From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: remove dma_zalloc_coherent Date: Tue, 8 Jan 2019 08:06:58 -0500 Message-ID: <20190108130701.14161-1-hch@lst.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Linus Torvalds Cc: Luis Chamberlain , Julia Lawall , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org List-Id: iommu@lists.linux-foundation.org Hi Linus and world, We've always had a weird situation around dma_zalloc_coherent. To safely support mapping the allocations to userspace major architectures like x86 and arm have always zeroed allocations from dma_alloc_coherent, but a couple other architectures were missing that zeroing either always or in corner cases. Then later we grew anothe dma_zalloc_coherent interface to explicitly request zeroing, but that just added __GFP_ZERO to the allocation flags, which for some allocators that didn't end up using the page allocator ended up being a no-op and still not zeroing the allocations. So for this merge window I fixed up all remaining architectures to zero the memory in dma_alloc_coherent, and made dma_zalloc_coherent a no-op wrapper around dma_alloc_coherent, which fixes all of the above issues. dma_zalloc_coherent is now pointless and can go away, and Luis helped me writing a cocchinelle script and patch series to kill it, which I think we should apply now just after -rc1 to finally settle these issue. The script that generated the first patch is included here: @ replace_dma_zalloc_coherent @ expression dev, size, data, handle, flags; @@ -dma_zalloc_coherent(dev, size, handle, flags) +dma_alloc_coherent(dev, size, handle, flags)