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Subject: Re: MPC8540 : What's "SPE used in kernel" ?
From: Johannes Berg <johannes@sipsolutions.net>
To: Philippe De Muyter <phdm@macqel.be>
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Date: Fri, 22 Feb 2008 16:29:11 +0100
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> I wonder why a kernel configured for E500 and compiled by a E500-specific=
 gcc
> triggers this message.  Is it invalid to use SPE instructions in the kern=
el=20
> or do I misunderstand the message ?

I think it's like floating point/altivec, we don't always save the FP
registers on kernel/userspace transitions and so have to explicitly save
them to use them in the kernel, otherwise we'd clobber the userspace
register state.

I guess there's something like kernel_enter_spe()?

johannes

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