Messages in this thread | | | Date | Tue, 12 Sep 2017 05:37:16 -0700 | From | "" <> | Subject | Re: uio_dmem_genirq.c and DMA mapping to user space ? |
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On Tue, Sep 12, 2017 at 12:18:27PM +0000, Joakim Tjernlund wrote: > Hi > > I am trying to use the uio_dmem_genirq.c driver for allocating DMA memory to a PCI device > using the uio_pci_generic.c driver. > > I got as far as defining an UIO dev containing only Dynamic DMA memory and > now I am stuck. > I can see how DMA memory is allocated when opening the /dev/uio device but I cannot > figure out how to mmap this memory to User space as well so I can share this > memory with the PCI device and my user space driver. > > What am I missing?
Why can't you call mmap() on the fd you created when you opened /dev/uio? What happens when you do that?
thanks,
greg k-h
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