[PATCH 03/10] PCI, alpha: clip firmware assigned resource under parent bridge's

[Yinghai Lu <yinghai@kernel.org>]

Some bios put range that is not fully coverred by root bus resources.
Try to clip them and update them in pci bridge bars.

We'd like to fix other arches instead of just x86.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=85491
Reported-by: Marek Kordik <kordikmarek@gmail.com>
Fixes: 5b28541552ef ("PCI: Restrict 64-bit prefetchable bridge windows to 64-bit resources")
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: linux-alpha@vger.kernel.org
---
 arch/alpha/kernel/pci.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/arch/alpha/kernel/pci.c b/arch/alpha/kernel/pci.c
index 076c35c..b54b40f 100644
--- a/arch/alpha/kernel/pci.c
+++ b/arch/alpha/kernel/pci.c
@@ -277,6 +277,7 @@ pcibios_claim_one_bus(struct pci_bus *b)
 	struct pci_bus *child_bus;
 
 	list_for_each_entry(dev, &b->devices, bus_list) {
+		bool changed = false;
 		int i;
 
 		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
@@ -285,9 +286,28 @@ pcibios_claim_one_bus(struct pci_bus *b)
 			if (r->parent || !r->start || !r->flags)
 				continue;
 			if (pci_has_flag(PCI_PROBE_ONLY) ||
-			    (r->flags & IORESOURCE_PCI_FIXED))
-				pci_claim_resource(dev, i);
+			    (r->flags & IORESOURCE_PCI_FIXED)) {
+				if (pci_claim_resource(dev, i) >= 0)
+					continue;
+
+				if (dev->subordinate &&
+				    i >= PCI_BRIDGE_RESOURCES &&
+				    i < PCI_NUM_RESOURCES &&
+				    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI &&
+				    pci_bus_clip_resource(dev, r)) {
+					changed = true;
+					pci_claim_resource(dev, i);
+				} else if (i < PCI_BRIDGE_RESOURCES &&
+					   i != PCI_ROM_RESOURCE &&
+					   pci_bus_clip_resource(dev, r)) {
+						pci_update_resource(dev, i);
+						pci_claim_resource(dev, i);
+				}
+			}
 		}
+
+		if (changed)
+			pci_setup_bridge(dev->subordinate);
 	}
 
 	list_for_each_entry(child_bus, &b->children, node)
-- 
1.8.4.5