7bc08d2f49
TGL/RKL/ADLS/ADLP are all supposed to use the same MOCS table, with values defined in the bspec. Any entries listed in the bspec as reserved/error/undefined should always be initialized to the most cached and least coherent setting possible so that any userspace accidentally referencing those undefined entries will only experience an increase in coherency if spec updates down the road start defining real values. The TGL and gen12 table entries defined in the driver today are identical except that the TGL includes one additional (incorrect) setting for table index 1. Furthermore, the TGL-specific initialization does not define a dedicated value for info->unused_entries_index, so this incorrect table entry 1 also gets used to populate the MOCS registers for all reserved/unused table entries. This incorrect behavior is a holdover from i915 where the platform was enabled with an incorrect setting and by the time we noticed, it was too late to fix the table without breaking ABI compatibility (and on TGL we did indeed have some buggy userspace that was referencing the 'reserved' entry 1). Since the Xe driver starts fresh with a clean slate on ABI, there's no need to repeat the mistakes of i915 here. v2: - Reword/clarify commit message. (Lucas) Bspec: 45101 Signed-off-by: Matt Roper <matthew.d.roper@intel.com> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
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.