user/sven/linux.git/kernel/dma/contiguous.c, branch v5.5.13

kernel: dma-contiguous: mark CMA parameters initdata/initconst

2019-10-30T18:10:45Z

These parameters are only referenced by __init routine calls during early boot so they should be marked as __initdata and __initconst accordingly. Signed-off-by: Shyam Saini Reviewed-by: Robin Murphy Signed-off-by: Christoph Hellwig

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: page-align the size in dma_free_contiguous()

2019-07-29T06:50:04Z

According to the original dma_direct_alloc_pages() code: { unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; if (!dma_release_from_contiguous(dev, page, count)) __free_pages(page, get_order(size)); } The count parameter for dma_release_from_contiguous() was page aligned before the right-shifting operation, while the new API dma_free_contiguous() forgets to have PAGE_ALIGN() at the size. So this patch simply adds it to prevent any corner case. Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers") Signed-off-by: Nicolin Chen Reviewed-by: Christoph Hellwig Signed-off-by: Christoph Hellwig

dma-contiguous: do not overwrite align in dma_alloc_contiguous()

2019-07-29T06:50:04Z

The dma_alloc_contiguous() limits align at CONFIG_CMA_ALIGNMENT for cma_alloc() however it does not restore it for the fallback routine. This will result in a size mismatch between the allocation and free when running into the fallback routines after cma_alloc() fails, if the align is larger than CONFIG_CMA_ALIGNMENT. This patch adds a cma_align to take care of cma_alloc() and prevent the align from being overwritten. Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers") Reported-by: Dafna Hirschfeld Signed-off-by: Nicolin Chen Signed-off-by: Christoph Hellwig

dma-contiguous: use fallback alloc_pages for single pages

2019-06-03T14:00:07Z

The addresses within a single page are always contiguous, so it's not so necessary to always allocate one single page from CMA area. Since the CMA area has a limited predefined size of space, it may run out of space in heavy use cases, where there might be quite a lot CMA pages being allocated for single pages. However, there is also a concern that a device might care where a page comes from -- it might expect the page from CMA area and act differently if the page doesn't. This patch tries to use the fallback alloc_pages path, instead of one-page size allocations from the global CMA area in case that a device does not have its own CMA area. This'd save resources from the CMA global area for more CMA allocations, and also reduce CMA fragmentations resulted from trivial allocations. Signed-off-by: Nicolin Chen Tested-by: dann frazier 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

dma-mapping: fix panic caused by passing empty cma command line argument

2018-09-20T07:01:08Z

early_cma does not check input argument before passing it to simple_strtoull. The argument would be a NULL pointer if "cma", without its value, is set in command line and thus causes the following panic. PANIC: early exception 0xe3 IP 10:ffffffffa3e9db8d error 0 cr2 0x0 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #7 [ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70 ... [ 0.000000] Call Trace: [ 0.000000] simple_strtoull+0x29/0x70 [ 0.000000] memparse+0x26/0x90 [ 0.000000] early_cma+0x17/0x6a [ 0.000000] do_early_param+0x57/0x8e [ 0.000000] parse_args+0x208/0x320 [ 0.000000] ? rdinit_setup+0x30/0x30 [ 0.000000] parse_early_options+0x29/0x2d [ 0.000000] ? rdinit_setup+0x30/0x30 [ 0.000000] parse_early_param+0x36/0x4d [ 0.000000] setup_arch+0x336/0x99e [ 0.000000] start_kernel+0x6f/0x4e6 [ 0.000000] x86_64_start_reservations+0x24/0x26 [ 0.000000] x86_64_start_kernel+0x6f/0x72 [ 0.000000] secondary_startup_64+0xa4/0xb0 This patch adds a check to prevent the panic. Signed-off-by: He Zhe Reviewed-by: Marek Szyprowski Cc: stable@vger.kernel.org Signed-off-by: Christoph Hellwig

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

mm/cma: remove unsupported gfp_mask parameter from cma_alloc()

2018-08-17T23:20:32Z

cma_alloc() doesn't really support gfp flags other than __GFP_NOWARN, so convert gfp_mask parameter to boolean no_warn parameter. 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/20180709122019eucas1p2340da484acfcc932537e6014f4fd2c29~-sqTPJKij2939229392eucas1p2j@eucas1p2.samsung.com Signed-off-by: Marek Szyprowski Acked-by: Michal Hocko Acked-by: Michał Nazarewicz Acked-by: Laura Abbott Acked-by: Vlastimil Babka Reviewed-by: Christoph Hellwig 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

user/sven/linux.git/kernel/dma/contiguous.c, branch v5.5.13

kernel: dma-contiguous: mark CMA parameters __initdata/__initconst

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

dma-contiguous: page-align the size in dma_free_contiguous()

dma-contiguous: do not overwrite align in dma_alloc_contiguous()

dma-contiguous: use fallback alloc_pages for single pages

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

dma-mapping: fix panic caused by passing empty cma command line argument

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

mm/cma: remove unsupported gfp_mask parameter from cma_alloc()

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

kernel: dma-contiguous: mark CMA parameters initdata/initconst