12 Mar
2020
12 Mar
'20
10:14 a.m.
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.