From: Michael Neuling <mikey@neuling•org>
To: Jimi Xenidis <jimix@pobox•com>
Cc: Andrew T Tauferner <ataufer@us•ibm.com>,
Kumar Gala <kumar.gala@gmail•com>,
Jay Bryant <jsbryant@us•ibm.com>,
Josh Boyer <jwboyer@linux•vnet.ibm.com>,
Todd Inglett <tinglett@us•ibm.com>,
linuxppc-dev <linuxppc-dev@lists•ozlabs.org>
Subject: Re: [RFC] Add IBM Blue Gene/Q Platform
Date: Fri, 07 Dec 2012 16:55:55 +1100 [thread overview]
Message-ID: <22952.1354859755@neuling.org> (raw)
In-Reply-To: <22874.1354859652@neuling.org>
Michael Neuling <mikey@neuling•org> wrote:
> > commit 279c0615917b959a652e81f4ad0d886e2d426d85
> > Author: Jimi Xenidis <jimix@pobox•com>
> > Date: Wed Dec 5 13:43:22 2012 -0500
> >
> > powerpc/book3e: IBM Blue Gene/Q Quad Processing eXtention (QPX)
> >
> > This enables kernel support for the QPX extention and is intended for
> > processors that support it, usually an IBM Blue Gene processor.
> > Turning it on does not effect other processors but it does add code
> > and will quadruple the per thread save and restore area for the FPU
> > (hense the name). If you have enabled VSX it will only double the
> > space.
> >
> > Signed-off-by: Jimi Xenidis <jimix@pobox•com>
>
> Can you give a diagram of how the QPX registers are layed out.
>
> +#if defined(CONFIG_PPC_QPX)
> +#define TS_FPRWIDTH 4
> +#elif defined(CONFIG_VSX)
>
> Are they 256 bits wide?
>
>
> +#define QVLFDXA(QRT,RA,RB) \
> + .long (0x7c00048f | ((QRT) << 21) | ((RA) << 16) | ((RB) << 11))
>
> Put this in ppc-opcode.h.
>
> +#if defined(CONFIG_VSX) || defined(CONFIG_PPC_QPX)
> + /* they are the same MSR bit */
>
> OMG!
>
>
> +BEGIN_FTR_SECTION \
> + SAVE_32VSRS(n,c,base); \
> +END_FTR_SECTION_IFSET(CPU_FTR_VSX); \
> +BEGIN_FTR_SECTION \
> + SAVE_32QRS(n,c,base); \
> +END_FTR_SECTION_IFSET(CPU_FTR_QPX);
>
> I don't think we want to do this. We are going to end up with 64
> NOPS here somewhere.
>
> I'd like to see this patch broken into different parts.
>
> Also, have you boot tested this change on a VSX enabled box?
Also, this is going to clash with the transactional memory patches.
Mikey
next prev parent reply other threads:[~2012-12-07 5:55 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-07 1:53 [RFC] Add IBM Blue Gene/Q Platform Jimi Xenidis
2012-12-07 5:41 ` Michael Neuling
2012-12-07 13:12 ` Jimi Xenidis
2012-12-10 0:12 ` Michael Neuling
2012-12-07 5:54 ` Michael Neuling
2012-12-07 5:55 ` Michael Neuling [this message]
2012-12-07 13:38 ` Jimi Xenidis
2012-12-08 22:22 ` Jimi Xenidis
2012-12-10 0:47 ` Michael Neuling
2012-12-10 5:56 ` Jimi Xenidis
2012-12-10 6:06 ` Michael Neuling
2012-12-10 0:18 ` Michael Neuling
2012-12-07 5:56 ` Michael Neuling
2012-12-07 13:44 ` Jimi Xenidis
2012-12-07 14:31 ` Andrew Tauferner
2012-12-10 21:32 ` Jimi Xenidis
2012-12-10 21:33 ` Jimi Xenidis
2012-12-10 0:26 ` Michael Neuling
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