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 <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
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 <vkoul@kernel.org>
"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 <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
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 <vkoul@kernel.org>
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 <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
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 <vkoul@kernel.org>
Do not expose register definitions, structures and helpers via a .h file
because there are used only by at_hdmac.c. Since there are no other users,
remove the ambiguity and move all the .h contents to the .c file.
One may notice some checkpatch warnings and errors with this move. The move
was done "as it was", checkpatch complaints can be fixed in a further
patch.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-28-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Use the resource-managed kzalloc to simplify error logic. Memory allocated
with this function is automatically freed on driver detach. Use
struct_size() helper to calculate the size of the atdma structure with its
trailing flexible array. While here, move the mem allocation higher in the
probe method, as failing to allocate memory indicates a serious system
issue, and everything else does not matter anyway. All these help the code
look a bit cleaner.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-23-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
struct dma_tx_state defines residue as u32. atc_get_bytes_left() returned
an int which could be either an error or the value of the residue. This
could cause problems if the controller supported a u32 buffer transfer size
and the u32 value was past the max int can hold. Our controller does not
support u32 buffer transfer size, but even so, improve the code and pass
the residue by address to avoid unnecessary implicit casts and make
atc_get_bytes_left() return 0 on success or -errno on errors.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-20-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
atc_complete_all() had concurrency bugs, thus remove it:
1/ atc_complete_all() in its entirety was buggy, as when the atchan->queue
list (the one that contains descriptors that are not yet issued to the
hardware) contained descriptors, it fired just the first from the
atchan->queue, but moved all the desc from atchan->queue to
atchan->active_list and considered them all as fired. This could result in
calling the completion of a descriptor that was not yet issued to the
hardware.
2/ when in tasklet at atc_advance_work() time, atchan->active_list was
queried without holding the lock of the chan. This can result in
atchan->active_list concurrency problems between the tasklet and
issue_pending().
Fixes: dc78baa2b9 ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-8-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
tx_submit is supposed to push the current transaction descriptor to a
pending queue, waiting for issue_pending() to be called. issue_pending()
must start the transfer, not tx_submit(), thus remove atc_dostart() from
atc_tx_submit(). Clients of at_xdmac that assume that tx_submit() starts
the transfer must be updated and call dma_async_issue_pending() if they
miss to call it.
The vdbg print was moved to after the lock is released. It is desirable to
do the prints without the lock held if possible, and because the if
statement disappears there's no reason why to do the print while holding
the lock.
Fixes: dc78baa2b9 ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-3-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The value passed in to .prep_dma_memset is to be treated as a single
byte repeating pattern.
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20220301182551.883474-3-benjamin.walker@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
linux/platform_data/dma-atmel.h is only used by the at_hdmac driver. Move
the CFG bits definitions back in at_hdmac_regs.h and the remaining
definitions in the driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201228203022.2674133-1-alexandre.belloni@bootlin.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
In preparation for unconditionally passing the
struct tasklet_struct pointer to all tasklet
callbacks, switch to using the new tasklet_setup()
and from_tasklet() to pass the tasklet pointer explicitly.
Signed-off-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Link: https://lore.kernel.org/r/20200831103542.305571-3-allen.lkml@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
If memory allocation for 'atslave' succeed, at_dma_xlate() doesn't have a
corresponding kfree() in exception handling. Thus add kfree() for this
function implementation.
Fixes: bbe89c8e3d ("at_hdmac: move to generic DMA binding")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20200817115728.1706719-4-yukuai3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
If of_find_device_by_node() succeed, at_dma_xlate() doesn't have a
corresponding put_device(). Thus add put_device() to fix the exception
handling for this function implementation.
Fixes: bbe89c8e3d ("at_hdmac: move to generic DMA binding")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20200817115728.1706719-3-yukuai3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The reurn value of of_find_device_by_node() is not checked, thus null
pointer dereference will be triggered if of_find_device_by_node()
failed.
Fixes: bbe89c8e3d ("at_hdmac: move to generic DMA binding")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20200817115728.1706719-2-yukuai3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Fixes the following W=1 kernel build warning(s):
drivers/dma/at_hdmac.c:666: warning: Function parameter or member 'tx' not described in 'atc_tx_submit'
drivers/dma/at_hdmac.c:666: warning: Excess function parameter 'desc' description in 'atc_tx_submit'
drivers/dma/at_hdmac.c:1206: warning: Function parameter or member 'reg_width' not described in 'atc_dma_cyclic_check_values'
drivers/dma/at_hdmac.c:1206: warning: Function parameter or member 'buf_addr' not described in 'atc_dma_cyclic_check_values'
drivers/dma/at_hdmac.c:1206: warning: Function parameter or member 'period_len' not described in 'atc_dma_cyclic_check_values'
drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'chan' not described in 'atc_dma_cyclic_fill_desc'
drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'desc' not described in 'atc_dma_cyclic_fill_desc'
drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'period_index' not described in 'atc_dma_cyclic_fill_desc'
drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'buf_addr' not described in 'atc_dma_cyclic_fill_desc'
drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'reg_width' not described in 'atc_dma_cyclic_fill_desc'
drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'period_len' not described in 'atc_dma_cyclic_fill_desc'
drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'direction' not described in 'atc_dma_cyclic_fill_desc'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Link: https://lore.kernel.org/r/20200714111546.1755231-9-lee.jones@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Fix the following deadlocks:
1/ atc_handle_cyclic() and atc_chain_complete() called
dmaengine_desc_get_callback_invoke() while wrongly holding the
atchan->lock. Clients can set the callback to dmaengine_terminate_sync()
which will end up trying to get the same lock, thus a deadlock occurred.
2/ dma_run_dependencies() was called with the atchan->lock held, but the
method calls device_issue_pending() which tries to get the same lock,
and so a deadlock occurred.
The driver must not hold the lock when invoking the callback or when
running dependencies. Releasing the spinlock within a called function
before calling the callback is not a nice thing to do -> called functions
become non-atomic when called within an atomic region. Thus the lock is
now taken in the child routines whereever is needed.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-6-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Avoids sleeping without depleting the emergency pool.
The rationale being that in most cases a dma device is either
offloading an operation that will automatically fallback to
software when the descriptor allocation fails, or we can simply poll
and wait for the dma device to release some in use descriptors.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-5-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Having a list of descriptors allocated for the channel at
device_alloc_chan_resources() time is a sign for bad free usage.
Return err and add a debug message in case the channel is not
free from a previous use.
atchan->descs_allocated becomes useless, get rid of it. More,
drop the error message in atc_desc_get() because now it would
introduce an extra if statement. The callers of atc_desc_get()
already print error messages in case the callee fails, no one
is hurt.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-3-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
There is no need for locking in device_alloc_chan_resources(),
the DMA core takes care of it by using a dma_list_mutex around
the DMA devices.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-2-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
All members of the structure are initialized below in the function,
there is no need to use kzalloc.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-1-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drop LIST_HEAD where the variable it declares is never used.
tmp_list has been declared since the introduction of the driver
and has never been used. The two declarations of list were
introduced with the containing functions but were also not used.
The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
identifier x;
@@
- LIST_HEAD(x);
... when != x
// </smpl>
Fixes: dc78baa2b9 ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Fixes: 4facfe7f09 ("dmaengine: hdmac: Split device_control")
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
of_dma_controller_free() was not called on module onloading.
This lead to a soft lockup:
watchdog: BUG: soft lockup - CPU#0 stuck for 23s!
Modules linked in: at_hdmac [last unloaded: at_hdmac]
when of_dma_request_slave_channel() tried to call ofdma->of_dma_xlate().
Cc: stable@vger.kernel.org
Fixes: bbe89c8e3d ("at_hdmac: move to generic DMA binding")
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The leak was found when opening/closing a serial port a great number of
time, increasing kmalloc-32 in slabinfo.
Each time the port was opened, dma_request_slave_channel() was called.
Then, in at_dma_xlate(), atslave was allocated with devm_kzalloc() and
never freed. (Well, it was free at module unload, but that's not what we
want).
So, here, kzalloc is more suited for the job since it has to be freed in
atc_free_chan_resources().
Cc: stable@vger.kernel.org
Fixes: bbe89c8e3d ("at_hdmac: move to generic DMA binding")
Reported-by: Mario Forner <m.forner@be4energy.com>
Suggested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dma_slave_config direction was marked as deprecated quite some
time back, remove the usage from this driver so that the field
can be removed
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tudor Ambarus