PCI: designware-ep: Fix the Header Type check

The current check will result in the multiple function device
fails to initialize. So fix the check by masking out the
multiple function bit.

Link: https://lore.kernel.org/r/20200818092746.24366-1-Zhiqiang.Hou@nxp.com
Fixes: 0b24134f ("PCI: dwc: Add validation that PCIe core is set to correct mode")
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>

drivers/pci/controller/dwc/pcie-designware-ep.c

@@ -505,7 +505,8 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
 	u32 reg;
 	int i;
 
-	hdr_type = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE);
+	hdr_type = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE) &
+		   PCI_HEADER_TYPE_MASK;
 	if (hdr_type != PCI_HEADER_TYPE_NORMAL) {
 		dev_err(pci->dev,
 			"PCIe controller is not set to EP mode (hdr_type:0x%x)!\n",

include/uapi/linux/pci_regs.h

@@ -76,6 +76,7 @@
 #define PCI_CACHE_LINE_SIZE	0x0c	/* 8 bits */
 #define PCI_LATENCY_TIMER	0x0d	/* 8 bits */
 #define PCI_HEADER_TYPE		0x0e	/* 8 bits */
+#define  PCI_HEADER_TYPE_MASK		0x7f
 #define  PCI_HEADER_TYPE_NORMAL		0
 #define  PCI_HEADER_TYPE_BRIDGE		1
 #define  PCI_HEADER_TYPE_CARDBUS	2