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powerpc/eeh_sysfs: Make clearing EEH_DEV_SYSFS saner

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The eeh_sysfs_remove_device() function is supposed to clear the
EEH_DEV_SYSFS flag since it indicates the EEH sysfs entries have been added
for a pci_dev.

When the sysfs files are removed eeh_remove_device() the eeh_dev and the
pci_dev have already been de-associated. This then causes the
pci_dev_to_eeh_dev() call in eeh_sysfs_remove_device() to return NULL so
the flag can't be cleared from the still-live eeh_dev. This problem is
worked around in the caller by clearing the flag manually. However, this
behaviour doesn't make a whole lot of sense, so this patch fixes it by:

a) Re-ordering eeh_remove_device() so that eeh_sysfs_remove_device() is
   called before de-associating the pci_dev and eeh_dev.

b) Making eeh_sysfs_remove_device() emit a warning if there's no
   corresponding eeh_dev for a pci_dev. The paths where the sysfs
   files are only reachable if EEH was setup for the device
   for the device in the first place so hitting this warning
   indicates a programming error.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-6-oohall@gmail.com
This commit is contained in:
Oliver O'Halloran 2019-07-15 18:56:12 +10:00 committed by Michael Ellerman
parent 758b423275
commit 3489cdc417
2 changed files with 25 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

30
arch/powerpc/kernel/eeh.c
View file

@ -1191,7 +1191,6 @@ void eeh_add_device_late(struct pci_dev *dev)
eeh_rmv_from_parent_pe(edev);
eeh_addr_cache_rmv_dev(edev->pdev);
eeh_sysfs_remove_device(edev->pdev);
edev->mode &= ~EEH_DEV_SYSFS;
/*
* We definitely should have the PCI device removed
@ -1295,6 +1294,23 @@ void eeh_remove_device(struct pci_dev *dev)
*/
edev->pdev = NULL;
/*
* eeh_sysfs_remove_device() uses pci_dev_to_eeh_dev() so we need to
* remove the sysfs files before clearing dev.archdata.edev
*/
if (edev->mode & EEH_DEV_SYSFS)
eeh_sysfs_remove_device(dev);
/*
* We're removing from the PCI subsystem, that means
* the PCI device driver can't support EEH or not
* well. So we rely on hotplug completely to do recovery
* for the specific PCI device.
*/
edev->mode |= EEH_DEV_NO_HANDLER;
eeh_addr_cache_rmv_dev(dev);
/*
* The flag "in_error" is used to trace EEH devices for VFs
* in error state or not. It's set in eeh_report_error(). If
@ -1307,18 +1323,6 @@ void eeh_remove_device(struct pci_dev *dev)
eeh_rmv_from_parent_pe(edev);
else
edev->mode |= EEH_DEV_DISCONNECTED;
/*
* We're removing from the PCI subsystem, that means
* the PCI device driver can't support EEH or not
* well. So we rely on hotplug completely to do recovery
* for the specific PCI device.
*/
edev->mode |= EEH_DEV_NO_HANDLER;
eeh_addr_cache_rmv_dev(dev);
eeh_sysfs_remove_device(dev);
edev->mode &= ~EEH_DEV_SYSFS;
}
int eeh_unfreeze_pe(struct eeh_pe *pe)

15
arch/powerpc/kernel/eeh_sysfs.c
View file

@ -159,22 +159,23 @@ void eeh_sysfs_remove_device(struct pci_dev *pdev)
{
struct eeh_dev *edev = pci_dev_to_eeh_dev(pdev);
if (!edev) {
WARN_ON(eeh_enabled());
return;
}
edev->mode &= ~EEH_DEV_SYSFS;
/*
* The parent directory might have been removed. We needn't
* continue for that case.
*/
if (!pdev->dev.kobj.sd) {
if (edev)
edev->mode &= ~EEH_DEV_SYSFS;
if (!pdev->dev.kobj.sd)
return;
}
device_remove_file(&pdev->dev, &dev_attr_eeh_mode);
device_remove_file(&pdev->dev, &dev_attr_eeh_pe_config_addr);
device_remove_file(&pdev->dev, &dev_attr_eeh_pe_state);
eeh_notify_resume_remove(pdev);
if (edev)
edev->mode &= ~EEH_DEV_SYSFS;
}