[ Upstream commit 23d9f5531c7c28546954b0bf332134a9b8a38c0a ]

NFP supports fairly enormous ring sizes (up to 256k descriptors).
In commit 46627170 ("nfp: use kvcalloc() to allocate SW buffer
descriptor arrays") we have started using kvcalloc() functions to
make sure the allocation of software state arrays doesn't hit
the MAX_ORDER limit.  Unfortunately, we can't use virtual mappings
for the DMA region holding HW descriptors.  In case this allocation
fails instead of the generic (and fairly scary) warning/splat in
the logs print a helpful message explaining what happened and
suggesting how to fix it.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NDirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>