[RFC PATCH 19/30] PCI: endpoint: Add support to link a physical function to a virtual function

[Kishon Vijay Abraham I]

While the physical function has to be linked to endpoint controller, the
virtual function has to be linked to a physical function. Add support to
link a physical function to a virtual function in pci-ep-cfs.

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
 drivers/pci/endpoint/pci-ep-cfs.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
index e7e8367eead1..c18ef626ada5 100644
--- a/drivers/pci/endpoint/pci-ep-cfs.c
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -350,6 +350,28 @@ static struct configfs_attribute *pci_epf_attrs[] = {
 	NULL,
 };
 
+static int pci_epf_vepf_link(struct config_item *epf_pf_item,
+			     struct config_item *epf_vf_item)
+{
+	struct pci_epf_group *epf_vf_group = to_pci_epf_group(epf_vf_item);
+	struct pci_epf_group *epf_pf_group = to_pci_epf_group(epf_pf_item);
+	struct pci_epf *epf_pf = epf_pf_group->epf;
+	struct pci_epf *epf_vf = epf_vf_group->epf;
+
+	return pci_epf_add_vepf(epf_pf, epf_vf);
+}
+
+static void pci_epf_vepf_unlink(struct config_item *epf_pf_item,
+				struct config_item *epf_vf_item)
+{
+	struct pci_epf_group *epf_vf_group = to_pci_epf_group(epf_vf_item);
+	struct pci_epf_group *epf_pf_group = to_pci_epf_group(epf_pf_item);
+	struct pci_epf *epf_pf = epf_pf_group->epf;
+	struct pci_epf *epf_vf = epf_vf_group->epf;
+
+	pci_epf_remove_vepf(epf_pf, epf_vf);
+}
+
 static void pci_epf_release(struct config_item *item)
 {
 	struct pci_epf_group *epf_group = to_pci_epf_group(item);
@@ -362,6 +384,8 @@ static void pci_epf_release(struct config_item *item)
 }
 
 static struct configfs_item_operations pci_epf_ops = {
+	.allow_link		= pci_epf_vepf_link,
+	.drop_link		= pci_epf_vepf_unlink,
 	.release		= pci_epf_release,
 };
 
-- 
2.17.1