[PATCH V9 04/18] PCI: Take additional PF's IOV BAR alignment in sizing and assigning

[Wei Yang <weiyang@linux.vnet.ibm.com>]

At resource sizing/assigning stage, resources are divided into two lists,
requested list and additional list, while the alignement of the additional
IOV BAR is not taken into the sizing and assigning procedure.

This is reasonable in the original implementation, since IOV BAR's alignment is
mostly the size of a PF BAR alignemt. This means the alignment is already taken
into consideration. While this rule may be violated on some platform, eg.
PowerNV platform.

This patch takes the additional IOV BAR alignment in sizing and assigning stage
explicitly. When system MMIO space is not enough, the PF's IOV BAR alignment
will not contribute to the bridge. When system MMIO space is enough, the
additional alignment will contribute to the bridge.

Also it take advantage of pci_dev_resource::min_align to store this additional
alignment.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
---
 drivers/pci/setup-bus.c |   85 +++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 71 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 0482235..05c7df0 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -99,8 +99,8 @@ static void remove_from_list(struct list_head *head,
 	}
 }
 
-static resource_size_t get_res_add_size(struct list_head *head,
-					struct resource *res)
+static struct pci_dev_resource *res_to_dev_res(struct list_head *head,
+					       struct resource *res)
 {
 	struct pci_dev_resource *dev_res;
 
@@ -109,17 +109,37 @@ static resource_size_t get_res_add_size(struct list_head *head,
 			int idx = res - &dev_res->dev->resource[0];
 
 			dev_printk(KERN_DEBUG, &dev_res->dev->dev,
-				 "res[%d]=%pR get_res_add_size add_size %llx\n",
+				 "res[%d]=%pR res_to_dev_res add_size %llx min_align %llx\n",
 				 idx, dev_res->res,
-				 (unsigned long long)dev_res->add_size);
+				 (unsigned long long)dev_res->add_size,
+				 (unsigned long long)dev_res->min_align);
 
-			return dev_res->add_size;
+			return dev_res;
 		}
 	}
 
-	return 0;
+	return NULL;
+}
+
+static resource_size_t get_res_add_size(struct list_head *head,
+					struct resource *res)
+{
+	struct pci_dev_resource *dev_res;
+
+	dev_res = res_to_dev_res(head, res);
+	return dev_res ? dev_res->add_size : 0;
+}
+
+static resource_size_t get_res_add_align(struct list_head *head,
+		struct resource *res)
+{
+	struct pci_dev_resource *dev_res;
+
+	dev_res = res_to_dev_res(head, res);
+	return dev_res ? dev_res->min_align : 0;
 }
 
+
 /* Sort resources by alignment */
 static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
 {
@@ -368,8 +388,9 @@ static void __assign_resources_sorted(struct list_head *head,
 	LIST_HEAD(save_head);
 	LIST_HEAD(local_fail_head);
 	struct pci_dev_resource *save_res;
-	struct pci_dev_resource *dev_res, *tmp_res;
+	struct pci_dev_resource *dev_res, *tmp_res, *dev_res2;
 	unsigned long fail_type;
+	resource_size_t add_align, align;
 
 	/* Check if optional add_size is there */
 	if (!realloc_head || list_empty(realloc_head))
@@ -384,10 +405,38 @@ static void __assign_resources_sorted(struct list_head *head,
 	}
 
 	/* Update res in head list with add_size in realloc_head list */
-	list_for_each_entry(dev_res, head, list)
+	list_for_each_entry_safe(dev_res, tmp_res, head, list) {
 		dev_res->res->end += get_res_add_size(realloc_head,
 							dev_res->res);
 
+		/* 
+		 * There are two kinds additional resources in the list:
+		 * 1. bridge resource  -- IORESOURCE_STARTALIGN
+		 * 2. SRIOV resource   -- IORESOURCE_SIZEALIGN
+		 * Here just fix the additional alignment for bridge
+		 */
+		if (!(dev_res->res->flags & IORESOURCE_STARTALIGN))
+			continue;
+
+		add_align = get_res_add_align(realloc_head, dev_res->res);
+
+		/* Reorder the list by their alignment */
+		if (add_align > dev_res->res->start) {
+			dev_res->res->start = add_align;
+			dev_res->res->end = add_align +
+				            resource_size(dev_res->res);
+
+			list_for_each_entry(dev_res2, head, list) {
+				align = pci_resource_alignment(dev_res2->dev,
+							       dev_res2->res);
+				if (add_align > align)
+					list_move_tail(&dev_res->list,
+						       &dev_res2->list);
+			}
+               }
+
+	}
+
 	/* Try updated head list with add_size added */
 	assign_requested_resources_sorted(head, &local_fail_head);
 
@@ -930,6 +979,8 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 	struct resource *b_res = find_free_bus_resource(bus,
 					mask | IORESOURCE_PREFETCH, type);
 	resource_size_t children_add_size = 0;
+	resource_size_t children_add_align = 0;
+	resource_size_t add_align = 0;
 
 	if (!b_res)
 		return -ENOSPC;
@@ -954,6 +1005,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 			/* put SRIOV requested res to the optional list */
 			if (realloc_head && i >= PCI_IOV_RESOURCES &&
 					i <= PCI_IOV_RESOURCE_END) {
+				add_align = max(pci_resource_alignment(dev, r), add_align);
 				r->end = r->start - 1;
 				add_to_list(realloc_head, dev, r, r_size, 0/* don't care */);
 				children_add_size += r_size;
@@ -984,19 +1036,23 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 			if (order > max_order)
 				max_order = order;
 
-			if (realloc_head)
+			if (realloc_head) {
 				children_add_size += get_res_add_size(realloc_head, r);
+				children_add_align = get_res_add_align(realloc_head, r);
+				add_align = max(add_align, children_add_align);
+			}
 		}
 	}
 
 	min_align = calculate_mem_align(aligns, max_order);
 	min_align = max(min_align, window_alignment(bus, b_res->flags));
 	size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);
+	add_align = max(min_align, add_align);
 	if (children_add_size > add_size)
 		add_size = children_add_size;
 	size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
 		calculate_memsize(size, min_size, add_size,
-				resource_size(b_res), min_align);
+				resource_size(b_res), add_align);
 	if (!size0 && !size1) {
 		if (b_res->start || b_res->end)
 			dev_info(&bus->self->dev, "disabling bridge window %pR to %pR (unused)\n",
@@ -1008,10 +1064,11 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 	b_res->end = size0 + min_align - 1;
 	b_res->flags |= IORESOURCE_STARTALIGN;
 	if (size1 > size0 && realloc_head) {
-		add_to_list(realloc_head, bus->self, b_res, size1-size0, min_align);
-		dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window %pR to %pR add_size %llx\n",
-			   b_res, &bus->busn_res,
-			   (unsigned long long)size1-size0);
+		add_to_list(realloc_head, bus->self, b_res, size1-size0, add_align);
+		dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window "
+				 "%pR to %pR add_size %llx add_align %llx\n", b_res,
+				 &bus->busn_res, (unsigned long long)size1-size0,
+				 add_align);
 	}
 	return 0;
 }
-- 
1.7.9.5