dev_reset_slot_function(dev, 1);
if (rc != -ENOTTY)
return rc;
return pci_parent_bus_reset(dev, 1);
return pci_reset_bus_function(dev, 1);
}
/**