Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support

From: Gregory CLEMENT
Date: Wed Oct 24 2012 - 09:56:37 EST


On 10/24/2012 02:24 PM, Arnd Bergmann wrote:
> On Wednesday 24 October 2012, Gregory CLEMENT wrote:
>> On 10/24/2012 01:48 PM, Gregory CLEMENT wrote:
>>> On 10/24/2012 01:36 PM, Arnd Bergmann wrote:
>>>>
>>>> I think it would be cleaner to statically define the operations in a constant
>>>> structure and point directly to the functions you need. If necessary, use
>>>> multiple structures.
>>>
>>> My problem was that these functions are not exposed, only arm_dma_op and
>>> arm_coherent_dma_ops are exported.
>>> Or do you think about something like this:
>>
>> struct dma_map_ops *dma_ops = {
>> .alloc = arm_coherent_dma_ops.arm_coherent_dma_alloc,
>> .free = arm_coherent_dma_ops.arm_coherent_dma_free,
>> .mmap = arm_coherent_dma_ops.arm_dma_mmap,
>> .get_sgtable = arm_coherent_dma_ops.arm_dma_get_sgtable,
>> .map_sg = arm_coherent_dma_ops.arm_dma_map_sg,
>> .set_dma_mask = arm_coherent_dma_ops.arm_dma_set_mask,
>> .map_page = armada_xp_dma_map_page,
>> .unmap_page = armada_xp_dma_unmap_page,
>> .unmap_sg = arm_dma_ops.unmap_sg,
>> .sync_single_for_cpu = armada_xp_dma_sync,
>> .sync_single_for_device = armada_xp_dma_sync,
>> .sync_sg_for_cpu = arm_dma_ops.sync_sg_for_cpu,
>> .sync_sg_for_device = arm_dma_ops.sync_sg_for_device,
>> };
>
> No, I was thinking of making the underlying functions globally visible
> and have extern declarations in a header file so you can access them
> directly.
>
> Generally speaking, when you run into a problem with common code, your
> first approach should be to fix the common code before you try to work
> around it.

OK I thought it was done on purpose. But if you consider it needs to be
fixed I will add patch for it in next version.

>
> Arnd
>


--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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