Xeon-SP boards: Factor out OCP VPD get_cxl_mode() impl

There's two copies of the `get_cxl_mode()` function to map the OCP VPD
value to the values expected by platform code. As this is unnecessary,
have a single copy of this function in the OCP VPD driver code. As the
`get_cxl_mode()` function is Xeon-SP only, keep it in a separate file.

This change simplifies things for boards using OCP VPD for CXL and has
no impact for boards *not* using OCP VPD:

- Boards not using OCP VPD can still define get_cxl_mode() in mainboard
  code as needed, just like they were able to do before.
- Boards using OCP VPD but without CXL (`SOC_INTEL_HAS_CXL` is not
  enabled), this code won't get compiled in at all (see `Makefile.mk`).
- Boards using OCP VPD and CXL will automatically make use of this
  `get_cxl_mode()` definition, which should be the same for all boards.

It is possible that this may need to be expanded/adapted in the future,
which is easy to handle in a follow-up commit when the need arises.

TEST=Build and boot on intel/archercity CRB

Change-Id: I935c4eb5b2392e2d0dc01b9f66d46c79b8141ea7
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82224
Reviewed-by: Shuo Liu <shuo.liu@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>

src/drivers/ocp/vpd/Makefile.mk

@@ -1,7 +1,14 @@
 ## SPDX-License-Identifier: GPL-2.0-only
 
-romstage-$(CONFIG_OCP_VPD) += vpd_util.c
-ramstage-$(CONFIG_OCP_VPD) += vpd_util.c
+ifeq ($(CONFIG_OCP_VPD),y)
+romstage-y += vpd_util.c
+ramstage-y += vpd_util.c
+ifeq ($(CONFIG_XEON_SP_COMMON_BASE),y)
+romstage-$(CONFIG_SOC_INTEL_HAS_CXL) += xeonsp_cxl.c
+ramstage-$(CONFIG_SOC_INTEL_HAS_CXL) += xeonsp_cxl.c
+endif
+endif
+
 ramstage-$(CONFIG_LINUXPAYLOAD_CMDLINE_VPD_OVERWRITE) += vpd_cmdline.c
 ifeq ($(CONFIG_VPD),y)
 all-$(CONFIG_CONSOLE_OVERRIDE_LOGLEVEL) += loglevel_vpd.c

src/drivers/ocp/vpd/xeonsp_cxl.c

@@ -3,7 +3,6 @@
 #include <drivers/ocp/include/vpd.h>
 #include <soc/config.h>
 
-#if CONFIG(SOC_INTEL_HAS_CXL)
 enum xeonsp_cxl_mode get_cxl_mode(void)
 {
 	int ocp_cxl_mode = get_cxl_mode_from_vpd();
@@ -16,4 +15,3 @@ enum xeonsp_cxl_mode get_cxl_mode(void)
 		return XEONSP_CXL_DISABLED;
 	}
 }
-#endif

src/mainboard/intel/archercity_crb/Makefile.mk

@@ -2,7 +2,5 @@
 
 bootblock-y += bootblock.c
 romstage-y += romstage.c
-romstage-y += util.c
 ramstage-y += ramstage.c
-ramstage-y += util.c
 CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/include

src/mainboard/intel/archercity_crb/util.c

@@ -1,19 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-
-#include <drivers/ocp/include/vpd.h>
-#include <soc/config.h>
-
-#if CONFIG(SOC_INTEL_HAS_CXL) && CONFIG(OCP_VPD)
-enum xeonsp_cxl_mode get_cxl_mode(void)
-{
-	int ocp_cxl_mode = get_cxl_mode_from_vpd();
-	switch (ocp_cxl_mode) {
-	case CXL_SYSTEM_MEMORY:
-		return XEONSP_CXL_SYS_MEM;
-	case CXL_SPM:
-		return XEONSP_CXL_SP_MEM;
-	default:
-		return XEONSP_CXL_DISABLED;
-	}
-}
-#endif

src/mainboard/inventec/transformers/Makefile.mk

@@ -2,7 +2,5 @@
 
 bootblock-y += bootblock.c
 romstage-y += romstage.c
-romstage-y += util.c
 romstage-$(CONFIG_IPMI_KCS_ROMSTAGE) += ipmi.c
-ramstage-y += util.c
 CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/include