PCI: xgene: Fix IB window setup

Commit 6dce5aa ("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@mail.gmail.com/
Link: https://lore.kernel.org/r/[email protected]
Fixes: 6dce5aa ("PCI: xgene: Use inbound resources for setup")
Reported-by: Stéphane Graber <[email protected]>
Tested-by: Stéphane Graber <[email protected]>
Signed-off-by: Rob Herring <[email protected]>
Signed-off-by: Lorenzo Pieralisi <[email protected]>
Reviewed-by: Krzysztof Wilczyński <[email protected]>
Cc: [email protected] # v5.5+

Author: robherring

drivers/pci/controller/pci-xgene.c

@@ -465,7 +465,7 @@ static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
 		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;
 	}