From 0871b7248113ebfccbfabcd3fd1f867a2bc681f4 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Fri, 17 Jul 2015 10:33:04 +0100
Subject: [PATCH] ARM: fix __virt_to_idmap build error on !MMU

Fengguang Wu reports that building ARM with !MMU results in the
following build error:

   arch/arm/kernel/built-in.o: In function `__soft_restart':
>> :(.text+0x1624): undefined reference to `arch_virt_to_idmap'

Fix this by adding an appropriate IS_ENABLED(CONFIG_MMU) into the
__virt_to_idmap() inline function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/include/asm/memory.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index 6f225acc07c5..b7f6fb462ea0 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -286,7 +286,7 @@ extern phys_addr_t (*arch_virt_to_idmap)(unsigned long x);
  */
 static inline phys_addr_t __virt_to_idmap(unsigned long x)
 {
-	if (arch_virt_to_idmap)
+	if (IS_ENABLED(CONFIG_MMU) && arch_virt_to_idmap)
 		return arch_virt_to_idmap(x);
 	else
 		return __virt_to_phys(x);
-- 
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