On 13/01/15 11:08, Stefano Stabellini wrote:
On Mon, 12 Jan 2015, Robin Murphy wrote:
Hi all,
Whilst it's a long way off perfect, this has reached the point of being
functional and stable enough to be useful, so here it is. The core
consists of the meat of the arch/arm implementation modified to remove
the assumption of PAGE_SIZE pages and ported over to the Intel IOVA
allocator instead of the bitmap-based one. For that, this series depends
on my "Genericise the IOVA allocator" series posted earlier[1].
There are plenty of obvious things still to do, including:
* Domain and group handling is all wrong, but that's a bigger problem.
For the moment it does more or less the same thing as the arch/arm
code, which at least works for the one-IOMMU-per-device situation.
* IOMMU domains and IOVA domains probably want to be better integrated
with devices and each other, rather than having a proliferation of
arch-specific structs.
* The temporary map_sg implementation - I have a 'proper' iommu_map_sg
based one in progress, but since the simple one works it's not been
as high a priority.
* Port arch/arm over to it. I'd guess it might be preferable to merge
this through arm64 first, though, rather than overcomplicate matters.
* There may well be scope for streamlining and tidying up the copied
parts - In general I've simply avoided touching anything I don't
fully understand.
* In the same vein, I'm sure lots of it is fairly ARM-specific, so will
need longer-term work to become truly generic.
[1]:http://thread.gmane.org/gmane.linux.kernel.iommu/8208
I tried to git-am and build a v3.19-rc4 kernel with this series (config
file attached), but I get:
In file included from include/linux/dma-mapping.h:82:0,
from arch/arm64/kernel/asm-offsets.c:23:
./arch/arm64/include/asm/dma-mapping.h: In function ‘phys_to_dma’:
./arch/arm64/include/asm/dma-mapping.h:69:2: error: ‘struct dev_archdata’ has
no member named ‘mapping’
./arch/arm64/include/asm/dma-mapping.h: In function ‘dma_to_phys’:
./arch/arm64/include/asm/dma-mapping.h:81:19: error: ‘struct dev_archdata’ has
no member named ‘mapping’
make[1]: *** [arch/arm64/kernel/asm-offsets.s] Error 1
Oops, looks like I've been relying on having an actual IOMMU driver
select CONFIG_IOMMU_API - enabling the ARM SMMU driver as well as "IOMMU
hardware support" makes everything build, even if it doesn't actually
work with the new framework (the patches for that exist, but are
currently a big ugly mess).
The nested #include guard in arch/arm64/include/asm/device.h in patch 4
is to blame - on reflection, I guess that isn't a great idea regardless
of the logical dependency (I don't think my Kconfig-fu is strong enough
to guarantee that dependency is enforced).
Robin.
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