Messages in this thread | | | Date | Fri, 26 Apr 2019 17:13:30 +0200 | From | Christoph Hellwig <> | Subject | Re: [RFC PATCH] dma-mapping: create iommu mapping for newly allocated dma coherent mem |
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On Thu, Apr 25, 2019 at 11:30:54AM +0000, Laurentiu Tudor wrote: > > I think the first step is to move the two USB controller that can only > > DMA to their own BAR off the existing DMA coherent infrastructure. The > > controllers are already identified using the HCD_LOCAL_MEM flag, so we > > just need to key off that in the hcd_buffer_* routines and call into a > > So if HCD_LOCAL_MEM is set I should call into the gen_pool api instead > of existing dma_{alloc,free}_coherent().
Yes.
> > genalloc that has been fed using the bar, replacing the current > > dma_declare_coherent usage. Take a look at drivers/pci/p2pdma.c > > for another example of allocating bits of a BAR using genalloc. > > Where should I place the reference to the gen_pool? How does local_pool > in 'struct hcd_usb' sound?
Sounds fine to me, but in the end the usb maintainers will have to decide.
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