Avoid the ttm_bo_unreserve() spinlocks by calling
ttm_eu_backoff_reservation_locked under the lru spinlock.
Signed-off-by: NThomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: NJerome Glisse <j.glisse@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Makes it possible to reserve a list of buffer objects with a single
spin lock / unlock if there is no contention.
Should improve cpu usage on SMP kernels.

v2: Initialize private list members on reserve and don't call
ttm_bo_list_ref_sub() with zero put_count.
Signed-off-by: NThomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Utilities to reserve, unreserve and fence a list of TTM
buffer objects in a deadlock-safe manner.

Used by the vmwgfx driver.
Signed-off-by: NThomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>