powerpc/powernv/npu: Add set/unset window helpers

The upcoming NVLink passthrough support will require NPU code to cope
with two DMA windows.

This adds a pnv_npu_set_window() helper which programs 32bit window to
the hardware. This also adds multilevel TCE support.

This adds a pnv_npu_unset_window() helper which removes the DMA window
from the hardware. This does not make difference now as the caller -
pnv_npu_dma_set_bypass() - enables bypass in the hardware but the next
patch will use it to manage TCE table lists for TCE Kill handling.

Signed-off-by: Alexey Kardashevskiy <[email protected]>
Reviewed-By: Alistair Popple <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>

0 files changed, 0 insertions, 0 deletions