From: joro@8bytes•org (joro at 8bytes.org)
To: linux-arm-kernel@lists•infradead.org
Subject: RFC: extend IOMMU attributes
Date: Thu, 25 Feb 2016 15:38:55 +0100 [thread overview]
Message-ID: <20160225143855.GD16675@8bytes.org> (raw)
In-Reply-To: <HE1PR04MB1641F22E38710B68F4ED891F8DAF0@HE1PR04MB1641.eurprd04.prod.outlook.com>
On Thu, Feb 18, 2016 at 04:16:26PM +0000, Stuart Yoder wrote:
> #define IOMMU_READ (1 << 0)
> #define IOMMU_WRITE (1 << 1)
> -#define IOMMU_CACHE (1 << 2) /* DMA cache coherency */
> +#define IOMMU_CACHE_COHERENT (1 << 2) /* cacheable and coherent */
> #define IOMMU_NOEXEC (1 << 3)
> #define IOMMU_MMIO (1 << 4) /* e.g. things like MSI doorbells */
> +#define IOMMU_CACHEABLE (1 << 5) /* cacheable, not coherent */
> +#define IOMMU_CACHE_ALLOCATE (1 << 6) /* hint to allocate in the cache */
Hmm, this might be a valid use-case to introduce the
map_attr()/unmap_attr() calls to the IOMMU-API. I have been resistant to
these functions until now because the proposed use-cases were not
convincing, but for hardware-specific map-attributes like this one it
could make sense.
Joerg
next prev parent reply other threads:[~2016-02-25 14:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-18 16:16 RFC: extend IOMMU attributes Stuart Yoder
2016-02-18 16:21 ` Will Deacon
2016-02-18 19:33 ` Stuart Yoder
2016-02-25 14:38 ` joro at 8bytes.org [this message]
2016-02-25 15:00 ` Will Deacon
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