linux-toradex.git/drivers/dma/mv_xor.h, branch v4.4.36

dmaengine: mv_xor: improve descriptors list handling and reduce locking

2015-06-10T16:48:31+00:00

This patch change the way free descriptors are marked.

Instead of having a field for descriptor in use, all the descriptors in the
all_slots list are free for use.

This simplify the allocation method and reduce the locking needed.

Signed-off-by: Lior Amsalem 
Reviewed-by: Ofer Heifetz 
Signed-off-by: Maxime Ripard 
Signed-off-by: Vinod Koul

dmaengine: mv_xor: Enlarge descriptor pool size

2015-06-10T16:48:31+00:00

Now that we have 2 channels assigned to 2 CPUs and all requests are chained
on same channels, we need much more descriptors available to satisfy
async_tx workload.

3072 descriptors was found in our lab as the number of descriptors which
allow the async_tx stack to work without waiting for free descriptors on
submission of new requests.

Signed-off-by: Lior Amsalem 
Reviewed-by: Nadav Haklai 
Tested-by: Nadav Haklai 
Signed-off-by: Maxime Ripard 
Signed-off-by: Vinod Koul

dmaengine: mv_xor: add support for a38x command in descriptor mode

2015-06-10T16:48:30+00:00

The Marvell Armada 38x SoC introduce new features to the XOR engine,
especially the fact that the engine mode (MEMCPY/XOR/PQ/etc) can be part of
the descriptor and not set through the controller registers.

This new feature allows mixing of different commands (even PQ) on the same
channel/chain without the need to stop the engine to reconfigure the engine
mode.

Refactor the driver to be able to use that new feature on the Armada 38x,
while keeping the old behaviour on the older SoCs.

Signed-off-by: Lior Amsalem 
Reviewed-by: Ofer Heifetz 
Signed-off-by: Maxime Ripard 
Signed-off-by: Vinod Koul

dmaengine: mv_xor: bug fix for racing condition in descriptors cleanup

2015-06-10T16:48:30+00:00

This patch fixes a bug in the XOR driver where the cleanup function can be
called and free descriptors that never been processed by the engine (which
result in data errors).

The cleanup function will free descriptors based on the ownership bit in
the descriptors.

Fixes: ff7b04796d98 ("dmaengine: DMA engine driver for Marvell XOR engine")
Signed-off-by: Lior Amsalem 
Signed-off-by: Maxime Ripard 
Reviewed-by: Ofer Heifetz 
Cc: stable@vger.kernel.org
Signed-off-by: Vinod Koul

dmaengine: Remove FSF mailing addresses

2015-03-16T16:58:15+00:00

Free Software Foundation mailing address has been moved in the past and some
of the addresses here are outdated. Remove them from file headers since the
COPYING file in the kernel sources includes it.

Signed-off-by: Jarkko Nikula 
Signed-off-by: Vinod Koul

dma: mv_xor: Add support for DMA_INTERRUPT

2014-09-23T14:47:01+00:00

The driver is capable of supporting DMA_INTERRUPT by issuing a dummy 128-byte
transfer. This helps removing a poll in the async_tx stack, replacing it with
a completion interrupt.

Signed-off-by: Lior Amsalem 
Signed-off-by: Ezequiel Garcia 
Signed-off-by: Vinod Koul

dma: mv_xor: Remove dead code

2014-09-23T14:47:01+00:00

The driver currently defines the USE_TIMER macro, but the timer-feature
is never used in the code. The XOR and CRC32 results are never used.

The 'unmap_xxx' fields are no longer needed, they were made obsolete
in commit: 54f8d501e842 dmaengine: remove DMA unmap from drivers.

Let's remove all this dead code.

Signed-off-by: Ezequiel Garcia 
Signed-off-by: Vinod Koul

dma: mv_xor: Reduce interrupts by enabling EOD only when needed

2014-09-23T14:47:01+00:00

This commit unmasks the end-of-chain interrupt and removes the
end-of-descriptor command setting on all transactions, except those
explicitly flagged with DMA_PREP_INTERRUPT.

This allows to raise an interrupt only on chain completion, instead of
on each descriptor completion, which reduces interrupt count.

Signed-off-by: Lior Amsalem 
Signed-off-by: Ezequiel Garcia 
Signed-off-by: Vinod Koul

dma: mv_xor: Remove all interrupt magic numbers

2014-09-23T14:47:00+00:00

This commit replaces the current magic numbers in the interrupt handling
with proper macros, which makes more readable and self-documenting.

While here replace the BUG() with a noisy WARN_ON(). There's no reason
to tear down the entire system for an DMA IRQ error.

Signed-off-by: Ezequiel Garcia 
Signed-off-by: Vinod Koul

dma: mv_xor: Remove multi-slot support

2014-09-23T14:47:00+00:00

Although the driver supported multiple-slot allocation, only one slot was
ever allocated for each transaction. So, given we have no users of the
multi-slot support, we can remove it and greatly simplify the code.

Signed-off-by: Lior Amsalem 
Signed-off-by: Ezequiel Garcia 
Signed-off-by: Vinod Koul