powerpc/mpc85xx: move debug tlb entry after TLB is in known state

Previously, in many if not all configs we were creating overlapping TLB entries
which is illegal.  This caused a crash during boot when moving p2020rdb NAND SPL
into L2 SRAM.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Prabhakar Kushwaha <prabhakar@freescale.com>
Cc: Andy Fleming <afleming@freescale.com>
--
Prabhakar, please test that debug still works.

arch/powerpc/cpu/mpc85xx/start.S

@@ -282,46 +282,6 @@ l2_disabled:
 	isync
 	.endm
 
-#if defined(CONFIG_SYS_PPC_E500_DEBUG_TLB) && !defined(CONFIG_NAND_SPL)
-/*
- * TLB entry for debuggging in AS1
- * Create temporary TLB entry in AS0 to handle debug exception
- * As on debug exception MSR is cleared i.e. Address space is changed
- * to 0. A TLB entry (in AS0) is required to handle debug exception generated
- * in AS1.
- */
-
-#if !defined(CONFIG_SYS_RAMBOOT) && !defined(CONFIG_SECURE_BOOT)
-/*
- * TLB entry is created for IVPR + IVOR15 to map on valid OP code address
- * bacause flash's virtual address maps to 0xff800000 - 0xffffffff.
- * and this window is outside of 4K boot window.
- */
-	create_tlb1_entry CONFIG_SYS_PPC_E500_DEBUG_TLB, \
-		0, BOOKE_PAGESZ_4M, \
-		CONFIG_SYS_MONITOR_BASE & 0xffc00000,  MAS2_I|MAS2_G, \
-		0xffc00000, MAS3_SX|MAS3_SW|MAS3_SR, \
-		0, r6
-
-#elif !defined(CONFIG_SYS_RAMBOOT) && defined(CONFIG_SECURE_BOOT)
-	create_tlb1_entry CONFIG_SYS_PPC_E500_DEBUG_TLB, \
-		0, BOOKE_PAGESZ_1M, \
-		CONFIG_SYS_MONITOR_BASE, MAS2_I|MAS2_G, \
-		CONFIG_SYS_PBI_FLASH_WINDOW, MAS3_SX|MAS3_SW|MAS3_SR, \
-		0, r6
-#else
-/*
- * TLB entry is created for IVPR + IVOR15 to map on valid OP code address
- * because "nexti" will resize TLB to 4K
- */
-	create_tlb1_entry CONFIG_SYS_PPC_E500_DEBUG_TLB, \
-		0, BOOKE_PAGESZ_256K, \
-		CONFIG_SYS_MONITOR_BASE, MAS2_I, \
-		CONFIG_SYS_MONITOR_BASE, MAS3_SX|MAS3_SW|MAS3_SR, \
-		0, r6
-#endif
-#endif
-
 /*
  * Ne need to setup interrupt vector for NAND SPL
  * because NAND SPL never compiles it.
@@ -534,10 +494,6 @@ nexti:	mflr	r1		/* R1 = our PC */
 	li	r3, 0
 	mtspr	MAS1, r3
 1:	cmpw	r3, r14
-#if defined(CONFIG_SYS_PPC_E500_DEBUG_TLB) && !defined(CONFIG_NAND_SPL)
-	cmpwi	cr1, r3, CONFIG_SYS_PPC_E500_DEBUG_TLB
-	cror	cr0*4+eq, cr0*4+eq, cr1*4+eq
-#endif
 	rlwinm	r5, r3, 16, MAS0_ESEL_MSK
 	addi	r3, r3, 1
 	beq	2f		/* skip the entry we're executing from */
@@ -553,6 +509,46 @@ nexti:	mflr	r1		/* R1 = our PC */
 2:	cmpw	r3, r4
 	blt	1b
 
+#if defined(CONFIG_SYS_PPC_E500_DEBUG_TLB) && !defined(MINIMAL_SPL)
+/*
+ * TLB entry for debuggging in AS1
+ * Create temporary TLB entry in AS0 to handle debug exception
+ * As on debug exception MSR is cleared i.e. Address space is changed
+ * to 0. A TLB entry (in AS0) is required to handle debug exception generated
+ * in AS1.
+ */
+
+#if !defined(CONFIG_SYS_RAMBOOT) && !defined(CONFIG_SECURE_BOOT)
+/*
+ * TLB entry is created for IVPR + IVOR15 to map on valid OP code address
+ * bacause flash's virtual address maps to 0xff800000 - 0xffffffff.
+ * and this window is outside of 4K boot window.
+ */
+	create_tlb1_entry CONFIG_SYS_PPC_E500_DEBUG_TLB, \
+		0, BOOKE_PAGESZ_4M, \
+		CONFIG_SYS_MONITOR_BASE & 0xffc00000,  MAS2_I|MAS2_G, \
+		0xffc00000, MAS3_SX|MAS3_SW|MAS3_SR, \
+		0, r6
+
+#elif !defined(CONFIG_SYS_RAMBOOT) && defined(CONFIG_SECURE_BOOT)
+	create_tlb1_entry CONFIG_SYS_PPC_E500_DEBUG_TLB, \
+		0, BOOKE_PAGESZ_1M, \
+		CONFIG_SYS_MONITOR_BASE, MAS2_I|MAS2_G, \
+		CONFIG_SYS_PBI_FLASH_WINDOW, MAS3_SX|MAS3_SW|MAS3_SR, \
+		0, r6
+#else
+/*
+ * TLB entry is created for IVPR + IVOR15 to map on valid OP code address
+ * because "nexti" will resize TLB to 4K
+ */
+	create_tlb1_entry CONFIG_SYS_PPC_E500_DEBUG_TLB, \
+		0, BOOKE_PAGESZ_256K, \
+		CONFIG_SYS_MONITOR_BASE & 0xfffc0000, MAS2_I, \
+		CONFIG_SYS_MONITOR_BASE & 0xfffc0000, MAS3_SX|MAS3_SW|MAS3_SR, \
+		0, r6
+#endif
+#endif
+
 /*
  * Relocate CCSR, if necessary.  We relocate CCSR if (obviously) the default
  * location is not where we want it.  This typically happens on a 36-bit