From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from kirsty.vergenet.net ([202.4.237.240]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Zmu8F-0000hc-W9 for kexec@lists.infradead.org; Fri, 16 Oct 2015 01:48:32 +0000 Date: Fri, 16 Oct 2015 10:48:03 +0900 From: Simon Horman Subject: Re: [PATCH v2 2/3] ppc64: Avoid rfid if no need to clear MSR_LE Message-ID: <20151016014803.GF20667@verge.net.au> References: <1444172150-29493-1-git-send-email-scottwood@freescale.com> <1444172150-29493-2-git-send-email-scottwood@freescale.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1444172150-29493-2-git-send-email-scottwood@freescale.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Scott Wood Cc: kexec@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, Samuel Mendoza-Jonas , Michael Ellerman On Tue, Oct 06, 2015 at 05:55:49PM -0500, Scott Wood wrote: > Commit a304e2d82a8c3 ("ppc64: purgatory: Reset primary cpu endian to > big-endian) changed bctr to rfid. rfid is book3s-only and will cause a > fatal exception on book3e. > > Purgatory is an isolated environment which makes importing information > about the subarch awkward, so instead rely on the fact that MSR_LE > should never be set on book3e, and the rfid is only needed if MSR_LE is > set (and thus needs to be cleared). In theory that MSR bit is reserved > on book3e, rather than zero, but in practice I have not seen it set. > > Signed-off-by: Scott Wood > Cc: Samuel Mendoza-Jonas > --- > v2: new patch Could I get a review of this from at lest one ppc person? > purgatory/arch/ppc64/v2wrap.S | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/purgatory/arch/ppc64/v2wrap.S b/purgatory/arch/ppc64/v2wrap.S > index 179ade9..3534080 100644 > --- a/purgatory/arch/ppc64/v2wrap.S > +++ b/purgatory/arch/ppc64/v2wrap.S > @@ -116,9 +116,17 @@ master: > stw 7,0x5c(4) # and patch it into the kernel > mr 3,16 # restore dt address > > + mfmsr 5 > + andi. 10,5,1 # test MSR_LE > + bne little_endian > + > + li 5,0 # r5 will be 0 for kernel > + mtctr 4 # prepare branch to > + bctr # start kernel > + > +little_endian: # book3s-only > mtsrr0 4 # prepare branch to > > - mfmsr 5 > clrrdi 5,5,1 # clear MSR_LE > mtsrr1 5 > > -- > 2.1.4 > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec