such as
load/store, scatter/gather, bcopy, AMOs, etc.  The GRU is directly
accessed by user instructions using user virtual addresses.  GRU
instructions (ex., bcopy) use user virtual addresses for operands.

The GRU contains a large TLB that is functionally very similar to
processor TLBs.  Because the external contains a TLB with user virtual
address, it requires callouts from the core VM system when certain types
of changes are made to the process page tables.  There are several MMUOPS
patches currently being discussed but none has been accepted into the
kernel.  The GRU driver is built using version V18 from Andrea Arcangeli.

This patch:

Contains the definitions of the hardware GRU data structures that are used
by the driver to manage the GRU.

[akpm@linux-foundation;org: export hpage_shift]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
أخƒ“/x