[ofa-general] libmlx4 wc flash

[Michael S. Tsirkin]

Roland,
	libmlx4 has this comments:

	/* FIXME flush wc buffers */

	and since it does *not* currently actually flush the buffers, if we
	enable WC for blueflame, WRs gets mixed in the WC buffer, and QP gets
	corrupted/stuck.

It seems we should we have arch.h under mthca and stick
some macro like wc_wmb() in there.

Or, would infiniband/arch.h under libibverbs be a better place?

If WC is not enabled, userspace can avoid the flush - so, should we
return such a bit as part of kernel abi?

-- 
MST