powerpc/8xx: Const for TLB RPN forced value

Value 0x00f0 is used to force bits in TLB level 2 entry. This value is linked
to the page size and will vary when we change the page size. Lets define a const
for it in order to have it at only one place.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>

arch/powerpc/kernel/head_8xx.S

@@ -40,6 +40,13 @@
 #else
 #define DO_8xx_CPU6(val, reg)
 #endif
+
+/*
+ * Value for the bits that have fixed value in RPN entries.
+ * Also used for tagging DAR for DTLBerror.
+ */
+#define RPN_PATTERN	0x00f0
+
 	__HEAD
 _ENTRY(_stext);
 _ENTRY(_start);
@@ -211,7 +218,7 @@ MachineCheck:
 	EXCEPTION_PROLOG
 	mfspr r4,SPRN_DAR
 	stw r4,_DAR(r11)
-	li r5,0x00f0
+	li r5,RPN_PATTERN
 	mtspr SPRN_DAR,r5	/* Tag DAR, to be used in DTLB Error */
 	mfspr r5,SPRN_DSISR
 	stw r5,_DSISR(r11)
@@ -239,7 +246,7 @@ Alignment:
 	EXCEPTION_PROLOG
 	mfspr	r4,SPRN_DAR
 	stw	r4,_DAR(r11)
-	li	r5,0x00f0
+	li	r5,RPN_PATTERN
 	mtspr	SPRN_DAR,r5	/* Tag DAR, to be used in DTLB Error */
 	mfspr	r5,SPRN_DSISR
 	stw	r5,_DSISR(r11)
@@ -343,7 +350,7 @@ InstructionTLBMiss:
 	 * set.  All other Linux PTE bits control the behavior
 	 * of the MMU.
 	 */
-	li	r11, 0x00f0
+	li	r11, RPN_PATTERN
 	rlwimi	r10, r11, 0, 0x07f8	/* Set 24-27, clear 21-23,28 */
 	DO_8xx_CPU6(0x2d80, r3)
 	mtspr	SPRN_MI_RPN, r10	/* Update TLB entry */
@@ -447,7 +454,7 @@ DataStoreTLBMiss:
 	 * set.  All other Linux PTE bits control the behavior
 	 * of the MMU.
 	 */
-2:	li	r11, 0x00f0
+2:	li	r11, RPN_PATTERN
 	rlwimi	r10, r11, 0, 24, 28	/* Set 24-27, clear 28 */
 	DO_8xx_CPU6(0x3d80, r3)
 	mtspr	SPRN_MD_RPN, r10	/* Update TLB entry */
@@ -482,7 +489,7 @@ DataTLBError:
 	EXCEPTION_PROLOG_0
 
 	mfspr	r11, SPRN_DAR
-	cmpwi	cr0, r11, 0x00f0
+	cmpwi	cr0, r11, RPN_PATTERN
 	beq-	FixupDAR	/* must be a buggy dcbX, icbi insn. */
 DARFixed:/* Return from dcbx instruction bug workaround */
 	EXCEPTION_PROLOG_1
@@ -491,7 +498,7 @@ DARFixed:/* Return from dcbx instruction bug workaround */
 	stw	r10,_DSISR(r11)
 	mr	r5,r10
 	mfspr	r4,SPRN_DAR
-	li	r10,0x00f0
+	li	r10,RPN_PATTERN
 	mtspr	SPRN_DAR,r10	/* Tag DAR, to be used in DTLB Error */
 	/* 0x300 is DataAccess exception, needed by bad_page_fault() */
 	EXC_XFER_LITE(0x300, handle_page_fault)