32d94048b9
The gen7 cmdparser is primarily a promotion-based system to allow access to additional registers beyond the HW validation, and allows fallback to normal execution of the user batch buffer if valid and requires chaining. In the next patch, we will do the cmdparser validation in the pipeline asynchronously and so at the point of request construction we will not know if we want to execute the privileged and validated batch, or the original user batch. The solution employed here is to execute both batches, one with raised privileges and one as normal. This is because the gen7 MI_BATCH_BUFFER_START command cannot change privilege level within a batch and must strictly use the current privilege level (or undefined behaviour kills the GPU). So in order to execute the original batch, we need a second non-priviledged batch buffer chain from the ring, i.e. we need to emit two batches for each user batch. Inside the two batches we determine which one should actually execute, we provide a conditional trampoline to call the original batch. Implementation-wise, we create a single buffer and write the shadow and the trampoline inside it at different offsets; and bind the buffer into both the kernel GGTT for the privileged execution of the shadow and into the user ppGTT for the non-privileged execution of the trampoline and original batch. One buffer, two batches and two vma. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191211230858.599030-1-chris@chris-wilson.co.uk |
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| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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.