sparc32: always define boot_cpu_id

Define boot_cpu_id in single-processor kernels as well. This is
to support architectures which can boot on other than CPU0.

Sam Ravnborg has written the cleanup parts by extracting
boot_cpu_id from smp_32.c into setup_32.c and cleaned up
sun4d_irq.c.

boot_cpu_id was initialized before BSS was cleared in
sun4c_continue_boot, instead boot_cpu_id is set to 0xff to
avoid BSS. If boot_cpu_id is untouched (0xff) by bootup code
it will be overwritten to 0. boot_cpu_id4 is automatically
calculated in common code.

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/kernel/head_32.S b/arch/sparc/kernel/head_32.S
index 5942349..520c615 100644
--- a/arch/sparc/kernel/head_32.S
+++ b/arch/sparc/kernel/head_32.S
@@ -816,10 +816,7 @@
 
 		.global leon_smp_init
 leon_smp_init:
-		sethi	%hi(boot_cpu_id), %g1    ! master always 0
-		stb	%g0, [%g1 + %lo(boot_cpu_id)]
-		sethi	%hi(boot_cpu_id4), %g1   ! master always 0
-		stb	%g0, [%g1 + %lo(boot_cpu_id4)]
+		/* let boot_cpu_id default to 0 (master always 0) */
 
 		rd     %asr17,%g1
 		srl    %g1,28,%g1
@@ -893,9 +890,6 @@
 	sta     %g4, [%g0] ASI_M_VIKING_TMP1
 	sethi	%hi(boot_cpu_id), %g5
 	stb	%g4, [%g5 + %lo(boot_cpu_id)]
-	sll	%g4, 2, %g4
-	sethi	%hi(boot_cpu_id4), %g5
-	stb	%g4, [%g5 + %lo(boot_cpu_id4)]
 #endif
 
 	/* Fall through to sun4m_init */
@@ -1024,14 +1018,28 @@
 		bl	1b
 		 add	%o0, 0x1, %o0
 
+		/* If boot_cpu_id has not been setup by machine specific
+		 * init-code above we default it to zero.
+		 */
+		sethi	%hi(boot_cpu_id), %g2
+		ldub	[%g2 + %lo(boot_cpu_id)], %g3
+		cmp	%g3, 0xff
+		bne	1f
+		 nop
+		mov	%g0, %g3
+		stub	%g3, [%g2 + %lo(boot_cpu_id)]
+
+1:		/* boot_cpu_id set. calculate boot_cpu_id4 = boot_cpu_id*4 */
+		sll	%g3, 2, %g3
+		sethi	%hi(boot_cpu_id4), %g2
+		stub	%g3, [%g2 + %lo(boot_cpu_id4)]
+
 		/* Initialize the uwinmask value for init task just in case.
 		 * But first make current_set[boot_cpu_id] point to something useful.
 		 */
 		set	init_thread_union, %g6
 		set	current_set, %g2
 #ifdef CONFIG_SMP
-		sethi	%hi(boot_cpu_id4), %g3
-		ldub	[%g3 + %lo(boot_cpu_id4)], %g3
 		st	%g6, [%g2]
 		add	%g2, %g3, %g2
 #endif