[PATCH v3 0/3] rpmsg offchannel deadcoding

[PATCH v3 0/3] rpmsg offchannel deadcoding

[linux]

From: "Dr. David Alan Gilbert" <linux@treblig.org>

Hi,
  This removes a couple of unused functions in rpmsg,
and (v2) after discussions with Arnaud, follows the thread
and removes code that they would call.

(Build tested only)

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>

V3
  Fixup comment on rpmsg_send_offchannel_raw(),
  removing the reference to "_offchannel" - as per Mathieu's
  review

Dr. David Alan Gilbert (3):
  rpmsg: core:  Remove deadcode
  rpmsg: virtio: Remove uncallable offchannel functions
  rpmsg: Remove unused method pointers *send_offchannel

 Documentation/staging/rpmsg.rst  | 46 -----------------------
 drivers/rpmsg/rpmsg_core.c       | 63 --------------------------------
 drivers/rpmsg/rpmsg_internal.h   |  6 ---
 drivers/rpmsg/virtio_rpmsg_bus.c | 24 +-----------
 include/linux/rpmsg.h            | 22 -----------
 5 files changed, 1 insertion(+), 160 deletions(-)

-- 
2.49.0

[PATCH v3 1/3] rpmsg: core: Remove deadcode

[linux]

From: "Dr. David Alan Gilbert" <linux@treblig.org>

rpmsg_send_offchannel() and rpmsg_trysend_offchannel() have been
unused since they were added in 2011's
commit bcabbccabffe ("rpmsg: add virtio-based remote processor messaging
bus")

Remove them and associated docs.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
---
 Documentation/staging/rpmsg.rst | 46 ------------------------
 drivers/rpmsg/rpmsg_core.c      | 63 ---------------------------------
 include/linux/rpmsg.h           | 22 ------------
 3 files changed, 131 deletions(-)

diff --git a/Documentation/staging/rpmsg.rst b/Documentation/staging/rpmsg.rst
index 3713adaa1608..40282cca86ca 100644
--- a/Documentation/staging/rpmsg.rst
+++ b/Documentation/staging/rpmsg.rst
@@ -110,31 +110,6 @@ or a timeout of 15 seconds elapses. When the latter happens,
 The function can only be called from a process context (for now).
 Returns 0 on success and an appropriate error value on failure.
 
-::
-
-  int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
-							void *data, int len);
-
-
-sends a message across to the remote processor, using the src and dst
-addresses provided by the user.
-
-The caller should specify the endpoint, the data it wants to send,
-its length (in bytes), and explicit source and destination addresses.
-The message will then be sent to the remote processor to which the
-endpoint's channel belongs, but the endpoint's src and channel dst
-addresses will be ignored (and the user-provided addresses will
-be used instead).
-
-In case there are no TX buffers available, the function will block until
-one becomes available (i.e. until the remote processor consumes
-a tx buffer and puts it back on virtio's used descriptor ring),
-or a timeout of 15 seconds elapses. When the latter happens,
--ERESTARTSYS is returned.
-
-The function can only be called from a process context (for now).
-Returns 0 on success and an appropriate error value on failure.
-
 ::
 
   int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len);
@@ -173,27 +148,6 @@ return -ENOMEM without waiting until one becomes available.
 The function can only be called from a process context (for now).
 Returns 0 on success and an appropriate error value on failure.
 
-::
-
-  int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
-							void *data, int len);
-
-
-sends a message across to the remote processor, using source and
-destination addresses provided by the user.
-
-The user should specify the channel, the data it wants to send,
-its length (in bytes), and explicit source and destination addresses.
-The message will then be sent to the remote processor to which the
-channel belongs, but the channel's src and dst addresses will be
-ignored (and the user-provided addresses will be used instead).
-
-In case there are no TX buffers available, the function will immediately
-return -ENOMEM without waiting until one becomes available.
-
-The function can only be called from a process context (for now).
-Returns 0 on success and an appropriate error value on failure.
-
 ::
 
   struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev,
diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 207b64c0a2fe..6ee36adcbdba 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -193,38 +193,6 @@ int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
 }
 EXPORT_SYMBOL(rpmsg_sendto);
 
-/**
- * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
- * @ept: the rpmsg endpoint
- * @src: source address
- * @dst: destination address
- * @data: payload of message
- * @len: length of payload
- *
- * This function sends @data of length @len to the remote @dst address,
- * and uses @src as the source address.
- * The message will be sent to the remote processor which the @ept
- * endpoint belongs to.
- * In case there are no TX buffers available, the function will block until
- * one becomes available, or a timeout of 15 seconds elapses. When the latter
- * happens, -ERESTARTSYS is returned.
- *
- * Can only be called from process context (for now).
- *
- * Return: 0 on success and an appropriate error value on failure.
- */
-int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
-			  void *data, int len)
-{
-	if (WARN_ON(!ept))
-		return -EINVAL;
-	if (!ept->ops->send_offchannel)
-		return -ENXIO;
-
-	return ept->ops->send_offchannel(ept, src, dst, data, len);
-}
-EXPORT_SYMBOL(rpmsg_send_offchannel);
-
 /**
  * rpmsg_trysend() - send a message across to the remote processor
  * @ept: the rpmsg endpoint
@@ -301,37 +269,6 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
 }
 EXPORT_SYMBOL(rpmsg_poll);
 
-/**
- * rpmsg_trysend_offchannel() - send a message using explicit src/dst addresses
- * @ept: the rpmsg endpoint
- * @src: source address
- * @dst: destination address
- * @data: payload of message
- * @len: length of payload
- *
- * This function sends @data of length @len to the remote @dst address,
- * and uses @src as the source address.
- * The message will be sent to the remote processor which the @ept
- * endpoint belongs to.
- * In case there are no TX buffers available, the function will immediately
- * return -ENOMEM without waiting until one becomes available.
- *
- * Can only be called from process context (for now).
- *
- * Return: 0 on success and an appropriate error value on failure.
- */
-int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
-			     void *data, int len)
-{
-	if (WARN_ON(!ept))
-		return -EINVAL;
-	if (!ept->ops->trysend_offchannel)
-		return -ENXIO;
-
-	return ept->ops->trysend_offchannel(ept, src, dst, data, len);
-}
-EXPORT_SYMBOL(rpmsg_trysend_offchannel);
-
 /**
  * rpmsg_set_flow_control() - request remote to pause/resume transmission
  * @ept:	the rpmsg endpoint
diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index 90d8e4475f80..fb7ab9165645 100644
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h
@@ -184,13 +184,9 @@ struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *,
 
 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len);
 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
-int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
-			  void *data, int len);
 
 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len);
 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
-int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
-			     void *data, int len);
 
 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
 			poll_table *wait);
@@ -271,15 +267,6 @@ static inline int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
 
 }
 
-static inline int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
-					u32 dst, void *data, int len)
-{
-	/* This shouldn't be possible */
-	WARN_ON(1);
-
-	return -ENXIO;
-}
-
 static inline int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
 {
 	/* This shouldn't be possible */
@@ -297,15 +284,6 @@ static inline int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
 	return -ENXIO;
 }
 
-static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
-					   u32 dst, void *data, int len)
-{
-	/* This shouldn't be possible */
-	WARN_ON(1);
-
-	return -ENXIO;
-}
-
 static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept,
 				      struct file *filp, poll_table *wait)
 {
-- 
2.49.0

[PATCH v3 2/3] rpmsg: virtio: Remove uncallable offchannel functions

[linux]

From: "Dr. David Alan Gilbert" <linux@treblig.org>

The virtio_rpmsg_send_offchannel() and virtio_rpmsg_trysend_offchannel()
are wired up to the send_offchannel and trysend_offchannel members
of rpmsg_endpoint_ops, the only dereference of those was by
the unused, and now removed rpmsg_send_offchannel() and
rpmsg_trysend_offchannel() functions.

Remove them.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
---
 drivers/rpmsg/virtio_rpmsg_bus.c | 24 +-----------------------
 1 file changed, 1 insertion(+), 23 deletions(-)

diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index 89d7a3b8c48b..4730b1c8b322 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -141,13 +141,9 @@ static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept);
 static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len);
 static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
 			       u32 dst);
-static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
-					u32 dst, void *data, int len);
 static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len);
 static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
 				  int len, u32 dst);
-static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
-					   u32 dst, void *data, int len);
 static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept);
 static struct rpmsg_device *__rpmsg_create_channel(struct virtproc_info *vrp,
 						   struct rpmsg_channel_info *chinfo);
@@ -156,10 +152,8 @@ static const struct rpmsg_endpoint_ops virtio_endpoint_ops = {
 	.destroy_ept = virtio_rpmsg_destroy_ept,
 	.send = virtio_rpmsg_send,
 	.sendto = virtio_rpmsg_sendto,
-	.send_offchannel = virtio_rpmsg_send_offchannel,
 	.trysend = virtio_rpmsg_trysend,
 	.trysendto = virtio_rpmsg_trysendto,
-	.trysend_offchannel = virtio_rpmsg_trysend_offchannel,
 	.get_mtu = virtio_rpmsg_get_mtu,
 };
 
@@ -545,7 +539,7 @@ static void rpmsg_downref_sleepers(struct virtproc_info *vrp)
  * the function will immediately fail, and -ENOMEM will be returned.
  *
  * Normally drivers shouldn't use this function directly; instead, drivers
- * should use the appropriate rpmsg_{try}send{to, _offchannel} API
+ * should use the appropriate rpmsg_{try}send{to} API
  * (see include/linux/rpmsg.h).
  *
  * Return: 0 on success and an appropriate error value on failure.
@@ -665,14 +659,6 @@ static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
 }
 
-static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
-					u32 dst, void *data, int len)
-{
-	struct rpmsg_device *rpdev = ept->rpdev;
-
-	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
-}
-
 static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
 {
 	struct rpmsg_device *rpdev = ept->rpdev;
@@ -690,14 +676,6 @@ static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
 }
 
-static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
-					   u32 dst, void *data, int len)
-{
-	struct rpmsg_device *rpdev = ept->rpdev;
-
-	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
-}
-
 static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept)
 {
 	struct rpmsg_device *rpdev = ept->rpdev;
-- 
2.49.0

[PATCH v3 3/3] rpmsg: Remove unused method pointers *send_offchannel

[linux]

From: "Dr. David Alan Gilbert" <linux@treblig.org>

After the previous patch, there are no implementers of the
send_offchannel() and trysend_offchannel() methods.

Remove them.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
---
 drivers/rpmsg/rpmsg_internal.h | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index 42c7007be1b5..397e4926bd02 100644
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h
@@ -50,10 +50,8 @@ struct rpmsg_device_ops {
  * @destroy_ept:	see @rpmsg_destroy_ept(), required
  * @send:		see @rpmsg_send(), required
  * @sendto:		see @rpmsg_sendto(), optional
- * @send_offchannel:	see @rpmsg_send_offchannel(), optional
  * @trysend:		see @rpmsg_trysend(), required
  * @trysendto:		see @rpmsg_trysendto(), optional
- * @trysend_offchannel:	see @rpmsg_trysend_offchannel(), optional
  * @poll:		see @rpmsg_poll(), optional
  * @set_flow_control:	see @rpmsg_set_flow_control(), optional
  * @get_mtu:		see @rpmsg_get_mtu(), optional
@@ -67,13 +65,9 @@ struct rpmsg_endpoint_ops {
 
 	int (*send)(struct rpmsg_endpoint *ept, void *data, int len);
 	int (*sendto)(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
-	int (*send_offchannel)(struct rpmsg_endpoint *ept, u32 src, u32 dst,
-				  void *data, int len);
 
 	int (*trysend)(struct rpmsg_endpoint *ept, void *data, int len);
 	int (*trysendto)(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
-	int (*trysend_offchannel)(struct rpmsg_endpoint *ept, u32 src, u32 dst,
-			     void *data, int len);
 	__poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
 			     poll_table *wait);
 	int (*set_flow_control)(struct rpmsg_endpoint *ept, bool pause, u32 dst);
-- 
2.49.0

Re: [PATCH v3 0/3] rpmsg offchannel deadcoding

[Arnaud POULIQUEN]

On 4/30/25 01:45, linux@treblig.org wrote:
> From: "Dr. David Alan Gilbert" <linux@treblig.org>
> 
> Hi,
>   This removes a couple of unused functions in rpmsg,
> and (v2) after discussions with Arnaud, follows the thread
> and removes code that they would call.

Acked-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>

Thanks,
Arnaud

> 
> (Build tested only)
> 
> Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
> 
> V3
>   Fixup comment on rpmsg_send_offchannel_raw(),
>   removing the reference to "_offchannel" - as per Mathieu's
>   review
> 
> Dr. David Alan Gilbert (3):
>   rpmsg: core:  Remove deadcode
>   rpmsg: virtio: Remove uncallable offchannel functions
>   rpmsg: Remove unused method pointers *send_offchannel
> 
>  Documentation/staging/rpmsg.rst  | 46 -----------------------
>  drivers/rpmsg/rpmsg_core.c       | 63 --------------------------------
>  drivers/rpmsg/rpmsg_internal.h   |  6 ---
>  drivers/rpmsg/virtio_rpmsg_bus.c | 24 +-----------
>  include/linux/rpmsg.h            | 22 -----------
>  5 files changed, 1 insertion(+), 160 deletions(-)
> 

Re: [PATCH v3 0/3] rpmsg offchannel deadcoding

[Mathieu Poirier]

On Wed, Apr 30, 2025 at 12:45:56AM +0100, linux@treblig.org wrote:
> From: "Dr. David Alan Gilbert" <linux@treblig.org>
> 
> Hi,
>   This removes a couple of unused functions in rpmsg,
> and (v2) after discussions with Arnaud, follows the thread
> and removes code that they would call.
> 
> (Build tested only)
> 
> Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
> 
> V3
>   Fixup comment on rpmsg_send_offchannel_raw(),
>   removing the reference to "_offchannel" - as per Mathieu's
>   review
> 
> Dr. David Alan Gilbert (3):
>   rpmsg: core:  Remove deadcode
>   rpmsg: virtio: Remove uncallable offchannel functions
>   rpmsg: Remove unused method pointers *send_offchannel
> 
>  Documentation/staging/rpmsg.rst  | 46 -----------------------
>  drivers/rpmsg/rpmsg_core.c       | 63 --------------------------------
>  drivers/rpmsg/rpmsg_internal.h   |  6 ---
>  drivers/rpmsg/virtio_rpmsg_bus.c | 24 +-----------
>  include/linux/rpmsg.h            | 22 -----------
>  5 files changed, 1 insertion(+), 160 deletions(-)

I have applied this patchet.

Thanks,
Mathieu

> 
> -- 
> 2.49.0
> 

Re: [PATCH v3 0/3] rpmsg offchannel deadcoding

[Dr. David Alan Gilbert]

* Mathieu Poirier (mathieu.poirier@linaro.org) wrote:
> On Wed, Apr 30, 2025 at 12:45:56AM +0100, linux@treblig.org wrote:
> > From: "Dr. David Alan Gilbert" <linux@treblig.org>
> > 
> > Hi,
> >   This removes a couple of unused functions in rpmsg,
> > and (v2) after discussions with Arnaud, follows the thread
> > and removes code that they would call.
> > 
> > (Build tested only)
> > 
> > Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
> > 
> > V3
> >   Fixup comment on rpmsg_send_offchannel_raw(),
> >   removing the reference to "_offchannel" - as per Mathieu's
> >   review
> > 
> > Dr. David Alan Gilbert (3):
> >   rpmsg: core:  Remove deadcode
> >   rpmsg: virtio: Remove uncallable offchannel functions
> >   rpmsg: Remove unused method pointers *send_offchannel
> > 
> >  Documentation/staging/rpmsg.rst  | 46 -----------------------
> >  drivers/rpmsg/rpmsg_core.c       | 63 --------------------------------
> >  drivers/rpmsg/rpmsg_internal.h   |  6 ---
> >  drivers/rpmsg/virtio_rpmsg_bus.c | 24 +-----------
> >  include/linux/rpmsg.h            | 22 -----------
> >  5 files changed, 1 insertion(+), 160 deletions(-)
> 
> I have applied this patchet.

Thanks!

Dave

> Thanks,
> Mathieu
> 
> > 
> > -- 
> > 2.49.0
> > 
> 
-- 
 -----Open up your eyes, open up your mind, open up your code -------   
/ Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \ 
\        dave @ treblig.org |                               | In Hex /
 \ _________________________|_____ http://www.treblig.org   |_______/