[PATCH] PCI: Validate window resource type in pbus_select_window_for_type()

[Kai-Heng Feng]

Afer commit ebe091ad81e1 ("PCI: Use pbus_select_window_for_type() during
IO window sizing") and commit ae88d0b9c57f ("PCI: Use
pbus_select_window_for_type() during mem window sizing"), many bridge
window can't get resource assigned:
pci 0006:05:00.0: bridge window [??? 0x00001000-0x00001fff flags 0x20080000]: can't assign; no space
pci 0006:05:00.0: bridge window [??? 0x00001000-0x00001fff flags 0x20080000]: failed to assign
pci 0006:05:04.0: bridge window [??? 0x00001000-0x00001fff flags 0x20080000]: can't assign; no space
pci 0006:05:04.0: bridge window [??? 0x00001000-0x00001fff flags 0x20080000]: failed to assign
pci 0006:05:08.0: bridge window [??? 0x00001000-0x00001fff flags 0x20080000]: can't assign; no space
pci 0006:05:08.0: bridge window [??? 0x00001000-0x00001fff flags 0x20080000]: failed to assign
pci 0006:05:0c.0: bridge window [??? 0x00001000-0x00001fff flags 0x20080000]: can't assign; no space
pci 0006:05:0c.0: bridge window [??? 0x00001000-0x00001fff flags 0x20080000]: failed to assign

Those commits replace find_bus_resource_of_type() with
pbus_select_window_for_type(), and the latter lacks resource type
validation.

This commit adds the resource type validation back to
pbus_select_window_for_type() to match the original behavior.

Fixes: 74afce3dfcba ("PCI: Add bridge window selection functions")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=221072
Signed-off-by: Kai-Heng Feng <kaihengf@xxxxxxxxxx>
---
 drivers/pci/setup-bus.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index e680f75a5b5e..1b5185697011 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -224,14 +224,21 @@ static struct resource *pbus_select_window_for_type(struct pci_bus *bus,
 
 	switch (iores_type) {
 	case IORESOURCE_IO:
-		return pci_bus_resource_n(bus, PCI_BUS_BRIDGE_IO_WINDOW);
+		win = pci_bus_resource_n(bus, PCI_BUS_BRIDGE_IO_WINDOW);
+		if (win && (win->flags & IORESOURCE_IO))
+			return win;
+		return NULL;
 
 	case IORESOURCE_MEM:
 		mmio = pci_bus_resource_n(bus, PCI_BUS_BRIDGE_MEM_WINDOW);
 		mmio_pref = pci_bus_resource_n(bus, PCI_BUS_BRIDGE_PREF_MEM_WINDOW);
 
-		if (!(type & IORESOURCE_PREFETCH) ||
-		    !(mmio_pref->flags & IORESOURCE_MEM))
+		if (mmio && !(mmio->flags & IORESOURCE_MEM))
+			mmio = NULL;
+		if (mmio_pref && !(mmio_pref->flags & IORESOURCE_MEM))
+			mmio_pref = NULL;
+
+		if (!(type & IORESOURCE_PREFETCH) || !mmio_pref)
 			return mmio;
 
 		if ((type & IORESOURCE_MEM_64) ||
-- 
2.43.0