From: Christoph Hellwig <hch@lst.de>
To: iommu@lists.linux-foundation.org, Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: linuxppc-dev@lists.ozlabs.org,
Lu Baolu <baolu.lu@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Joerg Roedel <joro@8bytes.org>,
Robin Murphy <robin.murphy@arm.com>,
linux-kernel@vger.kernel.org
Subject: generic DMA bypass flag v3
Date: Tue, 14 Apr 2020 14:25:02 +0200 [thread overview]
Message-ID: <20200414122506.438134-1-hch@lst.de> (raw)
Hi all,
I've recently beeing chatting with Lu about using dma-iommu and
per-device DMA ops in the intel IOMMU driver, and one missing feature
in dma-iommu is a bypass mode where the direct mapping is used even
when an iommu is attached to improve performance. The powerpc
code already has a similar mode, so I'd like to move it to the core
DMA mapping code. As part of that I noticed that the current
powerpc code has a little bug in that it used the wrong check in the
dma_sync_* routines to see if the direct mapping code is used.
These two patches just add the generic code and move powerpc over,
the intel IOMMU bits will require a separate discussion.
The x86 AMD Gart code also has a bypass mode, but it is a lot
strange, so I'm not going to touch it for now.
Changes since v2:
- move the dma mapping helpers out of line
- check for possible direct mappings using the dma mask
Changes since v1:
- rebased to the current dma-mapping-for-next tree
next reply other threads:[~2020-04-14 12:25 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-14 12:25 Christoph Hellwig [this message]
2020-04-14 12:25 ` [PATCH 1/4] dma-mapping: move the remaining DMA API calls out of line Christoph Hellwig
2020-04-15 2:26 ` Alexey Kardashevskiy
2020-04-15 6:18 ` Christoph Hellwig
2020-04-15 11:21 ` Alexey Kardashevskiy
2020-04-17 7:58 ` Christoph Hellwig
2020-05-05 4:18 ` Alexey Kardashevskiy
2020-05-09 8:19 ` Christoph Hellwig
2020-05-09 14:07 ` Alexey Kardashevskiy
2020-06-03 4:13 ` Alexey Kardashevskiy
2020-07-07 0:43 ` Alexey Kardashevskiy
2020-07-07 14:51 ` Christoph Hellwig
2020-04-14 12:25 ` [PATCH 2/4] dma-mapping: inline the fast path dma-direct calls Christoph Hellwig
2020-04-14 12:25 ` [PATCH 3/4] dma-mapping: add a dma_ops_bypass flag to struct device Christoph Hellwig
2020-04-14 12:47 ` Greg Kroah-Hartman
2020-04-18 12:42 ` Joerg Roedel
2020-04-19 8:00 ` Christoph Hellwig
2020-04-19 12:25 ` Joerg Roedel
2020-04-19 14:46 ` Alexey Kardashevskiy
2020-04-14 12:25 ` [PATCH 4/4] powerpc: use the generic dma_ops_bypass mode Christoph Hellwig
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