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944c3d4dca
If we register the DMA API debug notification chain to
receive platform bus events:
dma_debug_add_bus(&platform_bus_type);
we start receiving warnings after a simple test like "modprobe caam_jr &&
modprobe caamhash && modprobe -r caamhash && modprobe -r caam_jr":
platform ffe301000.jr: DMA-API: device driver has pending DMA allocations while released from device [count=1938]
One of leaked entries details: [device address=0x0000000173fda090] [size=63 bytes] [mapped with DMA_TO_DEVICE] [mapped as single]
It turns out there are several issues with handling buf_dma (mapping of buffer
holding the previous chunk smaller than hash block size):
-detection of buf_dma mapping failure occurs too late, after a job descriptor
using that value has been submitted for execution
-dma mapping leak - unmapping is not performed in all places: for e.g.
in ahash_export or in most ahash_fin* callbacks (due to current back-to-back
implementation of buf_dma unmapping/mapping)
Fix these by:
-calling dma_mapping_error() on buf_dma right after the mapping and providing
an error code if needed
-unmapping buf_dma during the "job done" (ahash_done_*) callbacks
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.