Unnecessarily complex LE format used on Marvell controller was
main reason not to enable 64bit DMA addressing in driver. If high
32bit address of DMA address of TX/RX buffer is changed, driver has
to generate a new LE. In TX path, driver will keep track of lastly
used high 32bit address of DMA address and generate a new LE
whenever it sees high address change in the DMA address. In RX path,
driver will always use two LEs to specify 64bit DMA address of RX
buffer. If the high 32bit address of DMA address of RX buffer is
the same as previous DMA address of RX buffer, driver does not have
to use two LEs but driver will use two LEs for simplicity in RX
ring management.
One of draw back for switching to 64bit DMA addressing is that the
large amount of LEs are used to specify 64bit DMA address such that
number of available LEs for TX/RX buffers are considerably reduced.
To mitigate the issue, increase number of available LEs from 256 to
384 for TX and from 256 to 512 for RX. For 32bit architectures,
msk(4) does not use 64bit DMA addressing to save resources.
Tested by: das
355a415e92