From: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: "Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>,
"Pawel Osciak" <pawel@osciak.com>,
"Russell King" <linux@armlinux.org.uk>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
"Kyungmin Park" <kyungmin.park@samsung.com>,
linux-media@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-arm-kernel@lists.infradead.org,
"Marek Szyprowski" <m.szyprowski@samsung.com>
Subject: Re: [PATCH 3/3] videobuf2: replace a layering violation with dma_map_resource
Date: Fri, 11 Jan 2019 17:54:16 -0200 [thread overview]
Message-ID: <20190111175416.7d291e25@coco.lan> (raw)
In-Reply-To: <20190111181731.11782-4-hch@lst.de>
Em Fri, 11 Jan 2019 19:17:31 +0100
Christoph Hellwig <hch@lst.de> escreveu:
> vb2_dc_get_userptr pokes into arm direct mapping details to get the
> resemblance of a dma address for a a physical address that does is
> not backed by a page struct. Not only is this not portable to other
> architectures with dma direct mapping offsets, but also not to uses
> of IOMMUs of any kind. Switch to the proper dma_map_resource /
> dma_unmap_resource interface instead.
Makes sense to me. I'm assuming that you'll be pushing it together
with other mm patches, so:
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> .../common/videobuf2/videobuf2-dma-contig.c | 41 ++++---------------
> 1 file changed, 9 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> index aff0ab7bf83d..82389aead6ed 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> @@ -439,42 +439,14 @@ static void vb2_dc_put_userptr(void *buf_priv)
> set_page_dirty_lock(pages[i]);
> sg_free_table(sgt);
> kfree(sgt);
> + } else {
> + dma_unmap_resource(buf->dev, buf->dma_addr, buf->size,
> + buf->dma_dir, 0);
> }
> vb2_destroy_framevec(buf->vec);
> kfree(buf);
> }
>
> -/*
> - * For some kind of reserved memory there might be no struct page available,
> - * so all that can be done to support such 'pages' is to try to convert
> - * pfn to dma address or at the last resort just assume that
> - * dma address == physical address (like it has been assumed in earlier version
> - * of videobuf2-dma-contig
> - */
> -
> -#ifdef __arch_pfn_to_dma
> -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn)
> -{
> - return (dma_addr_t)__arch_pfn_to_dma(dev, pfn);
> -}
> -#elif defined(__pfn_to_bus)
> -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn)
> -{
> - return (dma_addr_t)__pfn_to_bus(pfn);
> -}
> -#elif defined(__pfn_to_phys)
> -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn)
> -{
> - return (dma_addr_t)__pfn_to_phys(pfn);
> -}
> -#else
> -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn)
> -{
> - /* really, we cannot do anything better at this point */
> - return (dma_addr_t)(pfn) << PAGE_SHIFT;
> -}
> -#endif
> -
> static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
> unsigned long size, enum dma_data_direction dma_dir)
> {
> @@ -528,7 +500,12 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
> for (i = 1; i < n_pages; i++)
> if (nums[i-1] + 1 != nums[i])
> goto fail_pfnvec;
> - buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, nums[0]);
> + buf->dma_addr = dma_map_resource(buf->dev,
> + __pfn_to_phys(nums[0]), size, buf->dma_dir, 0);
> + if (dma_mapping_error(buf->dev, buf->dma_addr)) {
> + ret = -ENOMEM;
> + goto fail_pfnvec;
> + }
> goto out;
> }
>
Thanks,
Mauro
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next prev parent reply other threads:[~2019-01-11 19:54 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20190111181841epcas3p2d7c0bf8f5c11a9863e22ec1b12da6e1b@epcas3p2.samsung.com>
2019-01-11 18:17 ` fix a layering violation in videobuf2 and improve dma_map_resource Christoph Hellwig
2019-01-11 18:17 ` [PATCH 1/3] dma-mapping: remove the default map_resource implementation Christoph Hellwig
2019-01-14 13:12 ` Robin Murphy
2019-01-14 17:08 ` Christoph Hellwig
2019-01-11 18:17 ` [PATCH 2/3] dma-mapping: don't BUG when calling dma_map_resource on RAM Christoph Hellwig
2019-01-14 14:16 ` Robin Murphy
2019-01-11 18:17 ` [PATCH 3/3] videobuf2: replace a layering violation with dma_map_resource Christoph Hellwig
2019-01-11 19:54 ` Mauro Carvalho Chehab [this message]
2019-01-14 10:31 ` Christoph Hellwig
2019-01-14 11:04 ` Mauro Carvalho Chehab
2019-01-14 11:12 ` Christoph Hellwig
2019-01-14 12:42 ` Marek Szyprowski
2019-01-17 17:21 ` Christoph Hellwig
2019-01-18 9:41 ` Marek Szyprowski
2019-01-31 15:31 ` Christoph Hellwig
2019-01-14 11:43 ` fix a layering violation in videobuf2 and improve dma_map_resource Marek Szyprowski
2019-01-18 11:37 fix a layering violation in videobuf2 and improve dma_map_resource v2 Christoph Hellwig
2019-01-18 11:37 ` [PATCH 3/3] videobuf2: replace a layering violation with dma_map_resource Christoph Hellwig
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