From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Tue, 13 Sep 2016 10:19:47 +0100 Subject: [RFCv3][PATCH 3/5] arm64: Implement ARCH_HAS_FORCE_CACHE In-Reply-To: <1473715978-11633-4-git-send-email-labbott@redhat.com> References: <1473715978-11633-1-git-send-email-labbott@redhat.com> <1473715978-11633-4-git-send-email-labbott@redhat.com> Message-ID: <20160913091946.GB7467@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Laura, On Mon, Sep 12, 2016 at 02:32:56PM -0700, Laura Abbott wrote: > > arm64 may need to guarantee the caches are synced. Implement versions of > the kernel_force_cache API to allow this. > > Signed-off-by: Laura Abbott > --- > v3: Switch to calling cache operations directly instead of relying on > DMA mapping. > --- > arch/arm64/include/asm/cacheflush.h | 8 ++++++++ > arch/arm64/mm/cache.S | 24 ++++++++++++++++++++---- > arch/arm64/mm/flush.c | 11 +++++++++++ > 3 files changed, 39 insertions(+), 4 deletions(-) I'm really hesitant to expose these cache routines as an API solely to support a driver sitting in staging/. I appreciate that there's a chicken and egg problem here, but we *really* don't want people using these routines in preference to the DMA API, and I fear that we'll simply grow a bunch more users of these things if we promote it as an API like you're proposing. Can the code not be contained under staging/, as part of ion? Will