x86: acpi: Export acpi_fill_mcfg() with __weak attribute

Some platforms might require different approach when filling memory
mappings configuration table.

Allow them to override the common method.

At the same time export acpi_create_mcfg_mmconfig().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/include/asm/acpi_table.h

@@ -314,6 +314,9 @@ int acpi_create_madt_irqoverride(struct acpi_madt_irqoverride *irqoverride,
 int acpi_create_madt_lapic_nmi(struct acpi_madt_lapic_nmi *lapic_nmi,
 			       u8 cpu, u16 flags, u8 lint);
 u32 acpi_fill_madt(u32 current);
+int acpi_create_mcfg_mmconfig(struct acpi_mcfg_mmconfig *mmconfig, u32 base,
+			      u16 seg_nr, u8 start, u8 end);
+u32 acpi_fill_mcfg(u32 current);
 void acpi_create_gnvs(struct acpi_global_nvs *gnvs);
 /**
  * enter_acpi_mode() - enter into ACPI mode

arch/x86/lib/acpi_table.c

@@ -293,8 +293,8 @@ static void acpi_create_madt(struct acpi_madt *madt)
 	header->checksum = table_compute_checksum((void *)madt, header->length);
 }
 
-static int acpi_create_mcfg_mmconfig(struct acpi_mcfg_mmconfig *mmconfig,
-				     u32 base, u16 seg_nr, u8 start, u8 end)
+int acpi_create_mcfg_mmconfig(struct acpi_mcfg_mmconfig *mmconfig, u32 base,
+			      u16 seg_nr, u8 start, u8 end)
 {
 	memset(mmconfig, 0, sizeof(*mmconfig));
 	mmconfig->base_address_l = base;
@@ -306,7 +306,7 @@ static int acpi_create_mcfg_mmconfig(struct acpi_mcfg_mmconfig *mmconfig,
 	return sizeof(struct acpi_mcfg_mmconfig);
 }
 
-static u32 acpi_fill_mcfg(u32 current)
+__weak u32 acpi_fill_mcfg(u32 current)
 {
 	current += acpi_create_mcfg_mmconfig
 		((struct acpi_mcfg_mmconfig *)current,