[PATCH AUTOSEL 5.10 22/30] PCI: Align extra resources for hotplug bridges properly

[Sasha Levin]

From: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

[ Upstream commit 08f0a15ee8adb4846b08ca5d5c175fbf0f652bc9 ]

After division the extra resource space per hotplug bridge may not be
aligned according to the window alignment, so align it before passing it
down for further distribution.

Link: https://lore.kernel.org/r/20230131092405.29121-2-mika.westerberg@xxxxxxxxxxxxxxx
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/pci/setup-bus.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 2ce636937c6ea..4a6b698b5dd10 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -2004,6 +2004,7 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 	 * resource space between hotplug bridges.
 	 */
 	for_each_pci_bridge(dev, bus) {
+		struct resource *res;
 		struct pci_bus *b;
 
 		b = dev->subordinate;
@@ -2015,16 +2016,28 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 		 * hotplug-capable downstream ports taking alignment into
 		 * account.
 		 */
-		io.end = io.start + io_per_hp - 1;
-		mmio.end = mmio.start + mmio_per_hp - 1;
-		mmio_pref.end = mmio_pref.start + mmio_pref_per_hp - 1;
+		res = &dev->resource[PCI_BRIDGE_IO_WINDOW];
+		align = pci_resource_alignment(dev, res);
+		io.end = align ? io.start + ALIGN_DOWN(io_per_hp, align) - 1
+			       : io.start + io_per_hp - 1;
+
+		res = &dev->resource[PCI_BRIDGE_MEM_WINDOW];
+		align = pci_resource_alignment(dev, res);
+		mmio.end = align ? mmio.start + ALIGN_DOWN(mmio_per_hp, align) - 1
+				 : mmio.start + mmio_per_hp - 1;
+
+		res = &dev->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
+		align = pci_resource_alignment(dev, res);
+		mmio_pref.end = align ? mmio_pref.start +
+					ALIGN_DOWN(mmio_pref_per_hp, align) - 1
+				      : mmio_pref.start + mmio_pref_per_hp - 1;
 
 		pci_bus_distribute_available_resources(b, add_list, io, mmio,
 						       mmio_pref);
 
-		io.start += io_per_hp;
-		mmio.start += mmio_per_hp;
-		mmio_pref.start += mmio_pref_per_hp;
+		io.start += io.end + 1;
+		mmio.start += mmio.end + 1;
+		mmio_pref.start += mmio_pref.end + 1;
 	}
 }
 
-- 
2.39.2