mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/
synced 2026-11-10 20:48:12 +00:00
No description
- C 96.8%
- Assembly 0.9%
- Rust 0.7%
- Shell 0.6%
- Python 0.5%
- Other 0.3%
e94dc6ddda
The hardware limitation "max=19" actually comes from SMMU Command Queue.
So, it'd be more natural for tegra241-cmdqv driver to read it out rather
than hardcoding it itself.
This is not an issue yet for a kernel on a baremetal system, but a guest
kernel setting the queue base/size in form of IPA/gPA might result in a
noncontiguous queue in the physical address space, if underlying physical
pages backing up the guest RAM aren't contiguous entirely: e.g. 2MB-page
backed guest RAM cannot guarantee a contiguous queue if it is 8MB (capped
to VCMDQ_LOG2SIZE_MAX=19). This might lead to command errors when HW does
linear-read from a noncontiguous queue memory.
Adding this extra IDR1.CMDQS cap (in the guest kernel) allows VMM to set
SMMU's IDR1.CMDQS=17 for the case mentioned above, so a guest-level queue
will be capped to maximum 2MB, ensuring a contiguous queue memory.
Fixes:
|
History
|
|
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| 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 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.