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Message-ID: <baa69103-f709-4cd2-85f0-a863c9b9ac06@collabora.com>
Date: Wed, 22 May 2024 14:21:20 +0200
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From: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Subject: Re: [PATCH v6,08/24] media: mediatek: vcodec: add tee client
 interface to communiate with optee-os
To: Yunfei Dong <yunfei.dong@mediatek.com>,
 Jeffrey Kardatzke <jkardatzke@google.com>,
 =?UTF-8?Q?N=C3=ADcolas_F_=2E_R_=2E_A_=2E_Prado?= <nfraprado@collabora.com>,
 Nathan Hebert <nhebert@chromium.org>,
 Nicolas Dufresne <nicolas.dufresne@collabora.com>,
 Hans Verkuil <hverkuil-cisco@xs4all.nl>,
 AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
 Benjamin Gaignard <benjamin.gaignard@collabora.com>,
 Sebastian Fricke <sebastian.fricke@collabora.com>,
 Tomasz Figa <tfiga@chromium.org>, Mauro Carvalho Chehab
 <mchehab@kernel.org>, Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Chen-Yu Tsai <wenst@chromium.org>, Yong Wu <yong.wu@mediatek.com>,
 Hsin-Yi Wang <hsinyi@chromium.org>, Fritz Koenig <frkoenig@chromium.org>,
 Daniel Vetter <daniel@ffwll.ch>, Steve Cho <stevecho@chromium.org>,
 Sumit Semwal <sumit.semwal@linaro.org>, Brian Starkey
 <Brian.Starkey@arm.com>, John Stultz <jstultz@google.com>,
 "T . J . Mercier" <tjmercier@google.com>,
 =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
 Matthias Brugger <matthias.bgg@gmail.com>, linux-media@vger.kernel.org,
 dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org,
 Project_Global_Chrome_Upstream_Group@mediatek.com
References: <20240516122102.16379-1-yunfei.dong@mediatek.com>
 <20240516122102.16379-9-yunfei.dong@mediatek.com>
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In-Reply-To: <20240516122102.16379-9-yunfei.dong@mediatek.com>
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Hi Yunfei & Jeffrey,

W dniu 16.05.2024 o 14:20, Yunfei Dong pisze:
> Open tee context to initialize the environment in order to communication
> with optee-os, then open tee session as the communication pipeline for
> lat and core to send data for hardware decode.
> 
> Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
> ---
>   .../platform/mediatek/vcodec/decoder/Makefile |   1 +
>   .../vcodec/decoder/mtk_vcodec_dec_drv.h       |   5 +
>   .../vcodec/decoder/mtk_vcodec_dec_optee.c     | 165 ++++++++++++++++++
>   .../vcodec/decoder/mtk_vcodec_dec_optee.h     |  73 ++++++++
>   4 files changed, 244 insertions(+)
>   create mode 100644 drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_optee.c
>   create mode 100644 drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_optee.h
> 
> diff --git a/drivers/media/platform/mediatek/vcodec/decoder/Makefile b/drivers/media/platform/mediatek/vcodec/decoder/Makefile
> index 904cd22def84..1624933dfd5e 100644
> --- a/drivers/media/platform/mediatek/vcodec/decoder/Makefile
> +++ b/drivers/media/platform/mediatek/vcodec/decoder/Makefile
> @@ -21,5 +21,6 @@ mtk-vcodec-dec-y := vdec/vdec_h264_if.o \
>   		mtk_vcodec_dec_stateful.o \
>   		mtk_vcodec_dec_stateless.o \
>   		mtk_vcodec_dec_pm.o \
> +		mtk_vcodec_dec_optee.o \
>   
>   mtk-vcodec-dec-hw-y := mtk_vcodec_dec_hw.o
> diff --git a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h
> index f975db4293da..76a0323f993c 100644
> --- a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h
> +++ b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h
> @@ -11,6 +11,7 @@
>   #include "../common/mtk_vcodec_dbgfs.h"
>   #include "../common/mtk_vcodec_fw_priv.h"
>   #include "../common/mtk_vcodec_util.h"
> +#include "mtk_vcodec_dec_optee.h"
>   #include "vdec_msg_queue.h"
>   
>   #define MTK_VCODEC_DEC_NAME	"mtk-vcodec-dec"
> @@ -261,6 +262,8 @@ struct mtk_vcodec_dec_ctx {
>    * @dbgfs: debug log related information
>    *
>    * @chip_name: used to distinguish platforms and select the correct codec configuration values
> + *
> + * @optee_private: optee private data
>    */
>   struct mtk_vcodec_dec_dev {
>   	struct v4l2_device v4l2_dev;
> @@ -303,6 +306,8 @@ struct mtk_vcodec_dec_dev {
>   	struct mtk_vcodec_dbgfs dbgfs;
>   
>   	enum mtk_vcodec_dec_chip_name chip_name;
> +
> +	struct mtk_vdec_optee_private *optee_private;
>   };
>   
>   static inline struct mtk_vcodec_dec_ctx *fh_to_dec_ctx(struct v4l2_fh *fh)
> diff --git a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_optee.c b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_optee.c
> new file mode 100644
> index 000000000000..38d9c1c1785a
> --- /dev/null
> +++ b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_optee.c
> @@ -0,0 +1,165 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2023 MediaTek Inc.
> + * Author: Yunfei Dong <yunfei.dong@mediatek.com>
> + */
> +
> +#include "mtk_vcodec_dec_drv.h"
> +#include "mtk_vcodec_dec_optee.h"
> +
> +/*
> + * Randomly generated, and must correspond to the GUID on the TA side.
> + */
> +static const uuid_t mtk_vdec_lat_uuid =
> +	UUID_INIT(0xBC50D971, 0xD4C9, 0x42C4,
> +		  0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x90);
> +
> +static const uuid_t mtk_vdec_core_uuid =
> +	UUID_INIT(0xBC50D971, 0xD4C9, 0x42C4,
> +		  0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x91);
> +
> +/*
> + * Check whether this driver supports decoder TA in the TEE instance,
> + * represented by the params (ver/data) of this function.
> + */
> +static int mtk_vcodec_dec_optee_match(struct tee_ioctl_version_data *ver_data, const void *not_used)
> +{
> +	if (ver_data->impl_id == TEE_IMPL_ID_OPTEE)
> +		return 1;
> +	else
> +		return 0;

maybe:

	return ver_data->impl_id == TEE_IMPL_ID_OPTEE;

> +}
> +
> +int mtk_vcodec_dec_optee_private_init(struct mtk_vcodec_dec_dev *vcodec_dev)
> +{
> +	vcodec_dev->optee_private = devm_kzalloc(&vcodec_dev->plat_dev->dev,
> +						 sizeof(*vcodec_dev->optee_private),
> +						 GFP_KERNEL);
> +	if (!vcodec_dev->optee_private)
> +		return -ENOMEM;
> +
> +	vcodec_dev->optee_private->vcodec_dev = vcodec_dev;
> +
> +	atomic_set(&vcodec_dev->optee_private->tee_active_cnt, 0);
> +	mutex_init(&vcodec_dev->optee_private->tee_mutex);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(mtk_vcodec_dec_optee_private_init);
> +
> +static int mtk_vcodec_dec_optee_init_hw_info(struct mtk_vdec_optee_private *optee_private,
> +					     enum mtk_vdec_hw_id hardware_index)
> +{
> +	struct device *dev = &optee_private->vcodec_dev->plat_dev->dev;
> +	struct tee_ioctl_open_session_arg session_arg;
> +	struct mtk_vdec_optee_ca_info *ca_info;
> +	int err = 0, session_func;
> +
> +	/* Open lat and core session with vdec TA. */
> +	switch (hardware_index) {
> +	case MTK_VDEC_LAT0:
> +		export_uuid(session_arg.uuid, &mtk_vdec_lat_uuid);
> +		session_func = MTK_VDEC_OPTEE_TA_LAT_SUBMIT_COMMAND;
> +		ca_info = &optee_private->lat_ca;
> +		break;
> +	case MTK_VDEC_CORE:
> +		export_uuid(session_arg.uuid, &mtk_vdec_core_uuid);
> +		session_func = MTK_VDEC_OPTEE_TA_CORE_SUBMIT_COMMAND;
> +		ca_info = &optee_private->core_ca;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	session_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
> +	session_arg.num_params = 0;
> +
> +	err = tee_client_open_session(optee_private->tee_vdec_ctx, &session_arg, NULL);
> +	if (err < 0 || session_arg.ret != 0) {
> +		dev_err(dev, MTK_DBG_VCODEC_STR "open vdec tee session fail hw_id:%d err:%x.\n",
> +			hardware_index, session_arg.ret);
> +		return -EINVAL;
> +	}
> +	ca_info->vdec_session_id = session_arg.session;
> +	ca_info->hw_id = hardware_index;
> +	ca_info->vdec_session_func = session_func;
> +
> +	dev_dbg(dev, MTK_DBG_VCODEC_STR "open vdec tee session hw_id:%d session_id=%x.\n",
> +		hardware_index, ca_info->vdec_session_id);
> +
> +	return err;

Can it return anything other than a zero? I'm asking, because "return err;"
looks a bit as if it were some error recovery path. If only a zero is
possible here then maybe you want "return 0;" instead?

> +}
> +
> +static void mtk_vcodec_dec_optee_deinit_hw_info(struct mtk_vdec_optee_private *optee_private,
> +						enum mtk_vdec_hw_id hw_id)
> +{
> +	struct mtk_vdec_optee_ca_info *ca_info;
> +
> +	if (hw_id == MTK_VDEC_LAT0)
> +		ca_info = &optee_private->lat_ca;
> +	else
> +		ca_info = &optee_private->core_ca;
> +
> +	tee_client_close_session(optee_private->tee_vdec_ctx, ca_info->vdec_session_id);
> +}
> +
> +int mtk_vcodec_dec_optee_open(struct mtk_vdec_optee_private *optee_private)
> +{
> +	struct device *dev = &optee_private->vcodec_dev->plat_dev->dev;
> +	int ret;
> +
> +	mutex_lock(&optee_private->tee_mutex);
> +	if (atomic_inc_return(&optee_private->tee_active_cnt) > 1) {
> +		mutex_unlock(&optee_private->tee_mutex);
> +		dev_dbg(dev, MTK_DBG_VCODEC_STR "already init vdec optee private data!\n");

maybe s/init/initialized ?

> +		return 0;
> +	}
> +
> +	/* Open context with TEE driver */
> +	optee_private->tee_vdec_ctx = tee_client_open_context(NULL, mtk_vcodec_dec_optee_match,
> +							      NULL, NULL);
> +	if (IS_ERR(optee_private->tee_vdec_ctx)) {
> +		dev_err(dev, MTK_DBG_VCODEC_STR "optee vdec tee context failed.\n");
> +		ret = PTR_ERR(optee_private->tee_vdec_ctx);
> +		goto err_ctx_open;
> +	}
> +
> +	ret = mtk_vcodec_dec_optee_init_hw_info(optee_private, MTK_VDEC_LAT0);
> +	if (ret < 0)
> +		goto err_lat_init;
> +
> +	if (IS_VDEC_LAT_ARCH(optee_private->vcodec_dev->vdec_pdata->hw_arch)) {
> +		ret = mtk_vcodec_dec_optee_init_hw_info(optee_private, MTK_VDEC_CORE);

Maybe it is ok (I'm not that much into vdec lat/core architecture), but it looks
suspicious, though. Few lines above this you initialize MTK_VDEC_LAT0, and here
you initialize MTK_VDEC_CORE but the condition asks if it is LAT. So reading
this I might conclude that if arch is not lat, then there's lat to be
initialized, but if arch is lat, then there's also core to be initialized.
Sounds confusing to me.

> +		if (ret < 0)
> +			goto err_core_init;
> +	}
> +
> +	mutex_unlock(&optee_private->tee_mutex);
> +	return 0;

I wouldn't mind an empty line before and after this return 0.

> +err_core_init:
> +	mtk_vcodec_dec_optee_deinit_hw_info(optee_private, MTK_VDEC_LAT0);
> +err_lat_init:
> +	tee_client_close_context(optee_private->tee_vdec_ctx);
> +err_ctx_open:
> +
> +	mutex_unlock(&optee_private->tee_mutex);

as well as here

> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(mtk_vcodec_dec_optee_open);
> +
> +void mtk_vcodec_dec_optee_release(struct mtk_vdec_optee_private *optee_private)

to me a counterpart to an _open() would be _close()...

> +{
> +	mutex_lock(&optee_private->tee_mutex);
> +	if (!atomic_dec_and_test(&optee_private->tee_active_cnt)) {
> +		mutex_unlock(&optee_private->tee_mutex);
> +		return;
> +	}
> +
> +	mtk_vcodec_dec_optee_deinit_hw_info(optee_private, MTK_VDEC_LAT0);
> +	if (IS_VDEC_LAT_ARCH(optee_private->vcodec_dev->vdec_pdata->hw_arch))
> +		mtk_vcodec_dec_optee_deinit_hw_info(optee_private, MTK_VDEC_CORE);
> +
> +	tee_client_close_context(optee_private->tee_vdec_ctx);

and indeed the context is being _closed_ here. Not a deal breaker, though.

Regards,

Andrzej

> +	mutex_unlock(&optee_private->tee_mutex);
> +}
> +EXPORT_SYMBOL_GPL(mtk_vcodec_dec_optee_release);
> diff --git a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_optee.h b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_optee.h
> new file mode 100644
> index 000000000000..8b1dca49331e
> --- /dev/null
> +++ b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_optee.h
> @@ -0,0 +1,73 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2023 MediaTek Inc.
> + * Author: Yunfei Dong <yunfei.dong@mediatek.com>
> + */
> +
> +#ifndef _MTK_VCODEC_DEC_OPTEE_H_
> +#define _MTK_VCODEC_DEC_OPTEE_H_
> +
> +#include <linux/tee_drv.h>
> +#include <linux/uuid.h>
> +
> +#include "mtk_vcodec_dec_drv.h"
> +
> +/* The TA ID implemented in this TA */
> +#define MTK_VDEC_OPTEE_TA_LAT_SUBMIT_COMMAND  (0x10)
> +#define MTK_VDEC_OPTEE_TA_CORE_SUBMIT_COMMAND  (0x20)
> +
> +#define MTK_OPTEE_MAX_TEE_PARAMS 4
> +
> +/**
> + * struct mtk_vdec_optee_ca_info - ca related param
> + * @vdec_session_id:   optee TA session identifier.
> + * @hw_id:             hardware index.
> + * @vdec_session_func: trusted application function id used specific to the TA.
> + */
> +struct mtk_vdec_optee_ca_info {
> +	u32 vdec_session_id;
> +	enum mtk_vdec_hw_id hw_id;
> +	u32 vdec_session_func;
> +};
> +
> +/**
> + * struct mtk_vdec_optee_private - optee private data
> + * @vcodec_dev:     pointer to the mtk_vcodec_dev of the device
> + * @tee_vdec_ctx:   decoder TEE context handler.
> + * @lat_ca:         lat hardware information used to communicate with TA.
> + * @core_ca:        core hardware information used to communicate with TA.
> + *
> + * @tee_active_cnt: used to mark whether need to init optee
> + * @tee_mutex:      mutex lock used for optee
> + */
> +struct mtk_vdec_optee_private {
> +	struct mtk_vcodec_dec_dev *vcodec_dev;
> +	struct tee_context *tee_vdec_ctx;
> +
> +	struct mtk_vdec_optee_ca_info lat_ca;
> +	struct mtk_vdec_optee_ca_info core_ca;
> +
> +	atomic_t tee_active_cnt;
> +	/* mutext used to lock optee open and release information. */
> +	struct mutex tee_mutex;
> +};
> +
> +/**
> + * mtk_vcodec_dec_optee_open - setup the communication channels with TA.
> + * @optee_private: optee private context
> + */
> +int mtk_vcodec_dec_optee_open(struct mtk_vdec_optee_private *optee_private);
> +
> +/**
> + * mtk_vcodec_dec_optee_private_init - init optee parameters.
> + * @vcodec_dev: pointer to the mtk_vcodec_dev of the device
> + */
> +int mtk_vcodec_dec_optee_private_init(struct mtk_vcodec_dec_dev *vcodec_dev);
> +
> +/**
> + * mtk_vcodec_dec_optee_release - close the communication channels with TA.
> + * @optee_private: optee private context
> + */
> +void mtk_vcodec_dec_optee_release(struct mtk_vdec_optee_private *optee_private);
> +
> +#endif /* _MTK_VCODEC_FW_OPTEE_H_ */