[PATCH 10/10] drm/exynos: consider memory releasing to exported gem buffer into dmabuf

[Inki Dae]

exported gem buffer into dmabuf should be released when a gem relese is
requested by user. with dma_buf_put() call, if file->f_count is 0 then
a release callback of exynos gem module(exporter) will be called to release
its own gem buffer.

Signed-off-by: Inki Dae <inki.dae at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_drv.c |    1 +
 drivers/gpu/drm/exynos/exynos_drm_gem.c |   16 ++++++++++++++++
 drivers/gpu/drm/exynos/exynos_drm_gem.h |    4 ++++
 3 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index d6de2e0..1501dd2 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -258,6 +258,7 @@ static struct drm_driver exynos_drm_driver = {
 	.gem_init_object	= exynos_drm_gem_init_object,
 	.gem_free_object	= exynos_drm_gem_free_object,
 	.gem_vm_ops		= &exynos_drm_gem_vm_ops,
+	.gem_close_object	= exynos_drm_gem_close_object,
 	.dumb_create		= exynos_drm_gem_dumb_create,
 	.dumb_map_offset	= exynos_drm_gem_dumb_map_offset,
 	.dumb_destroy		= exynos_drm_gem_dumb_destroy,
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index 411d82b..5ca8641 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -27,6 +27,7 @@
 #include "drm.h"
 
 #include <linux/shmem_fs.h>
+#include <linux/dma-buf.h>
 #include <drm/exynos_drm.h>
 
 #include "exynos_drm_drv.h"
@@ -749,6 +750,21 @@ int exynos_drm_gem_dumb_destroy(struct drm_file *file_priv,
 	return 0;
 }
 
+void exynos_drm_gem_close_object(struct drm_gem_object *obj,
+				struct drm_file *file)
+{
+	DRM_DEBUG_KMS("%s\n", __FILE__);
+
+	/*
+	 * exported dmabuf should be released when a gem is released by user.
+	 * with dma_buf_put() call, if file->f_count is 0 then a release
+	 * callback of gem module(exporter) will be called to release
+	 * its own gem buffer.
+	 */
+	if (obj->export_dma_buf)
+		dma_buf_put(obj->export_dma_buf);
+}
+
 int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct drm_gem_object *obj = vma->vm_private_data;
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h b/drivers/gpu/drm/exynos/exynos_drm_gem.h
index 14d038b..4f1ba1a 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h
@@ -162,4 +162,8 @@ int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
 /* set vm_flags and we can change the vm attribute to other one at here. */
 int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
 
+/* do extra release exynos gem module needs when gem close is called. */
+void exynos_drm_gem_close_object(struct drm_gem_object *obj,
+				struct drm_file *file);
+
 #endif
-- 
1.7.4.1