[PATCH 2/2] Revert "Revert "PCI: Distribute available resources for root buses, too""

[Mika Westerberg <mika.westerberg@linux.intel.com>]

This reverts commit 5632e2beaf9d5dda694c0572684dea783d8a9492.

Now that pci_bridge_distribute_available_resources() takes multifunction
devices int account we can revert this revert to fix the original issue.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
Hi Bjorn,

Let me know if you prefer re-sending the original patch over the revert.

 drivers/pci/setup-bus.c | 62 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 61 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index c8787b187ee4..e512f9ecb9d0 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1768,7 +1768,10 @@ static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res,
 	}
 
 	res->end = res->start + new_size - 1;
-	remove_from_list(add_list, res);
+
+	/* If the resource is part of the add_list remove it now */
+	if (add_list)
+		remove_from_list(add_list, res);
 }
 
 static void pci_bus_distribute_available_resources(struct pci_bus *bus,
@@ -1978,6 +1981,8 @@ static void pci_bridge_distribute_available_resources(struct pci_dev *bridge,
 	if (!bridge->is_hotplug_bridge)
 		return;
 
+	pci_dbg(bridge, "distributing available resources\n");
+
 	/* Take the initial extra resources from the hotplug port */
 	available_io = bridge->resource[PCI_BRIDGE_IO_WINDOW];
 	available_mmio = bridge->resource[PCI_BRIDGE_MEM_WINDOW];
@@ -1989,6 +1994,59 @@ static void pci_bridge_distribute_available_resources(struct pci_dev *bridge,
 					       available_mmio_pref);
 }
 
+static bool pci_bridge_resources_not_assigned(struct pci_dev *dev)
+{
+	const struct resource *r;
+
+	/*
+	 * Check the child device's resources and if they are not yet
+	 * assigned it means we are configuring them (not the boot
+	 * firmware) so we should be able to extend the upstream
+	 * bridge's (that's the hotplug downstream PCIe port) resources
+	 * in the same way we do with the normal hotplug case.
+	 */
+	r = &dev->resource[PCI_BRIDGE_IO_WINDOW];
+	if (!r->flags || !(r->flags & IORESOURCE_STARTALIGN))
+		return false;
+	r = &dev->resource[PCI_BRIDGE_MEM_WINDOW];
+	if (!r->flags || !(r->flags & IORESOURCE_STARTALIGN))
+		return false;
+	r = &dev->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
+	if (!r->flags || !(r->flags & IORESOURCE_STARTALIGN))
+		return false;
+
+	return true;
+}
+
+static void pci_root_bus_distribute_available_resources(struct pci_bus *bus,
+							struct list_head *add_list)
+{
+	struct pci_dev *dev, *bridge = bus->self;
+
+	for_each_pci_bridge(dev, bus) {
+		struct pci_bus *b;
+
+		b = dev->subordinate;
+		if (!b)
+			continue;
+
+		/*
+		 * Need to check "bridge" here too because it is NULL
+		 * in case of root bus.
+		 */
+		if (bridge && pci_bridge_resources_not_assigned(dev)) {
+			pci_bridge_distribute_available_resources(bridge, add_list);
+			/*
+			 * There is only PCIe upstream port on the bus
+			 * so we don't need to go futher.
+			 */
+			return;
+		}
+
+		pci_root_bus_distribute_available_resources(b, add_list);
+	}
+}
+
 /*
  * First try will not touch PCI bridge res.
  * Second and later try will clear small leaf bridge res.
@@ -2028,6 +2086,8 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
 	 */
 	__pci_bus_size_bridges(bus, add_list);
 
+	pci_root_bus_distribute_available_resources(bus, add_list);
+
 	/* Depth last, allocate resources and update the hardware. */
 	__pci_bus_assign_resources(bus, add_list, &fail_head);
 	if (add_list)
-- 
2.35.1