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

[CK Hu (胡俊光)]

Hi, Jason:


On Sun, 2023-12-24 at 02:29 +0800, Jason-JH.Lin wrote:
> From: CK Hu <ck.hu@xxxxxxxxxxxx>
> 
> Add an interface to allocate MediaTek GEM buffers, allow the IOCTLs
> to be used by render nodes.
> This patch also sets the RENDER driver feature.
> 
> Signed-off-by: CK Hu <ck.hu@xxxxxxxxxxxx>
> Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
> Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
> Reviewed-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> Reviewed-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
> Tested-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> Tested-by: Pi-Hsun Shih <pihsun@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_drv.c | 13 ++++++
>  drivers/gpu/drm/mediatek/mtk_drm_gem.c | 39 +++++++++++++++++
>  drivers/gpu/drm/mediatek/mtk_drm_gem.h | 12 ++++++
>  include/uapi/drm/mediatek_drm.h        | 58
> ++++++++++++++++++++++++++
>  4 files changed, 122 insertions(+)
>  create mode 100644 include/uapi/drm/mediatek_drm.h
> 
> 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),

For secure buffer, we don't need map offset function. If you really
need this function, separate this to another patch and describe why
need this.

Regards,
CK

> +};
> +
>  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 */