PCI: Add pci_probe_reset_slot() and pci_probe_reset_bus()

Users of pci_reset_bus() and pci_reset_slot() need a way to probe
whether the bus or slot supports reset.  Add trivial helper functions
and export them as vfio-pci will make use of these.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ea5e70486174..7f89372483dd 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3610,6 +3610,18 @@ static int pci_slot_reset(struct pci_slot *slot, int probe)
 }
 
 /**
+ * pci_probe_reset_slot - probe whether a PCI slot can be reset
+ * @slot: PCI slot to probe
+ *
+ * Return 0 if slot can be reset, negative if a slot reset is not supported.
+ */
+int pci_probe_reset_slot(struct pci_slot *slot)
+{
+        return pci_slot_reset(slot, 1);
+}
+EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
+
+/**
  * pci_reset_slot - reset a PCI slot
  * @slot: PCI slot to reset
  *
@@ -3662,6 +3674,18 @@ static int pci_bus_reset(struct pci_bus *bus, int probe)
 }
 
 /**
+ * pci_probe_reset_bus - probe whether a PCI bus can be reset
+ * @bus: PCI bus to probe
+ *
+ * Return 0 if bus can be reset, negative if a bus reset is not supported.
+ */
+int pci_probe_reset_bus(struct pci_bus *bus)
+{
+        return pci_bus_reset(bus, 1);
+}
+EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
+
+/**
  * pci_reset_bus - reset a PCI bus
  * @bus: top level PCI bus to reset
  *