6dd7b6ce43
Several drivers use GEM buffer objects as shadow buffers for the actual framebuffer memory. Right now, drivers do these vmap operations in their commit tail, which is actually not allowed by the locking rules for the dma-buf reservation lock. The involved BO has to be vmapped in the plane's prepare_fb callback and vunmapped in cleanup_fb. This patch introduces atomic helpers for such shadow planes. Plane functions manage the plane state for shadow planes. The provided implementations for prepare_fb and cleanup_fb vmap and vunmap all BOs of struct drm_plane_state.fb. The mappings are afterwards available in the plane's commit-tail functions. For now, all rsp drivers use the simple KMS helpers, so we add the plane callbacks and wrappers for simple KMS. The internal plane functions can later be exported as needed. v3: * documentation fixes v2: * make duplicate_state interface compatible with struct drm_plane_funcs Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Tested-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210208115538.6430-4-tzimmermann@suse.de
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.