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Diffstat (limited to 'include/asm-powerpc/ppc_asm.h')
-rw-r--r-- | include/asm-powerpc/ppc_asm.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/asm-powerpc/ppc_asm.h b/include/asm-powerpc/ppc_asm.h index 2dbd4e7884f..ef96bfd4ef4 100644 --- a/include/asm-powerpc/ppc_asm.h +++ b/include/asm-powerpc/ppc_asm.h @@ -356,6 +356,12 @@ END_FTR_SECTION_IFCLR(CPU_FTR_601) #define toreal(rd) #define fromreal(rd) +/* + * We use addis to ensure compatibility with the "classic" ppc versions of + * these macros, which use rs = 0 to get the tophys offset in rd, rather than + * converting the address in r0, and so this version has to do that too + * (i.e. set register rd to 0 when rs == 0). + */ #define tophys(rd,rs) \ addis rd,rs,0 |