From: "Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>
To: Christoph Hellwig <hch@lst.de>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>
Cc: "robin.murphy@arm.com" <robin.murphy@arm.com>
Subject: RE: [PATCH v2] dma-contiguous: cleanup dma_alloc_contiguous
Date: Mon, 27 Jul 2020 06:59:13 +0000 [thread overview]
Message-ID: <B926444035E5E2439431908E3842AFD25BE501@DGGEMI525-MBS.china.huawei.com> (raw)
In-Reply-To: <20200723120133.94105-1-hch@lst.de>
> -----Original Message-----
> From: iommu [mailto:iommu-bounces@lists.linux-foundation.org] On Behalf
> Of Christoph Hellwig
> Sent: Friday, July 24, 2020 12:02 AM
> To: iommu@lists.linux-foundation.org
> Cc: robin.murphy@arm.com
> Subject: [PATCH v2] dma-contiguous: cleanup dma_alloc_contiguous
>
> Split out a cma_alloc_aligned helper to deal with the "interesting"
> calling conventions for cma_alloc, which then allows to the main function to
> be written straight forward. This also takes advantage of the fact that NULL
> dev arguments have been gone from the DMA API for a while.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Barry Song <song.bao.hua@hisilicon.com>
And I have rebased per-numa CMA patchset on top of this one.
https://lore.kernel.org/linux-arm-kernel/20200723131344.41472-1-song.bao.hua@hisilicon.com/
> ---
>
> Changes since v1:
> - actually pass on the select struct cma
> - clean up cma_alloc_aligned a bit
>
> kernel/dma/contiguous.c | 31 ++++++++++++++-----------------
> 1 file changed, 14 insertions(+), 17 deletions(-)
>
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index
> 15bc5026c485f2..cff7e60968b9e1 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -215,6 +215,13 @@ bool dma_release_from_contiguous(struct device
> *dev, struct page *pages,
> return cma_release(dev_get_cma_area(dev), pages, count); }
>
> +static struct page *cma_alloc_aligned(struct cma *cma, size_t size,
> +gfp_t gfp) {
> + unsigned int align = min(get_order(size), CONFIG_CMA_ALIGNMENT);
> +
> + return cma_alloc(cma, size >> PAGE_SHIFT, align, gfp & __GFP_NOWARN);
> +}
> +
> /**
> * dma_alloc_contiguous() - allocate contiguous pages
> * @dev: Pointer to device for which the allocation is performed.
> @@ -231,24 +238,14 @@ bool dma_release_from_contiguous(struct device
> *dev, struct page *pages,
> */
> struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
> {
> - size_t count = size >> PAGE_SHIFT;
> - struct page *page = NULL;
> - struct cma *cma = NULL;
> -
> - if (dev && dev->cma_area)
> - cma = dev->cma_area;
> - else if (count > 1)
> - cma = dma_contiguous_default_area;
> -
> /* CMA can be used only in the context which permits sleeping */
> - if (cma && gfpflags_allow_blocking(gfp)) {
> - size_t align = get_order(size);
> - size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT);
> -
> - page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN);
> - }
> -
> - return page;
> + if (!gfpflags_allow_blocking(gfp))
> + return NULL;
> + if (dev->cma_area)
> + return cma_alloc_aligned(dev->cma_area, size, gfp);
> + if (size <= PAGE_SIZE || !dma_contiguous_default_area)
> + return NULL;
> + return cma_alloc_aligned(dma_contiguous_default_area, size, gfp);
> }
>
> /**
> --
> 2.27.0
Thanks
Barry
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prev parent reply other threads:[~2020-07-27 6:59 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-23 12:01 [PATCH v2] dma-contiguous: cleanup dma_alloc_contiguous Christoph Hellwig
2020-07-24 2:12 ` Nicolin Chen
2020-07-27 6:59 ` Song Bao Hua (Barry Song) [this message]
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