linux-kernel - Re: [PATCH 2/2] arm64: avoid increasing DMA masks above what hardware supports

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 11 Jan 2017 22:11:32 +0100
From:   Arnd Bergmann <arnd@...db.de>
To:     Nikita Yushchenko <nikita.yoush@...entembedded.com>
Cc:     Robin Murphy <robin.murphy@....com>,
        Will Deacon <will.deacon@....com>,
        linux-arm-kernel@...ts.infradead.org,
        linux-renesas-soc@...r.kernel.org,
        Simon Horman <horms@...ge.net.au>,
        Bjorn Helgaas <bhelgaas@...gle.com>, fkan@....com,
        linux-kernel@...r.kernel.org,
        Artemi Ivanov <artemi.ivanov@...entembedded.com>
Subject: Re: [PATCH 2/2] arm64: avoid increasing DMA masks above what hardware supports

On Wednesday, January 11, 2017 9:31:52 PM CET Nikita Yushchenko wrote:
> @@ -959,6 +990,15 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
>         if (!dev->archdata.dma_ops)
>                 dev->archdata.dma_ops = &swiotlb_dma_ops;
>  
> +       /*
> +        * Whatever the parent bus can set. A device must not set
> +        * a DMA mask larger than this.
> +        */
> +       if (enforce_range)
> +               dev->archdata.parent_dma_mask = size - 1;
> +       else
> +               dev->archdata.parent_dma_mask = DMA_BIT_MASK(64);
> +
>         dev->archdata.dma_coherent = coherent;
>         __iommu_setup_dma_ops(dev, dma_base, size, iommu);
> 

Could we just pass the mask instead of the size here?

	Arnd