From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] powerpc: ensure that swiotlb buffer is allocated from low memory Date: Wed, 4 Dec 2019 14:56:32 +0100 Message-ID: <20191204135632.GA31262@lst.de> References: <20191204123524.22919-1-rppt@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20191204123524.22919-1-rppt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Sender: "iommu" To: Mike Rapoport Cc: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Darren Stevens , Benjamin Herrenschmidt , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mike Rapoport , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Rob Herring , Paul Mackerras , Michael Ellerman , mad skateman , Christian Zigotzky , linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Christoph Hellwig , Nicolas Saenz Julienne , Robin Murphy List-Id: linux-arch.vger.kernel.org On Wed, Dec 04, 2019 at 02:35:24PM +0200, Mike Rapoport wrote: > From: Mike Rapoport > > Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G. If a > system has more physical memory than this limit, the swiotlb buffer is not > addressable because it is allocated from memblock using top-down mode. > > Force memblock to bottom-up mode before calling swiotlb_init() to ensure > that the swiotlb buffer is DMA-able. > > Link: https://lkml.kernel.org/r/F1EBB706-73DF-430E-9020-C214EC8ED5DA-KCoaydhb8eAb1SvskN2V4Q@public.gmane.org > Reported-by: Christian Zigotzky > Signed-off-by: Mike Rapoport Looks good: Reviewed-by: Christoph Hellwig From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 4 Dec 2019 14:56:32 +0100 From: Christoph Hellwig Subject: Re: [PATCH] powerpc: ensure that swiotlb buffer is allocated from low memory Message-ID: <20191204135632.GA31262@lst.de> References: <20191204123524.22919-1-rppt@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191204123524.22919-1-rppt@kernel.org> To: Mike Rapoport Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Mike Rapoport , Christian Zigotzky , Benjamin Herrenschmidt , Christoph Hellwig , Darren Stevens , mad skateman , Michael Ellerman , Nicolas Saenz Julienne , Paul Mackerras , Robin Murphy , Rob Herring List-ID: Message-ID: <20191204135632.U2I8bDW5Ye8CwNFtZLcL7fhP2-JVo3BfEScPJMoKhic@z> On Wed, Dec 04, 2019 at 02:35:24PM +0200, Mike Rapoport wrote: > From: Mike Rapoport > > Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G. If a > system has more physical memory than this limit, the swiotlb buffer is not > addressable because it is allocated from memblock using top-down mode. > > Force memblock to bottom-up mode before calling swiotlb_init() to ensure > that the swiotlb buffer is DMA-able. > > Link: https://lkml.kernel.org/r/F1EBB706-73DF-430E-9020-C214EC8ED5DA@xenosoft.de > Reported-by: Christian Zigotzky > Signed-off-by: Mike Rapoport Looks good: Reviewed-by: Christoph Hellwig