19aaf72c0c
A recent patch avoided doing 64-bit modulo operations by checking the alignment of some DMA allocations using only the lower 32 bits of the address. David Laight pointed out (after the fix was committed) that DMA allocations might already satisfy the alignment requirements. And he was right. Remove the alignment checks that occur after DMA allocation requests, and update comments to explain why the constraint is satisfied. The only place IPA_TABLE_ALIGN was used was to check the alignment; it is therefore no longer needed, so get rid of it. Add comments where GSI_RING_ELEMENT_SIZE and the tre_count and event_count channel data fields are defined to make explicit they are required to be powers of 2. Revise a comment in gsi_trans_pool_init_dma(), taking into account that dma_alloc_coherent() guarantees its result is aligned to a page size (or order thereof). Don't bother printing an error if a DMA allocation fails. Suggested-by: David Laight <David.Laight@ACULAB.COM> Signed-off-by: Alex Elder <elder@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| arch | ||
| block | ||
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| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
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| COPYING | ||
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| Kbuild | ||
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| MAINTAINERS | ||
| Makefile | ||
| 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 Restructured Text 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.