ANDROID: Eliminate vqueue map/unmap for each msg

Each time a TIPC message is sent from Linux to Trusty, the
shared memory is mapped and then unmapped even though the same
sections of shared memory are reused for all messages. This
patch allows Trusty to leave the mapping for future use, and
adds a list to store the free buffers for rx (previously only
done for free tx buffers). It also adds a ctrl msg to tell Trusty
that it can skip the unmap and adds a reclaim path so that the
message buffers can be reclaimed by shrinker. If Trusty doesn't
support this new functionality, the buffer will remain mapped
in a free list for reuse.

Bug: 279049197
Test: tipc-test -t echo && echo 2 > /proc/sys/vm/drop_caches
Change-Id: I699a2c0266a87b7f6a079608459f96883160dffe
Signed-off-by: Brandon Anderson <brandonand@google.com>
1 file changed
tree: 721d0d62063e6cd3debb9ed5284cfbf332e4c562
  1. Documentation/
  2. drivers/
  3. include/