From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758669AbcIMPCc (ORCPT ); Tue, 13 Sep 2016 11:02:32 -0400 Received: from mail-yw0-f180.google.com ([209.85.161.180]:35556 "EHLO mail-yw0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752971AbcIMPC0 (ORCPT ); Tue, 13 Sep 2016 11:02:26 -0400 Subject: Re: [RFCv3][PATCH 3/5] arm64: Implement ARCH_HAS_FORCE_CACHE To: Will Deacon References: <1473715978-11633-1-git-send-email-labbott@redhat.com> <1473715978-11633-4-git-send-email-labbott@redhat.com> <20160913091946.GB7467@arm.com> Cc: Sumit Semwal , John Stultz , =?UTF-8?Q?Arve_Hj=c3=b8nnev=c3=a5g?= , Riley Andrews , Daniel Vetter , linaro-mm-sig@lists.linaro.org, devel@driverdev.osuosl.org, Russell King , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Catalin Marinas , Eun Taik Lee , Rohit kumar , Liviu Dudau , Jon Medhurst , Jeremy Gebben , Bryan Huntsman , Greg Kroah-Hartman , Android Kernel Team , Arnd Bergmann From: Laura Abbott Message-ID: <27805ccf-1f2d-81ea-044e-b21207be8e7f@redhat.com> Date: Tue, 13 Sep 2016 08:02:20 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20160913091946.GB7467@arm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/13/2016 02:19 AM, Will Deacon wrote: > 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? > I proposed that in V1 and it was suggested I make it a proper API http://www.mail-archive.com/driverdev-devel@linuxdriverproject.org/msg47654.html http://www.mail-archive.com/driverdev-devel@linuxdriverproject.org/msg47672.html > Will > Thanks, Laura From mboxrd@z Thu Jan 1 00:00:00 1970 From: labbott@redhat.com (Laura Abbott) Date: Tue, 13 Sep 2016 08:02:20 -0700 Subject: [RFCv3][PATCH 3/5] arm64: Implement ARCH_HAS_FORCE_CACHE In-Reply-To: <20160913091946.GB7467@arm.com> References: <1473715978-11633-1-git-send-email-labbott@redhat.com> <1473715978-11633-4-git-send-email-labbott@redhat.com> <20160913091946.GB7467@arm.com> Message-ID: <27805ccf-1f2d-81ea-044e-b21207be8e7f@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 09/13/2016 02:19 AM, Will Deacon wrote: > 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? > I proposed that in V1 and it was suggested I make it a proper API http://www.mail-archive.com/driverdev-devel at linuxdriverproject.org/msg47654.html http://www.mail-archive.com/driverdev-devel at linuxdriverproject.org/msg47672.html > Will > Thanks, Laura