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authorMarc Zyngier <marc.zyngier@arm.com>2017-08-01 20:11:02 -0500
committerBjorn Helgaas <bhelgaas@google.com>2017-08-01 20:11:02 -0500
commita477b9cd37aa81a490dfa3265b7ff4f2c5a92463 (patch)
tree267e7a1f7da0e629dc7f8b5829f0afced68c41cf /drivers/pci
parent16f73eb02d7e1765ccab3d2018e0bd98eb93d973 (diff)
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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: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> [bhelgaas: folded in fix for conflict with 52354b9d1f46 ("PCI: Remove __pci_dev_reset() and pci_dev_reset()")] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: stable@vger.kernel.org # 4.11: 52354b9d1f46: PCI: Remove __pci_dev_reset() and pci_dev_reset() Cc: stable@vger.kernel.org # 4.11
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/pci.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index af0cc3456dc1..b4b7eab29400 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4260,6 +4260,41 @@ 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
*