x86, 64-bit: split x86_64_start_kernel

Split x86_64_start_kernel() into two pieces:

   The first essentially cleans up after head_64.S.  It clears the
   bss, zaps low identity mappings, sets up some early exception
   handlers.

   The second part preserves the boot data, reserves the kernel's
   text/data/bss, pagetables and ramdisk, and then starts the kernel
   proper.

This split is so that Xen can call the second part to do the set up it
needs done.  It doesn't need any of the first part setups, because it
doesn't boot via head_64.S, and its redundant or actively damaging.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index c970929bb15d56000f85902715d194b8c1238e7c..f684e3b3de4e6986d156db09dc1134ab619ac594 100644 (file)
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -108,6 +108,11 @@ void __init x86_64_start_kernel(char * real_mode_data)
 
        early_printk("Kernel really alive\n");
 
+       x86_64_start_reservations(real_mode_data);
+}
+
+void __init x86_64_start_reservations(char *real_mode_data)
+{
        copy_bootdata(__va(real_mode_data));
 
        reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS");

diff --git a/include/asm-x86/setup.h b/include/asm-x86/setup.h
index 42bc62b4b70ceb831be1976f3aaf58596589e267..1d121c632d9e7ad57a61144161886508d5ccb664 100644 (file)
--- a/include/asm-x86/setup.h
+++ b/include/asm-x86/setup.h
@@ -58,6 +58,8 @@ extern unsigned long init_pg_tables_end;
 
 #else
 void __init x86_64_start_kernel(char *real_mode);
+void __init x86_64_start_reservations(char *real_mode_data);
+
 #endif /* __i386__ */
 #endif /* _SETUP */
 #endif /* __ASSEMBLY__ */