[PATCH RFC v4 15/21] PCI: Allow the failed resources to be reassigned later

[Sergey Miroshnichenko <s.miroshnichenko@yadro.com>]

Don't lose the size of the requested EP's BAR if it can't be fit
in a current trial, so this can be retried.

But a failed bridge window must be dropped and recalculated in the
next trial.

Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
---
 drivers/pci/setup-bus.c |  3 ++-
 drivers/pci/setup-res.c | 12 ++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index f9d605cd1725..c1559a4a8564 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -309,7 +309,8 @@ static void assign_requested_resources_sorted(struct list_head *head,
 						    0 /* don't care */,
 						    0 /* don't care */);
 			}
-			reset_resource(res);
+			if (!pci_movable_bars_enabled())
+				reset_resource(res);
 		}
 	}
 }
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index d8ca40a97693..732d18f60f1b 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -298,6 +298,18 @@ static int _pci_assign_resource(struct pci_dev *dev, int resno,
 
 	bus = dev->bus;
 	while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
+		if (pci_movable_bars_enabled()) {
+			if (resno >= PCI_BRIDGE_RESOURCES &&
+			    resno <= PCI_BRIDGE_RESOURCE_END) {
+				struct resource *res = dev->resource + resno;
+
+				res->start = 0;
+				res->end = 0;
+				res->flags = 0;
+			}
+			break;
+		}
+
 		if (!bus->parent || !bus->self->transparent)
 			break;
 		bus = bus->parent;
-- 
2.20.1