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: 013b65101315 ("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
break;
}
+ atomic_inc(&bo->gpu_usecount);
job->mappings[i] = mapping;
}
struct mutex lock;
} mappings;
+ /*
+ * Count the number of jobs referencing this BO so we don't let the
+ * shrinker reclaim this object prematurely.
+ */
+ atomic_t gpu_usecount;
+
bool noexec :1;
bool is_heap :1;
};
struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+ if (atomic_read(&bo->gpu_usecount))
+ return false;
+
if (!mutex_trylock(&shmem->pages_lock))
return false;
dma_fence_put(job->render_done_fence);
if (job->mappings) {
- for (i = 0; i < job->bo_count; i++)
+ for (i = 0; i < job->bo_count; i++) {
+ if (!job->mappings[i])
+ break;
+
+ atomic_dec(&job->mappings[i]->obj->gpu_usecount);
panfrost_gem_mapping_put(job->mappings[i]);
+ }
kvfree(job->mappings);
}