Messages in this thread | | | Date | Mon, 22 Apr 2013 09:41:10 +1000 | From | Michael Ellerman <> | Subject | Re: [PATCH V3 1/5] powerpc, perf: Add new BHRB related instructions for POWER8 |
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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.
> @@ -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 ?
cheers
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