arch/x86: introduce HAVE_CONFIGURABLE_APMC_SMI_PORT

Introduce the HAVE_CONFIGURABLE_APMC_SMI_PORT Kconfig option that when
not selected will result in a default implementation of
pm_acpi_smi_cmd_port to be included in the build that returns APM_CNT.
SoCs that provide their own pm_acpi_smi_cmd_port implementation, need to
select this Kconfig option.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Iaceb61b0f2a630d7afe2e0780b6a2a9806ea62f9
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79566
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com>

src/arch/x86/Kconfig

@@ -316,6 +316,13 @@ config HAVE_CF9_RESET_PREPARE
 	bool
 	depends on HAVE_CF9_RESET
 
+config HAVE_CONFIGURABLE_APMC_SMI_PORT
+	bool
+	help
+	  SoCs that have a configurable APMC SMI command port, should select
+	  this option and implement pm_acpi_smi_cmd_port() that returns the IO
+	  port.
+
 config PIRQ_ROUTE
 	bool
 	default n

src/arch/x86/Makefile.inc

@@ -336,3 +336,8 @@ smm-$(CONFIG_X86_TOP4G_BOOTMEDIA_MAP) += mmap_boot.c
 smm-$(CONFIG_DEBUG_NULL_DEREF_BREAKPOINTS_IN_ALL_STAGES) += null_breakpoint.c
 
 smm-srcs += $(wildcard src/mainboard/$(MAINBOARDDIR)/smihandler.c)
+
+ifneq ($(CONFIG_HAVE_CONFIGURABLE_APMC_SMI_PORT),y)
+ramstage-y += apmc_smi_port.c
+smm-y += apmc_smi_port.c
+endif

src/arch/x86/apmc_smi_port.c

@@ -2,7 +2,7 @@
 
 #include <cpu/x86/smm.h>
 
-/* The X86 qemu target uses AMD64 save states but the APM port is not configurable. */
+/* default implementation of the !HAVE_CONFIGURABLE_APMC_SMI_PORT case */
 uint16_t pm_acpi_smi_cmd_port(void)
 {
 	return APM_CNT;

src/mainboard/emulation/qemu-q35/Makefile.inc

@@ -20,5 +20,4 @@ all-y += ../qemu-i440fx/bootmode.c
 
 ramstage-$(CONFIG_CHROMEOS) += chromeos.c
 
-smm-y += smi.c
 smm-y += memmap.c

src/soc/amd/common/block/smi/Kconfig

@@ -1,5 +1,6 @@
 config SOC_AMD_COMMON_BLOCK_SMI
 	bool
+	select HAVE_CONFIGURABLE_APMC_SMI_PORT
 	help
 	  Select this option to add the common functions for setting up the SMI
 	  configuration to the build.