[PATCH v8 14/24] PCI: hotplug: Add support of fixed BARs to pci_assign_resource()

[Sergei Miroshnichenko <s.miroshnichenko@yadro.com>]

Fixed BARs must be assigned within a bridge window first, before movable
BARs and neighboring bridge windows. Currently they are assigned last by
pdev_assign_fixed_resources().

Let the fixed BARs be handled by pci_assign_resource() in the same way as
it does for movable ones, assigning them in correct order, unifying the
code.

Allow matching IORESOURCE_PCI_FIXED prefetchable BARs to non-prefetchable
windows, so they follow the same rules as non-flagged fixed BARs.

Signed-off-by: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
---
 drivers/pci/setup-bus.c | 43 -----------------------------------------
 drivers/pci/setup-res.c | 41 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 39 insertions(+), 45 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index a6d8bb5ed43d..1f76a4dffb7d 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1344,47 +1344,6 @@ void pci_bus_size_bridges(struct pci_bus *bus)
 }
 EXPORT_SYMBOL(pci_bus_size_bridges);
 
-static void assign_fixed_resource_on_bus(struct pci_bus *b, struct resource *r)
-{
-	int i;
-	struct resource *parent_r;
-	unsigned long mask = IORESOURCE_IO | IORESOURCE_MEM |
-			     IORESOURCE_PREFETCH;
-
-	pci_bus_for_each_resource(b, parent_r, i) {
-		if (!parent_r)
-			continue;
-
-		if ((r->flags & mask) == (parent_r->flags & mask) &&
-		    resource_contains(parent_r, r))
-			request_resource(parent_r, r);
-	}
-}
-
-/*
- * Try to assign any resources marked as IORESOURCE_PCI_FIXED, as they are
- * skipped by pbus_assign_resources_sorted().
- */
-static void pdev_assign_fixed_resources(struct pci_dev *dev)
-{
-	int i;
-
-	for (i = 0; i <  PCI_NUM_RESOURCES; i++) {
-		struct pci_bus *b;
-		struct resource *r = &dev->resource[i];
-
-		if (r->parent || !(r->flags & IORESOURCE_PCI_FIXED) ||
-		    !(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
-			continue;
-
-		b = dev->bus;
-		while (b && !r->parent) {
-			assign_fixed_resource_on_bus(b, r);
-			b = b->parent;
-		}
-	}
-}
-
 void __pci_bus_assign_resources(const struct pci_bus *bus,
 				struct list_head *realloc_head,
 				struct list_head *fail_head)
@@ -1395,8 +1354,6 @@ void __pci_bus_assign_resources(const struct pci_bus *bus,
 	pbus_assign_resources_sorted(bus, realloc_head, fail_head);
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
-		pdev_assign_fixed_resources(dev);
-
 		b = dev->subordinate;
 		if (!b)
 			continue;
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 494eb5a2e98c..a1e61e74ce00 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -331,14 +331,51 @@ static int _pci_assign_resource(struct pci_dev *dev, int resno,
 	return ret;
 }
 
+static int assign_fixed_resource_on_bus(struct pci_dev *dev, int resno)
+{
+	int i;
+	struct resource *parent_r;
+	unsigned long mask = IORESOURCE_TYPE_BITS;
+	struct resource *r = dev->resource + resno;
+
+	/*
+	 * If we have a shadow copy in RAM, the PCI device doesn't respond
+	 * to the shadow range
+	 */
+	if (r->flags & IORESOURCE_ROM_SHADOW)
+		return 0;
+
+	pci_bus_for_each_resource(dev->bus, parent_r, i) {
+		if (!parent_r)
+			continue;
+
+		if ((r->flags & mask) != (parent_r->flags & mask))
+			continue;
+
+		if (parent_r->flags & IORESOURCE_PREFETCH &&
+		    !(r->flags & IORESOURCE_PREFETCH))
+			continue;
+
+		if (resource_contains(parent_r, r)) {
+			if (!request_resource(parent_r, r)) {
+				pci_info(dev, "BAR %d: assigned fixed %pR\n", resno, r);
+				return 0;
+			}
+		}
+	}
+
+	pci_err(dev, "BAR %d: failed to assign fixed %pR\n", resno, r);
+	return -ENOSPC;
+}
+
 int pci_assign_resource(struct pci_dev *dev, int resno)
 {
 	struct resource *res = dev->resource + resno;
 	resource_size_t align, size;
 	int ret;
 
-	if (res->flags & IORESOURCE_PCI_FIXED)
-		return 0;
+	if (res->flags && pci_dev_bar_fixed(dev, res))
+		return assign_fixed_resource_on_bus(dev, resno);
 
 	res->flags |= IORESOURCE_UNSET;
 	align = pci_resource_alignment(dev, res);
-- 
2.24.1