[RFC PATCH] iommu: map reserved memory as cacheable if device is coherent

[Laurentiu Tudor]

On 7/26/2023 3:22 PM, Jason Gunthorpe wrote:
> On Tue, Jul 25, 2023 at 05:00:55PM +0300, laurentiu.tudor at nxp.com wrote:
>> From: Laurentiu Tudor <laurentiu.tudor at nxp.com>
>>
>> Check if the device is marked as DMA coherent in the DT and if so,
>> map its reserved memory as cacheable in the IOMMU.
>>
>> Signed-off-by: Laurentiu Tudor <laurentiu.tudor at nxp.com>
>> ---
>>   drivers/iommu/of_iommu.c | 3 +++
>>   1 file changed, 3 insertions(+)
> 
> This only makes sense for IOMMU_RESV_DIRECT - is that your use case?
> Maybe mention that in the commit message

Yep. Will respin with an improved commit message.

> And add a fixes for the commit that introduces IOMMU_RESV_DIRECT into
> of_iommu.c

Would it make more sense to mention the commit [1] that actually added 
this support for mapping reserved memory in IOMMU?

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a5bf3cfce8cb77d9d24613ab52d520896f83dd48

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Thanks & Best Regards, Laurentiu