user/sven/linux.git/include/linux/dmaengine.h, branch v4.4.294

dmaengine: Fix access to uninitialized dma_slave_caps

2020-01-12T10:22:42Z

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

dmaengine: ensure dmaengine helpers check valid callback

2018-05-26T06:49:00Z

commit 757d12e5849be549076901b0d33c60d5f360269c upstream. 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 Signed-off-by: Fabrizio Castro Signed-off-by: Jianming Qiao Signed-off-by: Greg Kroah-Hartman

dma: Add support to program MIC x100 status descriptiors

2015-10-04T11:46:06Z

The MIC X100 DMA engine has a special status descriptor which writes an 8 byte value to a destination location. This is used to signal completion of all DMA descriptors prior to the status descriptor. This patch add a new DMA engine API which enables updating a destination address with an 8 byte immediate data value. Reviewed-by: Nikhil Rao Reviewed-by: Ashutosh Dixit Signed-off-by: Lawrynowicz, Jacek Signed-off-by: Sudeep Dutt Signed-off-by: Siva Yerramreddy Signed-off-by: Greg Kroah-Hartman

dmaengine: Stricter legacy checking in dma_request_slave_channel_compat()

2015-08-20T06:31:03Z

dma_request_slave_channel_compat() is meant for drivers that support both DT and legacy platform device based probing: if DT channel DMA setup fails, it will fall back to platform data based DMA channel setup, using hardcoded DMA channel IDs and a filter function. However, if the DTS doesn't provide a "dmas" property for the device, the fallback is also used. If the legacy filter function is not hardcoded in the DMA slave driver, but comes from platform data, it will be NULL. Then dma_request_slave_channel_compat() will succeed incorrectly, and return a DMA channel, as a NULL legacy filter function actually means "all channels are OK", not "do not match". Later, when trying to use that DMA channel, it will fail with: rcar-dmac e6700000.dma-controller: rcar_dmac_prep_slave_sg: bad parameter: len=1, id=-22 To fix this, ensure that both the filter function and the DMA channel ID are not NULL before using the legacy fallback. Note that some DMA slave drivers can handle this failure, and will fall back to PIO. See also commit 056f6c87028544de ("dmaengine: shdma: Make dummy shdma_chan_filter() always return false"), which fixed the same issue for the case where shdma_chan_filter() is hardcoded in a DMA slave driver. Suggested-by: Arnd Bergmann Signed-off-by: Geert Uytterhoeven Signed-off-by: Vinod Koul

dmaengine: Make __dma_request_slave_channel_compat() name argument constant

2015-08-17T09:22:10Z

Inline function __dma_request_slave_channel_compat() doesn't modify "name" argument but passes it to dma_request_slave_channel() which already takes it as a constant. Signed-off-by: Jarkko Nikula Signed-off-by: Vinod Koul

dmaengine: Add DMA_CTRL_REUSE

2015-08-17T09:22:02Z

This adds new descriptor flag for reusing a descriptor by submitting multiple times by a client, for example video buffer. Add helper APIs for this as well Signed-off-by: Vinod Koul Acked-by:Robert Jarzmik

dmaengine: Add scatter-gathered memset

2015-08-06T03:00:56Z

The current API allows the driver to accelerate memset by using the DMA controller. However, it does so over a contiguous memory area, which might proves inefficient when you have to do it over a non-contiguous yet repititive pattern, since you have to create a number of descriptors and then submit each other. Add a memset operation going over a scatter list to handle such cases in a single call. Signed-off-by: Maxime Ripard Acked-by: Ludovic Desroches Signed-off-by: Vinod Koul

dmaengine: Add an enum for the dmaengine alignment constraints

2015-08-05T05:23:52Z

Most drivers need to set constraints on the buffer alignment for async tx operations. However, even though it is documented, some drivers either use a defined constant that is not matching what the alignment variable expects (like DMA_BUSWIDTH_* constants) or fill the alignment in bytes instead of power of two. Add a new enum for these alignments that matches what the framework expects, and convert the drivers to it. Signed-off-by: Maxime Ripard Signed-off-by: Vinod Koul

Merge branch 'topic/xdmac' into for-linus

2015-06-25T03:51:49Z

Merge branch 'topic/omap' into for-linus

2015-06-25T03:51:43Z