From: Richard Henderson <rth@twiddle.net>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "qemu-ppc@nongnu.org list:PowerPC" <qemu-ppc@nongnu.org>,
Alexander Graf <agraf@suse.de>,
"qemu-devel@nongnu.org qemu-devel" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH 16/16] target-ppc: Convert to new ldst opcodes
Date: Thu, 05 Sep 2013 08:35:28 -0700 [thread overview]
Message-ID: <5228A4C0.4000201@twiddle.net> (raw)
In-Reply-To: <1378381255.4321.155.camel@pasglop>
On 09/05/2013 04:40 AM, Benjamin Herrenschmidt wrote:
> Only nit: I find "end_mode" a very confusing identifier :-) "end"
> usually means something else ! Why not endian_mode ?
80 column wrapping. A poor excuse, I know...
> I haven't seen the patch itself for some reason (and I'm about to go off
> for a few days). The early day powerpc endian mode can be safely ignored
> I think, I don't even remember the details myself, I think it induced
> some changes to the byte lanes ordering on the bus and thus required the
> host bridge to be adjusted.
This sounds like the ARM BE32 mode on early arms. Now discontinued, afaik.
> The embedded PPCs have simply a per-page E bit in the TLB controlling
> the endianness of accesses through the translation, the endianness is
> "clean" in that case, and the bus doesn't flip around so it's akin to
> what P7 does but with a finer granularity.
This would be significantly harder (and slower) to emulate. It would
require playing games at the cputlb level, and really nothing to do with
the code generation from tcg at all.
r~
prev parent reply other threads:[~2013-09-05 15:35 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-04 21:04 [Qemu-devel] [PATCH 00/16] Streamlining endian handling in TCG Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 01/16] tcg: Add TCGMemOp Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 02/16] tcg-i386: Use TCGMemOp within qemu_ldst routines Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 03/16] tcg-aarch64: " Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 04/16] tcg-arm: " Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 05/16] tcg-s390: " Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 06/16] tcg-ppc: " Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 07/16] tcg-ppc64: " Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 08/16] tcg-hppa: " Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 09/16] tcg-mips: " Richard Henderson
2013-09-04 21:04 ` [Qemu-devel] [PATCH 10/16] tcg-sparc: " Richard Henderson
2013-09-04 21:05 ` [Qemu-devel] [PATCH 11/16] tcg: Add qemu_ld_st_i32/64 Richard Henderson
2013-09-04 21:05 ` [Qemu-devel] [PATCH 12/16] exec: Add both big- and little-endian memory helpers Richard Henderson
2013-09-04 21:05 ` [Qemu-devel] [PATCH 13/16] tcg-i386: Tidy softmmu routines Richard Henderson
2013-09-04 21:05 ` [Qemu-devel] [PATCH 14/16] tcg-i386: Remove "cb" output restriction from qemu_st8 for i386 Richard Henderson
2013-09-04 21:05 ` [Qemu-devel] [PATCH 15/16] tcg-i386: Support new ldst opcodes Richard Henderson
2013-09-04 21:05 ` [Qemu-devel] [PATCH 16/16] target-ppc: Convert to " Richard Henderson
2013-09-05 9:08 ` [Qemu-devel] [Qemu-ppc] " Alexander Graf
2013-09-05 11:40 ` Benjamin Herrenschmidt
2013-09-05 12:59 ` Alexander Graf
2013-09-05 13:37 ` Benjamin Herrenschmidt
2013-09-05 15:35 ` Richard Henderson [this message]
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