powerpc/8xx: Declare SPRG2 as a SCRATCH register

Since commit 469d62be, SPRG2 is used as a
scratch register just like SPRG0 and SPRG1. So Declare it as such and fix
the comment which is not valid anymore since that commit.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>

arch/powerpc/include/asm/reg.h

@@ -950,7 +950,7 @@
  * 32-bit 8xx:
  *	- SPRG0 scratch for exception vectors
  *	- SPRG1 scratch for exception vectors
- *	- SPRG2 apparently unused but initialized
+ *	- SPRG2 scratch for exception vectors
  *
  */
 #ifdef CONFIG_PPC64
@@ -1060,6 +1060,7 @@
 #ifdef CONFIG_8xx
 #define SPRN_SPRG_SCRATCH0	SPRN_SPRG0
 #define SPRN_SPRG_SCRATCH1	SPRN_SPRG1
+#define SPRN_SPRG_SCRATCH2	SPRN_SPRG2
 #endif
 
 

arch/powerpc/kernel/head_8xx.S

@@ -301,7 +301,7 @@ InstructionTLBMiss:
 	stw	r11, 4(r0)
 #else
 	mtspr	SPRN_DAR, r10
-	mtspr	SPRN_SPRG2, r11
+	mtspr	SPRN_SPRG_SCRATCH2, r11
 #endif
 	mfspr	r10, SPRN_SRR0	/* Get effective address of fault */
 #ifdef CONFIG_8xx_CPU15
@@ -363,7 +363,7 @@ InstructionTLBMiss:
 	mfspr	r10, SPRN_DAR
 	mtcr	r10
 	mtspr	SPRN_DAR, r11	/* Tag DAR */
-	mfspr	r11, SPRN_SPRG2
+	mfspr	r11, SPRN_SPRG_SCRATCH2
 #else
 	lwz	r11, 0(r0)
 	mtcr	r11
@@ -386,7 +386,7 @@ InstructionTLBMiss:
 	mtcr	r10
 	li	r11, 0x00f0
 	mtspr	SPRN_DAR, r11	/* Tag DAR */
-	mfspr	r11, SPRN_SPRG2
+	mfspr	r11, SPRN_SPRG_SCRATCH2
 #else
 	lwz	r11, 0(r0)
 	mtcr	r11
@@ -409,7 +409,7 @@ DataStoreTLBMiss:
 	stw	r11, 4(r0)
 #else
 	mtspr	SPRN_DAR, r10
-	mtspr	SPRN_SPRG2, r11
+	mtspr	SPRN_SPRG_SCRATCH2, r11
 #endif
 	mfspr	r10, SPRN_M_TWB	/* Get level 1 table entry address */
 
@@ -487,7 +487,7 @@ DataStoreTLBMiss:
 	mfspr	r10, SPRN_DAR
 	mtcr	r10
 	mtspr	SPRN_DAR, r11	/* Tag DAR */
-	mfspr	r11, SPRN_SPRG2
+	mfspr	r11, SPRN_SPRG_SCRATCH2
 #else
 	mtspr	SPRN_DAR, r11	/* Tag DAR */
 	lwz	r11, 0(r0)