4186e2185b
We've been overloading uncore->lock to protect access to the MCR steering register. That's not really what uncore->lock is intended for, and it would be better if we didn't need to hold such a high-traffic spinlock for the whole sequence of (apply steering, access MCR register, restore steering). Let's create a dedicated MCR lock to protect the steering control register over this critical section and stop relying on the high-traffic uncore->lock. For now the new lock is a software lock. However some platforms (MTL and beyond) have a hardware-provided locking mechanism that can be used to serialize not only software accesses, but also hardware/firmware accesses as well; support for that hardware level lock will be added in a future patch. v2: - Use irqsave/irqrestore spinlock calls; platforms using execlist submission rather than GuC submission can perform MCR accesses in interrupt context because reset -> errordump happens in a tasklet. Cc: Chris Wilson <chris.p.wilson@linux.intel.com> Cc: Mika Kuoppala <mika.kuoppala@linux.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/20221128233014.4000136-4-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.