Paulo Zanoni
4bb41156b9
The residencyNonResidentStrict property requires that writes to unbound memory be ignored and reads return zero. We need this property, otherwise vkd3d will claim we don't support DX12. If a shader writes to a variable associated with an unbound memory region (i.e., mapped to a null tile), reads it back (in the same shader) and expects the value be 0 instead of what is wrote, it has to use the 'volatile' access qualifier to the variable associated with the access, otherwise the compiler will be allowed to optmize things and use the non-zero value. This is explained in the "Accessing Unbound Regions" section of the Vulkan spec. Our hardware adds an extra problem on top of the above. BSpec page "Overview of Memory Access" (47630, 57046) says: "If a read from a Null tile gets a cache-hit in a virtually-addressed GPU cache, then the read may not return zeroes." So, when we detect this type of access, we have to turn off the caching. There's a proposed Vulkan CTS test that does exactly the above. No shaders on shader_db seem to be using 'volatile'. v2: - Reorder commit order - Rewrite commit message v3: - Rework the patch after Caio pointed out the interaction with 'coherent'. - Remove previous R-B tags due to the patch differences. v4: - Rework the patch and commit message again after further discussions. v5: - Check for atomic first so we don't regress DG2 atomic tests. Fixes future test: dEQP-VK.sparse_resources.buffer.ssbo.read_write.sparse_residency_non_resident_strict Reviewed-by: Caio Oliveira <caio.oliveira@intel.com> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36150>
`Mesa <https://mesa3d.org>`_ - The 3D Graphics Library ====================================================== Source ------ This repository lives at https://gitlab.freedesktop.org/mesa/mesa. Other repositories are likely forks, and code found there is not supported. Build & install --------------- You can find more information in our documentation (`docs/install.rst <https://docs.mesa3d.org/install.html>`_), but the recommended way is to use Meson (`docs/meson.rst <https://docs.mesa3d.org/meson.html>`_): .. code-block:: sh $ meson setup build $ ninja -C build/ $ sudo ninja -C build/ install Support ------- Many Mesa devs hang on IRC; if you're not sure which channel is appropriate, you should ask your question on `OFTC's #dri-devel <irc://irc.oftc.net/dri-devel>`_, someone will redirect you if necessary. Remember that not everyone is in the same timezone as you, so it might take a while before someone qualified sees your question. To figure out who you're talking to, or which nick to ping for your question, check out `Who's Who on IRC <https://dri.freedesktop.org/wiki/WhosWho/>`_. The next best option is to ask your question in an email to the mailing lists: `mesa-dev\@lists.freedesktop.org <https://lists.freedesktop.org/mailman/listinfo/mesa-dev>`_ Bug reports ----------- If you think something isn't working properly, please file a bug report (`docs/bugs.rst <https://docs.mesa3d.org/bugs.html>`_). Contributing ------------ Contributions are welcome, and step-by-step instructions can be found in our documentation (`docs/submittingpatches.rst <https://docs.mesa3d.org/submittingpatches.html>`_). Note that Mesa uses gitlab for patches submission, review and discussions.