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From: Michael Ellerman <mpe@ellerman.id.au>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Scott Wood <scottwood@freescale.com>,
	linuxppc-dev@ozlabs.org, Ian Munsie <imunsie@au1.ibm.com>,
	Jeremy Kerr <jk@ozlabs.org>
Subject: Re: [PATCH 1/2] powerpc: Add a proper syscall for switching endianness
Date: Mon, 16 Mar 2015 14:10:28 +1100	[thread overview]
Message-ID: <1426475428.20210.7.camel@ellerman.id.au> (raw)
In-Reply-To: <1426464473.17565.223.camel@kernel.crashing.org>

On Mon, 2015-03-16 at 11:07 +1100, Benjamin Herrenschmidt wrote:
> On Mon, 2015-03-16 at 09:59 +1100, Tony Breeds wrote:
> > On Fri, Mar 13, 2015 at 05:38:46PM +1100, Michael Ellerman wrote:
> > 
> > > According to Paul there are no working implementations of LE on 32-bit cpus, so
> > > the syscall doesn't really make sense there.
> > 
> > Ummm that doesn't sound right.  I don't think there is an LE linux userspace
> > but I'm pretty sure we had 32-bit working on 44x.  Check where Ian did the
> > initial LE patchset.
> 
> Yes but that's done by using a per-page endian flag, not a global MSR
> bit, so we never supported a syscall to switch there and never will.

Yeah sorry, I should have said "implementations of MSR_LE on 32-bit cpus".

We can always add a 32-bit version in future if we need to, but we can't remove
it once it's there, so for now we won't do it on 32-bit.

cheers

      reply	other threads:[~2015-03-16  3:10 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-13  4:39 [PATCH 1/2] powerpc: Add a proper syscall for switching endianness Michael Ellerman
2015-03-13  4:39 ` [PATCH 2/2] selftests/powerpc: Add a test of the switch_endian() syscall Michael Ellerman
2015-03-13  5:01   ` Michael Ellerman
2015-03-13  7:10   ` Ram Pai
2015-03-13  7:16     ` Michael Ellerman
2015-03-13  6:38 ` [PATCH 1/2] powerpc: Add a proper syscall for switching endianness Michael Ellerman
2015-03-13 19:50   ` Scott Wood
2015-03-15 22:59   ` Tony Breeds
2015-03-16  0:07     ` Benjamin Herrenschmidt
2015-03-16  3:10       ` Michael Ellerman [this message]

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