drm/panfrost: Implement generic DRM object RSS reporting function

BO's RSS is updated every time new pages are allocated on demand and mapped
for the object at GPU page fault's IRQ handler, but only for heap buffers.
The reason this is unnecessary for non-heap buffers is that they are mapped
onto the GPU's VA space and backed by physical memory in their entirety at
BO creation time.

This calculation is unnecessary for imported PRIME objects, since heap
buffers cannot be exported by our driver, and the actual BO RSS size is the
one reported in its attached dmabuf structure.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230929181616.2769345-6-adrian.larumbe@collabora.com

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
index de238b71b321..0cf64456e29a 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -209,6 +209,20 @@ static enum drm_gem_object_status panfrost_gem_status(struct drm_gem_object *obj
 	return res;
 }
 
+static size_t panfrost_gem_rss(struct drm_gem_object *obj)
+{
+	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+
+	if (bo->is_heap) {
+		return bo->heap_rss_size;
+	} else if (bo->base.pages) {
+		WARN_ON(bo->heap_rss_size);
+		return bo->base.base.size;
+	}
+
+	return 0;
+}
+
 static const struct drm_gem_object_funcs panfrost_gem_funcs = {
 	.free = panfrost_gem_free_object,
 	.open = panfrost_gem_open,
@@ -221,6 +235,7 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = {
 	.vunmap = drm_gem_shmem_object_vunmap,
 	.mmap = drm_gem_shmem_object_mmap,
 	.status = panfrost_gem_status,
+	.rss = panfrost_gem_rss,
 	.vm_ops = &drm_gem_shmem_vm_ops,
 };