From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vinod Koul Subject: Re: [PATCHv9 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers Date: Wed, 10 Aug 2016 23:07:10 +0530 Message-ID: <20160810173710.GK9681@localhost> References: <20160810112219.17964-1-niklas.soderlund+renesas@ragnatech.se> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <20160810112219.17964-1-niklas.soderlund+renesas-1zkq55x86MTxsAP9Fp7wbw@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: Niklas =?iso-8859-1?Q?S=F6derlund?= Cc: hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org, linux-renesas-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Wed, Aug 10, 2016 at 01:22:13PM +0200, Niklas S=F6derlund wrote: > Hi, > = > This series tries to solve the problem with DMA with device registers > (MMIO registers) that are behind an IOMMU for the rcar-dmac driver. A > recent patch '9575632 (dmaengine: make slave address physical)' > clarifies that DMA slave address provided by clients is the physical > address. This puts the task of mapping the DMA slave address from a > phys_addr_t to a dma_addr_t on the DMA engine. > = > Without an IOMMU this is easy since the phys_addr_t and dma_addr_t are > the same and no special care is needed. However if you have a IOMMU you > need to map the DMA slave phys_addr_t to a dma_addr_t using something > like this. > = > This series is based on top of v4.8-rc1. And I'm hoping to be able to col= lect a > Ack from Russell King on patch 4/6 that adds the ARM specific part and th= en be > able to take the whole series through the dmaengine tree. If this is not = the > best route I'm more then happy to do it another way. > = > It's tested on a Koelsch with CONFIG_IPMMU_VMSA and by enabling the > ipmmu_ds node in r8a7791.dtsi. I verified operation by interacting with > /dev/mmcblk1, i2c and the serial console which are devices behind the > iommu. As I said in last one, the dmaengine parts look fine to me. But to go thru dmaengine tree I would need ACK on non dmaengine patches. -- = ~Vinod