On Tue, May 19, 2020 at 04:34:07PM -0400, Jim Quinlan wrote: > diff --git a/include/linux/device.h b/include/linux/device.h > index ac8e37cd716a..6cd916860b5f 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -493,6 +493,8 @@ struct dev_links_info { > * @bus_dma_limit: Limit of an upstream bridge or bus which imposes a smaller > * DMA limit than the device itself supports. > * @dma_pfn_offset: offset of DMA memory range relatively of RAM > + * @dma_map: Like dma_pfn_offset but used when there are multiple > + * pfn offsets for multiple dma-ranges. > * @dma_parms: A low level driver may set these to teach IOMMU code about > * segment limitations. > * @dma_pools: Dma pools (if dma'ble device). > @@ -578,7 +580,12 @@ struct device { > allocations such descriptors. */ > u64 bus_dma_limit; /* upstream dma constraint */ > unsigned long dma_pfn_offset; > - > +#ifdef CONFIG_DMA_PFN_OFFSET_MAP > + const void *dma_offset_map; /* Like dma_pfn_offset, but for > + * the unlikely case of multiple > + * offsets. If non-null, dma_pfn_offset > + * will be 0. */ > +#endif > struct device_dma_parameters *dma_parms; > > struct list_head dma_pools; /* dma pools (if dma'ble) */ I'll defer to Christoph here, but I thought we were trying to get rid of stuff like this from struct device, not add new things to it for dma apis. And why is it a void *? thanks, greg k-h