[PATCH v7 3/5] drm/panfrost: Add fdinfo support for memory stats

[Adrián Larumbe]

A new DRM GEM object function is added so that drm_show_memory_stats can
provide more accurate memory usage numbers.

Ideally, in panfrost_gem_status, the BO's purgeable flag would be checked
after locking the driver's shrinker mutex, but drm_show_memory_stats takes
over the drm file's object handle database spinlock, so there's potential
for a race condition here.

Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Reviewed-by: Steven Price <steven.price@xxxxxxx>
---
 drivers/gpu/drm/panfrost/panfrost_drv.c |  2 ++
 drivers/gpu/drm/panfrost/panfrost_gem.c | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index 97e5bc4a82c8..b834777b409b 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -568,6 +568,8 @@ static void panfrost_show_fdinfo(struct drm_printer *p, struct drm_file *file)
 	struct panfrost_device *pfdev = dev->dev_private;
 
 	panfrost_gpu_show_fdinfo(pfdev, file->driver_priv, p);
+
+	drm_show_memory_stats(p, file);
 }
 
 static const struct file_operations panfrost_drm_driver_fops = {
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
index 3c812fbd126f..7d8f83d20539 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -195,6 +195,19 @@ static int panfrost_gem_pin(struct drm_gem_object *obj)
 	return drm_gem_shmem_pin(&bo->base);
 }
 
+static enum drm_gem_object_status panfrost_gem_status(struct drm_gem_object *obj)
+{
+	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+	enum drm_gem_object_status res = 0;
+
+	res |= (bo->base.madv == PANFROST_MADV_DONTNEED) ?
+		DRM_GEM_OBJECT_PURGEABLE : 0;
+
+	res |= (bo->base.pages) ? DRM_GEM_OBJECT_RESIDENT : 0;
+
+	return res;
+}
+
 static const struct drm_gem_object_funcs panfrost_gem_funcs = {
 	.free = panfrost_gem_free_object,
 	.open = panfrost_gem_open,
@@ -206,6 +219,7 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = {
 	.vmap = drm_gem_shmem_object_vmap,
 	.vunmap = drm_gem_shmem_object_vunmap,
 	.mmap = drm_gem_shmem_object_mmap,
+	.status = panfrost_gem_status,
 	.vm_ops = &drm_gem_shmem_vm_ops,
 };
 
-- 
2.42.0