Re: [PATCH] optee: support wq_sleep_timeout

[Jerome Forissier]

On 1/25/24 06:27, gavin.liu via OP-TEE wrote:
> From: Gavin Liu <gavin.liu@xxxxxxxxxxxx>
> 
> Add wq_sleep_timeout to support self waking when timeout for secure
> driver usage.
> 
> Signed-off-by: Gavin Liu <gavin.liu@xxxxxxxxxxxx>
> ---
>  drivers/tee/optee/notif.c         |  9 +++++++--
>  drivers/tee/optee/optee_private.h |  2 +-
>  drivers/tee/optee/rpc.c           | 10 ++++++++--
>  3 files changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/tee/optee/notif.c b/drivers/tee/optee/notif.c
> index 05212842b0a5..d5e5c0645609 100644
> --- a/drivers/tee/optee/notif.c
> +++ b/drivers/tee/optee/notif.c
> @@ -29,7 +29,7 @@ static bool have_key(struct optee *optee, u_int key)
>  	return false;
>  }
>  
> -int optee_notif_wait(struct optee *optee, u_int key)
> +int optee_notif_wait(struct optee *optee, u_int key, u32 timeout)
>  {
>  	unsigned long flags;
>  	struct notif_entry *entry;
> @@ -70,7 +70,12 @@ int optee_notif_wait(struct optee *optee, u_int key)
>  	 * Unlock temporarily and wait for completion.
>  	 */
>  	spin_unlock_irqrestore(&optee->notif.lock, flags);
> -	wait_for_completion(&entry->c);
> +	if (timeout != 0) {
> +		if (!wait_for_completion_timeout(&entry->c, timeout))
> +			rc = -ETIMEDOUT;
> +	} else {
> +		wait_for_completion(&entry->c);
> +	}
>  	spin_lock_irqsave(&optee->notif.lock, flags);
>  
>  	list_del(&entry->link);
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 7a5243c78b55..da990c4016ec 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -252,7 +252,7 @@ struct optee_call_ctx {
>  
>  int optee_notif_init(struct optee *optee, u_int max_key);
>  void optee_notif_uninit(struct optee *optee);
> -int optee_notif_wait(struct optee *optee, u_int key);
> +int optee_notif_wait(struct optee *optee, u_int key, u32 timeout);
>  int optee_notif_send(struct optee *optee, u_int key);
>  
>  u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params,
> diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c
> index e69bc6380683..14e6246aaf05 100644
> --- a/drivers/tee/optee/rpc.c
> +++ b/drivers/tee/optee/rpc.c
> @@ -130,6 +130,8 @@ static void handle_rpc_func_cmd_i2c_transfer(struct tee_context *ctx,
>  static void handle_rpc_func_cmd_wq(struct optee *optee,
>  				   struct optee_msg_arg *arg)
>  {
> +	int rc = 0;
> +
>  	if (arg->num_params != 1)
>  		goto bad;
>  
> @@ -139,7 +141,8 @@ static void handle_rpc_func_cmd_wq(struct optee *optee,
>  
>  	switch (arg->params[0].u.value.a) {
>  	case OPTEE_RPC_NOTIFICATION_WAIT:
> -		if (optee_notif_wait(optee, arg->params[0].u.value.b))
> +		rc = optee_notif_wait(optee, arg->params[0].u.value.b, arg->params[0].u.value.c);

optee/optee_rpc_cmd.h needs updating (near "Waiting on notification") to reflect the meaning
of value.c.

Was value.c required to be zero prior to this change? Otherwise this could lead to undefined
behavior.
 

> +		if (rc)
>  			goto bad;
>  		break;
>  	case OPTEE_RPC_NOTIFICATION_SEND:
> @@ -153,7 +156,10 @@ static void handle_rpc_func_cmd_wq(struct optee *optee,
>  	arg->ret = TEEC_SUCCESS;
>  	return;
>  bad:
> -	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> +	if (rc == -ETIMEDOUT)
> +		arg->ret = TEEC_ERROR_BUSY;
> +	else
> +		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
>  }
>  
>  static void handle_rpc_func_cmd_wait(struct optee_msg_arg *arg)

-- 
Jerome