[v3,01/11] drm/mediatek: Add interface to allocate MediaTek GEM buffer.

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 2b0c35cacbc6..5d2a39e491aa 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -24,6 +24,7 @@ 
 #include <drm/drm_of.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
+#include <drm/mediatek_drm.h>
 
 #include "mtk_drm_crtc.h"
 #include "mtk_drm_ddp_comp.h"
@@ -569,6 +570,14 @@  static void mtk_drm_kms_deinit(struct drm_device *drm)
 	component_unbind_all(drm->dev, drm);
 }
 
+static const struct drm_ioctl_desc mtk_ioctls[] = {
+	DRM_IOCTL_DEF_DRV(MTK_GEM_CREATE, mtk_gem_create_ioctl,
+			  DRM_UNLOCKED | DRM_AUTH | DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(MTK_GEM_MAP_OFFSET,
+			  mtk_gem_map_offset_ioctl,
+			  DRM_UNLOCKED | DRM_AUTH | DRM_RENDER_ALLOW),
+};
+
 DEFINE_DRM_GEM_FOPS(mtk_drm_fops);
 
 /*
@@ -590,6 +599,10 @@  static const struct drm_driver mtk_drm_driver = {
 
 	.gem_prime_import = mtk_drm_gem_prime_import,
 	.gem_prime_import_sg_table = mtk_gem_prime_import_sg_table,
+
+	.ioctls = mtk_ioctls,
+	.num_ioctls = ARRAY_SIZE(mtk_ioctls),
+
 	.fops = &mtk_drm_fops,
 
 	.name = DRIVER_NAME,
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 4f2e3feabc0f..30e347adcbe9 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -4,6 +4,7 @@ 
  */
 
 #include <linux/dma-buf.h>
+#include <drm/mediatek_drm.h>
 
 #include <drm/drm.h>
 #include <drm/drm_device.h>
@@ -283,3 +284,41 @@  void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj,
 	mtk_gem->kvaddr = NULL;
 	kfree(mtk_gem->pages);
 }
+
+int mtk_gem_map_offset_ioctl(struct drm_device *drm, void *data,
+			     struct drm_file *file_priv)
+{
+	struct drm_mtk_gem_map_off *args = data;
+
+	return drm_gem_dumb_map_offset(file_priv, drm, args->handle,
+				       &args->offset);
+}
+
+int mtk_gem_create_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv)
+{
+	struct mtk_drm_gem_obj *mtk_gem;
+	struct drm_mtk_gem_create *args = data;
+	int ret;
+
+	mtk_gem = mtk_drm_gem_create(dev, args->size, false);
+	if (IS_ERR(mtk_gem))
+		return PTR_ERR(mtk_gem);
+
+	/*
+	 * allocate a id of idr table where the obj is registered
+	 * and handle has the id what user can see.
+	 */
+	ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle);
+	if (ret)
+		goto err_handle_create;
+
+	/* drop reference from allocate - handle holds it now. */
+	drm_gem_object_put(&mtk_gem->base);
+
+	return 0;
+
+err_handle_create:
+	mtk_drm_gem_free_object(&mtk_gem->base);
+	return ret;
+}
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.h b/drivers/gpu/drm/mediatek/mtk_drm_gem.h
index 78f23b07a02e..90f3d2916ec5 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.h
@@ -46,4 +46,16 @@  int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map);
 void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj,
 			      struct iosys_map *map);
 
+/*
+ * request gem object creation and buffer allocation as the size
+ * that it is calculated with framebuffer information such as width,
+ * height and bpp.
+ */
+int mtk_gem_create_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv);
+
+/* get buffer offset to map to user space. */
+int mtk_gem_map_offset_ioctl(struct drm_device *dev, void *data,
+			     struct drm_file *file_priv);
+
 #endif
diff --git a/include/uapi/drm/mediatek_drm.h b/include/uapi/drm/mediatek_drm.h
new file mode 100644
index 000000000000..f4d47577c94e
--- /dev/null
+++ b/include/uapi/drm/mediatek_drm.h
@@ -0,0 +1,58 @@ 
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _UAPI_MEDIATEK_DRM_H
+#define _UAPI_MEDIATEK_DRM_H
+
+#include <drm/drm.h>
+
+/**
+ * struct drm_mtk_gem_create - User-desired buffer creation information structure.
+ *
+ * @size: user-desired memory allocation size.
+ *	- this size value would be page-aligned internally.
+ * @flags: user request for setting memory type or cache attributes.
+ * @handle: returned a handle to created gem object.
+ *	- this handle will be set by gem module of kernel side.
+ */
+struct drm_mtk_gem_create {
+	uint64_t size;
+	uint32_t flags;
+	uint32_t handle;
+};
+
+/**
+ * struct drm_mtk_gem_map_off - A structure for getting buffer offset.
+ *
+ * @handle: a pointer to gem object created.
+ * @pad: just padding to be 64-bit aligned.
+ * @offset: relatived offset value of the memory region allocated.
+ *     - this value should be set by user.
+ */
+struct drm_mtk_gem_map_off {
+	uint32_t handle;
+	uint32_t pad;
+	uint64_t offset;
+};
+
+#define DRM_MTK_GEM_CREATE		0x00
+#define DRM_MTK_GEM_MAP_OFFSET		0x01
+
+#define DRM_IOCTL_MTK_GEM_CREATE	DRM_IOWR(DRM_COMMAND_BASE + \
+		DRM_MTK_GEM_CREATE, struct drm_mtk_gem_create)
+
+#define DRM_IOCTL_MTK_GEM_MAP_OFFSET	DRM_IOWR(DRM_COMMAND_BASE + \
+		DRM_MTK_GEM_MAP_OFFSET, struct drm_mtk_gem_map_off)
+
+#endif /* _UAPI_MEDIATEK_DRM_H */