Blackfin: optimize double fault boot checking

This moves the double fault data used at boot time into a single struct
which can then easily be addressed with indexed loads rather than having
to explicitly load multiple addresses.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/mach-common/head.S

@@ -85,37 +85,25 @@ ENTRY(__start)
 	SSYNC;
 
 	/* in case of double faults, save a few things */
-	p0.l = _init_retx;
-	p0.h = _init_retx;
-	R0 = RETX;
-	[P0] = R0;
-
+	p1.l = _initial_pda;
+	p1.h = _initial_pda;
+	r4 = RETX;
 #ifdef CONFIG_DEBUG_DOUBLEFAULT
 	/* Only save these if we are storing them,
 	 * This happens here, since L1 gets clobbered
 	 * below
 	 */
 	GET_PDA(p0, r0);
-	r5 = [p0 + PDA_DF_RETX];
-	p1.l = _init_saved_retx;
-	p1.h = _init_saved_retx;
-	[p1] = r5;
-
-	r5 = [p0 + PDA_DF_DCPLB];
-	p1.l = _init_saved_dcplb_fault_addr;
-	p1.h = _init_saved_dcplb_fault_addr;
-	[p1] = r5;
-
-	r5 = [p0 + PDA_DF_ICPLB];
-	p1.l = _init_saved_icplb_fault_addr;
-	p1.h = _init_saved_icplb_fault_addr;
-	[p1] = r5;
-
-	r5 = [p0 + PDA_DF_SEQSTAT];
-	p1.l = _init_saved_seqstat;
-	p1.h = _init_saved_seqstat;
-	[p1] = r5;
+	r0 = [p0 + PDA_DF_RETX];
+	r1 = [p0 + PDA_DF_DCPLB];
+	r2 = [p0 + PDA_DF_ICPLB];
+	r3 = [p0 + PDA_DF_SEQSTAT];
+	[p1 + PDA_INIT_DF_RETX] = r0;
+	[p1 + PDA_INIT_DF_DCPLB] = r1;
+	[p1 + PDA_INIT_DF_ICPLB] = r2;
+	[p1 + PDA_INIT_DF_SEQSTAT] = r3;
 #endif
+	[p1 + PDA_INIT_RETX] = r4;
 
 	/* Initialize stack pointer */
 	sp.l = _init_thread_union + THREAD_SIZE;