ia64/efi: Implement efi_enabled()

There's no good reason to keep efi_enabled() under CONFIG_X86 anymore,
since nothing about the implementation is specific to x86.

Set EFI feature flags in the ia64 boot path instead of claiming to
support all features. The old behaviour was actually buggy since
efi.memmap never points to a valid memory map, so we shouldn't be
claiming to support EFI_MEMMAP.

Fortunately, this bug was never triggered because EFI_MEMMAP isn't used
outside of arch/x86 currently, but that may not always be the case.
Reviewed-and-tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

arch/ia64/kernel/efi.c

@@ -477,6 +477,9 @@ efi_init (void)
 	char *cp, vendor[100] = "unknown";
 	int i;
 
+	set_bit(EFI_BOOT, &efi.flags);
+	set_bit(EFI_64BIT, &efi.flags);
+
 	/*
 	 * It's too early to be able to use the standard kernel command line
 	 * support...
@@ -529,6 +532,8 @@ efi_init (void)
 	       efi.systab->hdr.revision >> 16,
 	       efi.systab->hdr.revision & 0xffff, vendor);
 
+	set_bit(EFI_SYSTEM_TABLES, &efi.flags);
+
 	palo_phys      = EFI_INVALID_TABLE_ADDR;
 
 	if (efi_config_init(arch_tables) != 0)
@@ -657,6 +662,8 @@ efi_enter_virtual_mode (void)
 		return;
 	}
 
+	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+
 	/*
 	 * Now that EFI is in virtual mode, we call the EFI functions more
 	 * efficiently:

include/linux/efi.h

@@ -660,8 +660,6 @@ extern int __init efi_setup_pcdp_console(char *);
 #define EFI_ARCH_1		6	/* First arch-specific bit */
 
 #ifdef CONFIG_EFI
-# ifdef CONFIG_X86
-
 /*
  * Test whether the above EFI_* bits are enabled.
  */
@@ -669,12 +667,6 @@ static inline bool efi_enabled(int feature)
 {
 	return test_bit(feature, &efi.flags) != 0;
 }
-# else
-static inline bool efi_enabled(int feature)
-{
-	return true;
-}
-# endif
 #else
 static inline bool efi_enabled(int feature)
 {