nvmet_pci_epf_dma_filter
struct nvmet_pci_epf_dma_filter *filter = arg;
struct nvmet_pci_epf_dma_filter filter;
chan = dma_request_channel(mask, nvmet_pci_epf_dma_filter, &filter);
chan = dma_request_channel(mask, nvmet_pci_epf_dma_filter, &filter);