Commit Graph

107 Commits

Author SHA1 Message Date
Stephan Gerhold
9502ffcda0 dmaengine: qcom: bam_dma: Add "powered remotely" mode
In some configurations, the BAM DMA controller is set up by a remote
processor and the local processor can simply start making use of it
without setting up the BAM. This is already supported using the
"qcom,controlled-remotely" property.

However, for some reason another possible configuration is that the
remote processor is responsible for powering up the BAM, but we are
still responsible for initializing it (e.g. resetting it etc).

This configuration is quite challenging to handle properly because
the power control is handled through separate channels
(e.g. device-specific SMSM interrupts / smem-states). Great care
must be taken to ensure the BAM registers are not accessed while
the BAM is powered off since this results in a bus stall.

Attempt to support this configuration with minimal device-specific
code in the bam_dma driver by tracking the number of requested
channels. Consumers of DMA channels are responsible to only request
DMA channels when the BAM was powered on by the remote processor,
and to release them before the BAM is powered off.

When the first channel is requested the BAM is initialized (reset)
and it is also put into reset when the last channel was released.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Link: https://lore.kernel.org/r/20211018102421.19848-3-stephan@gerhold.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-10-28 22:42:30 +05:30
Linus Torvalds
18ef082713 Merge tag 'dmaengine-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine
Pull dmaengine updates from Vinod Koul:
 "This time around we have a smaller pull request than usual and this
  includes code removal, so should be good!

  New drivers/devices
   - Support for QCOM SM8250 GPI DMA
   - removal of shdma-of driver and binding

  Updates:
   - arm-pl08x yaml binding move
   - altera-msgdma gained DT support
   - removal of imx-sdma platform data support
   - idxd and xilinx driver updates"

* tag 'dmaengine-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (22 commits)
  dmaengine: imx-sdma: Remove platform data header
  dmaengine: xilinx: dpdma: Fix spacing around addr[i-1]
  dmaengine: xilinx: dpdma: Use kernel type u32 over uint32_t
  dmaengine: altera-msgdma: add OF support
  MAINTAINERS: add entry for Altera mSGDMA
  dt-bindings: dma: add schema for altera-msgdma
  dmaengine: xilinx: dpdma: fix kernel-doc
  dmaengine: sf-pdma: apply proper spinlock flags in sf_pdma_prep_dma_memcpy()
  dmaengine: sh: Remove unused shdma-of driver
  dt-bindings: dmaengine: Remove SHDMA Device Tree bindings
  dmaengine: qcom: gpi: Add SM8250 compatible
  dt-bindings: dmaengine: qcom: gpi: add compatible for sm8250
  dmaengine: sun4i: Use list_move_tail instead of list_del/list_add_tail
  dmaengine: ti: omap-dma: Skip pointless cpu_pm context restore on errors
  dmaengine: hsu: Account transferred bytes
  dmaengine: Move kdoc description of struct dma_chan_percpu closer to it
  dmaengine: xilinx: dpdma: Print debug message when losing vsync race
  dmaengine: xilinx: dpdma: Print channel number in kernel log messages
  dt-bindings: dma: convert arm-pl08x to yaml
  dmaengine: idxd: remove devm allocation for idxd->int_handles
  ...
2021-07-05 12:05:13 -07:00
Linus Torvalds
6b00bc639f Merge tag 'dmaengine-fix-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine
Pull dmaengine fixes from Vinod Koul:
 "A bunch of driver fixes, notably:

   - More idxd fixes for driver unregister, error handling and bus
     assignment

   - HAS_IOMEM depends fix for few drivers

   - lock fix in pl330 driver

   - xilinx drivers fixes for initialize registers, missing dependencies
     and limiting descriptor IDs

   - mediatek descriptor management fixes"

* tag 'dmaengine-fix-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine:
  dmaengine: mediatek: use GFP_NOWAIT instead of GFP_ATOMIC in prep_dma
  dmaengine: mediatek: do not issue a new desc if one is still current
  dmaengine: mediatek: free the proper desc in desc_free handler
  dmaengine: ipu: fix doc warning in ipu_irq.c
  dmaengine: rcar-dmac: Fix PM reference leak in rcar_dmac_probe()
  dmaengine: idxd: Fix missing error code in idxd_cdev_open()
  dmaengine: stedma40: add missing iounmap() on error in d40_probe()
  dmaengine: SF_PDMA depends on HAS_IOMEM
  dmaengine: QCOM_HIDMA_MGMT depends on HAS_IOMEM
  dmaengine: ALTERA_MSGDMA depends on HAS_IOMEM
  dmaengine: idxd: Add missing cleanup for early error out in probe call
  dmaengine: xilinx: dpdma: Limit descriptor IDs to 16 bits
  dmaengine: xilinx: dpdma: Add missing dependencies to Kconfig
  dmaengine: stm32-mdma: fix PM reference leak in stm32_mdma_alloc_chan_resourc()
  dmaengine: zynqmp_dma: Fix PM reference leak in zynqmp_dma_alloc_chan_resourc()
  dmaengine: xilinx: dpdma: initialize registers before request_irq
  dmaengine: pl330: fix wrong usage of spinlock flags in dma_cyclc
  dmaengine: fsl-dpaa2-qdma: Fix error return code in two functions
  dmaengine: idxd: add missing dsa driver unregister
  dmaengine: idxd: add engine 'struct device' missing bus type assignment
2021-06-16 09:03:52 -07:00
Konrad Dybcio
23e51f110f dmaengine: qcom: gpi: Add SM8250 compatible
SM8250 seems to work just fine, so add a shiny new compatible for it.

Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210614235358.444834-2-konrad.dybcio@somainline.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-06-16 16:06:10 +05:30
Randy Dunlap
0cfbb589d6 dmaengine: QCOM_HIDMA_MGMT depends on HAS_IOMEM
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: 67a2003e06 ("dmaengine: add Qualcomm Technologies HIDMA channel driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Sinan Kaya <okaya@codeaurora.org>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Link: https://lore.kernel.org/r/20210522021313.16405-3-rdunlap@infradead.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-05-31 09:44:14 +05:30
Phillip Potter
4df2a8b0ad dmaengine: qcom_hidma: comment platform_driver_register call
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 <vkoul@kernel.org>
Acked-By: Sinan Kaya <okaya@kernel.org>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210503115736.2104747-52-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13 18:32:29 +02:00
Greg Kroah-Hartman
43ed0fcf61 Revert "dmaengine: qcom_hidma: Check for driver register failure"
This reverts commit a474b3f042.

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 <pakki001@umn.edu>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-By: Sinan Kaya <okaya@kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-51-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13 18:32:28 +02:00
Felipe Balbi
0b0f93cf91 dt-bindings: dmaengine: qcom: gpi: add compatible for sm8150
No functional changes, just adding a new compatible for a diferent
SoC.

Signed-off-by: Felipe Balbi <felipe.balbi@microsoft.com>
Link: https://lore.kernel.org/r/20210417061951.2105530-2-balbi@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-04-20 15:37:03 +05:30
Jiapeng Chong
ee1bf567c9 dmaengine: qcom_hidma: remove unused code
Fix the following clang warning:

drivers/dma/qcom/hidma.c:94:20: warning: unused function 'to_hidma_desc'
[-Wunused-function].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/1617270816-36400-1-git-send-email-jiapeng.chong@linux.alibaba.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-04-12 17:14:09 +05:30
Linus Torvalds
143983e585 Merge tag 'dmaengine-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine
Pull dmaengine updates from Vinod Koul:
 "We have couple of drivers removed a new driver and bunch of new device
  support and few updates to drivers for this round.

  New drivers/devices:
   - Intel LGM SoC DMA driver
   - Actions Semi S500 DMA controller
   - Renesas r8a779a0 dma controller
   - Ingenic JZ4760(B) dma controller
   - Intel KeemBay AxiDMA controller

  Removed:
   - Coh901318 dma driver
   - Zte zx dma driver
   - Sirfsoc dma driver

  Updates:
   - mmp_pdma, mmp_tdma gained module support
   - imx-sdma become modern and dropped platform data support
   - dw-axi driver gained slave and cyclic dma support"

* tag 'dmaengine-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (58 commits)
  dmaengine: dw-axi-dmac: remove redundant null check on desc
  dmaengine: xilinx_dma: Alloc tx descriptors GFP_NOWAIT
  dmaengine: dw-axi-dmac: Virtually split the linked-list
  dmaengine: dw-axi-dmac: Set constraint to the Max segment size
  dmaengine: dw-axi-dmac: Add Intel KeemBay AxiDMA BYTE and HALFWORD registers
  dmaengine: dw-axi-dmac: Add Intel KeemBay AxiDMA handshake
  dmaengine: dw-axi-dmac: Add Intel KeemBay AxiDMA support
  dmaengine: drivers: Kconfig: add HAS_IOMEM dependency to DW_AXI_DMAC
  dmaengine: dw-axi-dmac: Add Intel KeemBay DMA register fields
  dt-binding: dma: dw-axi-dmac: Add support for Intel KeemBay AxiDMA
  dmaengine: dw-axi-dmac: Support burst residue granularity
  dmaengine: dw-axi-dmac: Support of_dma_controller_register()
  dmaegine: dw-axi-dmac: Support device_prep_dma_cyclic()
  dmaengine: dw-axi-dmac: Support device_prep_slave_sg
  dmaengine: dw-axi-dmac: Add device_config operation
  dmaengine: dw-axi-dmac: Add device_synchronize() callback
  dmaengine: dw-axi-dmac: move dma_pool_create() to alloc_chan_resources()
  dmaengine: dw-axi-dmac: simplify descriptor management
  dt-bindings: dma: Add YAML schemas for dw-axi-dmac
  dmaengine: ti: k3-psil: optimize struct psil_endpoint_config for size
  ...
2021-02-23 15:05:10 -08:00
Thara Gopinath
123935a4ca dmaengine: qcom: bam_dma: Manage clocks when controlled_remotely is set
When bam dma is "controlled remotely", thus far clocks were not controlled
from the Linux. In this scenario, Linux was disabling runtime pm in bam dma
driver and not doing any clock management in suspend/resume hooks.

With introduction of crypto engine bam dma, the clock is a rpmh resource
that can be controlled from both Linux and TZ/remote side.  Now bam dma
clock is getting enabled during probe even though the bam dma can be
"controlled remotely". But due to clocks not being handled properly,
bam_suspend generates a unbalanced clk_unprepare warning during system
suspend.

To fix the above issue and to enable proper clock-management, this patch
enables runtim-pm and handles bam dma clocks in suspend/resume hooks if
the clock node is present irrespective of controlled_remotely property.

Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Link: https://lore.kernel.org/r/20210126211859.790892-1-thara.gopinath@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-01-27 21:11:19 +05:30
Xu Wang
9ee8f3d968 dmaengine: qcom: gpi: Remove unneeded semicolon
fix semicolon.cocci warning:
drivers/dma/qcom/gpi.c:1703:2-3: Unneeded semicolon

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20210115100040.33364-1-vulab@iscas.ac.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-01-17 11:54:58 +05:30
Nathan Chancellor
0a6d3038d9 dmaengine: qcom: Always inline gpi_update_reg
When building with CONFIG_UBSAN_UNSIGNED_OVERFLOW, clang decides not to
inline gpi_update_reg, which causes a linkage failure around __bad_mask:

ld.lld: error: undefined symbol: __bad_mask
>>> referenced by bitfield.h:119 (include/linux/bitfield.h:119)
>>>               dma/qcom/gpi.o:(gpi_update_reg) in archive drivers/built-in.a
>>> referenced by bitfield.h:119 (include/linux/bitfield.h:119)
>>>               dma/qcom/gpi.o:(gpi_update_reg) in archive drivers/built-in.a

If gpi_update_reg is not inlined, the mask value will not be known at
compile time so the check in field_multiplier stays in the final
object file, causing the above linkage failure. Always inline
gpi_update_reg so that this check can never fail.

Fixes: 5d0c3533a1 ("dmaengine: qcom: Add GPI dma driver")
Link: https://github.com/ClangBuiltLinux/linux/issues/1243
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20210112191214.1264793-1-natechancellor@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-01-13 16:51:17 +05:30
Arnd Bergmann
0bd1bf86ab dmaengine: qcom: fix gpi undefined behavior
gcc points out an incorrect error handling loop:

drivers/dma/qcom/gpi.c: In function 'gpi_ch_init':
drivers/dma/qcom/gpi.c:1254:15: error: iteration 2 invokes undefined behavior [-Werror=aggressive-loop-optimizations]
 1254 |  struct gpii *gpii = gchan->gpii;
      |               ^~~~
drivers/dma/qcom/gpi.c:1951:2: note: within this loop
 1951 |  for (i = i - 1; i >= 0; i++) {
      |  ^~~

Change the loop to correctly walk backwards through the
initialized fields rather than off into the woods.

Fixes: 5d0c3533a1 ("dmaengine: qcom: Add GPI dma driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210103135738.3741123-1-arnd@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-01-04 18:08:36 +05:30
Zheng Yongjun
ba42f61b36 qcom: bam_dma: Delete useless kfree code
The parameter of kfree function is NULL, so kfree code is useless, delete it.
Therefore, goto expression is no longer needed, so simplify it.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20201216130649.13979-1-zhengyongjun3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-12-29 10:08:00 +05:30
Xiaoming Ni
8fb28795fb dmaengine: qcom: gpi: Fixes a format mismatch
drivers/dma/qcom/gpi.c:1419:3: warning: format '%lu' expects argument of
 type 'long unsigned int', but argument 8 has type 'size_t {aka unsigned
 int}' [-Wformat=]
drivers/dma/qcom/gpi.c:1427:31: warning: format '%lu' expects argument of
 type 'long unsigned int', but argument 3 has type 'size_t {aka unsigned
 int}' [-Wformat=]
drivers/dma/qcom/gpi.c:1447:3: warning: format '%llx' expects argument of
 type 'long long unsigned int', but argument 4 has type 'dma_addr_t {aka
 unsigned int}' [-Wformat=]
drivers/dma/qcom/gpi.c:1447:3: warning: format '%llx' expects argument of
 type 'long long unsigned int', but argument 5 has type 'phys_addr_t {aka
 unsigned int}' [-Wformat=]

Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20201218104137.59200-1-nixiaoming@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-12-29 10:07:59 +05:30
Parth Y Shah
4421fe5332 dmaengine: bam_dma: fix return of bam_dma_irq()
While performing suspend/resume, we were getting below kernel crash.

[   54.541672] [FTS][Info]gesture suspend...
[   54.605256] [FTS][Error][GESTURE]Enter into gesture(suspend) failed!
[   54.605256]
[   58.345850] irq event 10: bogus return value fffffff3
......

[   58.345966] [<ffff0000080830f0>] el1_irq+0xb0/0x124
[   58.345971] [<ffff000008085360>] arch_cpu_idle+0x10/0x18
[   58.345975] [<ffff0000081077f4>] do_idle+0x1ac/0x1e0
[   58.345979] [<ffff0000081079c8>] cpu_startup_entry+0x20/0x28
[   58.345983] [<ffff000008a80ed0>] rest_init+0xd0/0xdc
[   58.345988] [<ffff0000091c0b48>] start_kernel+0x390/0x3a4
[   58.345990] handlers:
[   58.345994] [<ffff0000085120d0>] bam_dma_irq

The reason for the crash we found is, bam_dma_irq() was returning
negative value when the device resumes in some conditions.

In addition, the irq handler should have one of the below return values.

IRQ_NONE            interrupt was not from this device or was not handled
IRQ_HANDLED         interrupt was handled by this device
IRQ_WAKE_THREAD     handler requests to wake the handler thread

Therefore, to resolve this crash, we have changed the return value to
IRQ_NONE.

Signed-off-by: Parth Y Shah <sparth1292@gmail.com>
Link: https://lore.kernel.org/r/1607322820-7450-1-git-send-email-sparth1292@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-12-11 19:48:28 +05:30
Jonathan McDowell
4facce4c12 dmaengine: qcom: Fix ADM driver kerneldoc markup
Update the kerneldoc function headers to fix build warnings:

drivers/dma/qcom/qcom_adm.c:180: warning: Function parameter or member 'chan' not described in 'adm_free_chan'
drivers/dma/qcom/qcom_adm.c:190: warning: Function parameter or member 'burst' not described in 'adm_get_blksize'
drivers/dma/qcom/qcom_adm.c:466: warning: Function parameter or member 'chan' not described in 'adm_terminate_all'
drivers/dma/qcom/qcom_adm.c:466: warning: Excess function parameter 'achan' description in 'adm_terminate_all'
drivers/dma/qcom/qcom_adm.c:503: warning: Function parameter or member 'achan' not described in 'adm_start_dma'

Signed-off-by: Jonathan McDowell <noodles@earth.li>
Link: https://lore.kernel.org/r/20201126184602.GA1008@earth.li
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-12-11 19:06:47 +05:30
Vinod Koul
5d0c3533a1 dmaengine: qcom: Add GPI dma driver
This controller provides DMAengine capabilities for a variety of peripheral
buses such as I2C, UART, and SPI. By using GPI dmaengine driver, bus
drivers can use a standardize interface that is protocol independent to
transfer data between memory and peripheral.

Link: https://lore.kernel.org/r/20201109085450.24843-4-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-11-24 21:42:07 +05:30
Jonathan McDowell
5c9f8c2dbd dmaengine: qcom: Add ADM driver
Add the DMA engine driver for the QCOM Application Data Mover (ADM) DMA
controller found in the MSM8x60 and IPQ/APQ8064 platforms.

The ADM supports both memory to memory transactions and memory
to/from peripheral device transactions.  The controller also provides
flow control capabilities for transactions to/from peripheral devices.

The initial release of this driver supports slave transfers to/from
peripherals and also incorporates CRCI (client rate control interface)
flow control.

The hardware only supports a 32 bit physical address, so specifying
!PHYS_ADDR_T_64BIT gives maximum COMPILE_TEST coverage without having to
spend effort on kludging things in the code that will never actually be
needed on real hardware.

Signed-off-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Thomas Pedersen <twp@codeaurora.org>
Signed-off-by: Jonathan McDowell <noodles@earth.li>
Link: https://lore.kernel.org/r/20201114140233.GM32650@earth.li
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-11-24 21:41:15 +05:30
Vinod Koul
a5e399a5a0 dmaengine: qcom: bam_dma: fix kernel-doc style for tasklet
Commit 00c4747a2f ("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: 00c4747a2f ("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 <vkoul@kernel.org>
2020-10-08 15:18:41 +05:30
Allen Pais
00c4747a2f dmaengine: qcom: convert tasklets to use new tasklet_setup() API
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/20200831103542.305571-23-allen.lkml@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-09-18 12:19:07 +05:30
Robin Murphy
4e06de43a9 dmaengine: qcom: bam_dma: Drop local dma_parms
Since commit 9495b7e92f ("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 <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/60ac2ef17e242dbf631db29ebde9d64d6df67030.1599164692.git.robin.murphy@arm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-09-11 17:42:13 +05:30
Masahiro Yamada
a7f7f6248d treewide: replace '---help---' in Kconfig files with 'help'
Since commit 84af7a6194 ("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 <masahiroy@kernel.org>
2020-06-14 01:57:21 +09:00
Gustavo A. R. Silva
c18b5bdebd dmaengine: qcom: bam_dma: Replace zero-length array with flexible-array
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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200508210707.GA24136@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-05-13 20:25:16 +05:30