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>

3 files changed, 63 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index ed3cdcb50198..391e01387248 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/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 */             \
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 376e36d707f9..c2d0e58aba31 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/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
 
 /*
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index af88486b0c23..1bdba54839b4 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/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 */