Userspace might tag a BO purgeable while it's still referenced by GPU
jobs. We need to make sure the shrinker does not purge such BOs until
all jobs referencing it are finished.
Fixes: 013b651013 ("drm/panfrost: Add madvise and shrinker support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191129135908.2439529-9-boris.brezillon@collabora.com
With the introduction of per-FD address space, the same BO can be mapped
in different address space if the BO is globally visible (GEM_FLINK)
and opened in different context or if the dmabuf is self-imported. The
current implementation does not take case into account, and attaches the
mapping directly to the panfrost_gem_object.
Let's create a panfrost_gem_mapping struct and allow multiple mappings
per BO.
The mappings are refcounted which helps solve another problem where
mappings were torn down (GEM handle closed by userspace) while GPU
jobs accessing those BOs were still in-flight. Jobs now keep a
reference on the mappings they use.
v2 (robh):
- Minor review comment clean-ups from Steven
- Use list_is_singular helper
- Just WARN if we add a mapping when madvise state is not WILLNEED.
With that, drop the use of object_name_lock.
v3 (robh):
- Revert returning list iterator in panfrost_gem_mapping_get()
Fixes: a5efb4c9a5 ("drm/panfrost: Restructure the GEM object creation")
Fixes: 7282f7645d ("drm/panfrost: Implement per FD address spaces")
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200116021554.15090-1-robh@kernel.org
Lockdep reports a circular locking dependency with pages_lock taken in
the shrinker callback. The deadlock can't actually happen with current
users at least as a BO will never be purgeable when pages_lock is held.
To be safe, let's use mutex_trylock() instead and bail if a BO is locked
already.
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190823021216.5862-7-robh@kernel.org
Add support for madvise and a shrinker similar to other drivers. This
allows userspace to mark BOs which can be freed when there is memory
pressure.
Unlike other implementations, we don't depend on struct_mutex. The
driver maintains a list of BOs which can be freed when the shrinker
is called. Access to the list is serialized with the shrinker_lock.
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190805143358.21245-2-robh@kernel.org
