IB on s390 broken with commit 99db94940 "IB/core: Remove ib_device.dma_device"

[Sebastian Ott]

Hi,

commit 99db94940 "IB/core: Remove ib_device.dma_device"
breaks infiniband on s390 (and I think also other archs that do something
like to_pci_dev(dev) in one of their dma_ops callbacks).

With this commit you use the dma_ops of the device that called
ib_register_device but you call e.g. dma_map with ib_device->dev
as an argument.

S390's (pci specific) dma_map uses to_pci_dev(dev) to look into the
pci device (and its arch specific data) and oopses.

Calling dma_map with ib_device->dev.parent would work but then it
wouldn't make sense to copy dma_ops and mask from ib_device->dev.parent
to ib_device->dev..

Regards,
Sebastian