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Commit a477b9cd authored by Marc Zyngier's avatar Marc Zyngier Committed by Bjorn Helgaas
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PCI: Add pci_reset_function_locked() 



The implementation of PCI workarounds may require that the device is reset
from its probe function.  This implies that the PCI device lock is already
held, and makes calling pci_reset_function() impossible (since it will
itself try to take that lock).

Add pci_reset_function_locked(), which is the equivalent of
pci_reset_function(), except that it requires the PCI device lock to be
already held by the caller.

Tested-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
[bhelgaas: folded in fix for conflict with 52354b9d ("PCI: Remove
__pci_dev_reset() and pci_dev_reset()")]
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org	# 4.11: 52354b9d: PCI: Remove __pci_dev_reset() and pci_dev_reset()
Cc: stable@vger.kernel.org	# 4.11
parent 16f73eb0

drivers/pci/pci.c

+35 −0
Original line number Diff line number Diff line
@@ -4259,6 +4259,41 @@ int pci_reset_function(struct pci_dev *dev) 
}

EXPORT_SYMBOL_GPL(pci_reset_function);



/**

 * pci_reset_function_locked - quiesce and reset a PCI device function

 * @dev: PCI device to reset

 *

 * Some devices allow an individual function to be reset without affecting

 * other functions in the same device.  The PCI device must be responsive

 * to PCI config space in order to use this function.

 *

 * This function does not just reset the PCI portion of a device, but

 * clears all the state associated with the device.  This function differs

 * from __pci_reset_function() in that it saves and restores device state

 * over the reset.  It also differs from pci_reset_function() in that it

 * requires the PCI device lock to be held.

 *

 * Returns 0 if the device function was successfully reset or negative if the

 * device doesn't support resetting a single function.

 */

int pci_reset_function_locked(struct pci_dev *dev)

{

	int rc;



	rc = pci_probe_reset_function(dev);

	if (rc)

		return rc;



	pci_dev_save_and_disable(dev);



	rc = __pci_reset_function_locked(dev);



	pci_dev_restore(dev);



	return rc;

}

EXPORT_SYMBOL_GPL(pci_reset_function_locked);



/**

 * pci_try_reset_function - quiesce and reset a PCI device function

 * @dev: PCI device to reset

include/linux/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -1067,6 +1067,7 @@ void pcie_flr(struct pci_dev *dev); 
int __pci_reset_function(struct pci_dev *dev);

int __pci_reset_function_locked(struct pci_dev *dev);

int pci_reset_function(struct pci_dev *dev);

int pci_reset_function_locked(struct pci_dev *dev);

int pci_try_reset_function(struct pci_dev *dev);

int pci_probe_reset_slot(struct pci_slot *slot);

int pci_reset_slot(struct pci_slot *slot);