Re: [PATCH v2 01/11] drm/mediatek: Add interface to allocate MediaTek GEM buffer.

["Jason-JH Lin (林睿祥)" <Jason-JH.Lin@mediatek.com>]

On Tue, 2023-10-24 at 10:37 +0200, AngeloGioacchino Del Regno wrote:
> Il 23/10/23 06:45, Jason-JH.Lin ha scritto:
> > From: CK Hu <ck.hu@mediatek.com>
> > 
> > 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@mediatek.com>
> > Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
> > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> > Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> > Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
> > Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
> > Tested-by: Daniel Kurtz <djkurtz@chromium.org>
> > Tested-by: Pi-Hsun Shih <pihsun@chromium.org>
> > 
> > ---
> >   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 93552d76b6e7..e3e9dbdf265b 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"
> > @@ -541,6 +542,14 @@ 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);
> >   
> >   /*
> > @@ -562,6 +571,10 @@ 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 9f364df52478..bcce723f257d 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>
> > @@ -272,3 +273,41 @@ 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..c050de320a84
> > --- /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>
> > +
> > +/**
> > + * User-desired buffer creation information structure.
> 
> You're almost there.... Read:
> 
> 
https://urldefense.com/v3/__https://docs.kernel.org/doc-guide/kernel-doc.html*structure-union-and-enumeration-documentation__;Iw!!CTRNKA9wMg0ARbw!kERlb86VAz8ud_XHQQwv1hHLb2Ffjz-ECgPk74SE7PUwOIyIbCh8cHKZj2w12qOeIKktUQQAIklBO9aQ8_W_A2VaNK09ty9HBQ$
>  

OK, Thanks for your help.
I can use that `scripts/kernel-doc` to scan my code now!

Will fix them in the next version.

Regards,
Jason-JH.Lin

> 
> Regards,
> Angelo
> 
>