[PATCH v4 3/5] PCI: Handle IORESOURCE_PCI_FIXED when sizing and assigning resources.

[David Daney <ddaney.cavm-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

From: David Daney <david.daney-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>

The new Enhanced Allocation (EA) capability support creates resources
with the IORESOURCE_PCI_FIXED set.  This creates a couple of problems:

1) Since these resources cannot be relocated or resized, their
   alignment is not really defined, and it is therefore not specified.
   This causes a problem in pbus_size_mem() where resources with
   unspecified alignment are disabled.

2) During resource assignment in pci_bus_assign_resources(),
   IORESOURCE_PCI_FIXED resources are not given a parent.  This, in
   turn, causes pci_enable_resources() to fail with a "not claimed"
   error.

So, in pbus_size_mem() skip IORESOURCE_PCI_FIXED resources, instead of
disabling them.

In __pci_bus_assign_resources(), for IORESOURCE_PCI_FIXED resources,
try to request the resource from a parent bus.

Signed-off-by: David Daney <david.daney-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>
---
 drivers/pci/setup-bus.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 57 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 508cc56..8f9ed9b 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1037,9 +1037,10 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 			struct resource *r = &dev->resource[i];
 			resource_size_t r_size;
 
-			if (r->parent || ((r->flags & mask) != type &&
-					  (r->flags & mask) != type2 &&
-					  (r->flags & mask) != type3))
+			if (r->parent || (r->flags | IORESOURCE_PCI_FIXED) ||
+			    ((r->flags & mask) != type &&
+			     (r->flags & mask) != type2 &&
+			     (r->flags & mask) != type3))
 				continue;
 			r_size = resource_size(r);
 #ifdef CONFIG_PCI_IOV
@@ -1340,6 +1341,57 @@ 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;
+		}
+		if (!r->parent) {
+			/*
+			 * If that didn't work, try to fallback to the
+			 * ultimate parent.
+			 */
+			if (r->flags &  IORESOURCE_IO)
+				request_resource(&ioport_resource, r);
+			else
+				request_resource(&iomem_resource, r);
+		}
+	}
+}
+
 void __pci_bus_assign_resources(const struct pci_bus *bus,
 				struct list_head *realloc_head,
 				struct list_head *fail_head)
@@ -1350,6 +1402,8 @@ 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;
-- 
1.9.1