[v2,3/4] tee: add supp_nowait flag in tee_context struct
diff mbox series

Message ID 1547123097-16431-4-git-send-email-sumit.garg@linaro.org
State Superseded
Delegated to: Herbert Xu
Headers show
Series
  • Introduce TEE bus driver framework
Related show

Commit Message

Sumit Garg Jan. 10, 2019, 12:24 p.m. UTC
This flag indicates that requests in this context should not wait for
tee-supplicant daemon to be started if not present and just return
with an error code. It is needed for requests which should be
non-blocking in nature like ones arising from TEE based kernel drivers
or any in kernel api that uses TEE internal client interface.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---
 drivers/tee/optee/supp.c | 10 +++++++++-
 drivers/tee/tee_core.c   |  2 ++
 include/linux/tee_drv.h  |  6 ++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

Comments

Daniel Thompson Jan. 10, 2019, 2:23 p.m. UTC | #1
On Thu, Jan 10, 2019 at 05:54:56PM +0530, Sumit Garg wrote:
> This flag indicates that requests in this context should not wait for
> tee-supplicant daemon to be started if not present and just return
> with an error code. It is needed for requests which should be
> non-blocking in nature like ones arising from TEE based kernel drivers
> or any in kernel api that uses TEE internal client interface.

This patch seems out of order in the patch set: Doesn't
optee_enumarate_devices() require this feature if it is to
work correctly with a TEE that does not implement the enumeate pTA.

If so better to implement the feature first so that
optee_emumerate_devices() works correctly when it first appears.

> 
> Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
> ---
>  drivers/tee/optee/supp.c | 10 +++++++++-
>  drivers/tee/tee_core.c   |  2 ++
>  include/linux/tee_drv.h  |  6 ++++++
>  3 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tee/optee/supp.c b/drivers/tee/optee/supp.c
> index 43626e1..92f56b8 100644
> --- a/drivers/tee/optee/supp.c
> +++ b/drivers/tee/optee/supp.c
> @@ -88,10 +88,18 @@ u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params,
>  {
>  	struct optee *optee = tee_get_drvdata(ctx->teedev);
>  	struct optee_supp *supp = &optee->supp;
> -	struct optee_supp_req *req = kzalloc(sizeof(*req), GFP_KERNEL);
> +	struct optee_supp_req *req;
>  	bool interruptable;
>  	u32 ret;
>  
> +	/*
> +	 * Return in case there is no supplicant available and
> +	 * non-blocking request.
> +	 */
> +	if (!supp->ctx && ctx->supp_nowait)
> +		return TEEC_ERROR_COMMUNICATION;
> +
> +	req = kzalloc(sizeof(*req), GFP_KERNEL);
>  	if (!req)
>  		return TEEC_ERROR_OUT_OF_MEMORY;
>  
> diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> index 9ddb89e..5d6c317 100644
> --- a/drivers/tee/tee_core.c
> +++ b/drivers/tee/tee_core.c
> @@ -105,6 +105,7 @@ static int tee_open(struct inode *inode, struct file *filp)
>  	if (IS_ERR(ctx))
>  		return PTR_ERR(ctx);
>  
> +	ctx->supp_nowait = false;
>  	filp->private_data = ctx;
>  	return 0;
>  }
> @@ -981,6 +982,7 @@ tee_client_open_context(struct tee_context *start,
>  	} while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
>  
>  	put_device(put_dev);
> +	ctx->supp_nowait = true;

Why automatically set supp_nowait inside open_context() ?


>  	return ctx;
>  }
>  EXPORT_SYMBOL_GPL(tee_client_open_context);
> diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> index ed16bf1..fe1a920 100644
> --- a/include/linux/tee_drv.h
> +++ b/include/linux/tee_drv.h
> @@ -49,6 +49,11 @@ struct tee_shm_pool;
>   * @releasing:  flag that indicates if context is being released right now.
>   *		It is needed to break circular dependency on context during
>   *              shared memory release.
> + * @supp_nowait: flag that indicates that requests in this context should not
> + *              wait for tee-supplicant daemon to be started if not present
> + *              and just return with an error code. It is needed for requests
> + *              that arises from TEE based kernel drivers that should be
> + *              non-blocking in nature.
>   */
>  struct tee_context {
>  	struct tee_device *teedev;
> @@ -56,6 +61,7 @@ struct tee_context {
>  	void *data;
>  	struct kref refcount;
>  	bool releasing;
> +	bool supp_nowait;
>  };
>  
>  struct tee_param_memref {
> -- 
> 2.7.4
>
Sumit Garg Jan. 11, 2019, 7:30 a.m. UTC | #2
On Thu, 10 Jan 2019 at 19:53, Daniel Thompson
<daniel.thompson@linaro.org> wrote:
>
> On Thu, Jan 10, 2019 at 05:54:56PM +0530, Sumit Garg wrote:
> > This flag indicates that requests in this context should not wait for
> > tee-supplicant daemon to be started if not present and just return
> > with an error code. It is needed for requests which should be
> > non-blocking in nature like ones arising from TEE based kernel drivers
> > or any in kernel api that uses TEE internal client interface.
>
> This patch seems out of order in the patch set: Doesn't
> optee_enumarate_devices() require this feature if it is to
> work correctly with a TEE that does not implement the enumeate pTA.
>
> If so better to implement the feature first so that
> optee_emumerate_devices() works correctly when it first appears.
>

Agree, will make this patch as #2 in next version.

> >
> > Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
> > ---
> >  drivers/tee/optee/supp.c | 10 +++++++++-
> >  drivers/tee/tee_core.c   |  2 ++
> >  include/linux/tee_drv.h  |  6 ++++++
> >  3 files changed, 17 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/tee/optee/supp.c b/drivers/tee/optee/supp.c
> > index 43626e1..92f56b8 100644
> > --- a/drivers/tee/optee/supp.c
> > +++ b/drivers/tee/optee/supp.c
> > @@ -88,10 +88,18 @@ u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params,
> >  {
> >       struct optee *optee = tee_get_drvdata(ctx->teedev);
> >       struct optee_supp *supp = &optee->supp;
> > -     struct optee_supp_req *req = kzalloc(sizeof(*req), GFP_KERNEL);
> > +     struct optee_supp_req *req;
> >       bool interruptable;
> >       u32 ret;
> >
> > +     /*
> > +      * Return in case there is no supplicant available and
> > +      * non-blocking request.
> > +      */
> > +     if (!supp->ctx && ctx->supp_nowait)
> > +             return TEEC_ERROR_COMMUNICATION;
> > +
> > +     req = kzalloc(sizeof(*req), GFP_KERNEL);
> >       if (!req)
> >               return TEEC_ERROR_OUT_OF_MEMORY;
> >
> > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> > index 9ddb89e..5d6c317 100644
> > --- a/drivers/tee/tee_core.c
> > +++ b/drivers/tee/tee_core.c
> > @@ -105,6 +105,7 @@ static int tee_open(struct inode *inode, struct file *filp)
> >       if (IS_ERR(ctx))
> >               return PTR_ERR(ctx);
> >
> > +     ctx->supp_nowait = false;
> >       filp->private_data = ctx;
> >       return 0;
> >  }
> > @@ -981,6 +982,7 @@ tee_client_open_context(struct tee_context *start,
> >       } while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
> >
> >       put_device(put_dev);
> > +     ctx->supp_nowait = true;
>
> Why automatically set supp_nowait inside open_context() ?
>

I think this is the default behaviour (non-blocking request) that any
in kernel client would expect. Also this flag could be configured
again before call to open_session() if any in kernel client requires
different behaviour.

-Sumit

>
> >       return ctx;
> >  }
> >  EXPORT_SYMBOL_GPL(tee_client_open_context);
> > diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> > index ed16bf1..fe1a920 100644
> > --- a/include/linux/tee_drv.h
> > +++ b/include/linux/tee_drv.h
> > @@ -49,6 +49,11 @@ struct tee_shm_pool;
> >   * @releasing:  flag that indicates if context is being released right now.
> >   *           It is needed to break circular dependency on context during
> >   *              shared memory release.
> > + * @supp_nowait: flag that indicates that requests in this context should not
> > + *              wait for tee-supplicant daemon to be started if not present
> > + *              and just return with an error code. It is needed for requests
> > + *              that arises from TEE based kernel drivers that should be
> > + *              non-blocking in nature.
> >   */
> >  struct tee_context {
> >       struct tee_device *teedev;
> > @@ -56,6 +61,7 @@ struct tee_context {
> >       void *data;
> >       struct kref refcount;
> >       bool releasing;
> > +     bool supp_nowait;
> >  };
> >
> >  struct tee_param_memref {
> > --
> > 2.7.4
> >
Daniel Thompson Jan. 11, 2019, 9:54 a.m. UTC | #3
On Fri, Jan 11, 2019 at 01:00:49PM +0530, Sumit Garg wrote:
> On Thu, 10 Jan 2019 at 19:53, Daniel Thompson
> <daniel.thompson@linaro.org> wrote:
> > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> > > index 9ddb89e..5d6c317 100644
> > > --- a/drivers/tee/tee_core.c
> > > +++ b/drivers/tee/tee_core.c
> > > @@ -105,6 +105,7 @@ static int tee_open(struct inode *inode, struct file *filp)
> > >       if (IS_ERR(ctx))
> > >               return PTR_ERR(ctx);
> > >
> > > +     ctx->supp_nowait = false;
> > >       filp->private_data = ctx;
> > >       return 0;
> > >  }
> > > @@ -981,6 +982,7 @@ tee_client_open_context(struct tee_context *start,
> > >       } while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
> > >
> > >       put_device(put_dev);
> > > +     ctx->supp_nowait = true;
> >
> > Why automatically set supp_nowait inside open_context() ?
> >
> 
> I think this is the default behaviour (non-blocking request) that any
> in kernel client would expect. Also this flag could be configured
> again before call to open_session() if any in kernel client requires
> different behaviour.

Makes sense. I think this is a deep enough behaviour to warrant proper
commenting though.


Daniel.
Sumit Garg Jan. 11, 2019, 9:57 a.m. UTC | #4
On Fri, 11 Jan 2019 at 15:24, Daniel Thompson
<daniel.thompson@linaro.org> wrote:
>
> On Fri, Jan 11, 2019 at 01:00:49PM +0530, Sumit Garg wrote:
> > On Thu, 10 Jan 2019 at 19:53, Daniel Thompson
> > <daniel.thompson@linaro.org> wrote:
> > > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> > > > index 9ddb89e..5d6c317 100644
> > > > --- a/drivers/tee/tee_core.c
> > > > +++ b/drivers/tee/tee_core.c
> > > > @@ -105,6 +105,7 @@ static int tee_open(struct inode *inode, struct file *filp)
> > > >       if (IS_ERR(ctx))
> > > >               return PTR_ERR(ctx);
> > > >
> > > > +     ctx->supp_nowait = false;
> > > >       filp->private_data = ctx;
> > > >       return 0;
> > > >  }
> > > > @@ -981,6 +982,7 @@ tee_client_open_context(struct tee_context *start,
> > > >       } while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
> > > >
> > > >       put_device(put_dev);
> > > > +     ctx->supp_nowait = true;
> > >
> > > Why automatically set supp_nowait inside open_context() ?
> > >
> >
> > I think this is the default behaviour (non-blocking request) that any
> > in kernel client would expect. Also this flag could be configured
> > again before call to open_session() if any in kernel client requires
> > different behaviour.
>
> Makes sense. I think this is a deep enough behaviour to warrant proper
> commenting though.
>

Sure, will add comments.

-Sumit

>
> Daniel.

Patch
diff mbox series

diff --git a/drivers/tee/optee/supp.c b/drivers/tee/optee/supp.c
index 43626e1..92f56b8 100644
--- a/drivers/tee/optee/supp.c
+++ b/drivers/tee/optee/supp.c
@@ -88,10 +88,18 @@  u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params,
 {
 	struct optee *optee = tee_get_drvdata(ctx->teedev);
 	struct optee_supp *supp = &optee->supp;
-	struct optee_supp_req *req = kzalloc(sizeof(*req), GFP_KERNEL);
+	struct optee_supp_req *req;
 	bool interruptable;
 	u32 ret;
 
+	/*
+	 * Return in case there is no supplicant available and
+	 * non-blocking request.
+	 */
+	if (!supp->ctx && ctx->supp_nowait)
+		return TEEC_ERROR_COMMUNICATION;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
 	if (!req)
 		return TEEC_ERROR_OUT_OF_MEMORY;
 
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 9ddb89e..5d6c317 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -105,6 +105,7 @@  static int tee_open(struct inode *inode, struct file *filp)
 	if (IS_ERR(ctx))
 		return PTR_ERR(ctx);
 
+	ctx->supp_nowait = false;
 	filp->private_data = ctx;
 	return 0;
 }
@@ -981,6 +982,7 @@  tee_client_open_context(struct tee_context *start,
 	} while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
 
 	put_device(put_dev);
+	ctx->supp_nowait = true;
 	return ctx;
 }
 EXPORT_SYMBOL_GPL(tee_client_open_context);
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index ed16bf1..fe1a920 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -49,6 +49,11 @@  struct tee_shm_pool;
  * @releasing:  flag that indicates if context is being released right now.
  *		It is needed to break circular dependency on context during
  *              shared memory release.
+ * @supp_nowait: flag that indicates that requests in this context should not
+ *              wait for tee-supplicant daemon to be started if not present
+ *              and just return with an error code. It is needed for requests
+ *              that arises from TEE based kernel drivers that should be
+ *              non-blocking in nature.
  */
 struct tee_context {
 	struct tee_device *teedev;
@@ -56,6 +61,7 @@  struct tee_context {
 	void *data;
 	struct kref refcount;
 	bool releasing;
+	bool supp_nowait;
 };
 
 struct tee_param_memref {