From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
commit 7e0cf7e9936c4358b0863357b90aa12afe6489da upstream.
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@xxxxxxxxxxxxxxx>
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Reviewed-by: Steven Price <steven.price@xxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20191129135908.2439529-9-boris.brezillon@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/panfrost/panfrost_drv.c | 1 +
drivers/gpu/drm/panfrost/panfrost_gem.h | 6 ++++++
drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c | 3 +++
drivers/gpu/drm/panfrost/panfrost_job.c | 7 ++++++-
4 files changed, 16 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -166,6 +166,7 @@ panfrost_lookup_bos(struct drm_device *d
break;
}
+ atomic_inc(&bo->gpu_usecount);
job->mappings[i] = mapping;
}
--- a/drivers/gpu/drm/panfrost/panfrost_gem.h
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
@@ -30,6 +30,12 @@ struct panfrost_gem_object {
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;
};
--- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
@@ -41,6 +41,9 @@ static bool panfrost_gem_purge(struct dr
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;
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -270,8 +270,13 @@ static void panfrost_job_cleanup(struct
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);
}
