PCI: rockchip-ep: Use a macro to define EP controller .align feature

Introduce the macro ROCKCHIP_PCIE_AT_SIZE_ALIGN to initialize the .align
field of the controller epc_features structure to 256. This is defined
as a shift using the macro ROCKCHIP_PCIE_AT_MIN_NUM_BITS (to avoid
using the "magic" value 8 directly).

Link: https://lore.kernel.org/r/20241017015849.190271-3-dlemoal@kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Author: damien-lemoal

drivers/pci/controller/pcie-rockchip-ep.c

@@ -449,7 +449,7 @@ static const struct pci_epc_features rockchip_pcie_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
 	.msix_capable = false,
-	.align = 256,
+	.align = ROCKCHIP_PCIE_AT_SIZE_ALIGN,
 };
 
 static const struct pci_epc_features*

drivers/pci/controller/pcie-rockchip.h

@@ -248,6 +248,7 @@
 
 #define ROCKCHIP_PCIE_AT_MIN_NUM_BITS  8
 #define ROCKCHIP_PCIE_AT_MAX_NUM_BITS  20
+#define ROCKCHIP_PCIE_AT_SIZE_ALIGN    (1UL << ROCKCHIP_PCIE_AT_MIN_NUM_BITS)
 
 #define ROCKCHIP_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar) \
 	(PCIE_CORE_AXI_CONF_BASE + 0x0828 + (fn) * 0x0040 + (bar) * 0x0008)