PCI: add support for function level reset
Sometimes, it's necessary to enable software's ability to quiesce and
reset endpoint hardware with function-level granularity, so provide
support for it.
The patch implement Function Level Reset(FLR) feature following PCI-e
spec. And this is the first step. We would add more generic method, like
D0/D3, to allow more devices support this function.
The patch contains two functions. pcie_reset_function() is the new
driver API, and, contains some action to quiesce a device. The other
function is a helper: pcie_execute_reset_function() just executes the
reset for a particular device function.
Current the usage model is in KVM. Function reset is necessary for
assigning device to a guest, or moving it between partitions.
For Function Level Reset(FLR), please refer to PCI Express spec chapter
6.6.2.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 085187b..f6f6810 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -626,6 +626,8 @@
int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc);
int pcie_get_readrq(struct pci_dev *dev);
int pcie_set_readrq(struct pci_dev *dev, int rq);
+int pci_reset_function(struct pci_dev *dev);
+int pci_execute_reset_function(struct pci_dev *dev);
void pci_update_resource(struct pci_dev *dev, struct resource *res, int resno);
int __must_check pci_assign_resource(struct pci_dev *dev, int i);
int pci_select_bars(struct pci_dev *dev, unsigned long flags);