Commit 3489cdc4 authored by Oliver O'Halloran's avatar Oliver O'Halloran Committed by Michael Ellerman
Browse files

powerpc/eeh_sysfs: Make clearing EEH_DEV_SYSFS saner 



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: default avatarOliver O'Halloran <oohall@gmail.com>
Reviewed-by: default avatarSam Bobroff <sbobroff@linux.ibm.com>
Tested-by: default avatarSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-6-oohall@gmail.com
parent 758b4232

arch/powerpc/kernel/eeh.c

+17 −13
Original line number Diff line number Diff line
@@ -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
@@ -1296,17 +1295,11 @@ void eeh_remove_device(struct pci_dev *dev) 
	edev->pdev = NULL;



	/*

	 * 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

	 * it's not set, eeh_report_{reset,resume}() won't be called

	 * for the VF EEH device.

	 * eeh_sysfs_remove_device() uses pci_dev_to_eeh_dev() so we need to

	 * remove the sysfs files before clearing dev.archdata.edev

	 */

	edev->in_error = false;

	dev->dev.archdata.edev = NULL;

	if (!(edev->pe->state & EEH_PE_KEEP))

		eeh_rmv_from_parent_pe(edev);

	else

		edev->mode |= EEH_DEV_DISCONNECTED;

	if (edev->mode & EEH_DEV_SYSFS)

		eeh_sysfs_remove_device(dev);



	/*

	 * We're removing from the PCI subsystem, that means
@@ -1317,8 +1310,19 @@ void eeh_remove_device(struct pci_dev *dev) 
	edev->mode |= EEH_DEV_NO_HANDLER;



	eeh_addr_cache_rmv_dev(dev);

	eeh_sysfs_remove_device(dev);

	edev->mode &= ~EEH_DEV_SYSFS;



	/*

	 * 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

	 * it's not set, eeh_report_{reset,resume}() won't be called

	 * for the VF EEH device.

	 */

	edev->in_error = false;

	dev->dev.archdata.edev = NULL;

	if (!(edev->pe->state & EEH_PE_KEEP))

		eeh_rmv_from_parent_pe(edev);

	else

		edev->mode |= EEH_DEV_DISCONNECTED;

}



int eeh_unfreeze_pe(struct eeh_pe *pe)

arch/powerpc/kernel/eeh_sysfs.c

+8 −7
Original line number Diff line number Diff line
@@ -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;

}

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