[PATCH 1/6] lib/scatterlist: add sg_set_dma_addr() function

[Christian König]

Am 11.03.20 um 16:28 schrieb Christoph Hellwig:
> On Wed, Mar 11, 2020 at 02:51:53PM +0100, Christian König wrote:
>> This can be used by drivers to setup P2P DMA between device
>> memory which is not backed by struct pages.
>>
>> The drivers of the involved devices are responsible for
>> setting up and tearing down DMA addresses as necessary
>> using dma_map_resource().
>>
>> The page pointer is set to NULL and only the DMA address,
>> length and offset values are valid.
> NAK.  The only valid way to fill DMA address in scatterlists is
> dma_map_sg / dma_map_sg_attr.

How can we then map PCIe BARs into an scatterlist which are not backed 
by struct pages?

Regards,
Christian.