From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Ellerman Subject: Re: [PATCH] powerpc: ensure that swiotlb buffer is allocated from low memory Date: Wed, 18 Dec 2019 15:05:09 +1100 (AEDT) Message-ID: <47d1cj4B0Fz9sRc@ozlabs.org> References: <20191204123524.22919-1-rppt@kernel.org> Return-path: In-Reply-To: <20191204123524.22919-1-rppt@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Mike Rapoport , linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, Darren Stevens , Robin Murphy , Mike Rapoport , linux-mm@kvack.org, iommu@lists.linux-foundation.org, Rob Herring , Paul Mackerras , mad skateman , Christian Zigotzky , linuxppc-dev@lists.ozlabs.org, Christoph Hellwig , Nicolas Saenz Julienne List-Id: linux-arch.vger.kernel.org On Wed, 2019-12-04 at 12:35:24 UTC, 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 Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/8fabc623238e68b3ac63c0dd1657bf86c1fa33af cheers From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: In-Reply-To: <20191204123524.22919-1-rppt@kernel.org> From: Michael Ellerman Subject: Re: [PATCH] powerpc: ensure that swiotlb buffer is allocated from low memory Message-ID: <47d1cj4B0Fz9sRc@ozlabs.org> Date: Wed, 18 Dec 2019 15:05:09 +1100 (AEDT) To: Mike Rapoport , linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, Darren Stevens , Robin Murphy , Mike Rapoport , linux-mm@kvack.org, iommu@lists.linux-foundation.org, Rob Herring , Paul Mackerras , mad skateman , Christian Zigotzky , linuxppc-dev@lists.ozlabs.org, Christoph Hellwig , Nicolas Saenz Julienne List-ID: Message-ID: <20191218040509.Z9VHujpyadSJVctdcyTArRpCSPek5_f_9Rjy_0Sjur8@z> On Wed, 2019-12-04 at 12:35:24 UTC, 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 Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/8fabc623238e68b3ac63c0dd1657bf86c1fa33af cheers