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

Message ID 1547123097-16431-4-git-send-email-sumit.garg@linaro.org
State New
Headers show
Series
  • [v2,1/4] tee: add bus driver framework for TEE based devices
Related show

Commit Message

Sumit Garg Jan. 10, 2019, 12:24 p.m.
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(-)

-- 
2.7.4

Comments

Sumit Garg Jan. 11, 2019, 7:30 a.m. | #1
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. | #2
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. | #3
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 --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 {