linux-stable.git/drivers/dma/qcom, branch linux-5.10.y

dmaengine: qcom: bam_dma: Fix DT error handling for num-channels/ees

2025-10-02T11:35:39+00:00

commit 5068b5254812433e841a40886e695633148d362d upstream.

When we don't have a clock specified in the device tree, we have no way to
ensure the BAM is on. This is often the case for remotely-controlled or
remotely-powered BAM instances. In this case, we need to read num-channels
from the DT to have all the necessary information to complete probing.

However, at the moment invalid device trees without clock and without
num-channels still continue probing, because the error handling is missing
return statements. The driver will then later try to read the number of
channels from the registers. This is unsafe, because it relies on boot
firmware and lucky timing to succeed. Unfortunately, the lack of proper
error handling here has been abused for several Qualcomm SoCs upstream,
causing early boot crashes in several situations [1, 2].

Avoid these early crashes by erroring out when any of the required DT
properties are missing. Note that this will break some of the existing DTs
upstream (mainly BAM instances related to the crypto engine). However,
clearly these DTs have never been tested properly, since the error in the
kernel log was just ignored. It's safer to disable the crypto engine for
these broken DTBs.

[1]: https://lore.kernel.org/r/CY01EKQVWE36.B9X5TDXAREPF@fairphone.com/
[2]: https://lore.kernel.org/r/20230626145959.646747-1-krzysztof.kozlowski@linaro.org/

Cc: stable@vger.kernel.org
Fixes: 48d163b1aa6e ("dmaengine: qcom: bam_dma: get num-channels and num-ees from dt")
Signed-off-by: Stephan Gerhold 
Reviewed-by: Konrad Dybcio 
Link: https://lore.kernel.org/r/20250212-bam-dma-fixes-v1-8-f560889e65d8@linaro.org
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman

dmaengine: QCOM_HIDMA_MGMT depends on HAS_IOMEM

2021-06-23T12:42:40+00:00

[ Upstream commit 0cfbb589d67f16fa55b26ae02b69c31b52e344b1 ]

When CONFIG_HAS_IOMEM is not set/enabled, certain iomap() family
functions [including ioremap(), devm_ioremap(), etc.] are not
available.
Drivers that use these functions should depend on HAS_IOMEM so that
they do not cause build errors.

Rectifies these build errors:
s390-linux-ld: drivers/dma/qcom/hidma_mgmt.o: in function `hidma_mgmt_probe':
hidma_mgmt.c:(.text+0x780): undefined reference to `devm_ioremap_resource'
s390-linux-ld: drivers/dma/qcom/hidma_mgmt.o: in function `hidma_mgmt_init':
hidma_mgmt.c:(.init.text+0x126): undefined reference to `of_address_to_resource'
s390-linux-ld: hidma_mgmt.c:(.init.text+0x16e): undefined reference to `of_address_to_resource'

Fixes: 67a2003e0607 ("dmaengine: add Qualcomm Technologies HIDMA channel driver")
Signed-off-by: Randy Dunlap 
Reported-by: kernel test robot 
Cc: Sinan Kaya 
Cc: Vinod Koul 
Cc: dmaengine@vger.kernel.org
Link: https://lore.kernel.org/r/20210522021313.16405-3-rdunlap@infradead.org
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

dmaengine: qcom_hidma: comment platform_driver_register call

2021-06-03T07:00:42+00:00

[ Upstream commit 4df2a8b0ad634d98a67e540a4e18a60f943e7d9f ]

Place a comment in hidma_mgmt_init explaining why success must
currently be assumed, due to the cleanup issue that would need to
be considered were this module ever to be unloadable or were this
platform_driver_register call ever to fail.

Acked-By: Vinod Koul 
Acked-By: Sinan Kaya 
Signed-off-by: Phillip Potter 
Link: https://lore.kernel.org/r/20210503115736.2104747-52-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

Revert "dmaengine: qcom_hidma: Check for driver register failure"

2021-06-03T07:00:42+00:00

[ Upstream commit 43ed0fcf613a87dd0221ec72d1ade4d6544f2ffc ]

This reverts commit a474b3f0428d6b02a538aa10b3c3b722751cb382.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

The original change is NOT correct, as it does not correctly unwind from
the resources that was allocated before the call to
platform_driver_register().

Cc: Aditya Pakki 
Acked-By: Vinod Koul 
Acked-By: Sinan Kaya 
Link: https://lore.kernel.org/r/20210503115736.2104747-51-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

dmaengine: qcom: bam_dma: fix kernel-doc style for tasklet

2020-10-08T09:48:41+00:00

Commit 00c4747a2f64 ("dmaengine: qcom: convert tasklets to use new
tasklet_setup() API") updated driver to use new tasklet_setup() API but
missed to update the documentation for the tasklet function.

Fixes: 00c4747a2f64 ("dmaengine: qcom: convert tasklets to use new tasklet_setup() API")
Link: https://lore.kernel.org/r/20201007083113.567559-3-vkoul@kernel.org
Signed-off-by: Vinod Koul

dmaengine: qcom: convert tasklets to use new tasklet_setup() API

2020-09-18T06:49:07+00:00

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 
Signed-off-by: Allen Pais 
Link: https://lore.kernel.org/r/20200831103542.305571-23-allen.lkml@gmail.com
Signed-off-by: Vinod Koul

dmaengine: qcom: bam_dma: Drop local dma_parms

2020-09-11T12:12:13+00:00

Since commit 9495b7e92f71 ("driver core: platform: Initialize dma_parms
for platform devices"), struct platform_device already provides a
dma_parms structure, so we can save allocating another one.

Signed-off-by: Robin Murphy 
Link: https://lore.kernel.org/r/60ac2ef17e242dbf631db29ebde9d64d6df67030.1599164692.git.robin.murphy@arm.com
Signed-off-by: Vinod Koul

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-13T16:57:21+00:00

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada

dmaengine: qcom: bam_dma: Replace zero-length array with flexible-array

2020-05-13T14:55:16+00:00

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Reviewed-by: Jeffrey Hugo 
Signed-off-by: Gustavo A. R. Silva 
Link: https://lore.kernel.org/r/20200508210707.GA24136@embeddedor
Signed-off-by: Vinod Koul

dmaengine: qcom_hidma: use true,false for bool variable

2020-05-13T11:36:32+00:00

Fix the following coccicheck warning:

drivers/dma/qcom/hidma.c:553:1-17: WARNING: Assignment of 0/1 to bool
variable

Signed-off-by: Jason Yan 
Acked By: Sinan Kaya 
Link: https://lore.kernel.org/r/20200504113406.41530-1-yanaijie@huawei.com
Signed-off-by: Vinod Koul