Non existing DMA functions in ARC: dma_alloc_attrs, dma_free_attrs, dma_mmap_attrs

[Carlos Palminha]

Hi Vineet,

I'm using drm-next (its currently based on 4.4-rc3).

Regarding linux-next DMA patches I assume you are talking about these 3 commits:
* 19ab4d3aff0426058fe36aae4ac56320a6e4c6be
* 8ee24f794c2dfff85930f25eab4f11a9bde7f920
* c27a81903ba596c879a45e3028135a4f37fb1837

Regards,
C.Palminha

-----Original Message-----
From: Vineet Gupta 
Sent: quarta-feira, 2 de Dezembro de 2015 06:32
To: Carlos Palminha; linux-snps-arc at lists.infradead.org
Cc: Alexey Brodkin
Subject: Re: Non existing DMA functions in ARC: dma_alloc_attrs, dma_free_attrs, dma_mmap_attrs

On Wednesday 02 December 2015 01:09 AM, Carlos Palminha wrote:
> Hi guys,
>
> I'm bringing up a new ARC PGU driver for DRM framework with latest kernel tree.
> I'm using ARC AXS101 as a base and selected one the DRM required config: HAVE_DMA_ATTRS due to some memory allocation helpers in DRM.
>
> I'm getting some errors with DMA functions not implemented in ARC: dma_alloc_attrs, dma_free_attrs, dma_mmap_attrs
>
> Any clue?
>
> Regards,
> C.Palminha
>
> ---
> include/linux/dma-mapping.h: In function 'dma_alloc_writecombine':
> include/linux/dma-mapping.h:283:2: error: implicit declaration of function 'dma_alloc_attrs' [-Werror=implicit-function-declaration]
>   return dma_alloc_attrs(dev, size, dma_addr, gfp, &attrs);

This is because ARC port current lacks support for dma_attr_t and associated helpers.
There is a series in flight in linux-next, by Christoph, which already addresses that.

You can either cherry-pick those or in the interim use the hack attached.

P.S. Per your comment at top, I'm assuming you are working off of mainline 4.3 or 4.4

-Vineet