Date: Mon, 25 Nov 2013 21:26:18 +0700 From: Alexey Dokuchaev <danfe@nsu.ru> To: Nathan Whitehorn <nwhitehorn@freebsd.org> Cc: powerpc@freebsd.org Subject: Re: mfpvr instruction: how to get processor version info from userland? Message-ID: <20131125142618.GA79428@regency.nsu.ru> In-Reply-To: <5293599C.8080401@freebsd.org> References: <20131125124901.GA87016@regency.nsu.ru> <5293599C.8080401@freebsd.org>
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On Mon, Nov 25, 2013 at 08:07:24AM -0600, Nathan Whitehorn wrote: > >it seems that mfpvr should do the job, but it can only be called from > >kernel. Linux emulates it so user-space can have access to the info; but > >in FreeBSD, its prototype is hidden under #ifdef _KERNEL :( > > > >i haven't yet made my way through this code, but have a quick question: is > >there a way to obtain mfpvr() value from userland (thru kernel catching > >the trap that the processor raises when a non-privileged program tries to > >execute it), or i have to write my own kld for that? i also wonder why it > >was made privileged in the first place... thanks, > > You can use it fine from userland -- just copy the mfpvr() definition > our of the header file. The architecture makes it privileged for various > reasons (VM mobility for instance), but we emulate it. OK, i see. Would it more sense to open it to userland (in header file) in this case? Or there are reasons it's hidden behind #ifdef _KERNEL? ./danfe
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