[tip:x86/urgent] x86/purgatory: Fix sparse warning, symbol not declared

["tip-bot for Tobin C. Harding" <tipbot@zytor.com>]

Commit-ID:  e98fe5127b9cc8ab33d1094b81c19deb1f9082bf
Gitweb:     http://git.kernel.org/tip/e98fe5127b9cc8ab33d1094b81c19deb1f9082bf
Author:     Tobin C. Harding <me@tobin.cc>
AuthorDate: Mon, 20 Feb 2017 10:12:36 +1100
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 1 Mar 2017 11:27:26 +0100

x86/purgatory: Fix sparse warning, symbol not declared

Sparse emits warning, 'symbol not declared' for a function that has
neither file scope nor a forward declaration. The functions only call
site is an ASM file.

Add a header file with the function declaration. Include the header file in
the C source file defining the function in order to fix the sparse
warning. Include the header file in ASM file containing the call site to
document the usage.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Link: http://lkml.kernel.org/r/1487545956-2547-3-git-send-email-me@tobin.cc
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/x86/purgatory/purgatory.c    | 1 +
 arch/x86/purgatory/purgatory.h    | 8 ++++++++
 arch/x86/purgatory/setup-x86_64.S | 1 +
 3 files changed, 10 insertions(+)

diff --git a/arch/x86/purgatory/purgatory.c b/arch/x86/purgatory/purgatory.c
index 2a5f437..b6d5c89 100644
--- a/arch/x86/purgatory/purgatory.c
+++ b/arch/x86/purgatory/purgatory.c
@@ -11,6 +11,7 @@
  */
 
 #include "sha256.h"
+#include "purgatory.h"
 #include "../boot/string.h"
 
 struct sha_region {
diff --git a/arch/x86/purgatory/purgatory.h b/arch/x86/purgatory/purgatory.h
new file mode 100644
index 0000000..e2e365a
--- /dev/null
+++ b/arch/x86/purgatory/purgatory.h
@@ -0,0 +1,8 @@
+#ifndef PURGATORY_H
+#define PURGATORY_H
+
+#ifndef __ASSEMBLY__
+extern void purgatory(void);
+#endif	/* __ASSEMBLY__ */
+
+#endif /* PURGATORY_H */
diff --git a/arch/x86/purgatory/setup-x86_64.S b/arch/x86/purgatory/setup-x86_64.S
index fe3c91b..f90e9df 100644
--- a/arch/x86/purgatory/setup-x86_64.S
+++ b/arch/x86/purgatory/setup-x86_64.S
@@ -9,6 +9,7 @@
  * This source code is licensed under the GNU General Public License,
  * Version 2.  See the file COPYING for more details.
  */
+#include "purgatory.h"
 
 	.text
 	.globl purgatory_start