arch/x86/xen: Silence compiler warnings

Compiler complains in the following way when x86 32-bit kernel
with Xen support is build:

  CC      arch/x86/xen/enlighten.o
arch/x86/xen/enlighten.c: In function ‘xen_start_kernel’:
arch/x86/xen/enlighten.c:1726:3: warning: right shift count >= width of type [enabled by default]

Such line contains following EFI initialization code:

boot_params.efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32);

There is no issue if x86 64-bit kernel is build. However, 32-bit case
generate warning (even if that code will not be executed because Xen
does not work on 32-bit EFI platforms) due to __pa() returning unsigned long
type which has 32-bits width. So move whole EFI initialization stuff
to separate function and build it conditionally to avoid above mentioned
warning on x86 32-bit architecture.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 1 insertions, 14 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index bc89647f0325..2cd0463dd262 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -32,7 +32,6 @@
 #include <linux/gfp.h>
 #include <linux/memblock.h>
 #include <linux/edd.h>
-#include <linux/efi.h>
 
 #include <xen/xen.h>
 #include <xen/events.h>
@@ -1521,7 +1520,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
 {
         struct physdev_set_iopl set_iopl;
         int rc;
-        efi_system_table_t *efi_systab_xen;
 
         if (!xen_start_info)
                 return;
@@ -1717,18 +1715,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
 
         xen_setup_runstate_info(0);
 
-        efi_systab_xen = xen_efi_probe();
-
-        if (efi_systab_xen) {
-                strncpy((char *)&boot_params.efi_info.efi_loader_signature, "Xen",
-                                sizeof(boot_params.efi_info.efi_loader_signature));
-                boot_params.efi_info.efi_systab = (__u32)__pa(efi_systab_xen);
-                boot_params.efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32);
-
-                set_bit(EFI_BOOT, &efi.flags);
-                set_bit(EFI_PARAVIRT, &efi.flags);
-                set_bit(EFI_64BIT, &efi.flags);
-        }
+        xen_efi_init();
 
         /* Start the world */
 #ifdef CONFIG_X86_32