[PATCH 5.16 0872/1039] PCI: xgene: Fix IB window setup

[Greg Kroah-Hartman]

From: Rob Herring <robh@xxxxxxxxxx>

commit c7a75d07827a1f33d566e18e6098379cc2a0c2b2 upstream.

Commit 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup")
broke PCI support on XGene. The cause is the IB resources are now sorted
in address order instead of being in DT dma-ranges order. The result is
which inbound registers are used for each region are swapped. I don't
know the details about this h/w, but it appears that IB region 0
registers can't handle a size greater than 4GB. In any case, limiting
the size for region 0 is enough to get back to the original assignment
of dma-ranges to regions.

Link: https://lore.kernel.org/all/CA+enf=v9rY_xnZML01oEgKLmvY1NGBUUhnSJaETmXtDtXfaczA@xxxxxxxxxxxxxx/
Link: https://lore.kernel.org/r/20211129173637.303201-1-robh@xxxxxxxxxx
Fixes: 6dce5aa59e0b ("PCI: xgene: Use inbound resources for setup")
Reported-by: Stéphane Graber <stgraber@xxxxxxxxxx>
Tested-by: Stéphane Graber <stgraber@xxxxxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Reviewed-by: Krzysztof Wilczyński <kw@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.5+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/pci/controller/pci-xgene.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/pci/controller/pci-xgene.c
+++ b/drivers/pci/controller/pci-xgene.c
@@ -465,7 +465,7 @@ static int xgene_pcie_select_ib_reg(u8 *
 		return 1;
 	}
 
-	if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) {
+	if ((size > SZ_1K) && (size < SZ_4G) && !(*ib_reg_mask & (1 << 0))) {
 		*ib_reg_mask |= (1 << 0);
 		return 0;
 	}