[PATCH v6 35/53] PCI: Don't add too much optional size for hotplug bridge io

[Yinghai Lu <yinghai@kernel.org>]

Same as patch for MMIO (PCI: Don't add too much optional size for hotplug
bridge MMIO), and this one is for io port.

It will compare required+optional with min_sum_size to get smaller
optional size.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 drivers/pci/setup-bus.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index b6bfa1f..7cd6d32 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1139,7 +1139,6 @@ static resource_size_t window_alignment(struct pci_bus *bus,
  *
  * @bus : the bus
  * @min_size : the minimum io window that must to be allocated
- * @add_size : additional optional io window
  * @realloc_head : track the additional io window on this list
  *
  * Sizing the IO windows of the PCI-PCI bridge is trivial,
@@ -1148,9 +1147,11 @@ static resource_size_t window_alignment(struct pci_bus *bus,
  * We must be careful with the ISA aliasing though.
  */
 static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
-		resource_size_t add_size, struct list_head *realloc_head)
+			 struct list_head *realloc_head)
 {
 	struct pci_dev *dev;
+	resource_size_t min_sum_size = 0;
+	resource_size_t sum_add_size;
 	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO,
 							IORESOURCE_IO);
 	resource_size_t size = 0, size0 = 0, size1 = 0;
@@ -1160,6 +1161,11 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
 	if (!b_res)
 		return;
 
+	if (realloc_head) {
+		min_sum_size = min_size;
+		min_size = 0;
+	}
+
 	min_align = window_alignment(bus, IORESOURCE_IO);
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		int i;
@@ -1189,10 +1195,11 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
 
 	size0 = calculate_iosize(size, min_size, size1,
 			resource_size(b_res), min_align);
-	if (children_add_size > add_size)
-		add_size = children_add_size;
-	size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
-		calculate_iosize(size, min_size, add_size + size1,
+	sum_add_size = children_add_size + size + size1;
+	if (sum_add_size < min_sum_size)
+		sum_add_size = min_sum_size;
+	size1 = !realloc_head ? size0 :
+		calculate_iosize(size, min_size, sum_add_size - size,
 			resource_size(b_res), min_align);
 	if (!size0 && !size1) {
 		if (b_res->start || b_res->end)
@@ -1718,7 +1725,7 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 {
 	struct pci_dev *dev;
 	unsigned long mask, prefmask, type2 = 0, type3 = 0;
-	resource_size_t min_mem_size = 0, additional_io_size = 0;
+	resource_size_t min_mem_size = 0, min_io_size = 0;
 	struct resource *b_res;
 	int ret;
 
@@ -1751,13 +1758,12 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 	case PCI_CLASS_BRIDGE_PCI:
 		pci_bridge_check_ranges(bus);
 		if (bus->self->is_hotplug_bridge) {
-			additional_io_size  = pci_hotplug_io_size;
+			min_io_size  = pci_hotplug_io_size;
 			min_mem_size = pci_hotplug_mem_size;
 		}
 		/* Fall through */
 	default:
-		pbus_size_io(bus, realloc_head ? 0 : additional_io_size,
-			     additional_io_size, realloc_head);
+		pbus_size_io(bus, min_io_size, realloc_head);
 
 		/*
 		 * If there's a 64-bit prefetchable MMIO window, compute
-- 
1.8.4.5