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MTL's graphics IP (Xe_LPG) once again changes the multicast register types and steering details. Key changes from past platforms: * The number of instances of some MCR types (NODE, OAAL2, and GAM) vary according to the MTL subplatform and cannot be read from fuse registers. However steering to instance #0 will always provided a non-terminated value, so we can lump these all into a single "instance0" table. * The MCR steering register (and its bitfields) has changed. Unlike past platforms, we will be explicitly steering all types of MCR accesses, including those for "SLICE" and "DSS" ranges; we no longer rely on implicit steering. On previous platforms, various hardware/firmware agents that needed to access registers typically had their own steering control registers, allowing them to perform multicast steering without clobbering the CPU/kernel steering. Starting with MTL, more of these agents now share a single steering register (0xFD4) and it is no longer safe for us to assume that the value will remain unchanged from how we initialized it during startup. There is also a slight chance of race conditions between the driver and a hardware/firmware agent, so the hardware provides a semaphore register that can be used to coordinate access to the steering register. Support for the semaphore register will be introduced in a future patch. v2: - Use Xe_LPG terminology instead of "MTL 3D" since it's the IP version we're matching on now rather than the platform. - Don't combine l3bank and mslice masks into a union. It's not related to the other changes here and we might still need both of them on some future platform. - Separate debug dumping of steering settings to a separate helper function. (Tvrtko) - Update debug dumping to include DSS ranges (and future-proof it so that any new ranges added on future platforms will also be dumped). - Restore MULTICAST bit at the end of rw_with_mcr_steering_fw() if we cleared it. Also force the MULTICAST bit to true at the beginning of multicast writes just to be safe. (Bala) Bspec: 67788, 67112 Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com> Cc: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com> Signed-off-by: Matt Roper <matthew.d.roper@intel.com> Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221014230239.1023689-14-matthew.d.roper@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.