From mboxrd@z Thu Jan 1 00:00:00 1970 From: oss@buserror.net (Scott Wood) Date: Thu, 16 Mar 2017 15:08:32 -0500 Subject: [PATCH 06/10] soc/qbman: Add ARM equivalent for flush_dcache_range() In-Reply-To: References: <5414359.8GMja3pNrI@wuerfel> <1485570872.9266.22.camel@buserror.net> <3cc42823-0fc9-ed3e-1738-bf6e314dd569@arm.com> <20170206223721.GN27312@n2100.armlinux.org.uk> Message-ID: <1489694912.2944.30.camel@buserror.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 2017-03-16 at 00:43 +0000, Roy Pledge wrote: > Just wanted to follow up on this - turns out the no-map; attribute is > what I was missing. I now have the suggested mechanism working for ARM. > However when I went to test on PowePC the region wasn't being enabled > properly. It turns out the Kconfig in arch/powerpc doesn't define > HAVE_GENERIC_DMA_COHERENT so this mechanism isn't available. However I > added it and everything worked on my PPC board as it did on ARM. > > Does anyone know why HAVE_GENERIC_DMA_COHERENT isn't defined for > PowerPC? I did a quick search but didn't see previous discussion on this > topic. Probably because nothing on PPC needed it. In any case, the problems with doing this on PPC run deeper than that, as I pointed out in: https://www.spinics.net/lists/arm-kernel/msg560020.html -Scott