x86: acpi: Use an API to get the ACPI RSDP table address

At present the acpi_rsdp_addr variable is directly referenced in
setup_zimage(). This changes to use an API for better encapsulation
and extension.

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

arch/x86/include/asm/acpi_table.h

@@ -330,6 +330,15 @@ void enter_acpi_mode(int pm1_cnt);
 ulong write_acpi_tables(ulong start);
 
 /**
+ * acpi_get_rsdp_addr() - get ACPI RSDP table address
+ *
+ * This routine returns the ACPI RSDP table address in the system memory.
+ *
+ * @return:	ACPI RSDP table address
+ */
+ulong acpi_get_rsdp_addr(void);
+
+/**
  * acpi_find_fadt() - find ACPI FADT table in the sytem memory
  *
  * This routine parses the ACPI table to locate the ACPI FADT table.

arch/x86/lib/acpi_table.c

@@ -20,7 +20,6 @@
 #include <asm/mpspec.h>
 #include <asm/tables.h>
 #include <asm/arch/global_nvs.h>
-#include "acpi_table.h"
 
 /*
  * IASL compiles the dsdt entries and writes the hex values
@@ -29,7 +28,7 @@
 extern const unsigned char AmlCode[];
 
 /* ACPI RSDP address to be used in boot parameters */
-unsigned long acpi_rsdp_addr;
+static ulong acpi_rsdp_addr;
 
 static void acpi_write_rsdp(struct acpi_rsdp *rsdp, struct acpi_rsdt *rsdt,
 			    struct acpi_xsdt *xsdt)
@@ -480,6 +479,11 @@ ulong write_acpi_tables(ulong start)
 	return current;
 }
 
+ulong acpi_get_rsdp_addr(void)
+{
+	return acpi_rsdp_addr;
+}
+
 static struct acpi_rsdp *acpi_valid_rsdp(struct acpi_rsdp *rsdp)
 {
 	if (strncmp((char *)rsdp, RSDP_SIG, sizeof(RSDP_SIG) - 1) != 0)

arch/x86/lib/acpi_table.h

@@ -1,10 +0,0 @@
-/*
- * SPDX-License-Identifier:	GPL-2.0
- */
-
-#ifndef _X86_LIB_ACPI_TABLES_H
-#define _X86_LIB_ACPI_TABLES_H
-
-extern unsigned long acpi_rsdp_addr;
-
-#endif

arch/x86/lib/zimage.c

@@ -14,6 +14,7 @@
  */
 
 #include <common.h>
+#include <asm/acpi_table.h>
 #include <asm/io.h>
 #include <asm/ptrace.h>
 #include <asm/zimage.h>
@@ -24,7 +25,6 @@
 #include <asm/arch/timestamp.h>
 #endif
 #include <linux/compiler.h>
-#include "acpi_table.h"
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -258,7 +258,7 @@ int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
 
 #ifdef CONFIG_GENERATE_ACPI_TABLE
 	if (bootproto >= 0x020e)
-		hdr->acpi_rsdp_addr = acpi_rsdp_addr;
+		hdr->acpi_rsdp_addr = acpi_get_rsdp_addr();
 #endif
 
 	setup_video(&setup_base->screen_info);