This patch adds the helper netpoll_tx_running for use within
ndo_start_xmit. It returns non-zero if ndo_start_xmit is being
invoked by netpoll, and zero otherwise.
This is currently implemented by simply looking at the hardirq
count. This is because for all non-netpoll uses of ndo_start_xmit,
IRQs must be enabled while netpoll always disables IRQs before
calling ndo_start_xmit.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
c18370f5b2