kernel/linux.git/drivers/dma/dmaengine.c, branch v6.19.11

dmaengine: Add devm_dma_request_chan()

2025-06-26T22:18:04+00:00

Expand the arsenal of devm functions for DMA devices, this time for requesting channels. Signed-off-by: Bence Csókás Link: https://lore.kernel.org/r/20250610082256.400492-2-csokas.bence@prolan.hu Signed-off-by: Vinod Koul

dmaengine: Unify checks in dma_request_chan()

2025-02-10T10:58:53+00:00

Use dev_fwnode() to simplify the check logic for Device Tree and ACPI in dma_request_chan(). Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250205145757.889247-5-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul

dmaengine: Add a comment on why it's okay when kasprintf() fails

2025-02-10T10:58:53+00:00

Add a comment in dma_request_chan() to clarify kasprintf() missing return value check and it is correct functionality. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250205145757.889247-4-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul

dmaengine: avoid non-constant format string

2024-08-29T17:19:53+00:00

Using an arbitrary string as a printf-style format can be a security problem if that string contains % characters, as the optionalal -Wformat-security flag points out: drivers/dma/dmaengine.c: In function '__dma_async_device_channel_register': drivers/dma/dmaengine.c:1073:17: error: format not a string literal and no format arguments [-Werror=format-security] 1073 | dev_set_name(&chan->dev->device, name); | ^~~~~~~~~~~~ Change this newly added instance to use "%s" as the format instead to pass the actual name. Fixes: 10b8e0fd3f72 ("dmaengine: add channel device name to channel registration") Signed-off-by: Arnd Bergmann Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/20240719102319.546622-1-arnd@kernel.org Signed-off-by: Vinod Koul

dmaengine: add channel device name to channel registration

2024-06-11T18:25:34+00:00

Channel device name is used for sysfs, but also by dmatest filter function. With dynamic channel registration, channels can be registered after dma controller registration. Users may want to have specific channel names. If name is NULL, the channel name relies on previous implementation, dmachan. Signed-off-by: Amelie Delaunay Link: https://lore.kernel.org/r/20240531150712.2503554-11-amelie.delaunay@foss.st.com Signed-off-by: Vinod Koul

dmaengine: fix NULL pointer in channel unregistration function

2023-12-21T16:14:29+00:00

__dma_async_device_channel_register() can fail. In case of failure, chan->local is freed (with free_percpu()), and chan->local is nullified. When dma_async_device_unregister() is called (because of managed API or intentionally by DMA controller driver), channels are unconditionally unregistered, leading to this NULL pointer: [ 1.318693] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0 [...] [ 1.484499] Call trace: [ 1.486930] device_del+0x40/0x394 [ 1.490314] device_unregister+0x20/0x7c [ 1.494220] __dma_async_device_channel_unregister+0x68/0xc0 Look at dma_async_device_register() function error path, channel device unregistration is done only if chan->local is not NULL. Then add the same condition at the beginning of __dma_async_device_channel_unregister() function, to avoid NULL pointer issue whatever the API used to reach this function. Fixes: d2fb0a043838 ("dmaengine: break out channel registration") Signed-off-by: Amelie Delaunay Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/20231213160452.2598073-1-amelie.delaunay@foss.st.com Signed-off-by: Vinod Koul

dmaengine: Simplify dma_async_device_register()

2023-08-21T13:06:46+00:00

There are a lot of duplicate codes for checking if the dma has some capability. Define a temporary macro that is used to check if the dma claims some capability and if the corresponding function is implemented. Signed-off-by: Yajun Deng Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/20230815072346.2798927-1-yajun.deng@linux.dev Signed-off-by: Vinod Koul

dmaengine: Actually use devm_add_action_or_reset()

2023-03-17T17:43:42+00:00

It appears that the commit a1beaa50b583 ("dmaengine: Simplify dmaenginem_async_device_register() function") mentions devm_add_action_or_reset() the actual change utilised devm_add_action() call by mistake. Fix the issue by switching to devm_add_action_or_reset(). Fixes: a1beaa50b583 ("dmaengine: Simplify dmaenginem_async_device_register() function") Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20230213112138.32118-1-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul

Merge tag 'dmaengine-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine

2023-02-25T01:18:54+00:00

Pull dmaengine updates from Vinod Koul: "A new driver, couple of device support and binding conversion along with bunch of driver updates are the main features of this. New hardware support: - TI AM62Ax controller support - Xilinx xdma driver - Qualcomm SM6125, SM8550, QDU1000/QRU1000 GPI controller Updates: - Runtime pm support for at_xdmac driver - IMX sdma binding conversion to yaml and HDMI audio support - IMX mxs binding conversion to yaml" * tag 'dmaengine-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (35 commits) dmaengine: idma64: Update bytes_transferred field dmaengine: imx-sdma: Set DMA channel to be private dmaengine: dw: Move check for paused channel to dwc_get_residue() dmaengine: ptdma: check for null desc before calling pt_cmd_callback dmaengine: dw-axi-dmac: Do not dereference NULL structure dmaengine: idxd: Fix default allowed read buffers value in group dmaengine: sf-pdma: pdma_desc memory leak fix dmaengine: Simplify dmaenginem_async_device_register() function dmaengine: use sysfs_emit() to instead of scnprintf() dmaengine: Make an order in struct dma_device definition dt-bindings: dma: cleanup examples - indentation, lowercase hex dt-bindings: dma: drop unneeded quotes dmaengine: xilinx: xdma: Add user logic interrupt support dmaengine: xilinx: xdma: Add xilinx xdma driver dmaengine: drivers: Use devm_platform_ioremap_resource() dmaengine: at_xdmac: remove empty line dmaengine: at_xdmac: add runtime pm support dmaengine: at_xdmac: align properly function members dmaengine: ppc4xx: Convert to use sysfs_emit()/sysfs_emit_at() APIs dmaengine: sun6i: Set the maximum segment size ...

dmaengine: Simplify dmaenginem_async_device_register() function

2023-02-10T06:07:45+00:00

Use devm_add_action_or_reset() instead of devres_alloc() and devres_add(), which works the same. This will simplify the code. There is no functional changes. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20230130112830.52353-1-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul