[PATCH v6 35/76] x86/head/64: Make fixup_pointer() static inline

[Joerg Roedel]

From: Joerg Roedel <jroedel@xxxxxxx>

Also move it to a header file so that it can be used in the idt code
to setup the early IDT.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200724160336.5435-35-joro@xxxxxxxxxx
---
 arch/x86/include/asm/setup.h | 10 ++++++++++
 arch/x86/kernel/head64.c     |  5 -----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index 5c2fd05bd52c..8aa6ba0427b0 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -74,6 +74,16 @@ static inline void x86_ce4100_early_setup(void) { }
 extern struct boot_params boot_params;
 extern char _text[];
 
+/*
+ * This function is used in C code that runs while the kernel still runs on
+ * identity mapped addresses to get the correct address of kernel pointers in
+ * the identity mapping.
+ */
+static __always_inline void *fixup_pointer(void *ptr, unsigned long physaddr)
+{
+	return ptr - (void *)_text + (void *)physaddr;
+}
+
 static inline bool kaslr_enabled(void)
 {
 	return IS_ENABLED(CONFIG_RANDOMIZE_MEMORY) &&
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index b0ab5627900b..8703292a35e9 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -82,11 +82,6 @@ static struct desc_ptr startup_gdt_descr = {
 
 #define __head	__section(.head.text)
 
-static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
-{
-	return ptr - (void *)_text + (void *)physaddr;
-}
-
 static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr)
 {
 	return fixup_pointer(ptr, physaddr);
-- 
2.28.0