From mboxrd@z Thu Jan  1 00:00:00 1970
From: gregory.clement@free-electrons.com (Gregory CLEMENT)
Date: Wed, 24 Oct 2012 15:56:27 +0200
Subject: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
In-Reply-To: <201210241224.06791.arnd@arndb.de>
References: <1351065841-18654-1-git-send-email-gregory.clement@free-electrons.com>
 <5087D574.4030503@free-electrons.com> <5087D6B8.10209@free-electrons.com>
 <201210241224.06791.arnd@arndb.de>
Message-ID: <5087F38B.1010508@free-electrons.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

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