[PATCH v2] optee: add timeout value to optee_notif_wait() to support timeout

[Gavin Liu (劉哲廷)]

Hi Jens,

Thanks for the reviews.

On Mon, 2024-05-06 at 09:48 +0200, Jens Wiklander wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  On Thu, May 2, 2024 at 10:56 AM gavin.liu <gavin.liu at mediatek.com>
> wrote:
> >
> > From: Gavin Liu <gavin.liu at mediatek.com>
> >
> > Add timeout value to support self waking when timeout to avoid
> waiting
> > indefinitely.
> >
> > Signed-off-by: Gavin Liu <gavin.liu at mediatek.com>
> > ---
> > Change in v2:
> > Change commit message.
> > Add description for value[0].c in optee_rpc_cmd.h.
> > ---
> > ---
> >  drivers/tee/optee/notif.c         |  9 +++++++--
> >  drivers/tee/optee/optee_private.h |  2 +-
> >  drivers/tee/optee/optee_rpc_cmd.h |  1 +
> >  drivers/tee/optee/rpc.c           | 10 ++++++++--
> >  4 files changed, 17 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/optee_rpc_cmd.h
> b/drivers/tee/optee/optee_rpc_cmd.h
> > index f3f06e0994a7..99342aa66263 100644
> > --- a/drivers/tee/optee/optee_rpc_cmd.h
> > +++ b/drivers/tee/optee/optee_rpc_cmd.h
> > @@ -41,6 +41,7 @@
> >   * Waiting on notification
> >   * [in]    value[0].a      OPTEE_RPC_NOTIFICATION_WAIT
> >   * [in]    value[0].b      notification value
> > + * [in]    value[0].c      timeout in millisecond or 0 if no
> timeout
> 
> milliseconds

Ok, I'll change it.

> 
> >   *
> >   * Sending a synchronous notification
> >   * [in]    value[0].a      OPTEE_RPC_NOTIFICATION_SEND
> > 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);
> > +               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;
> 
> TEEC_ERROR_BUSY is confusing. How about TEE_ERROR_TIMEOUT? We
> normally
> only use TEEC_XXX error codes, but GP doesn't define a
> TEEC_ERROR_TIMEOUT so it's better to use the GP-defined
> TEE_ERROR_TIMEOUT.
> 
> Cheers,
> Jens
> 

Agreed, we also use TEE_ERROR_TIMEOUT in the corresponding patch for
optee-os. But, the "TEE_ERROR_TIMEOUT" is currently undefined in Linux
Kernel. Do you have a suggestion for which header would be better to
place it in?

Regards,
Gavin.Liu

> > +       else
> > +               arg->ret = TEEC_ERROR_BAD_PARAMETERS;
> >  }
> >
> >  static void handle_rpc_func_cmd_wait(struct optee_msg_arg *arg)
> > --
> > 2.18.0
> >