PCI: altera: Fix Requester ID for config accesses

The Requester ID should use the Root Port devfn and it should be always 0.
Previously we constructed the Requester ID using the *Completer* devfn,
i.e., the devfn of the Function we expect to respond to the config access.
This causes issues when accessing configuration space for devices other
than the Root Port.

Build the Requester ID using the Root Port devfn.

Tested on Ethernet adapter card with multi-functions.
Signed-off-by: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/host/pcie-altera.c

@@ -57,6 +57,7 @@
 #define TLP_REQ_ID(bus, devfn)		(((bus) << 8) | (devfn))
 #define TLP_HDR_SIZE			3
 #define TLP_LOOP			500
+#define RP_DEVFN			0
 
 #define INTX_NUM			4
 
@@ -233,7 +234,7 @@ static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
 	else
 		headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGRD1);
 
-	headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, devfn),
+	headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN),
 					TLP_READ_TAG, byte_en);
 	headers[2] = TLP_CFG_DW2(bus, devfn, where);
 
@@ -253,7 +254,7 @@ static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
 	else
 		headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGWR1);
 
-	headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, devfn),
+	headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN),
 					TLP_WRITE_TAG, byte_en);
 	headers[2] = TLP_CFG_DW2(bus, devfn, where);