[PATCH v7 14/26] PCI: hotplug: Sort immovable BARs before assignment

From: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
To: <linux-pci@vger.kernel.org>
Cc: Bjorn Helgaas <helgaas@kernel.org>, Stefan Roese <sr@denx.de>,
	<linux@yadro.com>,
	Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
Subject: [PATCH v7 14/26] PCI: hotplug: Sort immovable BARs before assignment
Date: Wed, 29 Jan 2020 18:29:25 +0300	[thread overview]
Message-ID: <20200129152937.311162-15-s.miroshnichenko@yadro.com> (raw)
In-Reply-To: <20200129152937.311162-1-s.miroshnichenko@yadro.com>

Immovable BARs and bridge windows containing immovable BARs must be
assigned before the "usual" ones.

When assigning an immovable BAR/bridge window, its start address is chosen
to be the lowest possible. To prevent conflicts, sort such resources based
on the start address of their immovable areas.

Add support of immovable BARs and bridge windows to pdev_sort_resources().

Signed-off-by: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
---
 drivers/pci/setup-bus.c | 66 +++++++++++++++++++++++++++++++++++------
 1 file changed, 57 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index cdbf4afe1334..573d5c67c136 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -122,9 +122,9 @@ static resource_size_t get_res_add_align(struct list_head *head,
 	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)
+static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head,
+				struct list_head *head_immovables)
 {
 	int i;
 
@@ -136,17 +136,31 @@ static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
 		struct pci_dev_resource *dev_res, *tmp;
 		resource_size_t r_align;
 		struct list_head *n;
+		struct resource *fixed_res = NULL;
 
 		r = &dev->resource[i];
 
-		if (r->flags & IORESOURCE_PCI_FIXED)
+		if (!(r->flags) || r->parent)
 			continue;
 
-		if (!(r->flags) || r->parent)
+		if (pci_can_move_bars) {
+			if (i >= PCI_BRIDGE_RESOURCES &&
+			    dev->subordinate) {
+				int idx = i - PCI_BRIDGE_RESOURCES;
+
+				fixed_res = &dev->subordinate->immovable_range[idx];
+			} else if (!pci_dev_bar_movable(dev, r)) {
+				fixed_res = r;
+			}
+
+			if (fixed_res && fixed_res->start >= fixed_res->end)
+				fixed_res = NULL;
+		} else if (r->flags & IORESOURCE_PCI_FIXED) {
 			continue;
+		}
 
 		r_align = pci_resource_alignment(dev, r);
-		if (!r_align) {
+		if (!r_align && !fixed_res) {
 			pci_warn(dev, "BAR %d: %pR has bogus alignment\n",
 				 i, r);
 			continue;
@@ -158,6 +172,30 @@ static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
 		tmp->res = r;
 		tmp->dev = dev;
 
+		if (fixed_res) {
+			n = head_immovables;
+			list_for_each_entry(dev_res, head_immovables, list) {
+				struct resource *c_fixed_res = NULL;
+				int c_resno = dev_res->res - dev_res->dev->resource;
+				int br_idx = c_resno - PCI_BRIDGE_RESOURCES;
+				struct pci_bus *cbus = dev_res->dev->subordinate;
+
+				if (br_idx >= 0)
+					c_fixed_res = &cbus->immovable_range[br_idx];
+				else
+					c_fixed_res = dev_res->res;
+
+				if (fixed_res->start < c_fixed_res->start) {
+					n = &dev_res->list;
+					break;
+				}
+			}
+			/* Insert it just before n */
+			list_add_tail(&tmp->list, n);
+
+			continue;
+		}
+
 		/* Fallback is smallest one or list is empty */
 		n = head;
 		list_for_each_entry(dev_res, head, list) {
@@ -176,7 +214,8 @@ static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
 	}
 }
 
-static void __dev_sort_resources(struct pci_dev *dev, struct list_head *head)
+static void __dev_sort_resources(struct pci_dev *dev, struct list_head *head,
+				 struct list_head *head_immovables)
 {
 	u16 class = dev->class >> 8;
 
@@ -195,7 +234,7 @@ static void __dev_sort_resources(struct pci_dev *dev, struct list_head *head)
 			return;
 	}
 
-	pdev_sort_resources(dev, head);
+	pdev_sort_resources(dev, head, head_immovables);
 }
 
 static inline void reset_resource(struct resource *res)
@@ -493,8 +532,13 @@ static void pdev_assign_resources_sorted(struct pci_dev *dev,
 					 struct list_head *fail_head)
 {
 	LIST_HEAD(head);
+	LIST_HEAD(head_immovables);
+
+	__dev_sort_resources(dev, &head, &head_immovables);
+
+	if (!list_empty(&head_immovables))
+		__assign_resources_sorted(&head_immovables, NULL, NULL);
 
-	__dev_sort_resources(dev, &head);
 	__assign_resources_sorted(&head, add_head, fail_head);
 
 }
@@ -505,9 +549,13 @@ static void pbus_assign_resources_sorted(const struct pci_bus *bus,
 {
 	struct pci_dev *dev;
 	LIST_HEAD(head);
+	LIST_HEAD(head_immovables);
 
 	list_for_each_entry(dev, &bus->devices, bus_list)
-		__dev_sort_resources(dev, &head);
+		__dev_sort_resources(dev, &head, &head_immovables);
+
+	if (!list_empty(&head_immovables))
+		__assign_resources_sorted(&head_immovables, NULL, NULL);
 
 	__assign_resources_sorted(&head, realloc_head, fail_head);
 }
-- 
2.24.1

