22574aa887
There can be scenarios, especially when re-importing an existing buffer, where you end up with multiple 'struct omap_bo's wrapping a single GEM object handle. Which causes badness when the first of the evil-clones is omap_bo_del()'d. To do this, introduce reference counting and a hashtable to track the handles per fd. First, to avoid bo's slipping through the crack if multiple 'struct omap_device's are created for one drm fd, a hashtable mapping drm fd to omap_device, and the omap_device itself is reference counted. Per omap_device, we keep a handle_table mapping GEM handle to omap_bo. When buffers are imported from flink name or dmabuf fd, the handle table is consulted, and if an omap_bo already exists, it's refcnt is incremented and it is returned. For good measure, to avoid the handle_table being deleted before the omap_bo is freed, the omap_bo holds a reference to the omap_device. TODO: check the overhead of the hashtable. If too much we could maybe get away with only tracking exported and imported bo's in the table. TODO: all the import/export flink/dmabuf operations are generic DRM ioctls. Really all this functionality could be handled by a generic drm_bo and drm_device "base class" that could be extended by omap, exynos, etc. That would also allow more common userspace code by avoiding artificial libdrm_omap dependencies. Signed-off-by: Rob Clark <rob@ti.com> |
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exynos | ||
include | ||
intel | ||
libkms | ||
m4 | ||
nouveau | ||
omap | ||
radeon | ||
tests | ||
.gitignore | ||
Makefile.am | ||
README | ||
RELEASING | ||
autogen.sh | ||
configure.ac | ||
libdrm.pc.in | ||
libdrm_lists.h | ||
xf86atomic.h | ||
xf86drm.c | ||
xf86drm.h | ||
xf86drmHash.c | ||
xf86drmMode.c | ||
xf86drmMode.h | ||
xf86drmRandom.c | ||
xf86drmSL.c | ||
xf86mm.h |
README
libdrm - userspace library for drm This is libdrm, a userspace library for accessing the DRM, direct rendering manager, on Linux, BSD and other operating systes that support the ioctl interface. The library provides wrapper functions for the ioctls to avoid exposing the kernel interface directly, and for chipsets with drm memory manager, support for tracking relocations and buffers. libdrm is a low-level library, typically used by graphics drivers such as the Mesa DRI drivers, the X drivers, libva and similar projects. New functionality in the kernel DRM drivers typically requires a new libdrm, but a new libdrm will always work with an older kernel. Compiling --------- libdrm is a standard autotools packages and follows the normal configure, build and install steps. The first step is to configure the package, which is done by running the configure shell script: ./configure By default, libdrm will install into the /usr/local/ prefix. If you want to install this DRM to replace your system copy, pass --prefix=/usr and --exec-prefix=/ to configure. If you are building libdrm from a git checkout, you first need to run the autogen.sh script. You can pass any options to autogen.sh that you would other wise pass to configure, or you can just re-run configure with the options you need once autogen.sh finishes. Next step is to build libdrm: make and once make finishes successfully, install the package using make install If you are install into a system location, you will need to be root to perform the install step.