[PATCH 2/2] pci: pciehp update the slot bridge res to get big range for pcie devices - v10

[Yinghai Lu <yinghai@kernel.org>]

move out bus_size_bridges and assign resources out of pciehp_add_bridge()
and at last do them all together one time including slot bridge, to avoid to
call assign resources several times, when there are several bridges under the
slot bridge.

need to introduce pci_bridge_assign_resources there.

handle the case the slot bridge that doesn't get pre-allocated big enough res
from FW.
for example pcie devices need 256M, but the bridge only get preallocated 2M...

pci_setup_bridge() will take extra check_enabled for the slot bridge, otherwise
update res is not updated to bridge BAR. that is bridge is enabled already for
port service.

v2: address Alex's concern about pci remove/rescan feature about
    pci_setup_bridge changes.
v3: Kenji pointed out that pci_config_slot need to be called before
    pci_bus_add_devices()
v4: move out pci_is_enabled checkout of pci_setup_bridge()
v5: change the applying sequence.
v6: change the functions name according to Jesse
v8: address Eric's concern, only overwrite leaf bridge resource that is not
     big enough
v9: refresh to be applied after bjorn's patch, and remove trick about save
    size and restore resource second try.
v10: alex found need to have export for pci_assign_unassigned_bridge_resources

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 drivers/pci/hotplug/pciehp_pci.c |   23 +++++-
 drivers/pci/setup-bus.c          |  130 +++++++++++++++++++++++++++++++++++++--
 include/linux/pci.h              |    1 
 3 files changed, 144 insertions(+), 10 deletions(-)

Index: linux-2.6/drivers/pci/hotplug/pciehp_pci.c
===================================================================
--- linux-2.6.orig/drivers/pci/hotplug/pciehp_pci.c
+++ linux-2.6/drivers/pci/hotplug/pciehp_pci.c
@@ -53,17 +53,15 @@ static int __ref pciehp_add_bridge(struc
 		busnr = pci_scan_bridge(parent, dev, busnr, pass);
 	if (!dev->subordinate)
 		return -1;
-	pci_bus_size_bridges(dev->subordinate);
-	pci_bus_assign_resources(parent);
-	pci_enable_bridges(parent);
-	pci_bus_add_devices(parent);
+
 	return 0;
 }
 
 int pciehp_configure_device(struct slot *p_slot)
 {
 	struct pci_dev *dev;
-	struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;
+	struct pci_dev *bridge = p_slot->ctrl->pcie->port;
+	struct pci_bus *parent = bridge->subordinate;
 	int num, fn;
 	struct controller *ctrl = p_slot->ctrl;
 
@@ -96,12 +94,25 @@ int pciehp_configure_device(struct slot
 				(dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)) {
 			pciehp_add_bridge(dev);
 		}
+		pci_dev_put(dev);
+	}
+
+	pci_assign_unassigned_bridge_resources(bridge);
+
+	for (fn = 0; fn < 8; fn++) {
+		dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
+		if (!dev)
+			continue;
+		if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {
+			pci_dev_put(dev);
+			continue;
+		}
 		pci_configure_slot(dev);
 		pci_dev_put(dev);
 	}
 
-	pci_bus_assign_resources(parent);
 	pci_bus_add_devices(parent);
+
 	return 0;
 }
 
Index: linux-2.6/drivers/pci/setup-bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-bus.c
+++ linux-2.6/drivers/pci/setup-bus.c
@@ -68,6 +68,52 @@ static void free_failed_list(struct reso
 	head->next = NULL;
 }
 
+static void pdev_assign_resources_sorted(struct pci_dev *dev,
+				 struct resource_list *fail_head)
+{
+	struct resource *res;
+	struct resource_list head, *list, *tmp;
+	int idx;
+	u16 class = dev->class >> 8;
+
+	head.next = NULL;
+
+	/* Don't touch classless devices or host bridges or ioapics.  */
+	if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)
+		return;
+
+	/* Don't touch ioapic devices already enabled by firmware */
+	if (class == PCI_CLASS_SYSTEM_PIC) {
+		u16 command;
+		pci_read_config_word(dev, PCI_COMMAND, &command);
+		if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
+			return;
+	}
+
+	pdev_sort_resources(dev, &head);
+
+	for (list = head.next; list;) {
+		res = list->res;
+		idx = res - &list->dev->resource[0];
+		if (pci_assign_resource(list->dev, idx)) {
+			if (fail_head && !list->dev->subordinate &&
+			    !pci_is_root_bus(list->dev->bus)) {
+				/*
+				 * device need to keep flags and size
+				 * for second try
+				 */
+				add_to_failed_list(fail_head, list->dev, res);
+			} else {
+				res->start = 0;
+				res->end = 0;
+				res->flags = 0;
+			}
+		}
+		tmp = list;
+		list = list->next;
+		kfree(tmp);
+	}
+}
 static void pbus_assign_resources_sorted(const struct pci_bus *bus,
 					 struct resource_list *fail_head)
 {
@@ -282,9 +328,6 @@ static void __pci_setup_bridge(struct pc
 {
 	struct pci_dev *bridge = bus->self;
 
-	if (pci_is_enabled(bridge))
-		return;
-
 	dev_info(&bridge->dev, "PCI bridge to [bus %02x-%02x]\n",
 		 bus->secondary, bus->subordinate);
 
@@ -645,7 +688,8 @@ static void __ref __pci_bus_assign_resou
 
 		switch (dev->class >> 8) {
 		case PCI_CLASS_BRIDGE_PCI:
-			pci_setup_bridge(b);
+			if (!pci_is_enabled(dev))
+				pci_setup_bridge(b);
 			break;
 
 		case PCI_CLASS_BRIDGE_CARDBUS:
@@ -666,6 +710,34 @@ void __ref pci_bus_assign_resources(cons
 }
 EXPORT_SYMBOL(pci_bus_assign_resources);
 
+static void __ref __pci_bridge_assign_resources(const struct pci_dev *bridge,
+					 struct resource_list *fail_head)
+{
+	struct pci_bus *b;
+
+	pdev_assign_resources_sorted((struct pci_dev *)bridge, fail_head);
+
+	b = bridge->subordinate;
+	if (!b)
+		return;
+
+	__pci_bus_assign_resources(b, fail_head);
+
+	switch (bridge->class >> 8) {
+	case PCI_CLASS_BRIDGE_PCI:
+		pci_setup_bridge(b);
+		break;
+
+	case PCI_CLASS_BRIDGE_CARDBUS:
+		pci_setup_cardbus(b);
+		break;
+
+	default:
+		dev_info(&bridge->dev, "not setting up bridge for bus "
+			 "%04x:%02x\n", pci_domain_nr(b), b->number);
+		break;
+	}
+}
 static void release_children_resource(struct resource *r)
 {
 	struct resource *p;
@@ -841,3 +913,53 @@ enable_and_dump:
 		pci_bus_dump_resources(bus);
 	}
 }
+
+void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
+{
+	struct pci_bus *bus;
+	struct pci_bus *parent = bridge->subordinate;
+	bool second_tried = false;
+	struct resource_list head, *list, *tmp;
+	int retval;
+	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+				  IORESOURCE_PREFETCH;
+
+again:
+	head.next = NULL;
+
+	pci_bus_size_bridges(parent);
+	pci_clear_master(bridge);
+	__pci_bridge_assign_resources(bridge, &head);
+	retval = pci_reenable_device(bridge);
+	pci_set_master(bridge);
+	pci_enable_bridges(parent);
+
+	/* any device complain? */
+	if (!head.next)
+		return;
+
+	if (second_tried) {
+		/* still fail, don't want to try more */
+		free_failed_list(&head);
+		return;
+	}
+
+	second_tried = true;
+	printk(KERN_DEBUG "PCI: second try to assign unassigned res\n");
+
+	/*
+	 * Try to release leaf bridge's resources that doesn't fit resource of
+	 * child device under that bridge
+	 */
+	for (list = head.next; list;) {
+		bus = list->dev->bus;
+		pci_bus_release_unused_bridge_res(bus,
+				 list->res->flags & type_mask);
+		tmp = list;
+		list = list->next;
+		kfree(tmp);
+	}
+
+	goto again;
+}
+EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
Index: linux-2.6/include/linux/pci.h
===================================================================
--- linux-2.6.orig/include/linux/pci.h
+++ linux-2.6/include/linux/pci.h
@@ -768,6 +768,7 @@ void pci_bus_assign_resources(const stru
 void pci_bus_size_bridges(struct pci_bus *bus);
 int pci_claim_resource(struct pci_dev *, int);
 void pci_assign_unassigned_resources(void);
+void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge);
 void pdev_enable_device(struct pci_dev *);
 void pdev_sort_resources(struct pci_dev *, struct resource_list *);
 int pci_enable_resources(struct pci_dev *, int mask);