Re: [PATCH v6,08/24] media: mediatek: vcodec: add tee client interface to communiate with optee-os

["Yunfei Dong (董云飞)" <Yunfei.Dong@mediatek.com>]

Hi Andrzej,

Thanks for your help to review this patch.
On Wed, 2024-05-22 at 14:21 +0200, Andrzej Pietrasiewicz wrote:
> 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_opt
> > ee.c
> > b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_opt
> > ee.c
> > new file mode 100644
> > index 000000000000..38d9c1c1785a
> > --- /dev/null
> > +++
> > b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_opt
> > ee.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.
Define the Lat is index 1, core is index 0.

For Lat + core, will use the lat and core.
For non lat, will use core only.

This logic is error, need to fix it.

Best Regards,
Yunfei Dong
> 
> > +		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_opt
> > ee.h
> > b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_opt
> > ee.h
> > new file mode 100644
> > index 000000000000..8b1dca49331e
> > --- /dev/null
> > +++
> > b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_opt
> > ee.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_ */
> 
>