Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
c8ed1ff88c
scatter_data_area() and gather_data_area() are not easy to understand since data is copied in nested loops over sg_list and tcmu dbi list. Since sg list can contain only partly filled pages, the loop has to be prepared to handle sg pages not matching dbi pages one by one. Existing implementation uses kmap_atomic()/kunmap_atomic() due to performance reasons. But instead of using these calls strictly nested for sg and dpi pages, the code holds the mappings in an overlapping way, which indeed is a bug that would trigger on archs using highmem. The scatterlist lib contains the sg_miter_start/_next/_stop functions which can be used to simplify such complicated loops. The new code now processes the dbi list in the outer loop, while sg list is handled by the inner one. That way the code can take advantage of the sg_miter_* family calls. Calling sg_miter_stop() after the end of the inner loop enforces strict nesting of atomic kmaps. Since the nested loops in scatter_/gather_data_area were very similar, I replaced them by the new helper function tcmu_copy_data(). Link: https://lore.kernel.org/r/20201019115118.11949-1-bostroesser@gmail.com Acked-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Bodo Stroesser <bostroesser@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
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| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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.