PCI: Split out pci_dev lock/unlock and save/restore
Only cosmetic code changes to existing paths. Expand the comment in
the new pci_dev_save_and_disable() function since there's a lot
hidden in that Command register write.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 9407aab..d48d9fe 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3317,22 +3317,49 @@
return rc;
}
+static void pci_dev_lock(struct pci_dev *dev)
+{
+ pci_cfg_access_lock(dev);
+ /* block PM suspend, driver probe, etc. */
+ device_lock(&dev->dev);
+}
+
+static void pci_dev_unlock(struct pci_dev *dev)
+{
+ device_unlock(&dev->dev);
+ pci_cfg_access_unlock(dev);
+}
+
+static void pci_dev_save_and_disable(struct pci_dev *dev)
+{
+ pci_save_state(dev);
+ /*
+ * Disable the device by clearing the Command register, except for
+ * INTx-disable which is set. This not only disables MMIO and I/O port
+ * BARs, but also prevents the device from being Bus Master, preventing
+ * DMA from the device including MSI/MSI-X interrupts. For PCI 2.3
+ * compliant devices, INTx-disable prevents legacy interrupts.
+ */
+ pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
+}
+
+static void pci_dev_restore(struct pci_dev *dev)
+{
+ pci_restore_state(dev);
+}
+
static int pci_dev_reset(struct pci_dev *dev, int probe)
{
int rc;
- if (!probe) {
- pci_cfg_access_lock(dev);
- /* block PM suspend, driver probe, etc. */
- device_lock(&dev->dev);
- }
+ if (!probe)
+ pci_dev_lock(dev);
rc = __pci_dev_reset(dev, probe);
- if (!probe) {
- device_unlock(&dev->dev);
- pci_cfg_access_unlock(dev);
- }
+ if (!probe)
+ pci_dev_unlock(dev);
+
return rc;
}
/**
@@ -3423,17 +3450,11 @@
if (rc)
return rc;
- pci_save_state(dev);
-
- /*
- * both INTx and MSI are disabled after the Interrupt Disable bit
- * is set and the Bus Master bit is cleared.
- */
- pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
+ pci_dev_save_and_disable(dev);
rc = pci_dev_reset(dev, 0);
- pci_restore_state(dev);
+ pci_dev_restore(dev);
return rc;
}