linux.git/drivers/dma/at_hdmac.c, branch v6.7

dmaengine: at_hdmac: Annotate struct at_desc with __counted_by

2023-09-28T11:12:02+00:00

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct at_desc.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Vinod Koul 
Cc: Ludovic Desroches 
Cc: Tudor Ambarus 
Cc: linux-arm-kernel@lists.infradead.org
Cc: dmaengine@vger.kernel.org
Signed-off-by: Kees Cook 
Reviewed-by: Tudor Ambarus 
Reviewed-by: "Gustavo A. R. Silva" 
Link: https://lore.kernel.org/r/20230817235859.49846-2-keescook@chromium.org
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: Convert to platform remove callback returning void

2023-09-28T07:40:45+00:00

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20230919133207.1400430-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Vinod Koul

dmaengine: Explicitly include correct DT includes

2023-08-01T18:21:27+00:00

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring 
Link: https://lore.kernel.org/r/20230718143138.1066177-1-robh@kernel.org
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: Extend the Flow Controller bitfield to three bits

2023-05-24T05:50:28+00:00

Some chips have two bits (e.g SAMA5D3), and some have three (e.g.
SAM9G45). A field width of three is compatible as long as valid
values are used for the different chips.

There is no current use of any value needing three bits, so the
fixed bug is relatively benign.

Fixes: d8840a7edcf0 ("dmaengine: at_hdmac: Use bitfield access macros")
Cc: stable@vger.kernel.org
Reviewed-by: Tudor Ambarus 
Signed-off-by: Peter Rosin 
Link: https://lore.kernel.org/r/e2c898ba-c3a3-5dd3-384b-0585661c79f2@axentia.se
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: Repair bitfield macros for peripheral ID handling

2023-05-24T05:50:27+00:00

The MSB part of the peripheral IDs need to go into the ATC_SRC_PER_MSB
and ATC_DST_PER_MSB fields. Not the LSB part.

This fixes a severe regression for TSE-850 devices (compatible
axentia,tse850v3) where output to the audio I2S codec (the main
purpose of the device) simply do not work.

Fixes: d8840a7edcf0 ("dmaengine: at_hdmac: Use bitfield access macros")
Cc: stable@vger.kernel.org
Signed-off-by: Peter Rosin 
Reviewed-by: Tudor Ambarus 
Link: https://lore.kernel.org/r/01e5dae1-d4b0-cf31-516b-423b11b077f1@axentia.se
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: Convert driver to use virt-dma

2022-11-11T06:45:09+00:00

Convert the driver to use the core virt-dma. The driver will be easier to
maintain as it uses the list handling and the tasklet from virt-dma.

With the conversion replace the election of a new transfer in the tasklet
with the election of the new transfer in the interrupt handler. With this
we have a shorter idle window as we remove the scheduling latency of the
tasklet. I chose to do this while doing the conversion to virt-dma,
because if I made a prerequisite patch with the new transfer election in
the irq handler, I would have to duplicate some virt-dma code in the
at_hdmac driver that would end up being removed at the virt-dma conversion
anyway. So do this in a single step.

Signed-off-by: Tudor Ambarus 
Acked-by: Nicolas Ferre 
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-33-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: Remove unused member of at_dma_chan

2022-11-11T06:45:09+00:00

The pointer to at_dma engine was never used, remove it.

Signed-off-by: Tudor Ambarus 
Acked-by: Nicolas Ferre 
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-32-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: Rename "chan_common" to "dma_chan"

2022-11-11T06:45:09+00:00

"chan_common" was misleading and did not suggest that's actually
a struct dma_chan underneath. Rename it so that readers can follow the
code easier. One may see some checks when running checkpatch. Those have
nothing to do with the rename and will be addressed in a further patch.

Signed-off-by: Tudor Ambarus 
Acked-by: Nicolas Ferre 
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-31-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: Rename "dma_common" to "dma_device"

2022-11-11T06:45:09+00:00

"dma_common" name was misleading and did not suggest that's actually
a struct dma_device underneath. Rename it so that readers can follow the
code easier. One may see some checks and a warning when running
checkpatch. Those have nothing to do with the rename and will be addressed
in a further patch.

Signed-off-by: Tudor Ambarus 
Acked-by: Nicolas Ferre 
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-30-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: Use bitfield access macros

2022-11-11T06:45:09+00:00

Use the bitfield access macros in order to clean and to make the driver
easier to read. One will see some "line length exceeds 100 columns"
checkpatch warnings. I chose to not introduce new lines for regs
descriptions in order to preserve the style of the comments throughout
the definitions. Style can be fixed in a further patch.

Signed-off-by: Tudor Ambarus 
Acked-by: Nicolas Ferre 
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-29-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul