Messages in this thread | | | Date | Thu, 10 Oct 2013 10:21:46 +0100 | From | Will Deacon <> | Subject | Re: SDIV / UDIV Question |
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[Adding Jonny]
On Thu, Oct 10, 2013 at 06:04:41AM +0100, Wang, Yalin wrote: > Oh , I see , > Thanks for your clarification ! > So R-class cores will not run linux ?
R-class cores can run Linux, but I don't reckon we touch SCTLR.DZ. I've added Jonny, so he can clarify the behaviour here. (I'm also not sure which cores have these instructions either).
Will
> -----Original Message----- > From: Will Deacon [mailto:will.deacon@arm.com] > Sent: Wednesday, October 09, 2013 6:54 PM > To: Wang, Yalin > Cc: 'linux-arm-msm-owner@vger.kernel.org'; linux-kernel@vger.kernel.org > Subject: Re: SDIV / UDIV Question > > On Wed, Oct 09, 2013 at 08:08:05AM +0100, Wang, Yalin wrote: > > I have a question about sdiv/ udiv instructions : > > In armv7 A/R TRM, it said sdiv/udiv will cause Divide by zero as > > undefined exception or just return zero (decided by implementation) . > > > > So in kernel , should we need register a undef hook to Get this > > undef exception and send SIGFPE to user space Process ? > > As far as I can see, this can only happen for R-class cores, based on SCTLR.DZ. > > Will >
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