x86-64/efi: Use EFI to deal with platform wall clock

Other than ix86, x86-64 on EFI so far didn't set the
{g,s}et_wallclock accessors to the EFI routines, thus
incorrectly using raw RTC accesses instead.

Simply removing the #ifdef around the respective code isn't
enough, however: While so far early get-time calls were done in
physical mode, this doesn't work properly for x86-64, as virtual
addresses would still need to be set up for all runtime regions
(which wasn't the case on the system I have access to), so
instead the patch moves the call to efi_enter_virtual_mode()
ahead (which in turn allows to drop all code related to calling
efi-get-time in physical mode).

Additionally the earlier calling of efi_set_executable()
requires the CPA code to cope, i.e. during early boot it must be
avoided to call cpa_flush_array(), as the first thing this
function does is a BUG_ON(irqs_disabled()).

Also make the two EFI functions in question here static -
they're not being referenced elsewhere.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Matt Fleming <matt.fleming@intel.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4FBFBF5F020000780008637F@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/init/main.c b/init/main.c
index 1ca6b32c4828..eef30128321a 100644
--- a/init/main.c
+++ b/init/main.c
@@ -460,6 +460,10 @@ static void __init mm_init(void)
         percpu_init_late();
         pgtable_cache_init();
         vmalloc_init();
+#ifdef CONFIG_X86
+        if (efi_enabled)
+                efi_enter_virtual_mode();
+#endif
 }
 
 asmlinkage void __init start_kernel(void)
@@ -601,10 +605,6 @@ asmlinkage void __init start_kernel(void)
         calibrate_delay();
         pidmap_init();
         anon_vma_init();
-#ifdef CONFIG_X86
-        if (efi_enabled)
-                efi_enter_virtual_mode();
-#endif
         thread_info_cache_init();
         cred_init();
         fork_init(totalram_pages);