x86: desc_empty

This replaces the desc_empty macro with an inline.  It now handles
easily any of the four different types used between 32/64 code to
refer to these 8 bytes.  It's identical in both asm-x86/processor_64.h
and asm-x86/processor_32.h, so if these files ever get merged this
function can be in the common code.

This also removes the desc_equal macro because nothing uses it.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/asm-x86/processor_32.h

@@ -28,11 +28,12 @@ struct desc_struct {
 	unsigned long a,b;
 };
 
-#define desc_empty(desc) \
-		(!((desc)->a | (desc)->b))
+static inline int desc_empty(const void *ptr)
+{
+	const u32 *desc = ptr;
+	return !(desc[0] | desc[1]);
+}
 
-#define desc_equal(desc1, desc2) \
-		(((desc1)->a == (desc2)->a) && ((desc1)->b == (desc2)->b))
 /*
  * Default implementation of macro that returns current
  * instruction pointer ("program counter").

include/asm-x86/processor_64.h

@@ -30,11 +30,11 @@
 #define VIP_MASK	0x00100000	/* virtual interrupt pending */
 #define ID_MASK		0x00200000
 
-#define desc_empty(desc) \
-               (!((desc)->a | (desc)->b))
-
-#define desc_equal(desc1, desc2) \
-               (((desc1)->a == (desc2)->a) && ((desc1)->b == (desc2)->b))
+static inline int desc_empty(const void *ptr)
+{
+	const u32 *desc = ptr;
+	return !(desc[0] | desc[1]);
+}
 
 /*
  * Default implementation of macro that returns current