When mlx4_buf_free() is called from the error path of
mlx4_buf_alloc(), it may be passed a buffer structure that does not
have all pages filled in.  Add a check for NULL to mlx4_buf_free() so
we avoid passing NULL to dma_free_coherent() (which will crash).
Signed-off-by: NAli Ayoub <ali@mellanox.co.il>
Signed-off-by: NJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Set last allocated object to the object after the one just allocated
before ORing in the extra top bits.  Also handle the case where this
wraps around.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NJeff Garzik <jeff@garzik.org>
Acked-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add an InfiniBand driver for Mellanox ConnectX adapters.  Because
these adapters can also be used as ethernet NICs and Fibre Channel 
HBAs, the driver is split into two modules: 
 
  mlx4_core: Handles low-level things like device initialization and 
    processing firmware commands.  Also controls resource allocation 
    so that the InfiniBand, ethernet and FC functions can share a 
    device without stepping on each other. 
 
  mlx4_ib: Handles InfiniBand-specific things; plugs into the 
    InfiniBand midlayer. 
Signed-off-by: NRoland Dreier <rolandd@cisco.com>