Messages in this thread | | | From | Laurentiu Tudor <> | Subject | Re: [RFC PATCH] dma-mapping: create iommu mapping for newly allocated dma coherent mem | Date | Thu, 25 Apr 2019 11:30:54 +0000 |
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Hi Christoph,
On 24.04.2019 17:57, Christoph Hellwig wrote: > I'd be happy to offload all of the mentioned tasks to you if you > volunteer.
Alright, I think I mostly got it and can start with the two usb drivers you mentioned. Just need a few clarifications, please see inline.
> 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().
> 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?
--- Thanks & Best Regards, Laurentiu | |