powerpc: Macros for saving/restore PPR

[PATCH 5/6] powerpc: Macros for saving/restore PPR

Several macros are defined for saving and restore user defined PPR value.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/exception-64s.h

@@ -108,6 +108,43 @@
 #define RESTORE_LR(reg, area)
 #endif
 
+/*
+ * PPR save/restore macros used in exceptions_64s.S  
+ * Used for P7 or later processors
+ */
+#define SAVE_PPR(area, ra, rb)						\
+BEGIN_FTR_SECTION_NESTED(940)						\
+	ld	ra,PACACURRENT(r13);					\
+	ld	rb,area+EX_PPR(r13);	/* Read PPR from paca */	\
+	std	rb,TASKTHREADPPR(ra);					\
+END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,940)
+
+#define RESTORE_PPR_PACA(area, ra)					\
+BEGIN_FTR_SECTION_NESTED(941)						\
+	ld	ra,area+EX_PPR(r13);					\
+	mtspr	SPRN_PPR,ra;						\
+END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,941)
+
+/*
+ * Increase the priority on systems where PPR save/restore is not
+ * implemented/ supported.
+ */
+#define HMT_MEDIUM_PPR_DISCARD						\
+BEGIN_FTR_SECTION_NESTED(942)						\
+	HMT_MEDIUM;							\
+END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,0,942)  /*non P7*/		
+
+/*
+ * Save PPR in paca whenever some register is available to use.
+ * Then increase the priority.
+ */
+#define HMT_MEDIUM_PPR_SAVE(area, ra)					\
+BEGIN_FTR_SECTION_NESTED(943)						\
+	mfspr	ra,SPRN_PPR;						\
+	std	ra,area+EX_PPR(r13);					\
+	HMT_MEDIUM;							\
+END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,943) 
+
 #define __EXCEPTION_PROLOG_1(area, extra, vec)				\
 	GET_PACA(r13);							\
 	std	r9,area+EX_R9(r13);	/* save r9 - r12 */		\

arch/powerpc/include/asm/ppc_asm.h

@@ -389,6 +389,31 @@ END_FTR_SECTION_IFCLR(CPU_FTR_601)
 	FTR_SECTION_ELSE_NESTED(848);	\
 	mtocrf (FXM), RS;		\
 	ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_NOEXECUTE, 848)
+
+/*
+ * PPR restore macros used in entry_64.S
+ * Used for P7 or later processors
+ */
+#define HMT_MEDIUM_LOW_HAS_PPR						\
+BEGIN_FTR_SECTION_NESTED(944)						\
+	HMT_MEDIUM_LOW;							\
+END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,944)
+
+#define SET_DEFAULT_THREAD_PPR(ra, rb)					\
+BEGIN_FTR_SECTION_NESTED(945)						\
+	lis	ra,INIT_PPR@highest;	/* default ppr=3 */		\
+	ld	rb,PACACURRENT(r13);					\
+	sldi	ra,ra,32;	/* 11- 13 bits are used for ppr */	\
+	std	ra,TASKTHREADPPR(rb);					\
+END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,945)
+
+#define RESTORE_PPR(ra, rb)						\
+BEGIN_FTR_SECTION_NESTED(946)						\
+	ld	ra,PACACURRENT(r13);					\
+	ld	rb,TASKTHREADPPR(ra);					\
+	mtspr	SPRN_PPR,rb;	/* Restore PPR */			\
+END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,946)
+
 #endif
 
 /*

arch/powerpc/include/asm/reg.h

@@ -289,6 +289,7 @@
 #define SPRN_DBAT6U	0x23C	/* Data BAT 6 Upper Register */
 #define SPRN_DBAT7L	0x23F	/* Data BAT 7 Lower Register */
 #define SPRN_DBAT7U	0x23E	/* Data BAT 7 Upper Register */
+#define SPRN_PPR	0x380	/* SMT Thread status Register */
 
 #define SPRN_DEC	0x016		/* Decrement Register */
 #define SPRN_DER	0x095		/* Debug Enable Regsiter */