powerpc: Add new CPU feature: CPU_FTR_UNALIGNED_LD_STD

Add a new CPU feature bit, CPU_FTR_UNALIGNED_LD_STD, to be added
to the 64bit powerpc chips that can do unaligned load double and
store double without any performance hit.

This is added to Power6 and Cell and will be used in the next commit
to disable the code that gets the destination address aligned on
those CPUs where doing that doesn't improve performance.

Signed-off-by: Mark Nelson <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>

Author: Mark Nelson

arch/powerpc/include/asm/cputable.h

@@ -194,6 +194,7 @@ extern const char *powerpc_base_platform;
 #define CPU_FTR_VSX			LONG_ASM_CONST(0x0010000000000000)
 #define CPU_FTR_SAO			LONG_ASM_CONST(0x0020000000000000)
 #define CPU_FTR_CP_USE_DCBTZ		LONG_ASM_CONST(0x0040000000000000)
+#define CPU_FTR_UNALIGNED_LD_STD	LONG_ASM_CONST(0x0080000000000000)
 
 #ifndef __ASSEMBLY__
 
@@ -404,7 +405,7 @@ extern const char *powerpc_base_platform;
 	    CPU_FTR_MMCRA | CPU_FTR_SMT | \
 	    CPU_FTR_COHERENT_ICACHE | CPU_FTR_LOCKLESS_TLBIE | \
 	    CPU_FTR_PURR | CPU_FTR_SPURR | CPU_FTR_REAL_LE | \
-	    CPU_FTR_DSCR)
+	    CPU_FTR_DSCR | CPU_FTR_UNALIGNED_LD_STD)
 #define CPU_FTRS_POWER7 (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    CPU_FTR_MMCRA | CPU_FTR_SMT | \
@@ -415,7 +416,8 @@ extern const char *powerpc_base_platform;
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    CPU_FTR_ALTIVEC_COMP | CPU_FTR_MMCRA | CPU_FTR_SMT | \
 	    CPU_FTR_PAUSE_ZERO | CPU_FTR_CI_LARGE_PAGE | \
-	    CPU_FTR_CELL_TB_BUG | CPU_FTR_CP_USE_DCBTZ)
+	    CPU_FTR_CELL_TB_BUG | CPU_FTR_CP_USE_DCBTZ | \
+	    CPU_FTR_UNALIGNED_LD_STD)
 #define CPU_FTRS_PA6T (CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
 	    CPU_FTR_HPTE_TABLE | CPU_FTR_PPCAS_ARCH_V2 | \
 	    CPU_FTR_ALTIVEC_COMP | CPU_FTR_CI_LARGE_PAGE | \