Sparse reports the following with regard to locking in the
tegra_dma_global_pause() and tegra_dma_global_resume() functions:

drivers/dma/tegra20-apb-dma.c:362:9: warning: context imbalance in
	'tegra_dma_global_pause' - wrong count at exit
drivers/dma/tegra20-apb-dma.c:366:13: warning: context imbalance in
	'tegra_dma_global_resume' - unexpected unlock

The warning is caused because tegra_dma_global_pause() acquires a lock
but does not release it. However, the lock is released by
tegra_dma_global_resume(). These pause/resume functions are called in
pairs and so it does appear to work.

This global pause is used on early tegra devices that do not have an
individual pause for each channel. The lock appears to be used to ensure
that multiple channels do not attempt to assert/de-assert the global pause
at the same time which could cause the DMA controller to be in the wrong
paused state. Rather than locking around the entire code between the pause
and resume, employ a simple counter to keep track of the global pause
requests. By using a counter, it is only necessary to hold the lock when
pausing and unpausing the DMA controller and hence, fixes the sparse
warning.

Please note that for devices that support individual channel pausing, the
DMA controller lock is not held between pausing and unpausing the channel.
Hence, this change will make the devices that use the global pause behave
in the same way, with regard to locking, as those that don't.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Some void functions have unnecessary return statements at the end
(reported by sparse) and so remove these. Also remove the return variables
from functions tegra_dma_prep_slave_sg() and tegra_dma_prep_slave_cyclic()
because the value is not used.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Everytime a DMA channel register is accessed, the channel base address
is calculated by adding the DMA base address and the channel register
offset. Avoid this calculation and simply calculate the channel base
address once at probe time for each DMA channel.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The callback and callback_param members of the tegra_dma_sg_req structure
are never used. The dma-engine structure, dma_async_tx_descriptor, defines
the same members and these are the ones used by the driver. Therefore,
remove the unused versions from the tegra_dma_sg_req structure.

The half_done member of tegra_dma_channel structure is configured but
never used and so remove it.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dma_request_slave_channel_compat() is meant for drivers that support
both DT and legacy platform device based probing: if DT channel DMA
setup fails, it will fall back to platform data based DMA channel setup,
using hardcoded DMA channel IDs and a filter function.

However, if the DTS doesn't provide a "dmas" property for the device,
the fallback is also used. If the legacy filter function is not
hardcoded in the DMA slave driver, but comes from platform data, it will
be NULL. Then dma_request_slave_channel_compat() will succeed
incorrectly, and return a DMA channel, as a NULL legacy filter function
actually means "all channels are OK", not "do not match".

Later, when trying to use that DMA channel, it will fail with:

    rcar-dmac e6700000.dma-controller: rcar_dmac_prep_slave_sg: bad parameter: len=1, id=-22

To fix this, ensure that both the filter function and the DMA channel ID
are not NULL before using the legacy fallback.

Note that some DMA slave drivers can handle this failure, and will fall
back to PIO.

See also commit 056f6c87 ("dmaengine: shdma: Make dummy
shdma_chan_filter() always return false"), which fixed the same issue
for the case where shdma_chan_filter() is hardcoded in a DMA slave
driver.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This patch adds ACPI support for the APM X-Gene DMA engine driver.
Signed-off-by: Rameshwar Prasad Sahu <rsahu@apm.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

clk_enable() may fail, so we should better check the return value and
propagate it in the case of error.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This patch adds support for the DMA engine present on Allwinner A10,
A13, A10S and A20 SoCs. This engine has two kinds of channels: normal
and dedicated. The main difference is in the mode of operation;
while a single normal channel may be operating at any given time,
dedicated channels may operate simultaneously provided there is no
overlap of source or destination.

Hardware documentation can be found on A10 User Manual (section 12), A13
User Manual (section 14) and A20 User Manual (section 1.12)
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Due to how async_tx behaves internally, having more XOR channels than
CPUs is actually hurting performance more than it improves it, because
memcpy requests get scheduled on a different channel than the XOR
requests, but async_tx will still wait for the completion of the
memcpy requests before scheduling the XOR requests.

It is in fact more efficient to have at most one channel per CPU,
which this patch implements by limiting the number of channels per
engine, and the number of engines registered depending on the number
of availables CPUs.

Marvell platforms are currently available in one CPU, two CPUs and
four CPUs configurations:

 - in the configurations with one CPU, only one channel from one
   engine is used.

 - in the configurations with two CPUs, only one channel from each
   engine is used (they are two XOR engines)

 - in the configurations with four CPUs, both channels of both engines
   are used.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The only reason why we had dmacap,* properties is because back when
DMA_MEMSET was supported, only one out of the two channels per engine
could do a memset operation. But this is something that the driver
already knows anyway, and since then, the DMA_MEMSET support has been
removed.

The driver is already well aware of what each channel supports and the
one to one mapping between Linux specific implementation details (such
as dmacap,interrupt enabling DMA_INTERRUPT) and DT properties is a
good indication that these DT properties are wrong.

Therefore, this commit simply gets rid of these dmacap,* properties,
they are now ignored, and the driver is responsible for knowing the
capabilities of the hardware with regard to the dmaengine subsystem
expectations.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

When there is only one burst required do not emit loop instructions to
loop exactly once. Emit just the body of the loop.
Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

set_irq_flags is ARM specific with custom flags which have genirq
equivalents. Convert drivers to use the genirq interfaces directly, so we
can kill off set_irq_flags. The translation of flags is as follows:

IRQF_VALID -> !IRQ_NOREQUEST
IRQF_PROBE -> !IRQ_NOPROBE
IRQF_NOAUTOEN -> IRQ_NOAUTOEN

For IRQs managed by an irqdomain, the irqdomain core code handles clearing
and setting IRQ_NOREQUEST already, so there is no need to do this in
.map() functions and we can simply remove the set_irq_flags calls. Some
users also modify IRQ_NOPROBE and this has been maintained although it
is not clear that is really needed. There appears to be a great deal of
blind copy and paste of this code.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The new Solo X has more requirements for SDMA events. So it creates
a event mux to remap most of event numbers in GPR (General Purpose
Register). If we want to use SDMA support for those module who do
not get the even number as default, we need to configure GPR first.

Thus this patch adds this support of GPR event remapping configuration
to the SDMA driver.
Signed-off-by: Zidan Wang <zidan.wang@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

In cyclic mode, the round chaining has been broken by the introduction
of at_xdmac_queue_desc(): AT_XDMAC_MBR_UBC_NDE is set for all descriptors
excepted for the last one. at_xdmac_queue_desc() has to be called one
more time to chain the last and the first descriptors.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Fixes: 0d0ee751 ("dmaengine: xdmac: Rework the chaining logic")
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Tasklets may have been scheduled as a result of an earlier interrupt
that could still be running. Kill them before unregistering the
device.
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

We must explicitly free the IRQ before the device is unregistered in
case any device interrupt still occurs, so there's no point in using
the managed variations of the IRQ functions. Change to the regular
versions.
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The header just includes definitions of hardware-specific numbers which
can be written directly in the device tree, there's no need for a public
header containing these definitions.
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

When scanning for a free DMA channel, the filter function should ensure
that the channel is on the controller that it was requested to be on in
the DT.
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

When the DT requests a specific channel to use it is not necesssary
to scan through all DMA channels in the system. Just return the
requested channel using dma_get_slave_channel().
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

There are a some signedness bugs such as testing for < 0 on unsigned
return values. Additionally there are some cases where functions which
should return NULL on error actually return a PTR_ERR value which can
result in oopses on error. Fix these issues.
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

For some reason the controller does not support 8 byte transfers (but
does support all other powers of 2 up to 128). In this case fall back
to 4 bytes. In addition, fall back to 128 bytes when any larger power
of 2 would be possible within the alignment constraints, as this is
the maximum supported.

It makes no sense to outright reject 8 or >128 bytes just because the
alignment constraints make those the maximum possible size given the
parameters for the transaction. For instance, this can result in a DMA
from/to an 8 byte aligned address failing.

It is perfectly safe to fall back to smaller transfer sizes, the only
consequence is reduced transfer efficiency, which is far better than
not allowing the transfer at all.
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Several function prototypes did not match the dmaengine API they were
implementing, resulting in build warnings. Correct these.
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

If DMA interrupt comes and is latched by IRQ controller during the
execution of dma_terminate_all(), dma_irq routine will be executed
after dma terminated, and it will cause kernel panic.
We clear DMA interrupts in dma_terminate_all() to avoid this useless
interrupt.
Signed-off-by: Yanchang Li <Yanchang.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Add device tree bindings documentation for the
lpc1850-dmamux DMA router.
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Add support for DMA on NXP LPC18xx/43xx platforms which has
a multiplexer in front of the PL080 dma request lines.

The mux is a single register in the LPC18xx/43xx CREG block
and can multiplex up to 4 request lines to each of the 16
lines on the PL080.
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This introduces device tree bindings for the PL08x DMA controllers
when used with fixed signal assignment per channel, i.e. if each
channel on the PL08x is assigned precisely one burst/single signal
set.

[je: remove channel sub-node parsing, use cell value to assign AHB]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Add support for assigning DMA channels from a device tree.

[je: remove channel sub-node parsing, dynamic channel creation on xlate]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This fixes the following error:
drivers/dma/pxa_dma.c: In function ‘dbg_show_requester_chan’:
drivers/dma/pxa_dma.c:192:2: error: void value not ignored as it ought to be
  pos += seq_printf(s, "DMA channel %d requester :\n", phy->idx);
  ^
drivers/dma/pxa_dma.c:197:8: error: void value not ignored as it ought to be
        !!(drcmr & DRCMR_MAPVLD));
        ^
scripts/Makefile.build:258: recipe for target 'drivers/dma/pxa_dma.o' failed
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Inline function __dma_request_slave_channel_compat() doesn't modify "name"
argument but passes it to dma_request_slave_channel() which already takes
it as a constant.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Don't use the direction passed in the configuration, and rely on each
transfer's direction to prepare the transfers. This will enable
future removal of direction parameter from dma_slave_config.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

This adds new descriptor flag for reusing a descriptor by submitting
multiple times by a client, for example video buffer.
Add helper APIs for this as well
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>

As discussed recently the meaning of DMA_CTRL_ACK is that a desc cannot be
reused by provider until the client acknowledges receipt, i.e. has has a
chance to establish any dependency chains. So update documentation
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>

IOAT_COMPLETION_PENDING flag was deprecated for v2 and v3 drivers but was
not cleaned up. Doing that now. The commit deprecated this flag was
4dec23d7 ioatdma: fix race between updating ioat->head and
IOAT_COMPLETION_PENDING.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

./scripts/kerne-doc is reporting errors on dma.h. Clean up all reported
errors.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Since we are a "single" device driver now we no longer require the function
pointers in ioatdma_device. Remove.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Moving the relevant functions to their respective .c files and removal of
dma_v3.c file. Also removed various ioat3 references when appropriate.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Move all DMA descriptor prepping functions to prep.c file. Fixup all
broken bits caused by the move.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Moving all the init routines to init.c and fixup anything broken during
the move.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Move and fixup all sysfs related bits to sysfs.c file.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>