PCI: Align extra resources for hotplug bridges properly

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@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index b4096598dbcbb9e3aee7079258fd6bc7e06a9450..e440f264accb8a6ab47fc68af4cdeccc71bff164 100644 (file)
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1891,6 +1891,7 @@ 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;
@@ -1902,16 +1903,28 @@ 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;
        }
 }