[PATCH 4/5] x86/boot/64: Remove copy_bootdata() call

[Brian Gerst]

On a normal boot, copy_bootdata() is first called in
x86_64_start_kernel().  The second call in x86_64_start_reservations()
is effectively a no-op.

Xen PV directly initializes boot_params, so it does not need to call
copy_bootdata() at all.

Remove the unnecessary call to copy_bootdata() from
x86_64_start_reservations().

Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
---
 arch/x86/include/asm/setup.h | 2 +-
 arch/x86/kernel/head64.c     | 8 ++------
 arch/x86/xen/enlighten_pv.c  | 2 +-
 3 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index d23f4272d930..18a4d3826af7 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -130,7 +130,7 @@ void __init mk_early_pgtbl_32(void);
 
 #else
 asmlinkage void __init __noreturn x86_64_start_kernel(char *real_mode);
-asmlinkage void __init __noreturn x86_64_start_reservations(char *real_mode_data);
+asmlinkage void __init __noreturn x86_64_start_reservations(void);
 
 #endif /* __i386__ */
 #endif /* _SETUP */
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 9f19635c6390..d895376e9346 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -276,15 +276,11 @@ asmlinkage __visible void __init __noreturn x86_64_start_kernel(char * real_mode
 	/* set init_top_pgt kernel high mapping*/
 	init_top_pgt[511] = early_top_pgt[511];
 
-	x86_64_start_reservations(real_mode_data);
+	x86_64_start_reservations();
 }
 
-void __init __noreturn x86_64_start_reservations(char *real_mode_data)
+void __init __noreturn x86_64_start_reservations(void)
 {
-	/* version is always not zero if it is copied */
-	if (!boot_params.hdr.version)
-		copy_bootdata(__va(real_mode_data));
-
 	x86_early_init_platform_quirks();
 
 	switch (boot_params.hdr.hardware_subarch) {
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 6aa13d19c0a4..e6e2666da5a1 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1556,7 +1556,7 @@ asmlinkage __visible void __init xen_start_kernel(struct start_info *si)
 
 	/* Start the world */
 	cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */
-	x86_64_start_reservations((char *)__pa_symbol(&boot_params));
+	x86_64_start_reservations();
 }
 
 static int xen_cpu_up_prepare_pv(unsigned int cpu)
-- 
2.55.0