[PATCH 11/12] ACPI/sleep: Convert acpi_wakeup_address into a function

[Sean Christopherson <sean.j.christopherson@intel.com>]

Convert acpi_wakeup_address from a raw variable into a function so that
x86 can wrap its dereference of the real mode boot header in a function
instead of broadcasting it to the world via a #define.  This sets the
stage for a future patch to move the definition of acpi_wakeup_address()
out of asm/acpi.h and thus break acpi.h's dependency on asm/realmode.h.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/ia64/include/asm/acpi.h | 5 ++++-
 arch/ia64/kernel/acpi.c      | 2 --
 arch/x86/include/asm/acpi.h  | 5 ++++-
 drivers/acpi/sleep.c         | 4 ++--
 4 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/arch/ia64/include/asm/acpi.h b/arch/ia64/include/asm/acpi.h
index f886d4dc9d55..36d7003eee71 100644
--- a/arch/ia64/include/asm/acpi.h
+++ b/arch/ia64/include/asm/acpi.h
@@ -38,7 +38,10 @@ int acpi_gsi_to_irq (u32 gsi, unsigned int *irq);
 /* Low-level suspend routine. */
 extern int acpi_suspend_lowlevel(void);
 
-extern unsigned long acpi_wakeup_address;
+static inline unsigned long acpi_wakeup_address(void)
+{
+	return 0;
+}
 
 /*
  * Record the cpei override flag and current logical cpu. This is
diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 70d1587ddcd4..a5636524af76 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -42,8 +42,6 @@ int acpi_lapic;
 unsigned int acpi_cpei_override;
 unsigned int acpi_cpei_phys_cpuid;
 
-unsigned long acpi_wakeup_address = 0;
-
 #define ACPI_MAX_PLATFORM_INTERRUPTS	256
 
 /* Array to record platform interrupt vectors for generic interrupt routing. */
diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index bc9693c9107e..57788ec6fa82 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -62,7 +62,10 @@ static inline void acpi_disable_pci(void)
 extern int (*acpi_suspend_lowlevel)(void);
 
 /* Physical address to resume after wakeup */
-#define acpi_wakeup_address ((unsigned long)(real_mode_header->wakeup_start))
+static inline unsigned long acpi_wakeup_address(void)
+{
+	return ((unsigned long)(real_mode_header->wakeup_start));
+}
 
 /*
  * Check if the CPU can handle C2 and deeper
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 2af937a8b1c5..9e66c4109556 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -63,9 +63,9 @@ static int acpi_sleep_prepare(u32 acpi_state)
 #ifdef CONFIG_ACPI_SLEEP
 	/* do we have a wakeup address for S2 and S3? */
 	if (acpi_state == ACPI_STATE_S3) {
-		if (!acpi_wakeup_address)
+		if (!acpi_wakeup_address())
 			return -EFAULT;
-		acpi_set_waking_vector(acpi_wakeup_address);
+		acpi_set_waking_vector(acpi_wakeup_address());
 
 	}
 	ACPI_FLUSH_CPU_CACHE();
-- 
2.24.0