[PATCH v2 2/6] x86/boot: Remove extra call to copy_bootdata()

Brian Gerst
2023-04-12T18:45:25Z

The call to copy_bootdata() in x86_64_start_reservations() is only
applicable to Xen, since native has already call it. Xen on the other
hand, has already filled in boot_params and just passes its address in,
so the copy ends up being a no-op and can be removed.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
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 f37cbff7354c..fd409b7dda74 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -129,7 +129,7 @@ asmlinkage void __init i386_start_kernel(void);

#else
asmlinkage void __init x86_64_start_kernel(char *real_mode);
-asmlinkage void __init x86_64_start_reservations(char *real_mode_data);
+asmlinkage void __init x86_64_start_reservations(void);

#endif /* __i386__ */
#endif /* _SETUP */
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 4a3b195c9002..6e0f53a66678 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -533,15 +533,11 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
/* 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 x86_64_start_reservations(char *real_mode_data)
+void __init 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));
-
sanitize_boot_params(&boot_params);

x86_early_init_platform_quirks();
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 5a034a994682..a4db5c28af57 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1430,7 +1430,7 @@ 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)
--
2.39.2