From mboxrd@z Thu Jan 1 00:00:00 1970 From: thierry.reding@gmail.com (Thierry Reding) Date: Mon, 30 Apr 2018 13:02:31 +0200 Subject: [PATCH v2 2/5] dma-mapping: Introduce dma_iommu_detach_device() API In-Reply-To: <20180426121136.GD11985@ulmo> References: <20180425101051.15349-1-thierry.reding@gmail.com> <20180425101051.15349-2-thierry.reding@gmail.com> <20180425151934.GC16075@infradead.org> <20180426121136.GD11985@ulmo> Message-ID: <20180430110231.GF2476@ulmo> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Apr 26, 2018 at 02:11:36PM +0200, Thierry Reding wrote: > On Wed, Apr 25, 2018 at 08:19:34AM -0700, Christoph Hellwig wrote: > > On Wed, Apr 25, 2018 at 12:10:48PM +0200, Thierry Reding wrote: > > > From: Thierry Reding > > > > > > The dma_iommu_detach_device() API can be used by drivers to forcibly > > > detach a device from an IOMMU that architecture code might have attached > > > to. This is useful for drivers that need explicit control over the IOMMU > > > using the IOMMU API directly. > > > > Given that no one else implements it making it a generic API seems > > rather confusing. For now I'd rename it to > > arm_dma_iommu_detach_device() and only implement it in arm. > > That'd be suboptimal because this code is used on both 32-bit and 64-bit > ARM. If we make the function 32-bit ARM specific then the driver code > would need to use an #ifdef to make sure compilation doesn't break on > 64-bit ARM. Do you still want me to make this ARM specific? While I haven't encountered this issue on 64-bit ARM yet, I think it would happen there as well, under the right circumstances. I could take a shot at implementing the equivalent there (which means essentially implementing it for drivers/iommu/dma-iommu.c and calling that from 64-bit ARM code). Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: