user/sven/linux.git/include/linux/dmaengine.h, branch v4.14.201

dmaengine: Store module owner in dma_device struct

2020-02-28T15:36:01Z

[ Upstream commit dae7a589c18a4d979d5f14b09374e871b995ceb1 ] dma_chan_to_owner() dereferences the driver from the struct device to obtain the owner and call module_[get|put](). However, if the backing device is unbound before the dma_device is unregistered, the driver will be cleared and this will cause a NULL pointer dereference. Instead, store a pointer to the owner module in the dma_device struct so the module reference can be properly put when the channel is put, even if the backing device was destroyed first. This change helps to support a safer unbind of DMA engines. If the dma_device is unregistered in the driver's remove function, there's no guarantee that there are no existing clients and a users action may trigger the WARN_ONCE in dma_async_device_unregister() which is unlikely to leave the system in a consistent state. Instead, a better approach is to allow the backing driver to go away and fail any subsequent requests to it. Signed-off-by: Logan Gunthorpe Link: https://lore.kernel.org/r/20191216190120.21374-2-logang@deltatee.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: Fix access to uninitialized dma_slave_caps

2020-01-09T09:17:55Z

commit 53a256a9b925b47c7e67fc1f16ca41561a7b877c upstream. dmaengine_desc_set_reuse() allocates a struct dma_slave_caps on the stack, populates it using dma_get_slave_caps() and then accesses one of its members. However dma_get_slave_caps() may fail and this isn't accounted for, leading to a legitimate warning of gcc-4.9 (but not newer versions): In file included from drivers/spi/spi-bcm2835.c:19:0: drivers/spi/spi-bcm2835.c: In function 'dmaengine_desc_set_reuse': >> include/linux/dmaengine.h:1370:10: warning: 'caps.descriptor_reuse' is used uninitialized in this function [-Wuninitialized] if (caps.descriptor_reuse) { Fix it, thereby also silencing the gcc-4.9 warning. The issue has been present for 4 years but surfaces only now that the first caller of dmaengine_desc_set_reuse() has been added in spi-bcm2835.c. Another user of reusable DMA descriptors has existed for a while in pxa_camera.c, but it sets the DMA_CTRL_REUSE flag directly instead of calling dmaengine_desc_set_reuse(). Nevertheless, tag this commit for stable in case there are out-of-tree users. Fixes: 272420214d26 ("dmaengine: Add DMA_CTRL_REUSE") Reported-by: kbuild test robot Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v4.3+ Link: https://lore.kernel.org/r/ca92998ccc054b4f2bfd60ef3adbab2913171eac.1575546234.git.lukas@wunner.de Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

Merge branch 'topic/dmatest' into for-linus

2017-09-06T16:25:10Z

dmaengine: add DMA_PREP_CMD for non-Data descriptors.

2017-08-28T11:10:18Z

Some of the DMA controllers are capable of issuing the commands to peripheral by the DMA. These commands can be list of register reads/writes and its different from normal data reads/writes. This patch adds new flag DMA_PREP_CMD in DMA API which tells the driver that the data passed to DMA API is command data and DMA controller driver will form descriptor in the required format. This flag can be used by any DMA controller driver which requires the descriptor in different format for non-Data descriptors. Signed-off-by: Abhishek Sahu Signed-off-by: Vinod Koul

dmaengine: remove DMA_SG as it is dead code in kernel

2017-08-22T03:52:11Z

There are no in kernel consumers for DMA_SG op. Removing operation, dead code, and test code in dmatest. Signed-off-by: Dave Jiang Reviewed-by: Linus Walleij Cc: Gary Hook Cc: Ludovic Desroches Cc: Kedareswara rao Appana Cc: Li Yang Cc: Michal Simek Signed-off-by: Vinod Koul

dmaengine: Provide a wrapper for memcpy operations

2017-01-31T03:33:20Z

Almost all ->device_prep_dma_xx() methods have a wrapper defined in dmaengine.h. Add one for ->device_prep_dma_memcpy(). Signed-off-by: Boris Brezillon Signed-off-by: Vinod Koul

dmaengine: dma_slave_config: add support for slave port window

2016-11-30T03:24:04Z

Some slave devices uses address window instead of single register for read and/or write of data. With the src/dst_port_window_size the address window can be specified and the DMAengine driver should use this information to correctly set up the transfer to loop within the provided window. Signed-off-by: Peter Ujfalusi Signed-off-by: Vinod Koul

dmaengine: add support to provide error result from a DMA transation

2016-08-08T02:41:42Z

Adding a new callback that will provide the error result for a transaction. The result is allocated on the stack and the callback should create a copy if it wishes to retain the information after exiting. The result parameter is now defined and takes over the dummy void pointer we placed in the helper functions previously. dmaengine drivers should start converting to the new "callback_result" callback in order to receive transaction results. Signed-off-by: Dave Jiang Reviewed-by: Lars-Peter Clausen Signed-off-by: Vinod Koul

dmaengine: ensure dmaengine helpers check valid callback

2016-04-12T15:37:06Z

dmaengine has various device callbacks and exposes helper functions to invoke these. These helpers should check if channel, device and callback is valid or not before invoking them. Reported-by: Jon Hunter Signed-off-by: Vinod Koul

Merge branch 'topic/pl330' into for-linus

2016-03-14T05:48:12Z