user/sven/linux.git/include/linux/dma-contiguous.h, branch v5.9.8

dma-direct: fix zone selection after an unaddressable CMA allocation

2019-08-20T22:14:10Z

The new dma_alloc_contiguous hides if we allocate CMA or regular pages, and thus fails to retry a ZONE_NORMAL allocation if the CMA allocation succeeds but isn't addressable. That means we either fail outright or dip into a small zone that might not succeed either. Thanks to Hillf Danton for debugging this issue. Fixes: b1d2dc009dec ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers") Reported-by: Tobias Klausmann Signed-off-by: Christoph Hellwig Tested-by: Tobias Klausmann

dma-contiguous: fix !CONFIG_DMA_CMA version of dma_{alloc, free}_contiguous()

2019-06-03T14:00:07Z

Commit fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers") adds a pair of new helper functions so as to abstract code in the dma-direct (and other places in the future), however it breaks QEMU boot feature using x86_64 defconfig. That's because x86_64 defconfig has CONFIG_DMA_CMA=n so those two newly introduced helper functions are empty in their !CONFIG_DMA_CMA version, while previously the platform independent dma-direct code had fallback alloc_pages_node() and __free_pages(). So this patch fixes it by adding alloc_pages_node() and __free_pages() in the !CONFIG_DMA_CMA version of the two helper functions. Tested with below QEMU command: qemu-system-x86_64 -m 512m \ -drive file=images/x86_64/rootfs.ext4,format=raw,if=ide \ -append 'console=ttyS0 root=/dev/sda' -nographic \ -kernel arch/x86_64/boot/bzImage with the rootfs from the below link: https://github.com/ClangBuiltLinux/continuous-integration/raw/master/images/x86_64/rootfs.ext4 Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers") Reported-by: Nathan Chancellor Signed-off-by: Nicolin Chen Signed-off-by: Christoph Hellwig

dma-contiguous: add dma_{alloc,free}_contiguous() helpers

2019-06-03T14:00:07Z

Both dma_alloc_from_contiguous() and dma_release_from_contiguous() are very simply implemented, but requiring callers to pass certain parameters like count and align, and taking a boolean parameter to check __GFP_NOWARN in the allocation flags. So every function call duplicates similar work: unsigned long order = get_order(size); size_t count = size >> PAGE_SHIFT; page = dma_alloc_from_contiguous(dev, count, order, gfp & __GFP_NOWARN); [...] dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT); Additionally, as CMA can be used only in the context which permits sleeping, most of callers do a gfpflags_allow_blocking() check and a corresponding fallback allocation of normal pages upon any false result: if (gfpflags_allow_blocking(flag)) page = dma_alloc_from_contiguous(); if (!page) page = alloc_pages(); [...] if (!dma_release_from_contiguous(dev, page, count)) __free_pages(page, get_order(size)); So this patch simplifies those function calls by abstracting these operations into the two new functions: dma_{alloc,free}_contiguous. As some callers of dma_{alloc,release}_from_contiguous() might be complicated, this patch just implements these two new functions to kernel/dma/direct.c only as an initial step. Suggested-by: Christoph Hellwig Signed-off-by: Nicolin Chen Tested-by: dann frazier Signed-off-by: Christoph Hellwig

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 98

2019-05-24T15:37:54Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your optional any later version of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Richard Fontana Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520075212.713472955@linutronix.de Signed-off-by: Greg Kroah-Hartman

kernel/dma: remove unsupported gfp_mask parameter from dma_alloc_from_contiguous()

2018-08-17T23:20:32Z

The CMA memory allocator doesn't support standard gfp flags for memory allocation, so there is no point having it as a parameter for dma_alloc_from_contiguous() function. Replace it by a boolean no_warn argument, which covers all the underlaying cma_alloc() function supports. This will help to avoid giving false feeling that this function supports standard gfp flags and callers can pass __GFP_ZERO to get zeroed buffer, what has already been an issue: see commit dd65a941f6ba ("arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag"). Link: http://lkml.kernel.org/r/20180709122020eucas1p21a71b092975cb4a3b9954ffc63f699d1~-sqUFoa-h2939329393eucas1p2Y@eucas1p2.samsung.com Signed-off-by: Marek Szyprowski Acked-by: Michał Nazarewicz Acked-by: Vlastimil Babka Reviewed-by: Christoph Hellwig Cc: Laura Abbott Cc: Michal Hocko Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dma-mapping: move all DMA mapping code to kernel/dma

2018-06-14T06:50:37Z

Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig

mm: wire up GFP flag passing in dma_alloc_from_contiguous

2017-02-25T01:46:55Z

The callers of the DMA alloc functions already provide the proper context GFP flags. Make sure to pass them through to the CMA allocator, to make the CMA compaction context aware. Link: http://lkml.kernel.org/r/20170127172328.18574-3-l.stach@pengutronix.de Signed-off-by: Lucas Stach Acked-by: Vlastimil Babka Acked-by: Michal Hocko Cc: Radim Krcmar Cc: Catalin Marinas Cc: Will Deacon Cc: Chris Zankel Cc: Ralf Baechle Cc: Paolo Bonzini Cc: Alexander Graf Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: cma: fix incorrect type conversion for size during dma allocation

2015-10-23T08:55:10Z

This was found during userspace fuzzing test when a large size dma cma allocation is made by driver(like ion) through userspace. show_stack+0x10/0x1c dump_stack+0x74/0xc8 kasan_report_error+0x2b0/0x408 kasan_report+0x34/0x40 __asan_storeN+0x15c/0x168 memset+0x20/0x44 __dma_alloc_coherent+0x114/0x18c Signed-off-by: Rohit Vaswani Acked-by: Greg Kroah-Hartman Cc: Marek Szyprowski Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

CMA: generalize CMA reserved area management functionality

2014-08-07T01:01:16Z

Currently, there are two users on CMA functionality, one is the DMA subsystem and the other is the KVM on powerpc. They have their own code to manage CMA reserved area even if they looks really similar. From my guess, it is caused by some needs on bitmap management. KVM side wants to maintain bitmap not for 1 page, but for more size. Eventually it use bitmap where one bit represents 64 pages. When I implement CMA related patches, I should change those two places to apply my change and it seem to be painful to me. I want to change this situation and reduce future code management overhead through this patch. This change could also help developer who want to use CMA in their new feature development, since they can use CMA easily without copying & pasting this reserved area management code. In previous patches, we have prepared some features to generalize CMA reserved area management and now it's time to do it. This patch moves core functions to mm/cma.c and change DMA APIs to use these functions. There is no functional change in DMA APIs. Signed-off-by: Joonsoo Kim Acked-by: Michal Nazarewicz Acked-by: Zhang Yanfei Acked-by: Minchan Kim Reviewed-by: Aneesh Kumar K.V Cc: Alexander Graf Cc: Aneesh Kumar K.V Cc: Gleb Natapov Acked-by: Marek Szyprowski Tested-by: Marek Szyprowski Cc: Paolo Bonzini Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cma: add placement specifier for "cma=" kernel parameter

2014-06-04T23:53:57Z

Currently, "cma=" kernel parameter is used to specify the size of CMA, but we can't specify where it is located. We want to locate CMA below 4GB for devices only supporting 32-bit addressing on 64-bit systems without iommu. This enables to specify the placement of CMA by extending "cma=" kernel parameter. Examples: 1. locate 64MB CMA below 4GB by "cma=64M@0-4G" 2. locate 64MB CMA exact at 512MB by "cma=64M@512M" Note that the DMA contiguous memory allocator on x86 assumes that page_address() works for the pages to allocate. So this change requires to limit end address of contiguous memory area upto max_pfn_mapped to prevent from locating it on highmem area by the argument of dma_contiguous_reserve(). Signed-off-by: Akinobu Mita Cc: Marek Szyprowski Cc: Konrad Rzeszutek Wilk Cc: David Woodhouse Cc: Don Dutile Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Andi Kleen Cc: Yinghai Lu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds