On 04/22/2013 08:20 AM, Michael Neuling wrote: > Michael Ellerman <mich...@ellerman.id.au> wrote: > >> On Mon, Apr 22, 2013 at 11:13:43AM +1000, Michael Neuling wrote: >>> Michael Ellerman <mich...@ellerman.id.au> 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" ? >>>> >>>>> 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. >>> >>> The rest of the defines in this file do this, so Anshuman's right. >> >> I don't see the point, but sure let's be consistent. Though in that case >> he should do the same for PPC_CLRBHRB below. > > Agreed. >
Sure, would define a new macro (PPC_INST_CLRBHRB) to encode 0x7c00035c before using it for PPC_CLRBHRB. > Mikey > >> >>>>> @@ -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 ? >>> >>> Actually, this is wrong. The number field should be 10 bits (0x3ff), >>> not 5 (0x1f) Anshuman please fix. >> >> ACK. I got it wrong, thought this as 32 instead of 1024. Would fix it. 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/
