Merge branch 'pci/resource'

  - Clear only bridge windows (not BARs) while assigning bus resources
    (Logan Gunthorpe)

  - Improve resource assignment for deep hotplug hierarchies, e.g.,
    Thunderbolt (Nicholas Johnson)

* pci/resource:
  PCI: Allow adjust_bridge_window() to shrink resource if necessary
  PCI: Set resource size directly in adjust_bridge_window()
  PCI: Rename extend_bridge_window() to adjust_bridge_window()
  PCI: Rename extend_bridge_window() parameter
  PCI: Consider alignment of hot-added bridges when assigning resources
  PCI: Remove local variable usage in pci_bus_distribute_available_resources()
  PCI: Pass size + alignment to pci_bus_distribute_available_resources()
  PCI: Rename variables
  PCI: Remove unnecessary braces
  PCI: Don't disable bridge BARs when assigning bus resources

1 files changed, 95 insertions, 68 deletions

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index f279826204eb..f2461bf9243d 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1803,12 +1803,18 @@ again:
 	/* Restore size and flags */
 	list_for_each_entry(fail_res, &fail_head, list) {
 		struct resource *res = fail_res->res;
+		int idx;
 
 		res->start = fail_res->start;
 		res->end = fail_res->end;
 		res->flags = fail_res->flags;
-		if (fail_res->dev->subordinate)
-			res->flags = 0;
+
+		if (pci_is_bridge(fail_res->dev)) {
+			idx = res - &fail_res->dev->resource[0];
+			if (idx >= PCI_BRIDGE_RESOURCES &&
+			    idx <= PCI_BRIDGE_RESOURCE_END)
+				res->flags = 0;
+		}
 	}
 	free_list(&fail_head);
 
@@ -1832,56 +1838,72 @@ void __init pci_assign_unassigned_resources(void)
 	}
 }
 
-static void extend_bridge_window(struct pci_dev *bridge, struct resource *res,
+static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res,
 				 struct list_head *add_list,
-				 resource_size_t available)
+				 resource_size_t new_size)
 {
-	struct pci_dev_resource *dev_res;
+	resource_size_t add_size, size = resource_size(res);
 
 	if (res->parent)
 		return;
 
-	if (resource_size(res) >= available)
+	if (!new_size)
 		return;
 
-	dev_res = res_to_dev_res(add_list, res);
-	if (!dev_res)
-		return;
-
-	/* Is there room to extend the window? */
-	if (available - resource_size(res) <= dev_res->add_size)
-		return;
+	if (new_size > size) {
+		add_size = new_size - size;
+		pci_dbg(bridge, "bridge window %pR extended by %pa\n", res,
+			&add_size);
+	} else if (new_size < size) {
+		add_size = size - new_size;
+		pci_dbg(bridge, "bridge window %pR shrunken by %pa\n", res,
+			&add_size);
+	}
 
-	dev_res->add_size = available - resource_size(res);
-	pci_dbg(bridge, "bridge window %pR extended by %pa\n", res,
-		&dev_res->add_size);
+	res->end = res->start + new_size - 1;
+	remove_from_list(add_list, res);
 }
 
 static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 					    struct list_head *add_list,
-					    resource_size_t available_io,
-					    resource_size_t available_mmio,
-					    resource_size_t available_mmio_pref)
+					    struct resource io,
+					    struct resource mmio,
+					    struct resource mmio_pref)
 {
-	resource_size_t remaining_io, remaining_mmio, remaining_mmio_pref;
 	unsigned int normal_bridges = 0, hotplug_bridges = 0;
 	struct resource *io_res, *mmio_res, *mmio_pref_res;
 	struct pci_dev *dev, *bridge = bus->self;
+	resource_size_t io_per_hp, mmio_per_hp, mmio_pref_per_hp, align;
 
 	io_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
 	mmio_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
 	mmio_pref_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
 
 	/*
-	 * Update additional resource list (add_list) to fill all the
-	 * extra resource space available for this port except the space
-	 * calculated in __pci_bus_size_bridges() which covers all the
-	 * devices currently connected to the port and below.
+	 * The alignment of this bridge is yet to be considered, hence it must
+	 * be done now before extending its bridge window.
+	 */
+	align = pci_resource_alignment(bridge, io_res);
+	if (!io_res->parent && align)
+		io.start = min(ALIGN(io.start, align), io.end + 1);
+
+	align = pci_resource_alignment(bridge, mmio_res);
+	if (!mmio_res->parent && align)
+		mmio.start = min(ALIGN(mmio.start, align), mmio.end + 1);
+
+	align = pci_resource_alignment(bridge, mmio_pref_res);
+	if (!mmio_pref_res->parent && align)
+		mmio_pref.start = min(ALIGN(mmio_pref.start, align),
+			mmio_pref.end + 1);
+
+	/*
+	 * Now that we have adjusted for alignment, update the bridge window
+	 * resources to fill as much remaining resource space as possible.
 	 */
-	extend_bridge_window(bridge, io_res, add_list, available_io);
-	extend_bridge_window(bridge, mmio_res, add_list, available_mmio);
-	extend_bridge_window(bridge, mmio_pref_res, add_list,
-			     available_mmio_pref);
+	adjust_bridge_window(bridge, io_res, add_list, resource_size(&io));
+	adjust_bridge_window(bridge, mmio_res, add_list, resource_size(&mmio));
+	adjust_bridge_window(bridge, mmio_pref_res, add_list,
+			     resource_size(&mmio_pref));
 
 	/*
 	 * Calculate how many hotplug bridges and normal bridges there
@@ -1902,11 +1924,9 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 	 */
 	if (hotplug_bridges + normal_bridges == 1) {
 		dev = list_first_entry(&bus->devices, struct pci_dev, bus_list);
-		if (dev->subordinate) {
+		if (dev->subordinate)
 			pci_bus_distribute_available_resources(dev->subordinate,
-				add_list, available_io, available_mmio,
-				available_mmio_pref);
-		}
+				add_list, io, mmio, mmio_pref);
 		return;
 	}
 
@@ -1919,12 +1939,9 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 	 * extra space reduced by the minimal required space for the
 	 * non-hotplug bridges.
 	 */
-	remaining_io = available_io;
-	remaining_mmio = available_mmio;
-	remaining_mmio_pref = available_mmio_pref;
-
 	for_each_pci_bridge(dev, bus) {
-		const struct resource *res;
+		resource_size_t used_size;
+		struct resource *res;
 
 		if (dev->is_hotplug_bridge)
 			continue;
@@ -1934,24 +1951,39 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 		 * bridge and devices below it occupy.
 		 */
 		res = &dev->resource[PCI_BRIDGE_RESOURCES + 0];
-		if (!res->parent && available_io > resource_size(res))
-			remaining_io -= resource_size(res);
+		align = pci_resource_alignment(dev, res);
+		align = align ? ALIGN(io.start, align) - io.start : 0;
+		used_size = align + resource_size(res);
+		if (!res->parent)
+			io.start = min(io.start + used_size, io.end + 1);
 
 		res = &dev->resource[PCI_BRIDGE_RESOURCES + 1];
-		if (!res->parent && available_mmio > resource_size(res))
-			remaining_mmio -= resource_size(res);
+		align = pci_resource_alignment(dev, res);
+		align = align ? ALIGN(mmio.start, align) - mmio.start : 0;
+		used_size = align + resource_size(res);
+		if (!res->parent)
+			mmio.start = min(mmio.start + used_size, mmio.end + 1);
 
 		res = &dev->resource[PCI_BRIDGE_RESOURCES + 2];
-		if (!res->parent && available_mmio_pref > resource_size(res))
-			remaining_mmio_pref -= resource_size(res);
+		align = pci_resource_alignment(dev, res);
+		align = align ? ALIGN(mmio_pref.start, align) -
+			mmio_pref.start : 0;
+		used_size = align + resource_size(res);
+		if (!res->parent)
+			mmio_pref.start = min(mmio_pref.start + used_size,
+				mmio_pref.end + 1);
 	}
 
+	io_per_hp = div64_ul(resource_size(&io), hotplug_bridges);
+	mmio_per_hp = div64_ul(resource_size(&mmio), hotplug_bridges);
+	mmio_pref_per_hp = div64_ul(resource_size(&mmio_pref),
+		hotplug_bridges);
+
 	/*
 	 * Go over devices on this bus and distribute the remaining
 	 * resource space between hotplug bridges.
 	 */
 	for_each_pci_bridge(dev, bus) {
-		resource_size_t align, io, mmio, mmio_pref;
 		struct pci_bus *b;
 
 		b = dev->subordinate;
@@ -1963,42 +1995,31 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 		 * hotplug-capable downstream ports taking alignment into
 		 * account.
 		 */
-		align = pci_resource_alignment(bridge, io_res);
-		io = div64_ul(available_io, hotplug_bridges);
-		io = min(ALIGN(io, align), remaining_io);
-		remaining_io -= io;
-
-		align = pci_resource_alignment(bridge, mmio_res);
-		mmio = div64_ul(available_mmio, hotplug_bridges);
-		mmio = min(ALIGN(mmio, align), remaining_mmio);
-		remaining_mmio -= mmio;
-
-		align = pci_resource_alignment(bridge, mmio_pref_res);
-		mmio_pref = div64_ul(available_mmio_pref, hotplug_bridges);
-		mmio_pref = min(ALIGN(mmio_pref, align), remaining_mmio_pref);
-		remaining_mmio_pref -= mmio_pref;
+		io.end = io.start + io_per_hp - 1;
+		mmio.end = mmio.start + mmio_per_hp - 1;
+		mmio_pref.end = mmio_pref.start + mmio_pref_per_hp - 1;
 
 		pci_bus_distribute_available_resources(b, add_list, io, mmio,
 						       mmio_pref);
+
+		io.start += io_per_hp;
+		mmio.start += mmio_per_hp;
+		mmio_pref.start += mmio_pref_per_hp;
 	}
 }
 
 static void pci_bridge_distribute_available_resources(struct pci_dev *bridge,
 						     struct list_head *add_list)
 {
-	resource_size_t available_io, available_mmio, available_mmio_pref;
-	const struct resource *res;
+	struct resource available_io, available_mmio, available_mmio_pref;
 
 	if (!bridge->is_hotplug_bridge)
 		return;
 
 	/* Take the initial extra resources from the hotplug port */
-	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
-	available_io = resource_size(res);
-	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
-	available_mmio = resource_size(res);
-	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
-	available_mmio_pref = resource_size(res);
+	available_io = bridge->resource[PCI_BRIDGE_RESOURCES + 0];
+	available_mmio = bridge->resource[PCI_BRIDGE_RESOURCES + 1];
+	available_mmio_pref = bridge->resource[PCI_BRIDGE_RESOURCES + 2];
 
 	pci_bus_distribute_available_resources(bridge->subordinate,
 					       add_list, available_io,
@@ -2055,12 +2076,18 @@ again:
 	/* Restore size and flags */
 	list_for_each_entry(fail_res, &fail_head, list) {
 		struct resource *res = fail_res->res;
+		int idx;
 
 		res->start = fail_res->start;
 		res->end = fail_res->end;
 		res->flags = fail_res->flags;
-		if (fail_res->dev->subordinate)
-			res->flags = 0;
+
+		if (pci_is_bridge(fail_res->dev)) {
+			idx = res - &fail_res->dev->resource[0];
+			if (idx >= PCI_BRIDGE_RESOURCES &&
+			    idx <= PCI_BRIDGE_RESOURCE_END)
+				res->flags = 0;
+		}
 	}
 	free_list(&fail_head);