Blackfin arch: unify duplicated bss init code

Signed-off-by: NMike Frysinger <vapier.adi@gmail.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>

arch/blackfin/mach-common/head.S

@@ -195,6 +195,19 @@ ENDPROC(__start)
 # define WDOG_CTL WDOGA_CTL
 #endif
 
+ENTRY(__init_clear_bss)
+	r2 = r2 - r1;
+	cc = r2 == 0;
+	if cc jump .L_bss_done;
+	r2 >>= 2;
+	p1 = r1;
+	p2 = r2;
+	lsetup (1f, 1f) lc0 = p2;
+1:	[p1++] = r0;
+.L_bss_done:
+	rts;
+ENDPROC(__init_clear_bss)
+
 ENTRY(_real_start)
 	/* Enable nested interrupts */
 	[--sp] = reti;
@@ -206,75 +219,34 @@ ENTRY(_real_start)
 	w[p0] = r0;
 	ssync;
 
+	r0 = 0 (x);
+	/* Zero out all of the fun bss regions */
 #if L1_DATA_A_LENGTH > 0
 	r1.l = __sbss_l1;
 	r1.h = __sbss_l1;
 	r2.l = __ebss_l1;
 	r2.h = __ebss_l1;
-	r0 = 0 (z);
-	r2 = r2 - r1;
-	cc = r2 == 0;
-	if cc jump .L_a_l1_done;
-	r2 >>= 2;
-	p1 = r1;
-	p2 = r2;
-	lsetup (.L_clear_a_l1, .L_clear_a_l1 ) lc0 = p2;
-.L_clear_a_l1:
-	[p1++] = r0;
-.L_a_l1_done:
+	call __init_clear_bss
 #endif
-
 #if L1_DATA_B_LENGTH > 0
 	r1.l = __sbss_b_l1;
 	r1.h = __sbss_b_l1;
 	r2.l = __ebss_b_l1;
 	r2.h = __ebss_b_l1;
-	r0 = 0 (z);
-	r2 = r2 - r1;
-	cc = r2 == 0;
-	if cc jump .L_b_l1_done;
-	r2 >>= 2;
-	p1 = r1;
-	p2 = r2;
-	lsetup (.L_clear_b_l1, .L_clear_b_l1 ) lc0 = p2;
-.L_clear_b_l1:
-	[p1++] = r0;
-.L_b_l1_done:
+	call __init_clear_bss
 #endif
-
 #if L2_LENGTH > 0
 	r1.l = __sbss_l2;
 	r1.h = __sbss_l2;
 	r2.l = __ebss_l2;
 	r2.h = __ebss_l2;
-	r0 = 0 (z);
-	r2 = r2 - r1;
-	cc = r2 == 0;
-	if cc jump .L_l2_done;
-	r2 >>= 2;
-	p1 = r1;
-	p2 = r2;
-	lsetup (.L_clear_l2, .L_clear_l2 ) lc0 = p2;
-.L_clear_l2:
-	[p1++] = r0;
-.L_l2_done:
+	call __init_clear_bss
 #endif
-
-	/* Zero out the bss region
-	 * Note: this will fail if bss is 0 bytes ...
-	 */
-	r0 = 0 (z);
 	r1.l = ___bss_start;
 	r1.h = ___bss_start;
 	r2.l = ___bss_stop;
 	r2.h = ___bss_stop;
-	r2 = r2 - r1;
-	r2 >>= 2;
-	p1 = r1;
-	p2 = r2;
-	lsetup (.L_clear_bss, .L_clear_bss) lc0 = p2;
-.L_clear_bss:
-	[p1++] = r0;
+	call __init_clear_bss
 
 	/* In case there is a NULL pointer reference,
 	 * zero out region before stext