Subject: [PATCH] powerpc/powernv: Fix PCI resource handling

From: Benjamin Herrenschmidt <[email-masked]>
Date: Wed, 25 Jan 2012 13:36:09 +1100

Recent changes to the handling of PCI resources for host bridges
are breaking the PowerNV code for assigning resources on IODA.

The root of the problem is that the pci_bus attached to a host
bridge no longer has its "legacy" resource pointers populated
but only uses the newer list instead.

Signed-off-by: Benjamin Herrenschmidt <[email-masked]>
---
 arch/powerpc/platforms/powernv/pci-ioda.c |   43 ++++++++++++++++++-----------
 1 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index f31162c..5e155df 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -204,11 +204,10 @@ static void __devinit pnv_ioda_offset_bus(struct pci_bus *bus,
 	pr_devel("  -> OBR %s [%x] +%016llx\n",
 		 bus->self ? pci_name(bus->self) : "root", flags, offset);
 
-	for (i = 0; i < 2; i++) {
-		r = bus->resource[i];
+	pci_bus_for_each_resource(bus, r, i) {
 		if (r && (r->flags & flags)) {
-			bus->resource[i]->start += offset;
-			bus->resource[i]->end += offset;
+			r->start += offset;
+			r->end += offset;
 		}
 	}
 	list_for_each_entry(dev, &bus->devices, bus_list)
@@ -288,12 +287,17 @@ static void __devinit pnv_ioda_calc_bus(struct pci_bus *bus, unsigned int flags,
 	 * assignment algorithm is going to be uber-trivial for now, we
 	 * can try to be smarter later at filling out holes.
 	 */
-	start = bus->self ? 0 : bus->resource[bres]->start;
-
-	/* Don't hand out IO 0 */
-	if ((flags & IORESOURCE_IO) && !bus->self)
-		start += 0x1000;
-
+	if (bus->self) {
+		/* No offset for downstream bridges */
+		start = 0;
+	} else {
+		/* Offset from the root */
+		if (flags & IORESOURCE_IO)
+			/* Don't hand out IO 0 */
+			start = hose->io_resource.start + 0x1000;
+		else
+			start = hose->mem_resources[0].start;
+	}
 	while(!list_empty(&head)) {
 		w = list_first_entry(&head, struct resource_wrap, link);
 		list_del(&w->link);
@@ -321,13 +325,20 @@ static void __devinit pnv_ioda_calc_bus(struct pci_bus *bus, unsigned int flags,
  empty:
 	/* Only setup P2P's, not the PHB itself */
 	if (bus->self) {
-		WARN_ON(bus->resource[bres] == NULL);
-		bus->resource[bres]->start = 0;
-		bus->resource[bres]->flags = (*size) ? flags : 0;
-		bus->resource[bres]->end = (*size) ? (*size - 1) : 0;
+		struct resource *res = bus->resource[bres];
+
+		if (WARN_ON(res == NULL))
+			return;
 
-		/* Clear prefetch bus resources for now */
-		bus->resource[2]->flags = 0;
+		/*
+		 * FIXME: We should probably export and call
+		 * pci_bridge_check_ranges() to properly re-initialize
+		 * the PCI portion of the flags here, and to detect
+		 * what the bridge actually supports.
+		 */
+		res->start = 0;
+		res->flags = (*size) ? flags : 0;
+		res->end = (*size) ? (*size - 1) : 0;
 	}
 
 	pr_devel("<- CBR %s [%x] *size=%016llx *align=%016llx\n",