https://github.com/nrfconnect/sdk-nrfxlib/blob/b02a54c3ae1421744d5fcd6b9519240f63192e8d/nrf_wifi/os_if/inc/osal_ops.h#L145-L155
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 * @bus_pcie_dev_dma_map: Map host memory of size @size pointed to by the virtual address
 *			  @virt_addr to be used by the PCIe device for DMAing contents.
 *			  The contents are available for DMAing to the device if @dir has a
 *			  value of @NRF_WIFI_OSAL_DMA_DIR_TO_DEV. Conversely the device can DMA
 *			  contents to the host memory if @dir has a value of
 *			  @NRF_WIFI_OSAL_DMA_DIR_FROM_DEV. The function returns the DMA address
 *			  of the mapped memory.
 * @bus_pcie_dev_dma_unmap: Unmap the host memory which was mapped for DMA using
 *			    @bus_pcie_dev_dma_map.
 *			    The address that will be passed to this Op to be unmapped will
 *			    be the DMA address returned by @dma_bus_pcie_dev_map.