pm_runtime_get_sync() will increase the runtime PM counter
even it returns an error. Thus a pairing decrement is needed
to prevent refcount leak. Fix this by replacing this API with
pm_runtime_resume_and_get(), which will not change the runtime
PM counter on error.
Signed-off-by: NDinghao Liu <dinghao.liu@zju.edu.cn>
Acked-by: NThierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20210409082805.23643-1-dinghao.liu@zju.edu.cnSigned-off-by: NVinod 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: NRomain Perier <romain.perier@gmail.com>
Signed-off-by: NAllen Pais <allen.lkml@gmail.com>
Link: https://lore.kernel.org/r/20200831103542.305571-28-allen.lkml@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>

DMA synchronization hook checks whether interrupt is raised by testing
corresponding bit in a hardware status register, and thus, clock should
be enabled in this case, otherwise CPU may hang if synchronization is
invoked while Runtime PM is in suspended state. This patch resumes the RPM
during of the DMA synchronization process in order to avoid potential
problems. It is a minor clean up of a previous commit, no real problem is
fixed by this patch because currently RPM is always in a resumed state
while DMA is synchronized, although this may change in the future.

Fixes: 6697255f ("dmaengine: tegra-apb: Improve DMA synchronization")
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200426190835.21950-1-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

Remove dev_err() messages after platform_get_irq*() failures.
platform_get_irq() already prints an error.

Generated by: scripts/coccinelle/api/platform_get_irq.cocci

Fixes: 6c41ac96 ("dmaengine: tegra-apb: Support COMPILE_TEST")
Signed-off-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NJulia Lawall <julia.lawall@inria.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NThierry Reding <treding@nvidia.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Vinod Koul <vinod.koul@linux.intel.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2002271133450.2973@hadrienSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Boot CPU0 always handles DMA interrupts and under some rare circumstances
it could stuck in uninterruptible state for a significant time (like in a
case of KASAN + NFS root). In this case sibling CPU, which waits for DMA
transfer completion, will get a DMA transfer timeout. In order to handle
this rare condition, interrupt status needs to be polled until interrupt
is handled.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200319212321.3297-2-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

The interrupt is already disabled while interrupt handler is running, and
thus, there is no need to save/restore the IRQ flags within the spinlock.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200319212321.3297-1-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

When CONFIG_PM is disabled, gcc warning this:

drivers/dma/tegra20-apb-dma.c:1587:12: warning: 'tegra_dma_runtime_resume' defined but not used [-Wunused-function]
drivers/dma/tegra20-apb-dma.c:1578:12: warning: 'tegra_dma_runtime_suspend' defined but not used [-Wunused-function]

Make it as __maybe_unused to fix the warnings,
also remove unneeded function declarations.

Fixes: ec8a1586 ("dma: tegra: add dmaengine based dma driver")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NThierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200320071337.59756-1-yuehaibing@huawei.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

Technically it is possible that DMA could be misconfigured in a way that
cyclic DMA transfer is processed slower than it takes to complete the
cycle and in this case the DMA is getting aborted with a not very
informative message about the problem, let's improve it.
Suggested-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-20-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

Remove unused function argument from handle_continuous_head_request().
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-19-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

Tegra APB DMA driver is an Open Firmware driver, so it uses OF alias
naming scheme which overrides MODULE_ALIAS, meaning that MODULE_ALIAS
does nothing and could be removed safely.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-17-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

The DMA controller shall be released on driver's removal.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-15-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

It is enough to check whether hardware is busy on suspend and to reset
it across of suspend-resume because:

  1. Channel's configuration is fully re-programmed on each DMA
     transfer anyways.

  2. Context save-restore of an active channel won't end up well without
     pausing transfer prior to the context's saving, but note that every
     channel shall be idling at the time of suspend, so save-restore is
     not needed at all.

  3. The only case where context save-restore may be useful is when
     channel is in a paused state during suspend. But channel's pausing
     could be supported only on Tegra114+ and this functionality wasn't
     implemented by the driver for years now because there is no need for
     it in upstream kernel.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-14-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

It's a bit impractical to enable hardware's clock at the time of DMA
channel's allocation because most of DMA client drivers allocate DMA
channel at the time of the driver's probing, and thus, DMA clock is kept
always-enabled in practice, defeating the whole purpose of runtime PM.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-13-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

There are few place in the code which check whether pending_sg_req list is
empty despite of the check already being done. Let's remove the duplicated
checks to keep code clean.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-12-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

The runtime PM is always available on all Tegra SoCs since the commit
40b2bb1b ("ARM: tegra: enforce PM requirement"), so there is no
need to handle the case of unavailable RPM in the code anymore.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-11-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

There is no need to re-initialize the already initialized variables.
The tdc->config_init=false after driver's probe and after channel's
freeing, so there is no need to re-initialize it on the channel's
allocation.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-10-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

This patch fixes few dozens of coding style problems reported by
checkpatch and prettifies code where makes sense.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-9-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

Use resource-managed variant of request_irq for brevity.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-8-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

Use devm_platform_ioremap_resource to keep code cleaner a tad.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-7-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

There is no need to kill tasklet when driver's probe fails because tasklet
can't be scheduled at this time. It is also cleaner to kill tasklet on
channel's freeing rather than to kill it on driver's removal, otherwise
tasklet could perform a dummy execution after channel's releasing, which
isn't very nice.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-6-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

It's incorrect to check the channel's "busy" state without taking a lock.
That shouldn't cause any real troubles, nevertheless it's always better
not to have any race conditions in the code.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-5-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

The ISR tasklet could be kept scheduled after DMA transfer termination,
let's add synchronization hook which blocks until tasklet is finished.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-4-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

The interrupt handler puts a half-completed DMA descriptor on a free list
and then schedules tasklet to process bottom half of the descriptor that
executes client's callback, this creates possibility to pick up the busy
descriptor from the free list. Thus, let's disallow descriptor's re-use
until it is fully processed.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200209163356.6439-3-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

I was doing some experiments with I2C and noticed that Tegra APB DMA
driver crashes sometime after I2C DMA transfer termination. The crash
happens because tegra_dma_terminate_all() bails out immediately if pending
list is empty, and thus, it doesn't release the half-completed descriptors
which are getting re-used before ISR tasklet kicks-in.

 tegra-i2c 7000c400.i2c: DMA transfer timeout
 elants_i2c 0-0010: elants_i2c_irq: failed to read data: -110
 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 142 at lib/list_debug.c:45 __list_del_entry_valid+0x45/0xac
 list_del corruption, ddbaac44->next is LIST_POISON1 (00000100)
 Modules linked in:
 CPU: 0 PID: 142 Comm: kworker/0:2 Not tainted 5.5.0-rc2-next-20191220-00175-gc3605715758d-dirty #538
 Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
 Workqueue: events_freezable_power_ thermal_zone_device_check
 [<c010e5c5>] (unwind_backtrace) from [<c010a1c5>] (show_stack+0x11/0x14)
 [<c010a1c5>] (show_stack) from [<c0973925>] (dump_stack+0x85/0x94)
 [<c0973925>] (dump_stack) from [<c011f529>] (__warn+0xc1/0xc4)
 [<c011f529>] (__warn) from [<c011f7e9>] (warn_slowpath_fmt+0x61/0x78)
 [<c011f7e9>] (warn_slowpath_fmt) from [<c042497d>] (__list_del_entry_valid+0x45/0xac)
 [<c042497d>] (__list_del_entry_valid) from [<c047a87f>] (tegra_dma_tasklet+0x5b/0x154)
 [<c047a87f>] (tegra_dma_tasklet) from [<c0124799>] (tasklet_action_common.constprop.0+0x41/0x7c)
 [<c0124799>] (tasklet_action_common.constprop.0) from [<c01022ab>] (__do_softirq+0xd3/0x2a8)
 [<c01022ab>] (__do_softirq) from [<c0124683>] (irq_exit+0x7b/0x98)
 [<c0124683>] (irq_exit) from [<c0168c19>] (__handle_domain_irq+0x45/0x80)
 [<c0168c19>] (__handle_domain_irq) from [<c043e429>] (gic_handle_irq+0x45/0x7c)
 [<c043e429>] (gic_handle_irq) from [<c0101aa5>] (__irq_svc+0x65/0x94)
 Exception stack(0xde2ebb90 to 0xde2ebbd8)
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200209163356.6439-2-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

Tegra's APB DMA engine updates words counter after each transferred burst
of data, hence it can report transfer's residual with more fidelity which
may be required in cases like audio playback. In particular this fixes
audio stuttering during playback in a chromium web browser. The patch is
based on the original work that was made by Ben Dooks and a patch from
downstream kernel. It was tested on Tegra20 and Tegra30 devices.

Link: https://lore.kernel.org/lkml/20190424162348.23692-1-ben.dooks@codethink.co.uk/
Link: https://nv-tegra.nvidia.com/gitweb/?p=linux-4.4.git;a=commit;h=c7bba40c6846fbf3eaad35c4472dcc7d8bbc02e5Inspired-by: NBen Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20190705150519.18171-1-digetx@gmail.comSigned-off-by: NVinod Koul <vkoul@kernel.org>

Apparently driver was never tested with DMA_PREP_INTERRUPT flag being
unset since it completely disables interrupt handling instead of skipping
the callbacks invocations, hence putting channel into unusable state.

The flag is always set by all of kernel drivers that use APB DMA, so let's
error out in otherwise case for consistency. It won't be difficult to
support that case properly if ever will be needed.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVinod 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 and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Reviewed-by: NSteve Winslow <swinslow@gmail.com>
Reviewed-by: NRichard Fontana <rfontana@redhat.com>
Reviewed-by: NAlexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NVinod Koul <vkoul@kernel.org>

Add some trace-points to the driver to allow for debuging via the
trace pipe.
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NVinod Koul <vkoul@kernel.org>

The name field is used for "apbdma.%d" which is rarely going to be
more than 10 bytes, so reduce the size from 30 to 12. This is only
being used by the interrupt registration, so is not critical to the
operation of the driver either.
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVinod Koul <vkoul@kernel.org>

The use of Dma is annoying, since it is an acronym so should be all
upper case. Fix this throughout the driver.
Reviewed-by: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVinod Koul <vkoul@kernel.org>

The buffer byte request length and counter are declared as signed integers
but the values should never be below zero, so make these unsigned integers
instead.
Reviewed-by: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: NVinod Koul <vkoul@kernel.org>

The dma_desc->bytes_transferred counter tracks the number of bytes
moved by the DMA channel. This is then used to calculate the information
passed back in the in the tegra_dma_tx_status callback, which is usually
fine.

When the DMA channel is configured as continous, then the bytes_transferred
counter will increase over time and eventually overflow to become negative
so the residue count will become invalid and the ALSA sound-dma code will
report invalid hardware pointer values to the application. This results in
some users becoming confused about the playout position and putting audio
data in the wrong place.

To fix this issue, always ensure the bytes_transferred field is modulo the
size of the request. We only do this for the case of the cyclic transfer
done ISR as anyone attempting to move 2GiB of DMA data in one transfer
is unlikely.

Note, we don't fix the issue that we should /never/ transfer a negative
number of bytes so we could make those fields unsigned.
Reviewed-by: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVinod Koul <vkoul@kernel.org>

This allows DMA client to issue a non-flow controlled TX. In particular
it is needed for the fuse driver that reads fuse registers using APBDMA
to workaround a HW bug that results in hang when CPU and DMA perform
simultaneous access to fuse peripheral.
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Reviewed-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Commit edd3bdbe ("dmaengine: tegra-apb: Correct runtime-pm usage")
added pm_runtime_get/put() calls to the tegra-apb DMA system suspend
callbacks. Runtime PM is disabled during system suspend and so these
APIs cannot be used. Fix the suspend handling for the tegra-apb DMA by
moving the save and restore of the DMA register context into the
runtime PM suspend and resume callbacks, and then use the
pm_runtime_force_suspend/resume() APIs to invoke the runtime PM
callbacks during system suspend.

Fixes: edd3bdbe ("dmaengine: tegra-apb: Correct runtime-pm usage")
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

This is in preperation of moving to a callback that provides results to the
callback for the transaction. The conversion will maintain current behavior
and the driver must convert to new callback mechanism at a later time in
order to receive results.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Commit 71f7e6cc ('dmaengine: tegra20-apb-dma: Only calculate residue
if txstate exists') changed the tegra_dma_tx_status() function to only
calculate the residue if there is a valid 'txstate' pointer for storing
the residue. Although this makes sense, this changed the behaviour of
the function tegra_dma_tx_status() such that if the pointer 'txstate' is
not valid, then we will return whatever state is returned by
dma_cookie_status() and no longer return the state by looking up the DMA
descriptor and returning it's state.

Please note that dma_cookie_status() will either return DMA_COMPLETE or
DMA_IN_PROGRESS. However, if dma_cookie_status() returns DMA_IN_PROGRESS
the actual status could be DMA_ERROR which will only be seen from
checking the descriptor status. Therefore, even if 'txstate' is not
valid, still check to see if there is a valid descriptor for the cookie
in question and if so return the descriptor state. Finally, ensure the
residue is still not calculated if the 'txstate' is not valid.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The calculation of the DMA residue for the Tegra APB DMA is duplicated
in two places in the tegra_dma_tx_status() function. Remove this
duplicated code by moving calculation to the end of the function and
only calculating if we found a valid descriptor.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Correct the grammar in the debug message when no descriptor is found.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>