f561ec8b2b
STM32 DMA3 driver supports the 3 hardware configurations of the STM32 DMA3 controller: - LPDMA (Low Power): 4 channels, no FIFO - GPDMA (General Purpose): 16 channels, FIFO from 8 to 32 bytes - HPDMA (High Performance): 16 channels, FIFO from 8 to 256 bytes Hardware configuration of the channels is retrieved from the hardware configuration registers. The client can specify its channel requirements through device tree. STM32 DMA3 channels can be individually reserved either because they are secure, or dedicated to another CPU. Indeed, channels availability depends on Resource Isolation Framework (RIF) configuration. RIF grants access to buses with Compartment ID (CID) filtering, secure and privilege level. It also assigns DMA channels to one or several processors. DMA channels used by Linux should be CID-filtered and statically assigned to CID1 or shared with other CPUs but using semaphore. In case CID filtering is not configured, dma-channel-mask property can be used to specify available DMA channels to the kernel, otherwise such channels will be marked as reserved and can't be used by Linux. STM32 DMA3 is a new STM32 DMA controller, not a new version of an existing one. stm32-dma is not considered for reuse because register layout is completely different and doesn't rely on descriptors mechanism. stm32-mdma is based on descriptors mechanism but there are significant differences in register layout and descriptors structure. Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com> Link: https://lore.kernel.org/r/20240531150712.2503554-6-amelie.delaunay@foss.st.com Signed-off-by: Vinod Koul <vkoul@kernel.org> |
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| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
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| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
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| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
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.