mirror of https://gitee.com/openkylin/linux.git
9ce9bdb00d
Broadwater and the rest of gen4 do support being able to saving and reloading context specific registers between contexts, providing isolation of the basic GPU state (as programmable by userspace). This allows userspace to assume that the GPU retains their state from one batch to the next, minimising the amount of state it needs to reload and manually save across batches. v2: CONSTANT_BUFFER woes Running through piglit turned up an interesting issue, a GPU hang inside the context load. The context image includes the CONSTANT_BUFFER command that loads an address into a on-gpu buffer, and the context load was executing that immediately. However, since it was reading from the GTT there is no guarantee that the GTT retains the same configuration as when the context was saved, resulting in stray reads and a GPU hang. Having tried issuing a CONSTANT_BUFFER (to disable the command) from the ring before saving the context to no avail, we resort to patching out the instruction inside the context image before loading. This does impose that gen4 always reissues CONSTANT_BUFFER commands on each batch, but due to the use of a shared GTT that was and will remain a requirement. v3: ECOSKPD to the rescue Ville found the magic bit in the ECOSKPD to disable saving and restoring the CONSTANT_BUFFER from the context image, thereby completely avoiding the GPU hangs from chasing invalid pointers. This appears to be the default behaviour for gen5, and so we just need to tweak gen4 to match. v4: Fix spelling of ECOSKPD and discover it already exists Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Kenneth Graunke <kenneth@whitecape.org> Reviewed-by: Kenneth Graunke <kenneth@whitecape.org> Link: https://patchwork.freedesktop.org/patch/msgid/20190419172720.5462-1-chris@chris-wilson.co.uk |
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| fs | ||
| include | ||
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| kernel | ||
| lib | ||
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| samples | ||
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| README | ||
README
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.