On 04/22/2013 05:11 AM, Michael Ellerman wrote: > On Thu, Apr 18, 2013 at 05:56:12PM +0530, Anshuman Khandual wrote: >> This patch adds new POWER8 instruction encoding for reading >> the BHRB buffer entries and also clearing it. Encoding for >> "clrbhrb" instruction is straight forward. > > Which is "clear branch history rolling buffer" ? > >> But "mfbhrbe" >> encoding involves reading a certain index of BHRB buffer >> into a particular GPR register. > > And "Move from branch history rolling buffer entry" ? >
Sure, would add these descriptions in the change log. >> diff --git a/arch/powerpc/include/asm/ppc-opcode.h >> b/arch/powerpc/include/asm/ppc-opcode.h >> index 8752bc8..93ae5a1 100644 >> --- a/arch/powerpc/include/asm/ppc-opcode.h >> +++ b/arch/powerpc/include/asm/ppc-opcode.h >> @@ -82,6 +82,7 @@ >> #define __REGA0_R31 31 >> >> /* sorted alphabetically */ >> +#define PPC_INST_BHRBE 0x7c00025c > > I don't think you really need this, just use the literal value below. > >> @@ -297,6 +298,12 @@ >> #define PPC_NAP stringify_in_c(.long PPC_INST_NAP) >> #define PPC_SLEEP stringify_in_c(.long PPC_INST_SLEEP) >> >> +/* BHRB instructions */ >> +#define PPC_CLRBHRB stringify_in_c(.long 0x7c00035c) >> +#define PPC_MFBHRBE(r, n) stringify_in_c(.long PPC_INST_BHRBE | \ >> + __PPC_RS(r) | \ >> + (((n) & 0x1f) << 11)) > > Why are you not using ___PPC_RB(n) here ? > I would replace __PPC_RS(r) with __PPC_RT(r) which makes more sense from instruction encoding point of view. Regards Anshuman -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
