Re: [PATCH 00/18] Clean up exposure of arch-internal code

[Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>]

[+ Heiko for comment on Rockchip IOMMU]

On Mon, Jul 27, 2015 at 01:28:24PM +0100, Russell King - ARM Linux wrote:
> This series of patches attempts to clean up the use of architecture
> internal functions in drivers, and removes some functions from view
> in the asm/ headers.  I'm also considering whether we need to add
> some linker magic to hide symbols when building the built-in.o files.
> 
> This was triggered by 3rd party drivers "going under the covers" of
> the DMA API and calling the dmac_*() functions directly, a practice
> which I have always refused to allow.  This also breaks module
> building (which is the big hint that they're doing something wrong.)
> 
> However, it also came to light that various drivers are using
> __cpuc_* functions directly, which are non-portable, and is another
> instance of "going under the covers" and tinkering with what should
> be kept as architecture implementation details.
> 
> This series addresses some of these points.  It:
> 
> (a) moves dmac_map_area() and dmac_unmap_area() prototypes out of
>     asm/cacheflush.h and into arch/arm/mm.
> (b) provide a secure_flush() call for the Qualcomm secure monitor
>     code.
> (c) stop tegra smmu driver(s) from using __cpuc_flush_dcache_area,
>     something which necessitates additional complexity to deal with
>     the ARM vs ARM64 differences.  It should be using the DMA API.
>     However, the Tegra SMMU driver is in really bad shape, and this
>     isn't a simple conversion - it requires a lot of additional
>     fixes to bring the code up to scratch.
> 
> It leaves the Rockchip IOMMU driver for the time being, but that is also
> something which needs cleaning up in the same way as the Tegra SMMU
> driver.
> 
>  arch/arm/include/asm/cacheflush.h |  21 ++-
>  arch/arm/include/asm/glue-cache.h |   2 -
>  arch/arm/mm/dma-mapping.c         |   1 +
>  arch/arm/mm/dma.h                 |  32 ++++
>  drivers/firmware/qcom_scm-32.c    |   4 +-
>  drivers/iommu/tegra-smmu.c        | 297 ++++++++++++++++++++++++--------------
>  drivers/memory/tegra/tegra114.c   |  17 ---
>  drivers/memory/tegra/tegra124.c   |  30 ----
>  drivers/memory/tegra/tegra30.c    |  17 ---
>  include/soc/tegra/mc.h            |   7 -
>  10 files changed, 242 insertions(+), 186 deletions(-)
> 
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