From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Clark Subject: Re: [PATCH v5 1/1] iommu-api: Add map_sg/unmap_sg functions Date: Mon, 18 Aug 2014 14:32:15 -0400 Message-ID: References: <1407797150-515-1-git-send-email-ohaugan@codeaurora.org> <1407797150-515-2-git-send-email-ohaugan@codeaurora.org> <871tsm5vcn.fsf@nvidia.com> <53EA472B.3020900@codeaurora.org> <20140818140730.GC9809@8bytes.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140818140730.GC9809-zLv9SwRftAIdnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: "joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org" Cc: "laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org" , "linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "will.deacon-5wv7dgnIgG8@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org" , "Varun.Sethi-KZfg59tc24xl57MIdRCFDg@public.gmane.org" , "dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org" , "kgene.kim-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: linux-arm-msm@vger.kernel.org On Mon, Aug 18, 2014 at 10:07 AM, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org wrote: > On Tue, Aug 12, 2014 at 09:56:11AM -0700, Olav Haugan wrote: >> On 8/12/2014 3:48 AM, Rob Clark wrote: >> > iirc, one plan for 'flags' was some sort of DONT_FLUSH_TLB flag for >> > drivers which wanted to map/unmap N buffers with a single flush at the >> > end. There might have been some other usages envisioned. >> >> Yes, that was the original intent of the flags for now. I am sure we can >> find other uses for this in the future. > > Do you have anything else in mind already besides the DONT_FLUSH_TLB > flag? > > How is the IOTLB supposed to be flushed when this flag is used? > well, I was thinking one of two ways: 1) add new flush() vfunc.. this, I think, would be most convenient for drivers using this feature 2) or driver simply doesn't set DONT_FLUSH_TLB flag on the last {map,unmap}.. that would be slightly more awkward to use, but would avoid adding a new vfunc BR, -R > Joerg > From mboxrd@z Thu Jan 1 00:00:00 1970 From: robdclark@gmail.com (Rob Clark) Date: Mon, 18 Aug 2014 14:32:15 -0400 Subject: [PATCH v5 1/1] iommu-api: Add map_sg/unmap_sg functions In-Reply-To: <20140818140730.GC9809@8bytes.org> References: <1407797150-515-1-git-send-email-ohaugan@codeaurora.org> <1407797150-515-2-git-send-email-ohaugan@codeaurora.org> <871tsm5vcn.fsf@nvidia.com> <53EA472B.3020900@codeaurora.org> <20140818140730.GC9809@8bytes.org> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Aug 18, 2014 at 10:07 AM, joro at 8bytes.org wrote: > On Tue, Aug 12, 2014 at 09:56:11AM -0700, Olav Haugan wrote: >> On 8/12/2014 3:48 AM, Rob Clark wrote: >> > iirc, one plan for 'flags' was some sort of DONT_FLUSH_TLB flag for >> > drivers which wanted to map/unmap N buffers with a single flush at the >> > end. There might have been some other usages envisioned. >> >> Yes, that was the original intent of the flags for now. I am sure we can >> find other uses for this in the future. > > Do you have anything else in mind already besides the DONT_FLUSH_TLB > flag? > > How is the IOTLB supposed to be flushed when this flag is used? > well, I was thinking one of two ways: 1) add new flush() vfunc.. this, I think, would be most convenient for drivers using this feature 2) or driver simply doesn't set DONT_FLUSH_TLB flag on the last {map,unmap}.. that would be slightly more awkward to use, but would avoid adding a new vfunc BR, -R > Joerg >