When oversubscribing SDMA gangs, a circular deadlock can occur since
gang enqueue is staggered with respect to SDMA engine leader based
on source to destination.
As a result, an enqueued leader may be waiting on a gang item that is
waiting on another enqueued leader or gang item and so on.
To prevent this, first lock the submission to ensure dma status query
and submissions are atomic. Once this is in place, be more stringent
with ganging in that all SDMA engines must be available in order to gang.
Finally, re-enable SDMA ganging by default.
Change-Id: I4511e3487db9d26475b5aece4897f10168cc5322
Use all available SDMA engines capped by xGMI bandwith for
all D2D copies within a hive.
By default, set the latency boundary copy size as 4KB and below.
Any copy size in within this boundary will not gang.
Avoid oversubscribing engines by not ganging on engines with
pending non-ganged work.
An enviroment variable HSA_ENABLE_SDMA_GANG has been provided
to override default ganging behaviour.
Change-Id: Iccde76aa1af1d47ea2a151789432c9db4f0ffa8d
Track and report the size, in bytes, of pending unexecuted blit
commands. To be used in copy ganging.
Change-Id: Ia7453ff88571e927df771c6c819b73c17e67708e
Jonathan Kim
Sean Keely
Ramesh Errabolu
Besar Wicaksono
Jay Cornwall
James Edwards (xN/A) TX