6a8fda8a73
commit 05d92ee782eeb7b939bdd0189e6efcab9195bf95 upstream.
Commit 2f4a4d63a193 ("ACPI: CPPC: Use access_width over bit_width for
system memory accesses") neglected to properly wrap the bit_offset shift
when it comes to applying the mask. This may cause incorrect values to be
read and may cause the cpufreq module not be loaded.
[ 11.059751] cpu_capacity: CPU0 missing/invalid highest performance.
[ 11.066005] cpu_capacity: partial information: fallback to 1024 for all CPUs
Also, corrected the bitmask generation in GENMASK (extra bit being added).
Fixes: 2f4a4d63a193 ("ACPI: CPPC: Use access_width over bit_width for system memory accesses")
Signed-off-by: Jarred White <jarredwhite@linux.microsoft.com>
Cc: 5.15+ <stable@vger.kernel.org> # 5.15+
Reviewed-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.