Karmjit Mahil
ce67f5ac94
Previously UBOs and various buffers, as well as the native descriptor sets were DMAed into the shared registers. This added complexity in allocating the registers and various other places. We also ended up being in situations were we wouldn't know the size of a buffer by the time the shaders were being compiled. It would be possible to determine the size by inspecting the shader but that would introduce more complexity in the compiler. To get things working sooner, avoid extra complexity for now, a different approach was devised. The driver will write the addresses of the currently bound descriptor sets into a device buffer. The device buffer is referred to as the descriptor set addrs table. The dev addr of the table is written into a shared register. To access the buffers the shader will first get the address of the descriptor set from the in memory table. Then get the primary descriptor from the descriptor set. And finally access the in memory buffer with the address it read from the descriptor. Essentially there's three level of indirection and all the buffers are in memory. The shader will know what offset the primary descriptor is located based on the descriptor set layout. The descriptor set address could have been written into the shareds directly but that would require extra handling on the compiler side so opted to just write the table address instead. Signed-off-by: Karmjit Mahil <Karmjit.Mahil@imgtec.com> Reviewed-by: Frank Binns <frank.binns@imgtec.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21331>
`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://mesa3d.org/install.html>`_), but the recommended way is to use Meson (`docs/meson.rst <https://mesa3d.org/meson.html>`_): .. code-block:: sh $ mkdir build $ cd build $ meson .. $ sudo ninja 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://mesa3d.org/bugs.html>`_). Contributing ------------ Contributions are welcome, and step-by-step instructions can be found in our documentation (`docs/submittingpatches.rst <https://mesa3d.org/submittingpatches.html>`_). Note that Mesa uses gitlab for patches submission, review and discussions.