a7b3a470fd
Sudeep writes: cacheinfo and arch_topology updates for v6.4 The cache information can be extracted from either a Device Tree(DT), the PPTT ACPI table, or arch registers (clidr_el1 for arm64). When the DT is used but no cache properties are advertised, the current code doesn't correctly fallback to using arch information. The changes fixes the same and also assuse the that L1 data/instruction caches are private and L2/higher caches are shared when the cache information is missing in DT/ACPI and is derived form clidr_el1/arch registers. Currently the cacheinfo is built from the primary CPU prior to secondary CPUs boot, if the DT/ACPI description contains cache information. However, if not present, it still reverts to the old behavior, which allocates the cacheinfo memory on each secondary CPUs which causes RT kernels to triggers a "BUG: sleeping function called from invalid context". The changes here attempts to enable automatic detection for RT kernels when no DT/ACPI cache information is available, by pre-allocating cacheinfo memory on the primary CPU. * tag 'cacheinfo-updates-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux: cacheinfo: Add use_arch[|_cache]_info field/function arch_topology: Remove early cacheinfo error message if -ENOENT cacheinfo: Check cache properties are present in DT cacheinfo: Check sib_leaf in cache_leaves_are_shared() cacheinfo: Allow early level detection when DT/ACPI info is missing/broken cacheinfo: Add arm64 early level initializer implementation cacheinfo: Add arch specific early level initializer
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.