Merge branch 'pci/resource'

- Distribute resources to unconfigured hotplug bridges at boot-time (not
  just when hot-adding such a bridge), which makes hot-adding devices to
  docks work (Mika Westerberg)

- Fix the "revert to firmware assignment" code so we do the revert only if
  the address is actually reachable.  Previously we sometimes assigned
  addresses that could not be reached via upstream bridges (Maciej W.
  Rozycki)

* pci/resource:
  PCI: Sanitise firmware BAR assignments behind a PCI-PCI bridge
  PCI: Fix typo in pci_scan_child_bus_extend()
  PCI: Fix whitespace and indentation
  PCI: Distribute available resources for root buses, too
  PCI: Move pci_assign_unassigned_root_bus_resources()
  PCI: Pass available buses even if the bridge is already configured
  PCI: Fix used_buses calculation in pci_scan_child_bus_extend()

Author: bjorn-helgaas

drivers/pci/probe.c

@@ -1297,7 +1297,7 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
 
 	if ((secondary || subordinate) && !pcibios_assign_all_busses() &&
 	    !is_cardbus && !broken) {
-		unsigned int cmax;
+		unsigned int cmax, buses;
 
 		/*
 		 * Bus already configured by firmware, process it in the
@@ -1322,7 +1322,8 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
 			child->bridge_ctl = bctl;
 		}
 
-		cmax = pci_scan_child_bus(child);
+		buses = subordinate - secondary;
+		cmax = pci_scan_child_bus_extend(child, buses);
 		if (cmax > subordinate)
 			pci_warn(dev, "bridge has subordinate %02x but max busn %02x\n",
 				 subordinate, cmax);
@@ -2920,16 +2921,15 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
 		 * hotplug bridges too much during the second scan below.
 		 */
 		used_buses++;
-		if (cmax - max > 1)
-			used_buses += cmax - max - 1;
+		if (max - cmax > 1)
+			used_buses += max - cmax - 1;
 	}
 
 	/* Scan bridges that need to be reconfigured */
 	for_each_pci_bridge(dev, bus) {
 		unsigned int buses = 0;
 
 		if (!hotplug_bridges && normal_bridges == 1) {
-
 			/*
 			 * There is only one bridge on the bus (upstream
 			 * port) so it gets all available buses which it
@@ -2938,7 +2938,6 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
 			 */
 			buses = available_buses;
 		} else if (dev->is_hotplug_bridge) {
-
 			/*
 			 * Distribute the extra buses between hotplug
 			 * bridges if any.
@@ -2957,7 +2956,7 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
 	/*
 	 * Make sure a hotplug bridge has at least the minimum requested
 	 * number of buses but allow it to grow up to the maximum available
-	 * bus number of there is room.
+	 * bus number if there is room.
 	 */
 	if (bus->self && bus->self->is_hotplug_bridge) {
 		used_buses = max_t(unsigned int, available_buses,

drivers/pci/setup-bus.c

@@ -1745,119 +1745,6 @@ static enum enable_type pci_realloc_detect(struct pci_bus *bus,
 }
 #endif
 
-/*
- * First try will not touch PCI bridge res.
- * Second and later try will clear small leaf bridge res.
- * Will stop till to the max depth if can not find good one.
- */
-void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
-{
-	LIST_HEAD(realloc_head);
-	/* List of resources that want additional resources */
-	struct list_head *add_list = NULL;
-	int tried_times = 0;
-	enum release_type rel_type = leaf_only;
-	LIST_HEAD(fail_head);
-	struct pci_dev_resource *fail_res;
-	int pci_try_num = 1;
-	enum enable_type enable_local;
-
-	/* Don't realloc if asked to do so */
-	enable_local = pci_realloc_detect(bus, pci_realloc_enable);
-	if (pci_realloc_enabled(enable_local)) {
-		int max_depth = pci_bus_get_depth(bus);
-
-		pci_try_num = max_depth + 1;
-		dev_info(&bus->dev, "max bus depth: %d pci_try_num: %d\n",
-			 max_depth, pci_try_num);
-	}
-
-again:
-	/*
-	 * Last try will use add_list, otherwise will try good to have as must
-	 * have, so can realloc parent bridge resource
-	 */
-	if (tried_times + 1 == pci_try_num)
-		add_list = &realloc_head;
-	/*
-	 * Depth first, calculate sizes and alignments of all subordinate buses.
-	 */
-	__pci_bus_size_bridges(bus, add_list);
-
-	/* Depth last, allocate resources and update the hardware. */
-	__pci_bus_assign_resources(bus, add_list, &fail_head);
-	if (add_list)
-		BUG_ON(!list_empty(add_list));
-	tried_times++;
-
-	/* Any device complain? */
-	if (list_empty(&fail_head))
-		goto dump;
-
-	if (tried_times >= pci_try_num) {
-		if (enable_local == undefined)
-			dev_info(&bus->dev, "Some PCI device resources are unassigned, try booting with pci=realloc\n");
-		else if (enable_local == auto_enabled)
-			dev_info(&bus->dev, "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
-
-		free_list(&fail_head);
-		goto dump;
-	}
-
-	dev_info(&bus->dev, "No. %d try to assign unassigned res\n",
-		 tried_times + 1);
-
-	/* Third times and later will not check if it is leaf */
-	if ((tried_times + 1) > 2)
-		rel_type = whole_subtree;
-
-	/*
-	 * Try to release leaf bridge's resources that doesn't fit resource of
-	 * child device under that bridge.
-	 */
-	list_for_each_entry(fail_res, &fail_head, list)
-		pci_bus_release_bridge_resources(fail_res->dev->bus,
-						 fail_res->flags & PCI_RES_TYPE_MASK,
-						 rel_type);
-
-	/* 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 (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);
-
-	goto again;
-
-dump:
-	/* Dump the resource on buses */
-	pci_bus_dump_resources(bus);
-}
-
-void __init pci_assign_unassigned_resources(void)
-{
-	struct pci_bus *root_bus;
-
-	list_for_each_entry(root_bus, &pci_root_buses, node) {
-		pci_assign_unassigned_root_bus_resources(root_bus);
-
-		/* Make sure the root bridge has a companion ACPI device */
-		if (ACPI_HANDLE(root_bus->bridge))
-			acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
-	}
-}
-
 static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res,
 				 struct list_head *add_list,
 				 resource_size_t new_size)
@@ -1881,7 +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,
@@ -2029,13 +1919,15 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 }
 
 static void pci_bridge_distribute_available_resources(struct pci_dev *bridge,
-						     struct list_head *add_list)
+						      struct list_head *add_list)
 {
 	struct resource available_io, available_mmio, available_mmio_pref;
 
 	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];
@@ -2047,6 +1939,174 @@ 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.
+ * Will stop till to the max depth if can not find good one.
+ */
+void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
+{
+	LIST_HEAD(realloc_head);
+	/* List of resources that want additional resources */
+	struct list_head *add_list = NULL;
+	int tried_times = 0;
+	enum release_type rel_type = leaf_only;
+	LIST_HEAD(fail_head);
+	struct pci_dev_resource *fail_res;
+	int pci_try_num = 1;
+	enum enable_type enable_local;
+
+	/* Don't realloc if asked to do so */
+	enable_local = pci_realloc_detect(bus, pci_realloc_enable);
+	if (pci_realloc_enabled(enable_local)) {
+		int max_depth = pci_bus_get_depth(bus);
+
+		pci_try_num = max_depth + 1;
+		dev_info(&bus->dev, "max bus depth: %d pci_try_num: %d\n",
+			 max_depth, pci_try_num);
+	}
+
+again:
+	/*
+	 * Last try will use add_list, otherwise will try good to have as must
+	 * have, so can realloc parent bridge resource
+	 */
+	if (tried_times + 1 == pci_try_num)
+		add_list = &realloc_head;
+	/*
+	 * Depth first, calculate sizes and alignments of all subordinate buses.
+	 */
+	__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)
+		BUG_ON(!list_empty(add_list));
+	tried_times++;
+
+	/* Any device complain? */
+	if (list_empty(&fail_head))
+		goto dump;
+
+	if (tried_times >= pci_try_num) {
+		if (enable_local == undefined)
+			dev_info(&bus->dev, "Some PCI device resources are unassigned, try booting with pci=realloc\n");
+		else if (enable_local == auto_enabled)
+			dev_info(&bus->dev, "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
+
+		free_list(&fail_head);
+		goto dump;
+	}
+
+	dev_info(&bus->dev, "No. %d try to assign unassigned res\n",
+		 tried_times + 1);
+
+	/* Third times and later will not check if it is leaf */
+	if ((tried_times + 1) > 2)
+		rel_type = whole_subtree;
+
+	/*
+	 * Try to release leaf bridge's resources that doesn't fit resource of
+	 * child device under that bridge.
+	 */
+	list_for_each_entry(fail_res, &fail_head, list)
+		pci_bus_release_bridge_resources(fail_res->dev->bus,
+						 fail_res->flags & PCI_RES_TYPE_MASK,
+						 rel_type);
+
+	/* 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 (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);
+
+	goto again;
+
+dump:
+	/* Dump the resource on buses */
+	pci_bus_dump_resources(bus);
+}
+
+void __init pci_assign_unassigned_resources(void)
+{
+	struct pci_bus *root_bus;
+
+	list_for_each_entry(root_bus, &pci_root_buses, node) {
+		pci_assign_unassigned_root_bus_resources(root_bus);
+
+		/* Make sure the root bridge has a companion ACPI device */
+		if (ACPI_HANDLE(root_bus->bridge))
+			acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
+	}
+}
+
 void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
 {
 	struct pci_bus *parent = bridge->subordinate;

drivers/pci/setup-res.c

@@ -214,6 +214,17 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
 
 	root = pci_find_parent_resource(dev, res);
 	if (!root) {
+		/*
+		 * If dev is behind a bridge, accesses will only reach it
+		 * if res is inside the relevant bridge window.
+		 */
+		if (pci_upstream_bridge(dev))
+			return -ENXIO;
+
+		/*
+		 * On the root bus, assume the host bridge will forward
+		 * everything.
+		 */
 		if (res->flags & IORESOURCE_IO)
 			root = &ioport_resource;
 		else