Enabling virtual mapped kernel stacks breaks the thunderx_zip
driver. On compression or decompression the executing CPU hangs
in an endless loop. The reason for this is the usage of __pa
by the driver which does no longer work for an address that is
not part of the 1:1 mapping.

The zip driver allocates a result struct on the stack and needs
to tell the hardware the physical address within this struct
that is used to signal the completion of the request.

As the hardware gets the wrong address after the broken __pa
conversion it writes to an arbitrary address. The zip driver then
waits forever for the completion byte to contain a non-zero value.

Allocating the result struct from 1:1 mapped memory resolves this
bug.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Reviewed-by: Robert Richter <rrichter@cavium.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>