Unlike DMA transfers descriptors that are preallocated and cached,
memory used to store hardware descriptors is allocated and freed with
the DMA coherent allocation API for every transfer. Besides degrading
performances, this creates a CMA stress test that seems to cause issues.
Running dmatest with the noverify option produces

[   50.066539] alloc_contig_range test_pages_isolated(6b845, 6b846) failed
[   50.235180] alloc_contig_range test_pages_isolated(6b848, 6b84e) failed
[   52.964584] alloc_contig_range test_pages_isolated(6b847, 6b848) failed
[   54.127113] alloc_contig_range test_pages_isolated(6b843, 6b844) failed
[   56.270253] alloc_contig_range test_pages_isolated(6b84c, 6b850) failed

The root cause needs to be fixed, but in the meantime, as a workaround
and a performance improvement, cache hardware descriptors.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

The DMAC supports hardware-based auto-configuration from descriptor
lists. This reduces the number of interrupts required for processing a
DMA transfer. Support that mode in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

The DMAC is a general purpose multi-channel DMA controller that supports
both slave and memcpy transfers.

The driver currently supports the DMAC found in the r8a7790 and r8a7791
SoCs. Support for compatible DMA controllers (such as the audio DMAC)
will be added later.

Feature-wise, automatic hardware handling of descriptors chains isn't
supported yet. LPAE support is implemented.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

DT bindings are complex enough without expressing the same information
twice in a slightly different way. Remove the duplicate.
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

The widths are missing, add them.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

driver comment refers to DMA_PAUSE which needs to be updated to
.device_pause
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

driver comment refers to DMA_SLAVE_CONFIG which needs to be updated to
.device_config
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

driver comment refers to DMA_SLAVE_CONFIG which needs to be updated to
.device_config
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

driver comment refers to DMA_SLAVE_CONFIG which needs to be updated to
.device_config
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/tegra20-apb-dma.c:1428:37: warning: assignment from incompatible pointer type [enabled by default]
drivers/dma/ste_dma40.c: In function 'd40_terminate_all':

The function prototype expects return type 'int' whereas these where void
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/ste_dma40.c:2627:3: warning: 'return' with a value, in function returning void [enabled by default]
drivers/dma/ste_dma40.c: In function 'd40_ops_init':
drivers/dma/ste_dma40.c:2869:28: warning: assignment from incompatible pointer type [enabled by default]

The function prototype expects return type 'int' whereas these where void
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/mxs-dma.c: In function 'mxs_dma_terminate_all':
drivers/dma/mxs-dma.c:662:23: warning: unused variable 'mxs_chan'[-Wunused-variable]
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/mxs-dma.c: In function 'mxs_dma_probe':
drivers/dma/mxs-dma.c:848:35: warning: assignment from incompatible pointer type [enabled by default]
drivers/dma/mxs-dma.c:849:36: warning: assignment from incompatible pointer type [enabled by default]

The function prototype expects return type 'int' whereas these where void
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dma_slave_config is expected to be set for slave operations Only, not for
memcpy ones
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Signed-off-by: Vinod Koul <vinod.koul@intel.com>

mxs_dma_reset_chan() expects struct dma_chan * as argument but we were
providing struct dma_chan, so fix this
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that we have splitted device_control and removed device_slave_caps in favor
of a few dma_device variables, update the documentation accordingly.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that device_control has been split into several functions, and
device_slave_caps rendered useless, we can safely remove them.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

For the slave caps retrieval to be really useful, most drivers need to
implement it.

Hence, we need to be slightly more aggressive, and trigger a warning at
registration time for drivers that don't fill their caps infos in order to
encourage them to implement it.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Rename the device_control callback of the TXX9 DMA driver to terminate_all
since it's all it's really doing. That will eventually be used to retrieve
slave capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Rename the device_control callback of the TXX9 DMA driver to terminate_all
since it's all it's really doing. That will eventually be used to retrieve
slave capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Rename the device_control callback of the Timberdal DMA driver to terminate_all
since it's all it's really doing. That will eventually be used to retrieve
slave capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Rename the device_control callback of the Intel PCH DMA driver to terminate_all
since it's all it's really doing. That will eventually be used to retrieve
slave capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The Marvell XOR engine doesn't allow any operations that use to be defined in
device_control, it shouldn't need to be defined. Since it's going to be
deprecated, remove it altogether.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Split the device_control callback of the Xilinx VDMA driver to make use of the
newly introduced callbacks, that will eventually be used to retrieve slave
capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Split the device_control callback of the NVidia Tegra20 APB DMA driver to make
use of the newly introduced callbacks, that will eventually be used to retrieve
slave capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Split the device_control callback of the ST-Ericsson DMA 40 driver to make use
of the newly introduced callbacks, that will eventually be used to retrieve
slave capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Split the device_control callback of the Allwinner A31 DMA driver to make use
of the newly introduced callbacks, that will eventually be used to retrieve
slave capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Split the device_control callback of the SiRF Prima 2 DMA driver to make use
of the newly introduced callbacks, that will eventually be used to retrieve
slave capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Split the device_control callback of the Super-H DMA driver to make use of the
newly introduced callbacks, that will eventually be used to retrieve slave
capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Split the device_control callback of the SA-11x0 DMA driver to make use of the
newly introduced callbacks, that will eventually be used to retrieve slave
capabilities.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>