[PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Cristian Marussi]

Hi all,

This series aims to introduce a new SCMI unified userspace interface meant
to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
from the perspective of the OSPM agent (non-secure world only ...)

It is proposed as a testing/development facility, it is NOT meant to be a
feature to use in production, but only enabled in Kconfig for test
deployments.

Currently an SCMI Compliance Suite like the one at [1] can only work by
injecting SCMI messages at the SCMI transport layer using the mailbox test
driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
the related replies from the SCMI backend Server.

This approach has a few drawbacks:

- the SCMI Server under test MUST be reachable through a mailbox based
  SCMI transport: any other SCMI Server placement is not possible (like in
  a VM reachable via SCMI Virtio). In order to cover other placements in
  the current scenario we should write some sort of test driver for each
  and every existent SCMI transport and for any future additional transport
  ...this clearly does not scale.

- even in the mailbox case the userspace Compliance suite cannot simply
  send and receive bare SCMI messages BUT it has to properly lay them out
  into the shared memory exposed by the mailbox test driver as expected by
  the transport definitions. In other words such a userspace test
  application has to, not only use a proper transport driver for the system
  at hand, but it also has to have a comprehensive knowledge of the
  internals of the underlying transport in order to operate.

- last but not least, the system under test has to be specifically
  configured and built, in terms of Kconfig and DT, to perform such kind of
  testing, it cannot be used for anything else, which is unfortunate for
  CI/CD deployments.

This series introduces a new SCMI Raw mode support feature that, when
configured and enabled exposes a new interface in debugfs through which:

- a userspace application can inject bare SCMI binary messages into the
  SCMI core stack; such messages will be routed by the SCMI regular kernel
  stack to the backend Server using the currently configured transport
  transparently: in other words you can test the SCMI server, no matter
  where it is placed, as long as it is reachable from the currently
  configured SCMI stack.
  Same goes the other way around on the reading path: any SCMI server reply
  can be read as a bare SCMI binary message from the same debugfs path.

- as a direct consequence of this way of injecting bare messages in the
  middle of the SCMI stack (instead of beneath it at the transport layer)
  the user application has to handle only bare SCMI messages without having
  to worry about the specific underlying transport internals that will be
  taken care of by the SCMI core stack itself using its own machinery,
  without duplicating such logic.

- a system under test, once configured with SCMI Raw support enabled in
  Kconfig, can be booted without any particular DT change.

In V2 the runtime enable/disable switching capability has been removed
(for now) since still not deemed to be stable/reliable enough: as a
consequence when SCMI Raw support is compiled in, the regular SCMI stack
drivers are now inhibited permanently for that Kernel.

A quick and trivial example from the shell...reading from a sensor
injecting a properly crafted packet in raw mode:

	# INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
	root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message

	# READING BACK THE REPLY...
	root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4
	0000000 00005406 00000000 00000335 00000000
	0000020

while doing that, since Raw mode makes (partial) use of the regular SCMI
stack, you can observe the messages going through the SCMI stack with the
usual traces:

              bash-329     [000] ..... 14183.446808: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000000000000
   irq/35-mhu_db_l-81      [000] ..... 14183.447809: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=0 pyld=3503000000000000


..trying to read in async when the backend server does NOT supports asyncs:

	# AN ASYNC SENSOR READING REQUEST...
	root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x01\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message_async

              bash-329     [000] ..... 16415.938739: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000001000000
   irq/35-mhu_db_l-81      [000] ..... 16415.944129: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=-1 pyld=

	# RETURNS A STATUS -1 FROM THE SERVER NOT SUPPORTING IT
	root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4
	0000000 00005406 ffffffff
	0000010

Note that this was on a JUNO, BUT exactly the same steps can be used to
reach an SCMI Server living on a VM reachable via virtio as long as the
system under test if properly configured to work with a virtio transport.

In a nutshell the exposed API is as follows:

/sys/kernel/debug/scmi_raw/
├── errors
├── message
├── message_async
├── notification
├── reset
├── transport_max_msg_size
├── transport_rx_timeout_ms
└── transport_tx_max_msg

where:

 - message*: used to send sync/async commands and read back immediate and
   delayed responses (if any)
 - errors: used to report timeout and unexpected replies
 - reset: used to reset the SCMI Raw stack, flushing all queues from
   received messages still pending to be read out (useful to be sure to
   cleanup between test suite runs...)
 - notification: used to read any notification being spit by the system
   (if previously enabled by the user app)
 - transport*: a bunch of configuration useful to setup the user
   application expectations in terms of timeouts and message
   characteristics.

Each write corresponds to one command request and the replies or delayed
response are read back one message at time (receiving an EOF at each
message boundary).

The user application running the test is in charge of handling timeouts
and properly choosing SCMI sequence numbers for the outgoing requests: note
that the same fixed number can be re-used (...though discouraged...) as
long as the suite does NOT expect to send multiple in-flight commands
concurrently.

Since the SCMI core regular stack is partially used to deliver and collect
the messages, late replies after timeouts and any other sort of unexpected
message sent by the SCMI server platform back can be identified by the SCMI
core as usual and it will be reported under /errors for later analysis.
(a userspace test-app will have anyway properly detected the timeout on
 /message* ...)

All of the above has been roughly tested against a standard JUNO SCP SCMI
Server (mailbox trans) and an emulated SCMI Server living in a VM (virtio
trans) using a custom experimental version of the scmi-tests Compliance
suite patched to support Raw mode and posted at [2]. (still in development
...certainly not up for review as of now...it is just a mean for me to
test the testing API ... O_o)

The series is based on sudeep/for-next/scmi [3] on top of:

commit 40d30cf680cb ("firmware: arm_scmi: Harmonize SCMI tracing message format")

Still todo:

- needs more complete testing, ideally running to completion at least the full
  SCMI compliance suite at [2] to use it as a reference
- more feedback on the API

Having said that (in such a concise and brief way :P) ...
	
...any feedback/comments are welcome !

Thanks,
Cristian

---
v2 --> v3
- fixed some sparse warning on LE and __poll_t
- reworked and simplified deferred worker in charge of xfer delayed waiting
- allow for injection of DT-unknown protocols messages when in Raw mode
  (needed for any kind of fuzzing...)

v1 --> v2
- added comments and debugfs docs
- added dedicated transport devices for channels initialization
- better channels handling in Raw mode
- removed runtime enable, moved to static compile time exclusion
  of SCMI regular stack

[1]: https://gitlab.arm.com/tests/scmi-tests
[2]: https://gitlab.arm.com/linux-arm/scmi-tests-cm/-/commits/raw_mode_support_V3/
[3]: https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/log/?h=for-next/scmi

Cristian Marussi (9):
  firmware: arm_scmi: Refactor xfer in-flight registration routines
  firmware: arm_scmi: Simplify chan_available transport operation
  firmware: arm_scmi: Use dedicated devices to initialize channels
  firmware: arm_scmi: Add xfer raw helpers
  firmware: arm_scmi: Move errors defs and code to common.h
  firmware: arm_scmi: Add raw transmission support
  firmware: arm_scmi: Add debugfs ABI documentation for Raw mode
  firmware: arm_scmi: Reject SCMI drivers while in Raw mode
  firmware: arm_scmi: Call Raw mode hooks from the core stack

 Documentation/ABI/testing/debugfs-scmi-raw |   88 ++
 drivers/firmware/arm_scmi/Kconfig          |   13 +
 drivers/firmware/arm_scmi/Makefile         |    1 +
 drivers/firmware/arm_scmi/common.h         |   51 +-
 drivers/firmware/arm_scmi/driver.c         |  389 ++++--
 drivers/firmware/arm_scmi/mailbox.c        |    4 +-
 drivers/firmware/arm_scmi/optee.c          |    4 +-
 drivers/firmware/arm_scmi/raw_mode.c       | 1235 ++++++++++++++++++++
 drivers/firmware/arm_scmi/raw_mode.h       |   29 +
 drivers/firmware/arm_scmi/smc.c            |    4 +-
 drivers/firmware/arm_scmi/virtio.c         |    2 +-
 11 files changed, 1714 insertions(+), 106 deletions(-)
 create mode 100644 Documentation/ABI/testing/debugfs-scmi-raw
 create mode 100644 drivers/firmware/arm_scmi/raw_mode.c
 create mode 100644 drivers/firmware/arm_scmi/raw_mode.h

-- 
2.32.0

[PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Cristian Marussi]

Hi all,

This series aims to introduce a new SCMI unified userspace interface meant
to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
from the perspective of the OSPM agent (non-secure world only ...)

It is proposed as a testing/development facility, it is NOT meant to be a
feature to use in production, but only enabled in Kconfig for test
deployments.

Currently an SCMI Compliance Suite like the one at [1] can only work by
injecting SCMI messages at the SCMI transport layer using the mailbox test
driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
the related replies from the SCMI backend Server.

This approach has a few drawbacks:

- the SCMI Server under test MUST be reachable through a mailbox based
  SCMI transport: any other SCMI Server placement is not possible (like in
  a VM reachable via SCMI Virtio). In order to cover other placements in
  the current scenario we should write some sort of test driver for each
  and every existent SCMI transport and for any future additional transport
  ...this clearly does not scale.

- even in the mailbox case the userspace Compliance suite cannot simply
  send and receive bare SCMI messages BUT it has to properly lay them out
  into the shared memory exposed by the mailbox test driver as expected by
  the transport definitions. In other words such a userspace test
  application has to, not only use a proper transport driver for the system
  at hand, but it also has to have a comprehensive knowledge of the
  internals of the underlying transport in order to operate.

- last but not least, the system under test has to be specifically
  configured and built, in terms of Kconfig and DT, to perform such kind of
  testing, it cannot be used for anything else, which is unfortunate for
  CI/CD deployments.

This series introduces a new SCMI Raw mode support feature that, when
configured and enabled exposes a new interface in debugfs through which:

- a userspace application can inject bare SCMI binary messages into the
  SCMI core stack; such messages will be routed by the SCMI regular kernel
  stack to the backend Server using the currently configured transport
  transparently: in other words you can test the SCMI server, no matter
  where it is placed, as long as it is reachable from the currently
  configured SCMI stack.
  Same goes the other way around on the reading path: any SCMI server reply
  can be read as a bare SCMI binary message from the same debugfs path.

- as a direct consequence of this way of injecting bare messages in the
  middle of the SCMI stack (instead of beneath it at the transport layer)
  the user application has to handle only bare SCMI messages without having
  to worry about the specific underlying transport internals that will be
  taken care of by the SCMI core stack itself using its own machinery,
  without duplicating such logic.

- a system under test, once configured with SCMI Raw support enabled in
  Kconfig, can be booted without any particular DT change.

In V2 the runtime enable/disable switching capability has been removed
(for now) since still not deemed to be stable/reliable enough: as a
consequence when SCMI Raw support is compiled in, the regular SCMI stack
drivers are now inhibited permanently for that Kernel.

A quick and trivial example from the shell...reading from a sensor
injecting a properly crafted packet in raw mode:

	# INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
	root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message

	# READING BACK THE REPLY...
	root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4
	0000000 00005406 00000000 00000335 00000000
	0000020

while doing that, since Raw mode makes (partial) use of the regular SCMI
stack, you can observe the messages going through the SCMI stack with the
usual traces:

              bash-329     [000] ..... 14183.446808: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000000000000
   irq/35-mhu_db_l-81      [000] ..... 14183.447809: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=0 pyld=3503000000000000


..trying to read in async when the backend server does NOT supports asyncs:

	# AN ASYNC SENSOR READING REQUEST...
	root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x01\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message_async

              bash-329     [000] ..... 16415.938739: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000001000000
   irq/35-mhu_db_l-81      [000] ..... 16415.944129: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=-1 pyld=

	# RETURNS A STATUS -1 FROM THE SERVER NOT SUPPORTING IT
	root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4
	0000000 00005406 ffffffff
	0000010

Note that this was on a JUNO, BUT exactly the same steps can be used to
reach an SCMI Server living on a VM reachable via virtio as long as the
system under test if properly configured to work with a virtio transport.

In a nutshell the exposed API is as follows:

/sys/kernel/debug/scmi_raw/
├── errors
├── message
├── message_async
├── notification
├── reset
├── transport_max_msg_size
├── transport_rx_timeout_ms
└── transport_tx_max_msg

where:

 - message*: used to send sync/async commands and read back immediate and
   delayed responses (if any)
 - errors: used to report timeout and unexpected replies
 - reset: used to reset the SCMI Raw stack, flushing all queues from
   received messages still pending to be read out (useful to be sure to
   cleanup between test suite runs...)
 - notification: used to read any notification being spit by the system
   (if previously enabled by the user app)
 - transport*: a bunch of configuration useful to setup the user
   application expectations in terms of timeouts and message
   characteristics.

Each write corresponds to one command request and the replies or delayed
response are read back one message at time (receiving an EOF at each
message boundary).

The user application running the test is in charge of handling timeouts
and properly choosing SCMI sequence numbers for the outgoing requests: note
that the same fixed number can be re-used (...though discouraged...) as
long as the suite does NOT expect to send multiple in-flight commands
concurrently.

Since the SCMI core regular stack is partially used to deliver and collect
the messages, late replies after timeouts and any other sort of unexpected
message sent by the SCMI server platform back can be identified by the SCMI
core as usual and it will be reported under /errors for later analysis.
(a userspace test-app will have anyway properly detected the timeout on
 /message* ...)

All of the above has been roughly tested against a standard JUNO SCP SCMI
Server (mailbox trans) and an emulated SCMI Server living in a VM (virtio
trans) using a custom experimental version of the scmi-tests Compliance
suite patched to support Raw mode and posted at [2]. (still in development
...certainly not up for review as of now...it is just a mean for me to
test the testing API ... O_o)

The series is based on sudeep/for-next/scmi [3] on top of:

commit 40d30cf680cb ("firmware: arm_scmi: Harmonize SCMI tracing message format")

Still todo:

- needs more complete testing, ideally running to completion at least the full
  SCMI compliance suite at [2] to use it as a reference
- more feedback on the API

Having said that (in such a concise and brief way :P) ...
	
...any feedback/comments are welcome !

Thanks,
Cristian

---
v2 --> v3
- fixed some sparse warning on LE and __poll_t
- reworked and simplified deferred worker in charge of xfer delayed waiting
- allow for injection of DT-unknown protocols messages when in Raw mode
  (needed for any kind of fuzzing...)

v1 --> v2
- added comments and debugfs docs
- added dedicated transport devices for channels initialization
- better channels handling in Raw mode
- removed runtime enable, moved to static compile time exclusion
  of SCMI regular stack

[1]: https://gitlab.arm.com/tests/scmi-tests
[2]: https://gitlab.arm.com/linux-arm/scmi-tests-cm/-/commits/raw_mode_support_V3/
[3]: https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/log/?h=for-next/scmi

Cristian Marussi (9):
  firmware: arm_scmi: Refactor xfer in-flight registration routines
  firmware: arm_scmi: Simplify chan_available transport operation
  firmware: arm_scmi: Use dedicated devices to initialize channels
  firmware: arm_scmi: Add xfer raw helpers
  firmware: arm_scmi: Move errors defs and code to common.h
  firmware: arm_scmi: Add raw transmission support
  firmware: arm_scmi: Add debugfs ABI documentation for Raw mode
  firmware: arm_scmi: Reject SCMI drivers while in Raw mode
  firmware: arm_scmi: Call Raw mode hooks from the core stack

 Documentation/ABI/testing/debugfs-scmi-raw |   88 ++
 drivers/firmware/arm_scmi/Kconfig          |   13 +
 drivers/firmware/arm_scmi/Makefile         |    1 +
 drivers/firmware/arm_scmi/common.h         |   51 +-
 drivers/firmware/arm_scmi/driver.c         |  389 ++++--
 drivers/firmware/arm_scmi/mailbox.c        |    4 +-
 drivers/firmware/arm_scmi/optee.c          |    4 +-
 drivers/firmware/arm_scmi/raw_mode.c       | 1235 ++++++++++++++++++++
 drivers/firmware/arm_scmi/raw_mode.h       |   29 +
 drivers/firmware/arm_scmi/smc.c            |    4 +-
 drivers/firmware/arm_scmi/virtio.c         |    2 +-
 11 files changed, 1714 insertions(+), 106 deletions(-)
 create mode 100644 Documentation/ABI/testing/debugfs-scmi-raw
 create mode 100644 drivers/firmware/arm_scmi/raw_mode.c
 create mode 100644 drivers/firmware/arm_scmi/raw_mode.h

-- 
2.32.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 1/9] firmware: arm_scmi: Refactor xfer in-flight registration routines

[Cristian Marussi]

Move the whole xfer in-flight registration process out of scmi_xfer_get
and while at that, split the sequence number selection steps from the
in-flight registration procedure itself.

No functional change.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 102 +++++++++++++++++++----------
 1 file changed, 68 insertions(+), 34 deletions(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 609ebedee9cb..e5193da2ce09 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -311,8 +311,6 @@ static int scmi_xfer_token_set(struct scmi_xfers_info *minfo,
 	if (xfer_id != next_token)
 		atomic_add((int)(xfer_id - next_token), &transfer_last_id);
 
-	/* Set in-flight */
-	set_bit(xfer_id, minfo->xfer_alloc_table);
 	xfer->hdr.seq = (u16)xfer_id;
 
 	return 0;
@@ -330,33 +328,77 @@ static inline void scmi_xfer_token_clear(struct scmi_xfers_info *minfo,
 	clear_bit(xfer->hdr.seq, minfo->xfer_alloc_table);
 }
 
+/**
+ * scmi_xfer_inflight_register_unlocked  - Register the xfer as in-flight
+ *
+ * @xfer: The xfer to register
+ * @minfo: Pointer to Tx/Rx Message management info based on channel type
+ *
+ * Note that this helper assumes that the xfer to be registered as in-flight
+ * had been built using an xfer sequence number which still corresponds to a
+ * free slot in the xfer_alloc_table.
+ *
+ * Context: Assumes to be called with @xfer_lock already acquired.
+ */
+static inline void
+scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer,
+				     struct scmi_xfers_info *minfo)
+{
+	/* Set in-flight */
+	set_bit(xfer->hdr.seq, minfo->xfer_alloc_table);
+	hash_add(minfo->pending_xfers, &xfer->node, xfer->hdr.seq);
+	xfer->pending = true;
+}
+
+/**
+ * scmi_xfer_pending_set  - Pick a proper sequence number and mark the xfer
+ * as pending in-flight
+ *
+ * @xfer: The xfer to act upon
+ * @minfo: Pointer to Tx/Rx Message management info based on channel type
+ *
+ * Return: 0 on Success or error otherwise
+ */
+static inline int scmi_xfer_pending_set(struct scmi_xfer *xfer,
+					struct scmi_xfers_info *minfo)
+{
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&minfo->xfer_lock, flags);
+	/* Set a new monotonic token as the xfer sequence number */
+	ret = scmi_xfer_token_set(minfo, xfer);
+	if (!ret)
+		scmi_xfer_inflight_register_unlocked(xfer, minfo);
+	spin_unlock_irqrestore(&minfo->xfer_lock, flags);
+
+	return ret;
+}
+
 /**
  * scmi_xfer_get() - Allocate one message
  *
  * @handle: Pointer to SCMI entity handle
  * @minfo: Pointer to Tx/Rx Message management info based on channel type
- * @set_pending: If true a monotonic token is picked and the xfer is added to
- *		 the pending hash table.
  *
  * Helper function which is used by various message functions that are
  * exposed to clients of this driver for allocating a message traffic event.
  *
- * Picks an xfer from the free list @free_xfers (if any available) and, if
- * required, sets a monotonically increasing token and stores the inflight xfer
- * into the @pending_xfers hashtable for later retrieval.
+ * Picks an xfer from the free list @free_xfers (if any available) and perform
+ * a basic initialization.
+ *
+ * Note that, at this point, still no sequence number is assigned to the
+ * allocated xfer, nor it is registered as a pending transaction.
  *
  * The successfully initialized xfer is refcounted.
  *
- * Context: Holds @xfer_lock while manipulating @xfer_alloc_table and
- *	    @free_xfers.
+ * Context: Holds @xfer_lock while manipulating @free_xfers.
  *
- * Return: 0 if all went fine, else corresponding error.
+ * Return: An initialized xfer if all went fine, else pointer error.
  */
 static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
-				       struct scmi_xfers_info *minfo,
-				       bool set_pending)
+				       struct scmi_xfers_info *minfo)
 {
-	int ret;
 	unsigned long flags;
 	struct scmi_xfer *xfer;
 
@@ -376,25 +418,8 @@ static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
 	 */
 	xfer->transfer_id = atomic_inc_return(&transfer_last_id);
 
-	if (set_pending) {
-		/* Pick and set monotonic token */
-		ret = scmi_xfer_token_set(minfo, xfer);
-		if (!ret) {
-			hash_add(minfo->pending_xfers, &xfer->node,
-				 xfer->hdr.seq);
-			xfer->pending = true;
-		} else {
-			dev_err(handle->dev,
-				"Failed to get monotonic token %d\n", ret);
-			hlist_add_head(&xfer->node, &minfo->free_xfers);
-			xfer = ERR_PTR(ret);
-		}
-	}
-
-	if (!IS_ERR(xfer)) {
-		refcount_set(&xfer->users, 1);
-		atomic_set(&xfer->busy, SCMI_XFER_FREE);
-	}
+	refcount_set(&xfer->users, 1);
+	atomic_set(&xfer->busy, SCMI_XFER_FREE);
 	spin_unlock_irqrestore(&minfo->xfer_lock, flags);
 
 	return xfer;
@@ -652,7 +677,7 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo,
 	ktime_t ts;
 
 	ts = ktime_get_boottime();
-	xfer = scmi_xfer_get(cinfo->handle, minfo, false);
+	xfer = scmi_xfer_get(cinfo->handle, minfo);
 	if (IS_ERR(xfer)) {
 		dev_err(dev, "failed to get free message slot (%ld)\n",
 			PTR_ERR(xfer));
@@ -1041,13 +1066,22 @@ static int xfer_get_init(const struct scmi_protocol_handle *ph,
 	    tx_size > info->desc->max_msg_size)
 		return -ERANGE;
 
-	xfer = scmi_xfer_get(pi->handle, minfo, true);
+	xfer = scmi_xfer_get(pi->handle, minfo);
 	if (IS_ERR(xfer)) {
 		ret = PTR_ERR(xfer);
 		dev_err(dev, "failed to get free message slot(%d)\n", ret);
 		return ret;
 	}
 
+	/* Pick a sequence number and register this xfer as in-flight */
+	ret = scmi_xfer_pending_set(xfer, minfo);
+	if (ret) {
+		dev_err(pi->handle->dev,
+			"Failed to get monotonic token %d\n", ret);
+		__scmi_xfer_put(minfo, xfer);
+		return ret;
+	}
+
 	xfer->tx.len = tx_size;
 	xfer->rx.len = rx_size ? : info->desc->max_msg_size;
 	xfer->hdr.type = MSG_TYPE_COMMAND;
-- 
2.32.0

[PATCH v3 1/9] firmware: arm_scmi: Refactor xfer in-flight registration routines

[Cristian Marussi]

Move the whole xfer in-flight registration process out of scmi_xfer_get
and while at that, split the sequence number selection steps from the
in-flight registration procedure itself.

No functional change.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 102 +++++++++++++++++++----------
 1 file changed, 68 insertions(+), 34 deletions(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 609ebedee9cb..e5193da2ce09 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -311,8 +311,6 @@ static int scmi_xfer_token_set(struct scmi_xfers_info *minfo,
 	if (xfer_id != next_token)
 		atomic_add((int)(xfer_id - next_token), &transfer_last_id);
 
-	/* Set in-flight */
-	set_bit(xfer_id, minfo->xfer_alloc_table);
 	xfer->hdr.seq = (u16)xfer_id;
 
 	return 0;
@@ -330,33 +328,77 @@ static inline void scmi_xfer_token_clear(struct scmi_xfers_info *minfo,
 	clear_bit(xfer->hdr.seq, minfo->xfer_alloc_table);
 }
 
+/**
+ * scmi_xfer_inflight_register_unlocked  - Register the xfer as in-flight
+ *
+ * @xfer: The xfer to register
+ * @minfo: Pointer to Tx/Rx Message management info based on channel type
+ *
+ * Note that this helper assumes that the xfer to be registered as in-flight
+ * had been built using an xfer sequence number which still corresponds to a
+ * free slot in the xfer_alloc_table.
+ *
+ * Context: Assumes to be called with @xfer_lock already acquired.
+ */
+static inline void
+scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer,
+				     struct scmi_xfers_info *minfo)
+{
+	/* Set in-flight */
+	set_bit(xfer->hdr.seq, minfo->xfer_alloc_table);
+	hash_add(minfo->pending_xfers, &xfer->node, xfer->hdr.seq);
+	xfer->pending = true;
+}
+
+/**
+ * scmi_xfer_pending_set  - Pick a proper sequence number and mark the xfer
+ * as pending in-flight
+ *
+ * @xfer: The xfer to act upon
+ * @minfo: Pointer to Tx/Rx Message management info based on channel type
+ *
+ * Return: 0 on Success or error otherwise
+ */
+static inline int scmi_xfer_pending_set(struct scmi_xfer *xfer,
+					struct scmi_xfers_info *minfo)
+{
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&minfo->xfer_lock, flags);
+	/* Set a new monotonic token as the xfer sequence number */
+	ret = scmi_xfer_token_set(minfo, xfer);
+	if (!ret)
+		scmi_xfer_inflight_register_unlocked(xfer, minfo);
+	spin_unlock_irqrestore(&minfo->xfer_lock, flags);
+
+	return ret;
+}
+
 /**
  * scmi_xfer_get() - Allocate one message
  *
  * @handle: Pointer to SCMI entity handle
  * @minfo: Pointer to Tx/Rx Message management info based on channel type
- * @set_pending: If true a monotonic token is picked and the xfer is added to
- *		 the pending hash table.
  *
  * Helper function which is used by various message functions that are
  * exposed to clients of this driver for allocating a message traffic event.
  *
- * Picks an xfer from the free list @free_xfers (if any available) and, if
- * required, sets a monotonically increasing token and stores the inflight xfer
- * into the @pending_xfers hashtable for later retrieval.
+ * Picks an xfer from the free list @free_xfers (if any available) and perform
+ * a basic initialization.
+ *
+ * Note that, at this point, still no sequence number is assigned to the
+ * allocated xfer, nor it is registered as a pending transaction.
  *
  * The successfully initialized xfer is refcounted.
  *
- * Context: Holds @xfer_lock while manipulating @xfer_alloc_table and
- *	    @free_xfers.
+ * Context: Holds @xfer_lock while manipulating @free_xfers.
  *
- * Return: 0 if all went fine, else corresponding error.
+ * Return: An initialized xfer if all went fine, else pointer error.
  */
 static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
-				       struct scmi_xfers_info *minfo,
-				       bool set_pending)
+				       struct scmi_xfers_info *minfo)
 {
-	int ret;
 	unsigned long flags;
 	struct scmi_xfer *xfer;
 
@@ -376,25 +418,8 @@ static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
 	 */
 	xfer->transfer_id = atomic_inc_return(&transfer_last_id);
 
-	if (set_pending) {
-		/* Pick and set monotonic token */
-		ret = scmi_xfer_token_set(minfo, xfer);
-		if (!ret) {
-			hash_add(minfo->pending_xfers, &xfer->node,
-				 xfer->hdr.seq);
-			xfer->pending = true;
-		} else {
-			dev_err(handle->dev,
-				"Failed to get monotonic token %d\n", ret);
-			hlist_add_head(&xfer->node, &minfo->free_xfers);
-			xfer = ERR_PTR(ret);
-		}
-	}
-
-	if (!IS_ERR(xfer)) {
-		refcount_set(&xfer->users, 1);
-		atomic_set(&xfer->busy, SCMI_XFER_FREE);
-	}
+	refcount_set(&xfer->users, 1);
+	atomic_set(&xfer->busy, SCMI_XFER_FREE);
 	spin_unlock_irqrestore(&minfo->xfer_lock, flags);
 
 	return xfer;
@@ -652,7 +677,7 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo,
 	ktime_t ts;
 
 	ts = ktime_get_boottime();
-	xfer = scmi_xfer_get(cinfo->handle, minfo, false);
+	xfer = scmi_xfer_get(cinfo->handle, minfo);
 	if (IS_ERR(xfer)) {
 		dev_err(dev, "failed to get free message slot (%ld)\n",
 			PTR_ERR(xfer));
@@ -1041,13 +1066,22 @@ static int xfer_get_init(const struct scmi_protocol_handle *ph,
 	    tx_size > info->desc->max_msg_size)
 		return -ERANGE;
 
-	xfer = scmi_xfer_get(pi->handle, minfo, true);
+	xfer = scmi_xfer_get(pi->handle, minfo);
 	if (IS_ERR(xfer)) {
 		ret = PTR_ERR(xfer);
 		dev_err(dev, "failed to get free message slot(%d)\n", ret);
 		return ret;
 	}
 
+	/* Pick a sequence number and register this xfer as in-flight */
+	ret = scmi_xfer_pending_set(xfer, minfo);
+	if (ret) {
+		dev_err(pi->handle->dev,
+			"Failed to get monotonic token %d\n", ret);
+		__scmi_xfer_put(minfo, xfer);
+		return ret;
+	}
+
 	xfer->tx.len = tx_size;
 	xfer->rx.len = rx_size ? : info->desc->max_msg_size;
 	xfer->hdr.type = MSG_TYPE_COMMAND;
-- 
2.32.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 2/9] firmware: arm_scmi: Simplify chan_available transport operation

[Cristian Marussi]

SCMI transport operation .chan_available determines in a transport-specific
way if an SCMI channel is still available and to be configured: such
information is derived analyzing bits of DT in a transport specific way;
al it needs is a DT node to operate upon, not necessarily a full blown
device.

Fix to receive in input a reference to adevice_node instead of a device
carrying a pointer to such device_node.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/common.h  | 2 +-
 drivers/firmware/arm_scmi/driver.c  | 2 +-
 drivers/firmware/arm_scmi/mailbox.c | 4 ++--
 drivers/firmware/arm_scmi/optee.c   | 4 ++--
 drivers/firmware/arm_scmi/smc.c     | 4 ++--
 drivers/firmware/arm_scmi/virtio.c  | 2 +-
 6 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 61aba7447c32..096b66442d84 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -150,7 +150,7 @@ struct scmi_chan_info {
  */
 struct scmi_transport_ops {
 	int (*link_supplier)(struct device *dev);
-	bool (*chan_available)(struct device *dev, int idx);
+	bool (*chan_available)(struct device_node *of_node, int idx);
 	int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
 			  bool tx);
 	int (*chan_free)(int id, void *p, void *data);
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index e5193da2ce09..62e02b6475ff 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2035,7 +2035,7 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
 	if (cinfo)
 		return 0;
 
-	if (!info->desc->ops->chan_available(dev, idx)) {
+	if (!info->desc->ops->chan_available(dev->of_node, idx)) {
 		cinfo = idr_find(idr, SCMI_PROTOCOL_BASE);
 		if (unlikely(!cinfo)) /* Possible only if platform has no Rx */
 			return -EINVAL;
diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c
index 08ff4d110beb..ed7e66788134 100644
--- a/drivers/firmware/arm_scmi/mailbox.c
+++ b/drivers/firmware/arm_scmi/mailbox.c
@@ -46,9 +46,9 @@ static void rx_callback(struct mbox_client *cl, void *m)
 	scmi_rx_callback(smbox->cinfo, shmem_read_header(smbox->shmem), NULL);
 }
 
-static bool mailbox_chan_available(struct device *dev, int idx)
+static bool mailbox_chan_available(struct device_node *of_node, int idx)
 {
-	return !of_parse_phandle_with_args(dev->of_node, "mboxes",
+	return !of_parse_phandle_with_args(of_node, "mboxes",
 					   "#mbox-cells", idx, NULL);
 }
 
diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
index f42dad997ac9..59e688767af2 100644
--- a/drivers/firmware/arm_scmi/optee.c
+++ b/drivers/firmware/arm_scmi/optee.c
@@ -328,11 +328,11 @@ static int scmi_optee_link_supplier(struct device *dev)
 	return 0;
 }
 
-static bool scmi_optee_chan_available(struct device *dev, int idx)
+static bool scmi_optee_chan_available(struct device_node *of_node, int idx)
 {
 	u32 channel_id;
 
-	return !of_property_read_u32_index(dev->of_node, "linaro,optee-channel-id",
+	return !of_property_read_u32_index(of_node, "linaro,optee-channel-id",
 					   idx, &channel_id);
 }
 
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index 745acfdd0b3d..0e21bd01348b 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -52,9 +52,9 @@ static irqreturn_t smc_msg_done_isr(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static bool smc_chan_available(struct device *dev, int idx)
+static bool smc_chan_available(struct device_node *of_node, int idx)
 {
-	struct device_node *np = of_parse_phandle(dev->of_node, "shmem", 0);
+	struct device_node *np = of_parse_phandle(of_node, "shmem", 0);
 	if (!np)
 		return false;
 
diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c
index 14709dbc96a1..e0c92037a9e6 100644
--- a/drivers/firmware/arm_scmi/virtio.c
+++ b/drivers/firmware/arm_scmi/virtio.c
@@ -392,7 +392,7 @@ static int virtio_link_supplier(struct device *dev)
 	return 0;
 }
 
-static bool virtio_chan_available(struct device *dev, int idx)
+static bool virtio_chan_available(struct device_node *of_node, int idx)
 {
 	struct scmi_vio_channel *channels, *vioch = NULL;
 
-- 
2.32.0

[PATCH v3 2/9] firmware: arm_scmi: Simplify chan_available transport operation

[Cristian Marussi]

SCMI transport operation .chan_available determines in a transport-specific
way if an SCMI channel is still available and to be configured: such
information is derived analyzing bits of DT in a transport specific way;
al it needs is a DT node to operate upon, not necessarily a full blown
device.

Fix to receive in input a reference to adevice_node instead of a device
carrying a pointer to such device_node.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/common.h  | 2 +-
 drivers/firmware/arm_scmi/driver.c  | 2 +-
 drivers/firmware/arm_scmi/mailbox.c | 4 ++--
 drivers/firmware/arm_scmi/optee.c   | 4 ++--
 drivers/firmware/arm_scmi/smc.c     | 4 ++--
 drivers/firmware/arm_scmi/virtio.c  | 2 +-
 6 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 61aba7447c32..096b66442d84 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -150,7 +150,7 @@ struct scmi_chan_info {
  */
 struct scmi_transport_ops {
 	int (*link_supplier)(struct device *dev);
-	bool (*chan_available)(struct device *dev, int idx);
+	bool (*chan_available)(struct device_node *of_node, int idx);
 	int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
 			  bool tx);
 	int (*chan_free)(int id, void *p, void *data);
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index e5193da2ce09..62e02b6475ff 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2035,7 +2035,7 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
 	if (cinfo)
 		return 0;
 
-	if (!info->desc->ops->chan_available(dev, idx)) {
+	if (!info->desc->ops->chan_available(dev->of_node, idx)) {
 		cinfo = idr_find(idr, SCMI_PROTOCOL_BASE);
 		if (unlikely(!cinfo)) /* Possible only if platform has no Rx */
 			return -EINVAL;
diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c
index 08ff4d110beb..ed7e66788134 100644
--- a/drivers/firmware/arm_scmi/mailbox.c
+++ b/drivers/firmware/arm_scmi/mailbox.c
@@ -46,9 +46,9 @@ static void rx_callback(struct mbox_client *cl, void *m)
 	scmi_rx_callback(smbox->cinfo, shmem_read_header(smbox->shmem), NULL);
 }
 
-static bool mailbox_chan_available(struct device *dev, int idx)
+static bool mailbox_chan_available(struct device_node *of_node, int idx)
 {
-	return !of_parse_phandle_with_args(dev->of_node, "mboxes",
+	return !of_parse_phandle_with_args(of_node, "mboxes",
 					   "#mbox-cells", idx, NULL);
 }
 
diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
index f42dad997ac9..59e688767af2 100644
--- a/drivers/firmware/arm_scmi/optee.c
+++ b/drivers/firmware/arm_scmi/optee.c
@@ -328,11 +328,11 @@ static int scmi_optee_link_supplier(struct device *dev)
 	return 0;
 }
 
-static bool scmi_optee_chan_available(struct device *dev, int idx)
+static bool scmi_optee_chan_available(struct device_node *of_node, int idx)
 {
 	u32 channel_id;
 
-	return !of_property_read_u32_index(dev->of_node, "linaro,optee-channel-id",
+	return !of_property_read_u32_index(of_node, "linaro,optee-channel-id",
 					   idx, &channel_id);
 }
 
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index 745acfdd0b3d..0e21bd01348b 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -52,9 +52,9 @@ static irqreturn_t smc_msg_done_isr(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static bool smc_chan_available(struct device *dev, int idx)
+static bool smc_chan_available(struct device_node *of_node, int idx)
 {
-	struct device_node *np = of_parse_phandle(dev->of_node, "shmem", 0);
+	struct device_node *np = of_parse_phandle(of_node, "shmem", 0);
 	if (!np)
 		return false;
 
diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c
index 14709dbc96a1..e0c92037a9e6 100644
--- a/drivers/firmware/arm_scmi/virtio.c
+++ b/drivers/firmware/arm_scmi/virtio.c
@@ -392,7 +392,7 @@ static int virtio_link_supplier(struct device *dev)
 	return 0;
 }
 
-static bool virtio_chan_available(struct device *dev, int idx)
+static bool virtio_chan_available(struct device_node *of_node, int idx)
 {
 	struct scmi_vio_channel *channels, *vioch = NULL;
 
-- 
2.32.0


_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 3/9] firmware: arm_scmi: Use dedicated devices to initialize channels

[Cristian Marussi]

Refactor channels initialization to use dedicated devices instead of using
devices borrowed from the SCMI drivers.

Initialize all channels as described in the DT upfront.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 94 ++++++++++++++++++++++--------
 1 file changed, 70 insertions(+), 24 deletions(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 62e02b6475ff..56b1a917f618 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2019,23 +2019,20 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo)
 	return ret;
 }
 
-static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
+static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node,
 			   int prot_id, bool tx)
 {
 	int ret, idx;
+	char name[32];
 	struct scmi_chan_info *cinfo;
 	struct idr *idr;
+	struct scmi_device *tdev = NULL;
 
 	/* Transmit channel is first entry i.e. index 0 */
 	idx = tx ? 0 : 1;
 	idr = tx ? &info->tx_idr : &info->rx_idr;
 
-	/* check if already allocated, used for multiple device per protocol */
-	cinfo = idr_find(idr, prot_id);
-	if (cinfo)
-		return 0;
-
-	if (!info->desc->ops->chan_available(dev->of_node, idx)) {
+	if (!info->desc->ops->chan_available(of_node, idx)) {
 		cinfo = idr_find(idr, SCMI_PROTOCOL_BASE);
 		if (unlikely(!cinfo)) /* Possible only if platform has no Rx */
 			return -EINVAL;
@@ -2046,26 +2043,41 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
 	if (!cinfo)
 		return -ENOMEM;
 
-	cinfo->dev = dev;
+	/* Create a unique name for this transport device */
+	snprintf(name, 32, "__scmi_transport_device_%s_%02X",
+		 idx ? "rx" : "tx", prot_id);
+	/* Create a uniquely named, dedicated transport device for this chan */
+	tdev = scmi_device_create(of_node, info->dev, prot_id, name);
+	if (!tdev) {
+		devm_kfree(info->dev, cinfo);
+		return -EINVAL;
+	}
 
+	cinfo->dev = &tdev->dev;
 	ret = info->desc->ops->chan_setup(cinfo, info->dev, tx);
-	if (ret)
+	if (ret) {
+		scmi_device_destroy(tdev);
+		devm_kfree(info->dev, cinfo);
 		return ret;
+	}
 
 	if (tx && is_polling_required(cinfo, info)) {
 		if (is_transport_polling_capable(info))
-			dev_info(dev,
+			dev_info(&tdev->dev,
 				 "Enabled polling mode TX channel - prot_id:%d\n",
 				 prot_id);
 		else
-			dev_warn(dev,
+			dev_warn(&tdev->dev,
 				 "Polling mode NOT supported by transport.\n");
 	}
 
 idr_alloc:
 	ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL);
 	if (ret != prot_id) {
-		dev_err(dev, "unable to allocate SCMI idr slot err %d\n", ret);
+		dev_err(info->dev,
+			"unable to allocate SCMI idr slot err %d\n", ret);
+		if (tdev)
+			scmi_device_destroy(tdev);
 		return ret;
 	}
 
@@ -2074,16 +2086,57 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
 }
 
 static inline int
-scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
+scmi_txrx_setup(struct scmi_info *info, struct device_node *of_node,
+		int prot_id)
 {
-	int ret = scmi_chan_setup(info, dev, prot_id, true);
+	int ret = scmi_chan_setup(info, of_node, prot_id, true);
 
 	if (!ret) /* Rx is optional, hence no error check */
-		scmi_chan_setup(info, dev, prot_id, false);
+		scmi_chan_setup(info, of_node, prot_id, false);
 
 	return ret;
 }
 
+/**
+ * scmi_channels_setup  - Helper to initialize all required channels
+ *
+ * @info: The SCMI instance descriptor.
+ *
+ * Initialize all the channels found described in the DT against the underlying
+ * configured transport using custom defined dedicated devices instead of
+ * borrowing devices from the SCMI drivers; this way channels are initialized
+ * upfront during core SCMI stack probing and are operational even if then no
+ * SCMI driver is loaded. (useful to operate in Raw mode)
+ *
+ * Return: 0 on Success
+ */
+static int scmi_channels_setup(struct scmi_info *info)
+{
+	int ret;
+	struct device_node *child, *top_np = info->dev->of_node;
+
+	ret = scmi_txrx_setup(info, top_np, SCMI_PROTOCOL_BASE);
+	if (ret)
+		return ret;
+
+	for_each_available_child_of_node(top_np, child) {
+		u32 prot_id;
+
+		if (of_property_read_u32(child, "reg", &prot_id))
+			continue;
+
+		if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id))
+			dev_err(info->dev,
+				"Out of range protocol %d\n", prot_id);
+
+		ret = scmi_txrx_setup(info, child, prot_id);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 /**
  * scmi_get_protocol_device  - Helper to get/create an SCMI device.
  *
@@ -2133,14 +2186,6 @@ scmi_get_protocol_device(struct device_node *np, struct scmi_info *info,
 		return NULL;
 	}
 
-	if (scmi_txrx_setup(info, &sdev->dev, prot_id)) {
-		dev_err(&sdev->dev, "failed to setup transport\n");
-		scmi_device_destroy(sdev);
-		mutex_unlock(&scmi_syspower_mtx);
-
-		return NULL;
-	}
-
 	if (prot_id == SCMI_PROTOCOL_SYSTEM)
 		scmi_syspower_registered = true;
 
@@ -2432,7 +2477,8 @@ static int scmi_probe(struct platform_device *pdev)
 			return ret;
 	}
 
-	ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
+	/* Setup all channels described in the DT at first */
+	ret = scmi_channels_setup(info);
 	if (ret)
 		return ret;
 
-- 
2.32.0

[PATCH v3 3/9] firmware: arm_scmi: Use dedicated devices to initialize channels

[Cristian Marussi]

Refactor channels initialization to use dedicated devices instead of using
devices borrowed from the SCMI drivers.

Initialize all channels as described in the DT upfront.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 94 ++++++++++++++++++++++--------
 1 file changed, 70 insertions(+), 24 deletions(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 62e02b6475ff..56b1a917f618 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2019,23 +2019,20 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo)
 	return ret;
 }
 
-static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
+static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node,
 			   int prot_id, bool tx)
 {
 	int ret, idx;
+	char name[32];
 	struct scmi_chan_info *cinfo;
 	struct idr *idr;
+	struct scmi_device *tdev = NULL;
 
 	/* Transmit channel is first entry i.e. index 0 */
 	idx = tx ? 0 : 1;
 	idr = tx ? &info->tx_idr : &info->rx_idr;
 
-	/* check if already allocated, used for multiple device per protocol */
-	cinfo = idr_find(idr, prot_id);
-	if (cinfo)
-		return 0;
-
-	if (!info->desc->ops->chan_available(dev->of_node, idx)) {
+	if (!info->desc->ops->chan_available(of_node, idx)) {
 		cinfo = idr_find(idr, SCMI_PROTOCOL_BASE);
 		if (unlikely(!cinfo)) /* Possible only if platform has no Rx */
 			return -EINVAL;
@@ -2046,26 +2043,41 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
 	if (!cinfo)
 		return -ENOMEM;
 
-	cinfo->dev = dev;
+	/* Create a unique name for this transport device */
+	snprintf(name, 32, "__scmi_transport_device_%s_%02X",
+		 idx ? "rx" : "tx", prot_id);
+	/* Create a uniquely named, dedicated transport device for this chan */
+	tdev = scmi_device_create(of_node, info->dev, prot_id, name);
+	if (!tdev) {
+		devm_kfree(info->dev, cinfo);
+		return -EINVAL;
+	}
 
+	cinfo->dev = &tdev->dev;
 	ret = info->desc->ops->chan_setup(cinfo, info->dev, tx);
-	if (ret)
+	if (ret) {
+		scmi_device_destroy(tdev);
+		devm_kfree(info->dev, cinfo);
 		return ret;
+	}
 
 	if (tx && is_polling_required(cinfo, info)) {
 		if (is_transport_polling_capable(info))
-			dev_info(dev,
+			dev_info(&tdev->dev,
 				 "Enabled polling mode TX channel - prot_id:%d\n",
 				 prot_id);
 		else
-			dev_warn(dev,
+			dev_warn(&tdev->dev,
 				 "Polling mode NOT supported by transport.\n");
 	}
 
 idr_alloc:
 	ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL);
 	if (ret != prot_id) {
-		dev_err(dev, "unable to allocate SCMI idr slot err %d\n", ret);
+		dev_err(info->dev,
+			"unable to allocate SCMI idr slot err %d\n", ret);
+		if (tdev)
+			scmi_device_destroy(tdev);
 		return ret;
 	}
 
@@ -2074,16 +2086,57 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
 }
 
 static inline int
-scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
+scmi_txrx_setup(struct scmi_info *info, struct device_node *of_node,
+		int prot_id)
 {
-	int ret = scmi_chan_setup(info, dev, prot_id, true);
+	int ret = scmi_chan_setup(info, of_node, prot_id, true);
 
 	if (!ret) /* Rx is optional, hence no error check */
-		scmi_chan_setup(info, dev, prot_id, false);
+		scmi_chan_setup(info, of_node, prot_id, false);
 
 	return ret;
 }
 
+/**
+ * scmi_channels_setup  - Helper to initialize all required channels
+ *
+ * @info: The SCMI instance descriptor.
+ *
+ * Initialize all the channels found described in the DT against the underlying
+ * configured transport using custom defined dedicated devices instead of
+ * borrowing devices from the SCMI drivers; this way channels are initialized
+ * upfront during core SCMI stack probing and are operational even if then no
+ * SCMI driver is loaded. (useful to operate in Raw mode)
+ *
+ * Return: 0 on Success
+ */
+static int scmi_channels_setup(struct scmi_info *info)
+{
+	int ret;
+	struct device_node *child, *top_np = info->dev->of_node;
+
+	ret = scmi_txrx_setup(info, top_np, SCMI_PROTOCOL_BASE);
+	if (ret)
+		return ret;
+
+	for_each_available_child_of_node(top_np, child) {
+		u32 prot_id;
+
+		if (of_property_read_u32(child, "reg", &prot_id))
+			continue;
+
+		if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id))
+			dev_err(info->dev,
+				"Out of range protocol %d\n", prot_id);
+
+		ret = scmi_txrx_setup(info, child, prot_id);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 /**
  * scmi_get_protocol_device  - Helper to get/create an SCMI device.
  *
@@ -2133,14 +2186,6 @@ scmi_get_protocol_device(struct device_node *np, struct scmi_info *info,
 		return NULL;
 	}
 
-	if (scmi_txrx_setup(info, &sdev->dev, prot_id)) {
-		dev_err(&sdev->dev, "failed to setup transport\n");
-		scmi_device_destroy(sdev);
-		mutex_unlock(&scmi_syspower_mtx);
-
-		return NULL;
-	}
-
 	if (prot_id == SCMI_PROTOCOL_SYSTEM)
 		scmi_syspower_registered = true;
 
@@ -2432,7 +2477,8 @@ static int scmi_probe(struct platform_device *pdev)
 			return ret;
 	}
 
-	ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
+	/* Setup all channels described in the DT at first */
+	ret = scmi_channels_setup(info);
 	if (ret)
 		return ret;
 
-- 
2.32.0


_______________________________________________
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[PATCH v3 4/9] firmware: arm_scmi: Add xfer raw helpers

[Cristian Marussi]

Add a few SCMI helpers useful to implement SCMI Raw access support.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
v1 --> v2
- added scmi_xfer_raw_channel_get
v2 --> v3
- allow for DT-unknown protocols to get a channel
---
 drivers/firmware/arm_scmi/common.h |   9 +++
 drivers/firmware/arm_scmi/driver.c | 115 +++++++++++++++++++++++++++++
 2 files changed, 124 insertions(+)

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 096b66442d84..6d2a57a696d8 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -212,6 +212,15 @@ struct scmi_desc {
 	const bool atomic_enabled;
 };
 
+void scmi_xfer_raw_put(const struct scmi_handle *handle,
+		       struct scmi_xfer *xfer);
+struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle);
+struct scmi_chan_info *
+scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id);
+
+int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
+				    struct scmi_xfer *xfer);
+
 #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX
 extern const struct scmi_desc scmi_mailbox_desc;
 #endif
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 56b1a917f618..c1292452e41f 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -350,6 +350,53 @@ scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer,
 	xfer->pending = true;
 }
 
+/**
+ * scmi_xfer_inflight_register  - Try to register an xfer as in-flight
+ *
+ * @xfer: The xfer to register
+ * @minfo: Pointer to Tx/Rx Message management info based on channel type
+ *
+ * Note that this helper does NOT assume anything about the sequence number
+ * that was baked into the provided xfer, so it checks at first if it can
+ * be mapped to a free slot and fails with an error if another xfer with the
+ * same sequence number is currently still registered as in-flight.
+ *
+ * Return: 0 on Success or -EBUSY if sequence number embedded in the xfer
+ *	   could not rbe mapped to a free slot in the xfer_alloc_table.
+ */
+static int scmi_xfer_inflight_register(struct scmi_xfer *xfer,
+				       struct scmi_xfers_info *minfo)
+{
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&minfo->xfer_lock, flags);
+	if (!test_bit(xfer->hdr.seq, minfo->xfer_alloc_table))
+		scmi_xfer_inflight_register_unlocked(xfer, minfo);
+	else
+		ret = -EBUSY;
+	spin_unlock_irqrestore(&minfo->xfer_lock, flags);
+
+	return ret;
+}
+
+/**
+ * scmi_xfer_raw_inflight_register  - An helper to register the given xfer as in
+ * flight on the TX channe, if possible.
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @xfer: The xfer to register
+ *
+ * Return: 0 on Success, error otherwise
+ */
+int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
+				    struct scmi_xfer *xfer)
+{
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	return scmi_xfer_inflight_register(xfer, &info->tx_minfo);
+}
+
 /**
  * scmi_xfer_pending_set  - Pick a proper sequence number and mark the xfer
  * as pending in-flight
@@ -425,6 +472,58 @@ static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
 	return xfer;
 }
 
+/**
+ * scmi_xfer_raw_get  - Helper to get a bare free xfer from the TX channel
+ *
+ * @handle: Pointer to SCMI entity handle
+ *
+ * Note that xfer is taken from the TX channel structures.
+ *
+ * Return: A valid xfer on Success, or an error-pointer otherwise
+ */
+struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle)
+{
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	return scmi_xfer_get(handle, &info->tx_minfo);
+}
+
+/**
+ * scmi_xfer_raw_channel_get  - Helper to get a reference to the proper channel
+ * to use for a specific protocol_id Raw transaction.
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @protocol_id: Identifier of the protocol
+ *
+ * Note that in a regular SCMI stack, usually, a protocol has to be defined in
+ * the DT to have an associated channel and be usable; but in Raw mode any
+ * protocol in range is allowed, resusing the Base channel, so as to enable
+ * fuzzing on any protocol without the need of a fully compiled DT.
+ *
+ * Return: A reference to the channel to use, or an ERR_PTR
+ */
+struct scmi_chan_info *
+scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id)
+{
+	struct scmi_chan_info *cinfo;
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	cinfo = idr_find(&info->tx_idr, protocol_id);
+	if (!cinfo) {
+		if (protocol_id == SCMI_PROTOCOL_BASE)
+			return ERR_PTR(-EINVAL);
+		/* Use Base channel for protocols not defined for DT */
+		cinfo = idr_find(&info->tx_idr, SCMI_PROTOCOL_BASE);
+		if (!cinfo)
+			return ERR_PTR(-EINVAL);
+		dev_warn_once(handle->dev,
+			      "Using Base channel for protocol 0x%X\n",
+			      protocol_id);
+	}
+
+	return cinfo;
+}
+
 /**
  * __scmi_xfer_put() - Release a message
  *
@@ -453,6 +552,22 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer)
 	spin_unlock_irqrestore(&minfo->xfer_lock, flags);
 }
 
+/**
+ * scmi_xfer_raw_put  - Release an xfer that was taken by @scmi_xfer_raw_get
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @xfer: A reference to the xfer to put
+ *
+ * Note that as with other xfer_put() handlers the xfer is really effectively
+ * released only if there are no more users on the system.
+ */
+void scmi_xfer_raw_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
+{
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	return __scmi_xfer_put(&info->tx_minfo, xfer);
+}
+
 /**
  * scmi_xfer_lookup_unlocked  -  Helper to lookup an xfer_id
  *
-- 
2.32.0

[PATCH v3 4/9] firmware: arm_scmi: Add xfer raw helpers

[Cristian Marussi]

Add a few SCMI helpers useful to implement SCMI Raw access support.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
v1 --> v2
- added scmi_xfer_raw_channel_get
v2 --> v3
- allow for DT-unknown protocols to get a channel
---
 drivers/firmware/arm_scmi/common.h |   9 +++
 drivers/firmware/arm_scmi/driver.c | 115 +++++++++++++++++++++++++++++
 2 files changed, 124 insertions(+)

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 096b66442d84..6d2a57a696d8 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -212,6 +212,15 @@ struct scmi_desc {
 	const bool atomic_enabled;
 };
 
+void scmi_xfer_raw_put(const struct scmi_handle *handle,
+		       struct scmi_xfer *xfer);
+struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle);
+struct scmi_chan_info *
+scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id);
+
+int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
+				    struct scmi_xfer *xfer);
+
 #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX
 extern const struct scmi_desc scmi_mailbox_desc;
 #endif
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 56b1a917f618..c1292452e41f 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -350,6 +350,53 @@ scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer,
 	xfer->pending = true;
 }
 
+/**
+ * scmi_xfer_inflight_register  - Try to register an xfer as in-flight
+ *
+ * @xfer: The xfer to register
+ * @minfo: Pointer to Tx/Rx Message management info based on channel type
+ *
+ * Note that this helper does NOT assume anything about the sequence number
+ * that was baked into the provided xfer, so it checks at first if it can
+ * be mapped to a free slot and fails with an error if another xfer with the
+ * same sequence number is currently still registered as in-flight.
+ *
+ * Return: 0 on Success or -EBUSY if sequence number embedded in the xfer
+ *	   could not rbe mapped to a free slot in the xfer_alloc_table.
+ */
+static int scmi_xfer_inflight_register(struct scmi_xfer *xfer,
+				       struct scmi_xfers_info *minfo)
+{
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&minfo->xfer_lock, flags);
+	if (!test_bit(xfer->hdr.seq, minfo->xfer_alloc_table))
+		scmi_xfer_inflight_register_unlocked(xfer, minfo);
+	else
+		ret = -EBUSY;
+	spin_unlock_irqrestore(&minfo->xfer_lock, flags);
+
+	return ret;
+}
+
+/**
+ * scmi_xfer_raw_inflight_register  - An helper to register the given xfer as in
+ * flight on the TX channe, if possible.
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @xfer: The xfer to register
+ *
+ * Return: 0 on Success, error otherwise
+ */
+int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
+				    struct scmi_xfer *xfer)
+{
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	return scmi_xfer_inflight_register(xfer, &info->tx_minfo);
+}
+
 /**
  * scmi_xfer_pending_set  - Pick a proper sequence number and mark the xfer
  * as pending in-flight
@@ -425,6 +472,58 @@ static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
 	return xfer;
 }
 
+/**
+ * scmi_xfer_raw_get  - Helper to get a bare free xfer from the TX channel
+ *
+ * @handle: Pointer to SCMI entity handle
+ *
+ * Note that xfer is taken from the TX channel structures.
+ *
+ * Return: A valid xfer on Success, or an error-pointer otherwise
+ */
+struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle)
+{
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	return scmi_xfer_get(handle, &info->tx_minfo);
+}
+
+/**
+ * scmi_xfer_raw_channel_get  - Helper to get a reference to the proper channel
+ * to use for a specific protocol_id Raw transaction.
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @protocol_id: Identifier of the protocol
+ *
+ * Note that in a regular SCMI stack, usually, a protocol has to be defined in
+ * the DT to have an associated channel and be usable; but in Raw mode any
+ * protocol in range is allowed, resusing the Base channel, so as to enable
+ * fuzzing on any protocol without the need of a fully compiled DT.
+ *
+ * Return: A reference to the channel to use, or an ERR_PTR
+ */
+struct scmi_chan_info *
+scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id)
+{
+	struct scmi_chan_info *cinfo;
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	cinfo = idr_find(&info->tx_idr, protocol_id);
+	if (!cinfo) {
+		if (protocol_id == SCMI_PROTOCOL_BASE)
+			return ERR_PTR(-EINVAL);
+		/* Use Base channel for protocols not defined for DT */
+		cinfo = idr_find(&info->tx_idr, SCMI_PROTOCOL_BASE);
+		if (!cinfo)
+			return ERR_PTR(-EINVAL);
+		dev_warn_once(handle->dev,
+			      "Using Base channel for protocol 0x%X\n",
+			      protocol_id);
+	}
+
+	return cinfo;
+}
+
 /**
  * __scmi_xfer_put() - Release a message
  *
@@ -453,6 +552,22 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer)
 	spin_unlock_irqrestore(&minfo->xfer_lock, flags);
 }
 
+/**
+ * scmi_xfer_raw_put  - Release an xfer that was taken by @scmi_xfer_raw_get
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @xfer: A reference to the xfer to put
+ *
+ * Note that as with other xfer_put() handlers the xfer is really effectively
+ * released only if there are no more users on the system.
+ */
+void scmi_xfer_raw_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
+{
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	return __scmi_xfer_put(&info->tx_minfo, xfer);
+}
+
 /**
  * scmi_xfer_lookup_unlocked  -  Helper to lookup an xfer_id
  *
-- 
2.32.0


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[PATCH v3 5/9] firmware: arm_scmi: Move errors defs and code to common.h

[Cristian Marussi]

Move SCMI error codes definitions and helper to the common.h header
together with the delayed response timeout define.

No functional change.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/common.h | 40 ++++++++++++++++++++++++++++++
 drivers/firmware/arm_scmi/driver.c | 40 ------------------------------
 2 files changed, 40 insertions(+), 40 deletions(-)

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 6d2a57a696d8..5334a2b272bf 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -27,6 +27,46 @@
 #include "protocols.h"
 #include "notify.h"
 
+#define SCMI_MAX_RESPONSE_TIMEOUT	(2 * MSEC_PER_SEC)
+
+enum scmi_error_codes {
+	SCMI_SUCCESS = 0,	/* Success */
+	SCMI_ERR_SUPPORT = -1,	/* Not supported */
+	SCMI_ERR_PARAMS = -2,	/* Invalid Parameters */
+	SCMI_ERR_ACCESS = -3,	/* Invalid access/permission denied */
+	SCMI_ERR_ENTRY = -4,	/* Not found */
+	SCMI_ERR_RANGE = -5,	/* Value out of range */
+	SCMI_ERR_BUSY = -6,	/* Device busy */
+	SCMI_ERR_COMMS = -7,	/* Communication Error */
+	SCMI_ERR_GENERIC = -8,	/* Generic Error */
+	SCMI_ERR_HARDWARE = -9,	/* Hardware Error */
+	SCMI_ERR_PROTOCOL = -10,/* Protocol Error */
+};
+
+static const int scmi_linux_errmap[] = {
+	/* better than switch case as long as return value is continuous */
+	0,			/* SCMI_SUCCESS */
+	-EOPNOTSUPP,		/* SCMI_ERR_SUPPORT */
+	-EINVAL,		/* SCMI_ERR_PARAM */
+	-EACCES,		/* SCMI_ERR_ACCESS */
+	-ENOENT,		/* SCMI_ERR_ENTRY */
+	-ERANGE,		/* SCMI_ERR_RANGE */
+	-EBUSY,			/* SCMI_ERR_BUSY */
+	-ECOMM,			/* SCMI_ERR_COMMS */
+	-EIO,			/* SCMI_ERR_GENERIC */
+	-EREMOTEIO,		/* SCMI_ERR_HARDWARE */
+	-EPROTO,		/* SCMI_ERR_PROTOCOL */
+};
+
+static inline int scmi_to_linux_errno(int errno)
+{
+	int err_idx = -errno;
+
+	if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap))
+		return scmi_linux_errmap[err_idx];
+	return -EIO;
+}
+
 #define MSG_ID_MASK		GENMASK(7, 0)
 #define MSG_XTRACT_ID(hdr)	FIELD_GET(MSG_ID_MASK, (hdr))
 #define MSG_TYPE_MASK		GENMASK(9, 8)
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index c1292452e41f..056796b2dcae 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -37,20 +37,6 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/scmi.h>
 
-enum scmi_error_codes {
-	SCMI_SUCCESS = 0,	/* Success */
-	SCMI_ERR_SUPPORT = -1,	/* Not supported */
-	SCMI_ERR_PARAMS = -2,	/* Invalid Parameters */
-	SCMI_ERR_ACCESS = -3,	/* Invalid access/permission denied */
-	SCMI_ERR_ENTRY = -4,	/* Not found */
-	SCMI_ERR_RANGE = -5,	/* Value out of range */
-	SCMI_ERR_BUSY = -6,	/* Device busy */
-	SCMI_ERR_COMMS = -7,	/* Communication Error */
-	SCMI_ERR_GENERIC = -8,	/* Generic Error */
-	SCMI_ERR_HARDWARE = -9,	/* Hardware Error */
-	SCMI_ERR_PROTOCOL = -10,/* Protocol Error */
-};
-
 /* List of all SCMI devices active in system */
 static LIST_HEAD(scmi_list);
 /* Protection for the entire list */
@@ -170,30 +156,6 @@ struct scmi_info {
 
 #define handle_to_scmi_info(h)	container_of(h, struct scmi_info, handle)
 
-static const int scmi_linux_errmap[] = {
-	/* better than switch case as long as return value is continuous */
-	0,			/* SCMI_SUCCESS */
-	-EOPNOTSUPP,		/* SCMI_ERR_SUPPORT */
-	-EINVAL,		/* SCMI_ERR_PARAM */
-	-EACCES,		/* SCMI_ERR_ACCESS */
-	-ENOENT,		/* SCMI_ERR_ENTRY */
-	-ERANGE,		/* SCMI_ERR_RANGE */
-	-EBUSY,			/* SCMI_ERR_BUSY */
-	-ECOMM,			/* SCMI_ERR_COMMS */
-	-EIO,			/* SCMI_ERR_GENERIC */
-	-EREMOTEIO,		/* SCMI_ERR_HARDWARE */
-	-EPROTO,		/* SCMI_ERR_PROTOCOL */
-};
-
-static inline int scmi_to_linux_errno(int errno)
-{
-	int err_idx = -errno;
-
-	if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap))
-		return scmi_linux_errmap[err_idx];
-	return -EIO;
-}
-
 void scmi_notification_instance_data_set(const struct scmi_handle *handle,
 					 void *priv)
 {
@@ -1092,8 +1054,6 @@ static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph,
 	xfer->rx.len = info->desc->max_msg_size;
 }
 
-#define SCMI_MAX_RESPONSE_TIMEOUT	(2 * MSEC_PER_SEC)
-
 /**
  * do_xfer_with_response() - Do one transfer and wait until the delayed
  *	response is received
-- 
2.32.0

[PATCH v3 5/9] firmware: arm_scmi: Move errors defs and code to common.h

[Cristian Marussi]

Move SCMI error codes definitions and helper to the common.h header
together with the delayed response timeout define.

No functional change.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/common.h | 40 ++++++++++++++++++++++++++++++
 drivers/firmware/arm_scmi/driver.c | 40 ------------------------------
 2 files changed, 40 insertions(+), 40 deletions(-)

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 6d2a57a696d8..5334a2b272bf 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -27,6 +27,46 @@
 #include "protocols.h"
 #include "notify.h"
 
+#define SCMI_MAX_RESPONSE_TIMEOUT	(2 * MSEC_PER_SEC)
+
+enum scmi_error_codes {
+	SCMI_SUCCESS = 0,	/* Success */
+	SCMI_ERR_SUPPORT = -1,	/* Not supported */
+	SCMI_ERR_PARAMS = -2,	/* Invalid Parameters */
+	SCMI_ERR_ACCESS = -3,	/* Invalid access/permission denied */
+	SCMI_ERR_ENTRY = -4,	/* Not found */
+	SCMI_ERR_RANGE = -5,	/* Value out of range */
+	SCMI_ERR_BUSY = -6,	/* Device busy */
+	SCMI_ERR_COMMS = -7,	/* Communication Error */
+	SCMI_ERR_GENERIC = -8,	/* Generic Error */
+	SCMI_ERR_HARDWARE = -9,	/* Hardware Error */
+	SCMI_ERR_PROTOCOL = -10,/* Protocol Error */
+};
+
+static const int scmi_linux_errmap[] = {
+	/* better than switch case as long as return value is continuous */
+	0,			/* SCMI_SUCCESS */
+	-EOPNOTSUPP,		/* SCMI_ERR_SUPPORT */
+	-EINVAL,		/* SCMI_ERR_PARAM */
+	-EACCES,		/* SCMI_ERR_ACCESS */
+	-ENOENT,		/* SCMI_ERR_ENTRY */
+	-ERANGE,		/* SCMI_ERR_RANGE */
+	-EBUSY,			/* SCMI_ERR_BUSY */
+	-ECOMM,			/* SCMI_ERR_COMMS */
+	-EIO,			/* SCMI_ERR_GENERIC */
+	-EREMOTEIO,		/* SCMI_ERR_HARDWARE */
+	-EPROTO,		/* SCMI_ERR_PROTOCOL */
+};
+
+static inline int scmi_to_linux_errno(int errno)
+{
+	int err_idx = -errno;
+
+	if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap))
+		return scmi_linux_errmap[err_idx];
+	return -EIO;
+}
+
 #define MSG_ID_MASK		GENMASK(7, 0)
 #define MSG_XTRACT_ID(hdr)	FIELD_GET(MSG_ID_MASK, (hdr))
 #define MSG_TYPE_MASK		GENMASK(9, 8)
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index c1292452e41f..056796b2dcae 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -37,20 +37,6 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/scmi.h>
 
-enum scmi_error_codes {
-	SCMI_SUCCESS = 0,	/* Success */
-	SCMI_ERR_SUPPORT = -1,	/* Not supported */
-	SCMI_ERR_PARAMS = -2,	/* Invalid Parameters */
-	SCMI_ERR_ACCESS = -3,	/* Invalid access/permission denied */
-	SCMI_ERR_ENTRY = -4,	/* Not found */
-	SCMI_ERR_RANGE = -5,	/* Value out of range */
-	SCMI_ERR_BUSY = -6,	/* Device busy */
-	SCMI_ERR_COMMS = -7,	/* Communication Error */
-	SCMI_ERR_GENERIC = -8,	/* Generic Error */
-	SCMI_ERR_HARDWARE = -9,	/* Hardware Error */
-	SCMI_ERR_PROTOCOL = -10,/* Protocol Error */
-};
-
 /* List of all SCMI devices active in system */
 static LIST_HEAD(scmi_list);
 /* Protection for the entire list */
@@ -170,30 +156,6 @@ struct scmi_info {
 
 #define handle_to_scmi_info(h)	container_of(h, struct scmi_info, handle)
 
-static const int scmi_linux_errmap[] = {
-	/* better than switch case as long as return value is continuous */
-	0,			/* SCMI_SUCCESS */
-	-EOPNOTSUPP,		/* SCMI_ERR_SUPPORT */
-	-EINVAL,		/* SCMI_ERR_PARAM */
-	-EACCES,		/* SCMI_ERR_ACCESS */
-	-ENOENT,		/* SCMI_ERR_ENTRY */
-	-ERANGE,		/* SCMI_ERR_RANGE */
-	-EBUSY,			/* SCMI_ERR_BUSY */
-	-ECOMM,			/* SCMI_ERR_COMMS */
-	-EIO,			/* SCMI_ERR_GENERIC */
-	-EREMOTEIO,		/* SCMI_ERR_HARDWARE */
-	-EPROTO,		/* SCMI_ERR_PROTOCOL */
-};
-
-static inline int scmi_to_linux_errno(int errno)
-{
-	int err_idx = -errno;
-
-	if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap))
-		return scmi_linux_errmap[err_idx];
-	return -EIO;
-}
-
 void scmi_notification_instance_data_set(const struct scmi_handle *handle,
 					 void *priv)
 {
@@ -1092,8 +1054,6 @@ static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph,
 	xfer->rx.len = info->desc->max_msg_size;
 }
 
-#define SCMI_MAX_RESPONSE_TIMEOUT	(2 * MSEC_PER_SEC)
-
 /**
  * do_xfer_with_response() - Do one transfer and wait until the delayed
  *	response is received
-- 
2.32.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 6/9] firmware: arm_scmi: Add raw transmission support

[Cristian Marussi]

Add SCMI Raw mode support which exposes a userspace interface to allow for
bare SCMI command injection and snooping from userspace.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
v1 --> v2
- make use of proper channel depending on protocol at hand (using
  scmi_xfer_raw_channel_get to lookup related DT config)
- refactored scmi_inflight_register call
- added debugfs docs and comments
v2 --> v3
- changed to dev_dbg when retrying inflight reg
- refactored and simplfiied waiters deferred worker
- fixed sparse errors about LE and __poll_t
---
 drivers/firmware/arm_scmi/Kconfig    |   13 +
 drivers/firmware/arm_scmi/Makefile   |    1 +
 drivers/firmware/arm_scmi/raw_mode.c | 1235 ++++++++++++++++++++++++++
 drivers/firmware/arm_scmi/raw_mode.h |   29 +
 4 files changed, 1278 insertions(+)
 create mode 100644 drivers/firmware/arm_scmi/raw_mode.c
 create mode 100644 drivers/firmware/arm_scmi/raw_mode.h

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index a14f65444b35..ab726a92ac2f 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig
@@ -23,6 +23,19 @@ config ARM_SCMI_PROTOCOL
 
 if ARM_SCMI_PROTOCOL
 
+config ARM_SCMI_RAW_MODE_SUPPORT
+	bool "Enable support for SCMI Raw transmission mode"
+	help
+	  Enable support for SCMI Raw transmission mode.
+
+	  If enabled allows the direct injection and snooping of SCMI bare
+	  messages through a dedicated debugfs interface.
+	  It is meant to be used by SCMI compliance/testing suites.
+
+	  When enabled regular SCMI drivers interactions are inhibited in
+	  order to avoid unexpected interactions with the SCMI Raw message
+	  flow. If unsure say N.
+
 config ARM_SCMI_HAVE_TRANSPORT
 	bool
 	help
diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 9ea86f8cc8f7..7c1aca60c8ce 100644
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 scmi-bus-y = bus.o
 scmi-driver-y = driver.o notify.o
+scmi-driver-$(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) += raw_mode.o
 scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o
 scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += mailbox.o
 scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) += smc.o
diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
new file mode 100644
index 000000000000..3ff333874724
--- /dev/null
+++ b/drivers/firmware/arm_scmi/raw_mode.c
@@ -0,0 +1,1235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Raw mode support
+ *
+ * Copyright (C) 2022 ARM Ltd.
+ */
+/**
+ * DOC: Theory of operation
+ *
+ * When enabled the SCMI Raw mode support exposes a userspace API which allows
+ * to send and receive SCMI commands, replies and notifications from a user
+ * application through injection and snooping of bare SCMI messages in binary
+ * little-endian format.
+ *
+ * Such injected SCMI transactions will then be routed through the SCMI core
+ * stack towards the SCMI backend server using whatever SCMI transport is
+ * currently configured on the system under test.
+ *
+ * It is meant to help in running any sort of SCMI backend server testing, no
+ * matter where the server is placed, as long as it is normally reachable via
+ * the transport configured on the system.
+ *
+ * It is activated by a Kernel configuration option since it is NOT meant to
+ * be used in production but only during development and in CI deployements.
+ *
+ * In order to avoid possible interferences between the SCMI Raw transactions
+ * originated from a test-suite and the normal operations of the SCMI drivers,
+ * when Raw mode is enabled, by default, all the regular SCMI drivers are
+ * inhibited.
+ *
+ * The exposed API is as follows:
+ *
+ *	/sys/kernel/debug/scmi_raw/
+ *	|-- errors
+ *	|-- message
+ *	|-- message_async
+ *	|-- notification
+ *	|-- reset
+ *	|-- transport_max_msg_size
+ *	|-- transport_rx_timeout_ms
+ *	|-- transport_tx_max_msg
+ *
+ * where:
+ *
+ *  - errors: used to read back timed-out and unexpected replies
+ *  - message*: used to send sync/async commands and read back immediate and
+ *		delayed reponses (if any)
+ *  - notification: used to read any notification being emitted by the system
+ *		    (if previously enabled by the user app)
+ *  - reset: used to flush the queues of messages (of any kind) still pending
+ *	     to be read; this is useful at test-suite start/stop to get
+ *	     rid of any unread messages from the previous run.
+ *  - transport*: a bunch of configurations useful to setup the user
+ *		  application expectations in terms of timeouts and message
+ *		  characteristics.
+ *
+ * Each write to the message* entries causes one command request to be built
+ * and sent while the replies or delayed response are read back from those same
+ * entries one message at time (receiving an EOF at each message boundary).
+ *
+ * The user application running the test is in charge of handling timeouts
+ * on replies and properly choosing SCMI sequence numbers for the outgoing
+ * requests (using the same sequence number is supported but discouraged).
+ *
+ * Injection of multiple in-flight requests is supported as long as the user
+ * application uses properly distinct sequence numbers for concurrent requests
+ * and takes care to properly manage all the related issues about concurrency
+ * and command/reply pairing. Keep in mind that, anyway, the real level of
+ * parallelism attainable in such scenario is dependent on the characteristics
+ * of the underlying transport being used.
+ *
+ * Since the SCMI core regular stack is partially used to deliver and collect
+ * the messages, late replies arrived after timeouts and any other sort of
+ * unexpected message can be identified by the SCMI core as usual and they will
+ * be reported as messages under "errors" for later analysis.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/idr.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+
+#include "common.h"
+
+#include "raw_mode.h"
+
+#include <trace/events/scmi.h>
+
+#define SCMI_XFER_RAW_MAX_RETRIES	10
+
+/**
+ * struct scmi_raw_mode_info  - Structure holding SCMI Raw instance data
+ *
+ * @handle: Pointer to SCMI entity handle to use
+ * @desc: Pointer to the transport descriptor to use
+ * @tx_max_msg: Maximum number of concurrent TX in-flight messages
+ * @free_raw_bufs: An array of freelists heads used to keep unused raw buffers
+ * @free_bufs_lock: Spinlocks used to protect access to each @free_raw_bufs
+ * @msg_q: An array of lists to queue snooped messages waiting to be read out
+ * @msg_q_lock: Spinlocks used to protect access to each @msg_q
+ * @wqs: An array of waitqueues used to wait and poll on related @msg_q
+ * @free_waiters: Head of freelist for unused waiters
+ * @free_mtx: A mutex to protect the waiters freelist
+ * @active_waiters: Head of list for currently active and used waiters
+ * @active_mtx: A mutex to protect the active waiters list
+ * @waiters_work: A work descriptor to be used with the workqueue machinery
+ * @wait_wq: A workqueue reference to the created workqueue
+ * @dentry: Top debugfs root dentry for SCMI Raw
+ * @gid: A group ID used for devres accounting
+ *
+ * Note that this descriptor is passed back to the core after SCMI Raw is
+ * initialized as an opaque handle to use by subsequent SCMI Raw call hooks.
+ *
+ */
+struct scmi_raw_mode_info {
+	const struct scmi_handle *handle;
+	const struct scmi_desc *desc;
+	int tx_max_msg;
+	struct list_head free_raw_bufs[SCMI_RAW_MAX_QUEUE];
+	/* Protect free_raw_bufs[] lists */
+	spinlock_t free_bufs_lock[SCMI_RAW_MAX_QUEUE];
+	struct list_head msg_q[SCMI_RAW_MAX_QUEUE];
+	/* Protect msg_q[] lists */
+	spinlock_t msg_q_lock[SCMI_RAW_MAX_QUEUE];
+	wait_queue_head_t wqs[SCMI_RAW_MAX_QUEUE];
+	struct list_head free_waiters;
+	/* Protect free_waiters list */
+	struct mutex free_mtx;
+	struct list_head active_waiters;
+	/* Protect active_waiters list */
+	struct mutex active_mtx;
+	struct work_struct waiters_work;
+	struct workqueue_struct	*wait_wq;
+	struct dentry *dentry;
+	void *gid;
+};
+
+/**
+ * struct scmi_xfer_raw_waiter  - Structure to describe an xfer to be waited for
+ *
+ * @start_jiffies: The timestamp in jiffies of when this structure was queued.
+ * @cinfo: A reference to the channel to use for this transaction
+ * @xfer: A reference to the xfer to be waited for
+ * @async_response: A completion to be, optionally, used for async waits: it
+ *		    will be setup by @scmi_do_xfer_raw_start, if needed, to be
+ *		    pointed at by xfer->async_done.
+ * @node: A list node.
+ */
+struct scmi_xfer_raw_waiter {
+	unsigned long start_jiffies;
+	struct scmi_chan_info *cinfo;
+	struct scmi_xfer *xfer;
+	struct completion async_response;
+	struct list_head node;
+};
+
+/**
+ * struct scmi_raw_buffer  - Structure to hold a full SCMI message
+ *
+ * @max_len: The maximum allowed message size (header included) that can be
+ *	     stored into @msg
+ * @msg: A message buffer used to collect a full message grabbed from an xfer.
+ * @node: A list node.
+ */
+struct scmi_raw_buffer {
+	size_t max_len;
+	struct scmi_msg msg;
+	struct list_head node;
+};
+
+/**
+ * struct scmi_dbg_raw_data  - Structure holding data needed by the debugfs
+ * layer
+ *
+ * @raw: A reference to the Raw instance.
+ * @tx: A message buffer used to collect TX message on write.
+ * @tx_size: The effective size of the TX message.
+ * @tx_req_size: The final expected size of the complete TX message.
+ * @rx: A message buffer to collect RX message on read.
+ * @rx_size: The effective size of the RX message.
+ */
+struct scmi_dbg_raw_data {
+	struct scmi_raw_mode_info *raw;
+	struct scmi_msg tx;
+	size_t tx_size;
+	size_t tx_req_size;
+	struct scmi_msg rx;
+	size_t rx_size;
+};
+
+static inline
+struct scmi_raw_buffer *scmi_raw_buffer_get(struct scmi_raw_mode_info *raw,
+					    unsigned int idx)
+{
+	unsigned long flags;
+	struct scmi_raw_buffer *rb = NULL;
+	struct list_head *head = &raw->free_raw_bufs[idx];
+
+	spin_lock_irqsave(&raw->free_bufs_lock[idx], flags);
+	if (!list_empty(head)) {
+		rb = list_first_entry(head, struct scmi_raw_buffer, node);
+		list_del_init(&rb->node);
+	}
+	spin_unlock_irqrestore(&raw->free_bufs_lock[idx], flags);
+
+	return rb;
+}
+
+static inline void scmi_raw_buffer_put(struct scmi_raw_mode_info *raw,
+				       struct scmi_raw_buffer *rb,
+				       unsigned int idx)
+{
+	unsigned long flags;
+
+	/* Reset to full buffer length */
+	rb->msg.len = rb->max_len;
+
+	spin_lock_irqsave(&raw->free_bufs_lock[idx], flags);
+	list_add_tail(&rb->node, &raw->free_raw_bufs[idx]);
+	spin_unlock_irqrestore(&raw->free_bufs_lock[idx], flags);
+}
+
+static inline void scmi_raw_buffer_enqueue(struct scmi_raw_mode_info *raw,
+					   struct scmi_raw_buffer *rb,
+					   unsigned int idx)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	list_add_tail(&rb->node, &raw->msg_q[idx]);
+	spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+	wake_up_interruptible(&raw->wqs[idx]);
+}
+
+static inline struct scmi_raw_buffer*
+scmi_raw_buffer_dequeue(struct scmi_raw_mode_info *raw, unsigned int idx)
+{
+	unsigned long flags;
+	struct scmi_raw_buffer *rb = NULL;
+
+	spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	if (!list_empty(&raw->msg_q[idx])) {
+		rb = list_first_entry(&raw->msg_q[idx],
+				      struct scmi_raw_buffer, node);
+		list_del_init(&rb->node);
+	}
+	spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+	return rb;
+}
+
+static void scmi_raw_buffer_queue_flush(struct scmi_raw_mode_info *raw,
+					unsigned int idx)
+{
+	struct scmi_raw_buffer *rb;
+
+	do {
+		rb = scmi_raw_buffer_dequeue(raw, idx);
+		if (rb)
+			scmi_raw_buffer_put(raw, rb, idx);
+	} while (rb);
+}
+
+static inline struct scmi_xfer_raw_waiter *
+scmi_xfer_raw_waiter_get(struct scmi_raw_mode_info *raw, struct scmi_xfer *xfer,
+			 struct scmi_chan_info *cinfo, bool async)
+{
+	struct scmi_xfer_raw_waiter *rw = NULL;
+
+	mutex_lock(&raw->free_mtx);
+	if (!list_empty(&raw->free_waiters)) {
+		rw = list_first_entry(&raw->free_waiters,
+				      struct scmi_xfer_raw_waiter, node);
+		list_del_init(&rw->node);
+
+		if (async) {
+			reinit_completion(&rw->async_response);
+			xfer->async_done = &rw->async_response;
+		}
+
+		rw->cinfo = cinfo;
+		rw->xfer = xfer;
+	}
+	mutex_unlock(&raw->free_mtx);
+
+	return rw;
+}
+
+static inline void scmi_xfer_raw_waiter_put(struct scmi_raw_mode_info *raw,
+					    struct scmi_xfer_raw_waiter *rw)
+{
+	if (rw->xfer) {
+		rw->xfer->async_done = NULL;
+		rw->xfer = NULL;
+	}
+
+	mutex_lock(&raw->free_mtx);
+	list_add_tail(&rw->node, &raw->free_waiters);
+	mutex_unlock(&raw->free_mtx);
+}
+
+static inline void scmi_xfer_raw_waiter_enqueue(struct scmi_raw_mode_info *raw,
+						struct scmi_xfer_raw_waiter *rw)
+{
+	/* A timestamp for the deferred worker to know how much this has aged */
+	rw->start_jiffies = jiffies;
+
+	trace_scmi_xfer_response_wait(rw->xfer->transfer_id, rw->xfer->hdr.id,
+				      rw->xfer->hdr.protocol_id,
+				      rw->xfer->hdr.seq,
+				      raw->desc->max_rx_timeout_ms,
+				      rw->xfer->hdr.poll_completion);
+
+	mutex_lock(&raw->active_mtx);
+	list_add_tail(&rw->node, &raw->active_waiters);
+	mutex_unlock(&raw->active_mtx);
+	/* kick waiter work */
+	queue_work(raw->wait_wq, &raw->waiters_work);
+}
+
+static struct scmi_xfer_raw_waiter*
+scmi_xfer_raw_waiter_dequeue(struct scmi_raw_mode_info *raw)
+{
+	struct scmi_xfer_raw_waiter *rw = NULL;
+
+	mutex_lock(&raw->active_mtx);
+	if (!list_empty(&raw->active_waiters)) {
+		rw = list_first_entry(&raw->active_waiters,
+				      struct scmi_xfer_raw_waiter, node);
+		list_del_init(&rw->node);
+	}
+	mutex_unlock(&raw->active_mtx);
+
+	return rw;
+}
+
+/**
+ * scmi_xfer_raw_worker  - Work function to wait for Raw xfers completions
+ *
+ * @work: A reference to the work.
+ *
+ * In SCMI Raw mode, once a user-provided injected SCMI message is sent, we
+ * cannot wait to receive its response (if any) in the context of the injection
+ * routines so as not to leave the userspace write syscall, which delivered the
+ * SCMI message to send, pending till eventually a reply is received.
+ * Userspace should and will poll/wait instead on the read syscalls which will
+ * be in charge of reading a received reply (if any).
+ *
+ * Even though reply messages are collected and reported into the SCMI Raw layer
+ * on the RX path, nonetheless we have to properly wait for their completion as
+ * usual (and async_completion too if needed) in order to properly release the
+ * xfer structure at the end: to do this out of the context of the write/send
+ * these waiting jobs are delegated to this deferred worker.
+ *
+ * Any sent xfer, to be waited for, is timestamped and queued for later
+ * consumption by this worker: queue aging is accounted for while choosing a
+ * timeout for the completion, BUT we do not really care here if we end up
+ * accidentally waiting for a bit too long.
+ */
+static void scmi_xfer_raw_worker(struct work_struct *work)
+{
+	struct scmi_raw_mode_info *raw;
+	struct device *dev;
+	unsigned long max_tmo;
+
+	raw = container_of(work, struct scmi_raw_mode_info, waiters_work);
+	dev = raw->handle->dev;
+	max_tmo = msecs_to_jiffies(raw->desc->max_rx_timeout_ms);
+
+	do {
+		int ret = 0;
+		unsigned long aging, tmo;
+		struct scmi_xfer *xfer;
+		struct scmi_xfer_raw_waiter *rw;
+
+		rw = scmi_xfer_raw_waiter_dequeue(raw);
+		if (!rw)
+			return;
+
+		xfer = rw->xfer;
+
+		/*
+		 * Waiters are queued by wait-deadline at the end, so some of
+		 * them could have been already expired when processed, BUT we
+		 * have to check the completion status anyway just in case a
+		 * virtually expired (aged) transaction was indeed completed
+		 * fine and we'll have to wait for the asynchronous part (if
+		 * any).
+		 */
+		aging = jiffies - rw->start_jiffies;
+		tmo = max_tmo > aging ? max_tmo - aging : 0;
+
+		if ((tmo && !wait_for_completion_timeout(&xfer->done, tmo)) ||
+		    (!tmo && !try_wait_for_completion(&xfer->done))) {
+			dev_err(dev, "timed out in RAW response - HDR:%08X\n",
+				pack_scmi_header(&xfer->hdr));
+			ret = -ETIMEDOUT;
+		}
+
+		/* Avoid unneeded async waits */
+		if (!ret && xfer->hdr.status)
+			ret = scmi_to_linux_errno(xfer->hdr.status);
+
+		if (raw->desc->ops->mark_txdone)
+			raw->desc->ops->mark_txdone(rw->cinfo, ret, xfer);
+
+		trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id,
+				    xfer->hdr.protocol_id, xfer->hdr.seq, ret);
+
+		/* Wait also for an async delayed response if needed */
+		if (!ret && xfer->async_done) {
+			tmo = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT);
+			if (!wait_for_completion_timeout(xfer->async_done, tmo))
+				dev_err(dev,
+					"timed out in RAW delayed resp - HDR:%08X\n",
+					pack_scmi_header(&xfer->hdr));
+		}
+
+		/* Release waiter and xfer */
+		scmi_xfer_raw_put(raw->handle, xfer);
+		scmi_xfer_raw_waiter_put(raw, rw);
+	} while (1);
+}
+
+static void scmi_xfer_raw_reset(struct scmi_raw_mode_info *raw)
+{
+	int i;
+
+	dev_info(raw->handle->dev, "Resetting SCMI Raw stack.\n");
+
+	for (i = 0; i < SCMI_RAW_MAX_QUEUE; i++)
+		scmi_raw_buffer_queue_flush(raw, i);
+}
+
+/**
+ * scmi_xfer_raw_get_init  - An helper to build a valid xfer from the provided
+ * bare SCMI message.
+ *
+ * @raw: A reference to the Raw instance.
+ * @buf: A buffer containing the whole SCMI message to send (including the
+ *	 header) in little-endian binary formmat.
+ * @len: Length of the message in @buf.
+ * @p: A pointer to return the initialized Raw xfer.
+ *
+ * After an xfer is picked from the TX pool and filled in with the message
+ * content, the xfer is registered as pending with the core in the usual way
+ * using the original sequence number provided by the user with the message.
+ *
+ * Note that, in case the testing user application is NOT using distinct
+ * sequence-numbers between successive SCMI messages such registration could
+ * fail temporarily if the previous message, using the same sequence number,
+ * had still not released; in such a case we just wait and retry.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_xfer_raw_get_init(struct scmi_raw_mode_info *raw, void *buf,
+				  size_t len, struct scmi_xfer **p)
+{
+	u32 msg_hdr;
+	size_t tx_size;
+	struct scmi_xfer *xfer;
+	int ret, retry = SCMI_XFER_RAW_MAX_RETRIES;
+	struct device *dev = raw->handle->dev;
+
+	if (!buf || len < sizeof(u32))
+		return -EINVAL;
+
+	tx_size = len - sizeof(u32);
+	/* Ensure we have sane transfer sizes */
+	if (tx_size > raw->desc->max_msg_size)
+		return -ERANGE;
+
+	xfer = scmi_xfer_raw_get(raw->handle);
+	if (IS_ERR(xfer)) {
+		dev_warn(dev, "RAW - Cannot get a free RAW xfer !\n");
+		return PTR_ERR(xfer);
+	}
+
+	/* Build xfer from the provided SCMI bare LE message */
+	msg_hdr = le32_to_cpu(*((__le32 *)buf));
+	unpack_scmi_header(msg_hdr, &xfer->hdr);
+	xfer->hdr.seq = (u16)MSG_XTRACT_TOKEN(msg_hdr);
+	/* Polling not supported */
+	xfer->hdr.poll_completion = false;
+	xfer->hdr.status = SCMI_SUCCESS;
+	xfer->tx.len = tx_size;
+	xfer->rx.len = raw->desc->max_msg_size;
+	/* Clear the whole TX buffer */
+	memset(xfer->tx.buf, 0x00, raw->desc->max_msg_size);
+	if (xfer->tx.len)
+		memcpy(xfer->tx.buf, (u8 *)buf + sizeof(msg_hdr), xfer->tx.len);
+	*p = xfer;
+
+	/*
+	 * In flight registration can temporarily fail in case of Raw messages
+	 * if the user injects messages without using monotonically increasing
+	 * sequence numbers since, in Raw mode, the xfer (and the token) is
+	 * finally released later by a deferred worker. Just retry for a while.
+	 */
+	do {
+		ret = scmi_xfer_raw_inflight_register(raw->handle, xfer);
+		if (ret) {
+			dev_dbg(dev,
+				"...retrying[%d] inflight registration\n",
+				retry);
+			msleep(raw->desc->max_rx_timeout_ms /
+			       SCMI_XFER_RAW_MAX_RETRIES);
+		}
+	} while (ret && --retry);
+
+	if (ret) {
+		dev_warn(dev,
+			 "RAW - Could NOT register xfer %d in-flight HDR:0x%08X\n",
+			 xfer->hdr.seq, msg_hdr);
+		scmi_xfer_raw_put(raw->handle, xfer);
+	}
+
+	return ret;
+}
+
+/**
+ * scmi_do_xfer_raw_start  - An helper to send a valid raw xfer
+ *
+ * @raw: A reference to the Raw instance.
+ * @xfer: The xfer to send
+ * @async: A flag stating if an asynchronous command is required.
+ *
+ * This function send a previously built raw xfer using an appropriate channel
+ * and queues the related waiting work.
+ *
+ * Note that we need to know explicitly if the required command is meant to be
+ * asynchronous in kind since we have to properly setup the waiter.
+ * (and deducing this from the payload is weak and do not scale given there is
+ *  NOT a common header-flag stating if the command is asynchronous or not)
+ *
+ * Return: 0 on Success
+ */
+static int scmi_do_xfer_raw_start(struct scmi_raw_mode_info *raw,
+				  struct scmi_xfer *xfer, bool async)
+{
+	int ret;
+	struct scmi_chan_info *cinfo;
+	struct scmi_xfer_raw_waiter *rw;
+	struct device *dev = raw->handle->dev;
+
+	cinfo = scmi_xfer_raw_channel_get(raw->handle, xfer->hdr.protocol_id);
+	if (IS_ERR(cinfo))
+		return PTR_ERR(cinfo);
+
+	rw = scmi_xfer_raw_waiter_get(raw, xfer, cinfo, async);
+	if (!rw) {
+		dev_warn(dev, "RAW - Cannot get a free waiter !\n");
+		return -ENOMEM;
+	}
+
+	trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id,
+			      xfer->hdr.protocol_id, xfer->hdr.seq,
+			      xfer->hdr.poll_completion);
+
+	reinit_completion(&xfer->done);
+	/* Make sure xfer state update is visible before sending */
+	smp_store_mb(xfer->state, SCMI_XFER_SENT_OK);
+
+	ret = raw->desc->ops->send_message(rw->cinfo, xfer);
+	if (ret) {
+		dev_err(dev, "Failed to send RAW message %d\n", ret);
+		scmi_xfer_raw_waiter_put(raw, rw);
+		return ret;
+	}
+
+	trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id, "CMND",
+			    xfer->hdr.seq, xfer->hdr.status,
+			    xfer->tx.buf, xfer->tx.len);
+
+	scmi_xfer_raw_waiter_enqueue(raw, rw);
+
+	return ret;
+}
+
+/**
+ * scmi_raw_message_send  - An helper to build and send an SCMI command using
+ * the provided SCMI bare message buffer
+ *
+ * @raw: A reference to the Raw instance.
+ * @buf: A buffer containing the whole SCMI message to send (including the
+ *	 header) in little-endian binary format.
+ * @len: Length of the message in @buf.
+ * @async: A flag stating if an asynchronous command is required.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_raw_message_send(struct scmi_raw_mode_info *raw,
+				 void *buf, size_t len, bool async)
+{
+	int ret;
+	struct scmi_xfer *xfer;
+
+	ret = scmi_xfer_raw_get_init(raw, buf, len, &xfer);
+	if (ret)
+		return ret;
+
+	ret = scmi_do_xfer_raw_start(raw, xfer, async);
+	if (ret)
+		scmi_xfer_raw_put(raw->handle, xfer);
+
+	return ret;
+}
+
+static struct scmi_raw_buffer *
+scmi_raw_message_dequeue(struct scmi_raw_mode_info *raw, unsigned int idx)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	while (list_empty(&raw->msg_q[idx])) {
+		spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+		if (wait_event_interruptible(raw->wqs[idx],
+					     !list_empty(&raw->msg_q[idx])))
+			return NULL;
+
+		spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	}
+	spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+	return scmi_raw_buffer_dequeue(raw, idx);
+}
+
+/**
+ * scmi_raw_message_receive  - An helper to dequeue and report the next
+ * available enqueued raw message payload that has been collected.
+ *
+ * @raw: A reference to the Raw instance.
+ * @buf: A buffer to get hold of the whole SCMI message received and represented
+ *	 in little-endian binary format.
+ * @len: Length of @buf.
+ * @size: The effective size of the message copied into @buf
+ * @idx: The index of the queue to pick the next queued message from.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_raw_message_receive(struct scmi_raw_mode_info *raw,
+				    void *buf, size_t len, size_t *size,
+				    unsigned int idx)
+{
+	int ret = 0;
+	struct scmi_raw_buffer *rb;
+
+	rb = scmi_raw_message_dequeue(raw, idx);
+	if (!rb) {
+		dev_dbg(raw->handle->dev, "RAW - No message available!\n");
+		return -ENODEV;
+	}
+
+	if (rb->msg.len <= len) {
+		memcpy(buf, rb->msg.buf, rb->msg.len);
+		*size = rb->msg.len;
+	} else {
+		ret = -ENOSPC;
+	}
+
+	scmi_raw_buffer_put(raw, rb, idx);
+
+	return ret;
+}
+
+/* SCMI Raw debugfs helpers */
+
+static inline ssize_t scmi_dbg_raw_mode_common_read(struct file *filp,
+						    char __user *buf,
+						    size_t count, loff_t *ppos,
+						    unsigned int idx)
+{
+	ssize_t cnt;
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+
+	if (!rd->rx_size) {
+		int ret;
+
+		ret = scmi_raw_message_receive(rd->raw, rd->rx.buf, rd->rx.len,
+					       &rd->rx_size, idx);
+		if (ret) {
+			rd->rx_size = 0;
+			return ret;
+		}
+
+		/* Reset any previous filepos change, including writes */
+		*ppos = 0;
+	} else if (*ppos == rd->rx_size) {
+		/* Return EOF once all the message has been read-out */
+		rd->rx_size = 0;
+		return 0;
+	}
+
+	cnt = simple_read_from_buffer(buf, count, ppos,
+				      rd->rx.buf, rd->rx_size);
+
+	return cnt;
+}
+
+static ssize_t scmi_dbg_raw_mode_common_write(struct file *filp,
+					      const char __user *buf,
+					      size_t count, loff_t *ppos,
+					      bool async)
+{
+	int ret;
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+
+	if (count > rd->tx.len - rd->tx_size)
+		return -ENOSPC;
+
+	/* On first write attempt @count carries the total full message size. */
+	if (!rd->tx_size)
+		rd->tx_req_size = count;
+
+	/*
+	 * Gather a full message, possibly across multiple interrupted wrrtes,
+	 * before sending it with a single RAW xfer.
+	 */
+	if (rd->tx_size < rd->tx_req_size) {
+		size_t cnt;
+
+		cnt = simple_write_to_buffer(rd->tx.buf, rd->tx.len, ppos,
+					     buf, count);
+		rd->tx_size += cnt;
+		if (cnt < count)
+			return cnt;
+	}
+
+	ret = scmi_raw_message_send(rd->raw, rd->tx.buf, rd->tx_size, async);
+
+	/* Reset ppos for next message ... */
+	rd->tx_size = 0;
+
+	return ret ?: count;
+}
+
+static inline __poll_t
+scmi_test_dbg_raw_common_poll(struct file *filp, struct poll_table_struct *wait,
+			      unsigned int idx)
+{
+	unsigned long flags;
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+	__poll_t mask = 0;
+
+	poll_wait(filp, &rd->raw->wqs[idx], wait);
+
+	spin_lock_irqsave(&rd->raw->msg_q_lock[idx], flags);
+	if (!list_empty(&rd->raw->msg_q[idx]))
+		mask = EPOLLIN | EPOLLRDNORM;
+	spin_unlock_irqrestore(&rd->raw->msg_q_lock[idx], flags);
+
+	return mask;
+}
+
+static ssize_t scmi_dbg_raw_mode_message_read(struct file *filp,
+					      char __user *buf,
+					      size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_read(filp, buf, count, ppos,
+					     SCMI_RAW_REPLY_QUEUE);
+}
+
+static ssize_t scmi_dbg_raw_mode_message_write(struct file *filp,
+					       const char __user *buf,
+					       size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, false);
+}
+
+static __poll_t scmi_dbg_raw_mode_message_poll(struct file *filp,
+					       struct poll_table_struct *wait)
+{
+	return scmi_test_dbg_raw_common_poll(filp, wait, SCMI_RAW_REPLY_QUEUE);
+}
+
+static int scmi_dbg_raw_mode_open(struct inode *inode, struct file *filp)
+{
+	struct scmi_raw_mode_info *raw;
+	struct scmi_dbg_raw_data *rd;
+
+	if (!inode->i_private)
+		return -ENODEV;
+
+	raw = inode->i_private;
+	rd = kzalloc(sizeof(*rd), GFP_KERNEL);
+	if (!rd)
+		return -ENOMEM;
+
+	rd->rx.len = raw->desc->max_msg_size + sizeof(u32);
+	rd->rx.buf = kzalloc(rd->rx.len, GFP_KERNEL);
+	if (!rd->rx.buf) {
+		kfree(rd);
+		return -ENOMEM;
+	}
+
+	rd->tx.len = raw->desc->max_msg_size + sizeof(u32);
+	rd->tx.buf = kzalloc(rd->tx.len, GFP_KERNEL);
+	if (!rd->tx.buf) {
+		kfree(rd->rx.buf);
+		kfree(rd);
+		return -ENOMEM;
+	}
+
+	rd->raw = raw;
+	filp->private_data = rd;
+
+	return 0;
+}
+
+static int scmi_dbg_raw_mode_release(struct inode *inode, struct file *filp)
+{
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+
+	kfree(rd->rx.buf);
+	kfree(rd->tx.buf);
+	kfree(rd);
+
+	return 0;
+}
+
+static ssize_t scmi_dbg_raw_mode_reset_write(struct file *filp,
+					     const char __user *buf,
+					     size_t count, loff_t *ppos)
+{
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+
+	scmi_xfer_raw_reset(rd->raw);
+
+	return count;
+}
+
+static const struct file_operations scmi_dbg_raw_mode_reset_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.write = scmi_dbg_raw_mode_reset_write,
+	.owner = THIS_MODULE,
+};
+
+static const struct file_operations scmi_dbg_raw_mode_message_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_dbg_raw_mode_message_read,
+	.write = scmi_dbg_raw_mode_message_write,
+	.poll = scmi_dbg_raw_mode_message_poll,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t scmi_dbg_raw_mode_message_async_write(struct file *filp,
+						     const char __user *buf,
+						     size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, true);
+}
+
+static const struct file_operations scmi_dbg_raw_mode_message_async_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_dbg_raw_mode_message_read,
+	.write = scmi_dbg_raw_mode_message_async_write,
+	.poll = scmi_dbg_raw_mode_message_poll,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t scmi_test_dbg_raw_mode_notif_read(struct file *filp,
+						 char __user *buf,
+						 size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_read(filp, buf, count, ppos,
+					     SCMI_RAW_NOTIF_QUEUE);
+}
+
+static __poll_t scmi_test_dbg_raw_mode_notif_poll(struct file *filp,
+						  struct poll_table_struct *wait)
+{
+	return scmi_test_dbg_raw_common_poll(filp, wait, SCMI_RAW_NOTIF_QUEUE);
+}
+
+static const struct file_operations scmi_dbg_raw_mode_notification_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_test_dbg_raw_mode_notif_read,
+	.poll = scmi_test_dbg_raw_mode_notif_poll,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t scmi_test_dbg_raw_mode_errors_read(struct file *filp,
+						  char __user *buf,
+						  size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_read(filp, buf, count, ppos,
+					     SCMI_RAW_ERRS_QUEUE);
+}
+
+static __poll_t scmi_test_dbg_raw_mode_errors_poll(struct file *filp,
+						   struct poll_table_struct *wait)
+{
+	return scmi_test_dbg_raw_common_poll(filp, wait, SCMI_RAW_ERRS_QUEUE);
+}
+
+static const struct file_operations scmi_dbg_raw_mode_errors_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_test_dbg_raw_mode_errors_read,
+	.poll = scmi_test_dbg_raw_mode_errors_poll,
+	.owner = THIS_MODULE,
+};
+
+static int scmi_xfer_raw_free_bufs_init(struct scmi_raw_mode_info *raw, int idx)
+{
+	int i;
+	struct scmi_raw_buffer *rb;
+	struct device *dev = raw->handle->dev;
+
+	rb = devm_kcalloc(dev, raw->tx_max_msg, sizeof(*rb), GFP_KERNEL);
+	if (!rb)
+		return -ENOMEM;
+
+	spin_lock_init(&raw->free_bufs_lock[idx]);
+	INIT_LIST_HEAD(&raw->free_raw_bufs[idx]);
+	for (i = 0; i < raw->tx_max_msg; i++, rb++) {
+		rb->max_len = raw->desc->max_msg_size + sizeof(u32);
+		rb->msg.buf = devm_kzalloc(dev, rb->max_len, GFP_KERNEL);
+		if (!rb->msg.buf)
+			return -ENOMEM;
+		scmi_raw_buffer_put(raw, rb, idx);
+	}
+
+	spin_lock_init(&raw->msg_q_lock[idx]);
+	INIT_LIST_HEAD(&raw->msg_q[idx]);
+	init_waitqueue_head(&raw->wqs[idx]);
+
+	return 0;
+}
+
+static int scmi_xfer_raw_worker_init(struct scmi_raw_mode_info *raw)
+{
+	int i;
+	struct scmi_xfer_raw_waiter *rw;
+	struct device *dev = raw->handle->dev;
+
+	rw = devm_kcalloc(dev, raw->tx_max_msg, sizeof(*rw), GFP_KERNEL);
+	if (!rw)
+		return -ENOMEM;
+
+	raw->wait_wq = alloc_workqueue("scmi-raw-wait-wq-%d",
+				       WQ_UNBOUND | WQ_FREEZABLE |
+				       WQ_HIGHPRI, WQ_SYSFS, 0);
+	if (!raw->wait_wq)
+		return -ENOMEM;
+
+	mutex_init(&raw->free_mtx);
+	INIT_LIST_HEAD(&raw->free_waiters);
+	mutex_init(&raw->active_mtx);
+	INIT_LIST_HEAD(&raw->active_waiters);
+
+	for (i = 0; i < raw->tx_max_msg; i++, rw++) {
+		init_completion(&rw->async_response);
+		scmi_xfer_raw_waiter_put(raw, rw);
+	}
+	INIT_WORK(&raw->waiters_work, scmi_xfer_raw_worker);
+
+	return 0;
+}
+
+static int scmi_raw_mode_setup(struct scmi_raw_mode_info *raw)
+{
+	int ret, idx;
+	void *gid;
+	struct device *dev = raw->handle->dev;
+
+	gid = devres_open_group(dev, NULL, GFP_KERNEL);
+	if (!gid)
+		return -ENOMEM;
+
+	for (idx = 0; idx < SCMI_RAW_MAX_QUEUE; idx++) {
+		ret = scmi_xfer_raw_free_bufs_init(raw, idx);
+		if (ret)
+			goto err;
+	}
+
+	ret = scmi_xfer_raw_worker_init(raw);
+	if (ret)
+		goto err;
+
+	devres_close_group(dev, gid);
+	raw->gid = gid;
+
+	return 0;
+
+err:
+	devres_release_group(dev, gid);
+	return ret;
+}
+
+/**
+ * scmi_raw_mode_init  - Function to initialize the SCMI Raw stack
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @desc: Reference to the transport operations
+ * @tx_max_msg: Max number of in-flight messages allowed by the transport
+ *
+ * This function prepare the SCMI Raw stack and creates the debugfs API.
+ *
+ * Return: An opaque handle to the Raw instance on Success, an ERR_PTR otherwise
+ */
+void *scmi_raw_mode_init(const struct scmi_handle *handle,
+			 const struct scmi_desc *desc, int tx_max_msg)
+{
+	int ret;
+	struct scmi_raw_mode_info *raw;
+	struct device *dev;
+
+	if (!handle || !desc)
+		return ERR_PTR(-EINVAL);
+
+	dev = handle->dev;
+	raw = devm_kzalloc(dev, sizeof(*raw), GFP_KERNEL);
+	if (!raw)
+		return ERR_PTR(-ENOMEM);
+
+	raw->handle = handle;
+	raw->desc = desc;
+	raw->tx_max_msg = tx_max_msg;
+
+	ret = scmi_raw_mode_setup(raw);
+	if (ret) {
+		devm_kfree(dev, raw);
+		return ERR_PTR(ret);
+	}
+
+	raw->dentry = debugfs_create_dir("scmi_raw", NULL);
+	if (IS_ERR(raw->dentry)) {
+		ret = PTR_ERR(raw->dentry);
+		devres_release_group(dev, raw->gid);
+		devm_kfree(dev, raw);
+		return ERR_PTR(ret);
+	}
+
+	debugfs_create_file("reset", 0200, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_reset_fops);
+
+	debugfs_create_u32("transport_rx_timeout_ms", 0400, raw->dentry,
+			   (u32 *)&raw->desc->max_rx_timeout_ms);
+
+	debugfs_create_u32("transport_max_msg_size", 0400, raw->dentry,
+			   (u32 *)&raw->desc->max_msg_size);
+
+	debugfs_create_u32("transport_tx_max_msg", 0400, raw->dentry,
+			   (u32 *)&raw->tx_max_msg);
+
+	debugfs_create_file("message", 0600, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_message_fops);
+
+	debugfs_create_file("message_async", 0600, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_message_async_fops);
+
+	debugfs_create_file("notification", 0400, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_notification_fops);
+
+	debugfs_create_file("errors", 0400, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_errors_fops);
+
+	return raw;
+}
+
+/**
+ * scmi_raw_mode_cleanup  - Function to cleanup the SCMI Raw stack
+ *
+ * @r: An opaque handle to an initialized SCMI Raw instance
+ */
+void scmi_raw_mode_cleanup(void *r)
+{
+	struct scmi_raw_mode_info *raw = r;
+
+	if (!raw)
+		return;
+
+	debugfs_remove_recursive(raw->dentry);
+
+	cancel_work_sync(&raw->waiters_work);
+	destroy_workqueue(raw->wait_wq);
+}
+
+static int scmi_xfer_raw_collect(struct scmi_xfer *xfer,
+				 void *msg, size_t *msg_len)
+{
+	__le32 *m;
+	size_t msg_size;
+
+	if (!xfer || !msg || !msg_len)
+		return -EINVAL;
+
+	/* Account for hdr ...*/
+	msg_size = xfer->rx.len + sizeof(u32);
+	/* ... and status if needed */
+	if (xfer->hdr.type != MSG_TYPE_NOTIFICATION)
+		msg_size += sizeof(u32);
+
+	if (msg_size > *msg_len)
+		return -ENOSPC;
+
+	m = msg;
+	*m = cpu_to_le32(pack_scmi_header(&xfer->hdr));
+	if (xfer->hdr.type != MSG_TYPE_NOTIFICATION)
+		*++m = cpu_to_le32(xfer->hdr.status);
+
+	memcpy(++m, xfer->rx.buf, xfer->rx.len);
+
+	*msg_len = msg_size;
+
+	return 0;
+}
+
+/**
+ * scmi_raw_message_report  - Helper to report back valid reponses/notifications
+ * to raw message requests.
+ *
+ * @r: An opaque reference to the raw instance configuration
+ * @xfer: The xfer containing the message to be reported
+ * @idx: The index of the queue.
+ *
+ * If Raw mode is enabled, this is called from the SCMI core on the regular RX
+ * path to save and enqueue the response/notification payload carried by this
+ * xfer into a dedicated scmi_raw_buffer for later consumption by the user.
+ *
+ * This way the caller can free the related xfer immediately afterwards and the
+ * user can read back the raw message payload at its own pace (if ever) without
+ * holding an xfer for too long.
+ */
+void scmi_raw_message_report(void *r, struct scmi_xfer *xfer, unsigned int idx)
+{
+	int ret;
+	struct scmi_raw_buffer *rb;
+	struct device *dev;
+	struct scmi_raw_mode_info *raw = r;
+
+	if (!raw)
+		return;
+
+	dev = raw->handle->dev;
+	rb = scmi_raw_buffer_get(raw, idx);
+	if (!rb) {
+		dev_warn(dev, "RAW[%d] - Cannot get a free RAW buffer\n", idx);
+		return;
+	}
+
+	ret = scmi_xfer_raw_collect(xfer, rb->msg.buf, &rb->msg.len);
+	if (ret) {
+		dev_warn(dev, "RAW - Cannot collect xfer into buffer !\n");
+		scmi_raw_buffer_put(raw, rb, idx);
+		return;
+	}
+
+	scmi_raw_buffer_enqueue(raw, rb, idx);
+}
+
+static void scmi_xfer_raw_fill(struct scmi_raw_mode_info *raw,
+			       struct scmi_chan_info *cinfo,
+			       struct scmi_xfer *xfer, u32 msg_hdr)
+{
+	/* Unpack received HDR as it is */
+	unpack_scmi_header(msg_hdr, &xfer->hdr);
+	xfer->hdr.seq = MSG_XTRACT_TOKEN(msg_hdr);
+
+	memset(xfer->rx.buf, 0x00, xfer->rx.len);
+
+	raw->desc->ops->fetch_response(cinfo, xfer);
+}
+
+/**
+ * scmi_raw_error_report  - Helper to report back timed-out or generally
+ * unexpected replies.
+ *
+ * @r: An opaque reference to the raw instance configuration
+ * @cinfo: A reference to the channel to use to retrieve the broken xfer
+ * @msg_hdr: The SCMI message header of the message to fetch and report
+ * @priv: Any private data related to the xfer.
+ *
+ * If Raw mode is enabled, this is called from the SCMI core on the RX path in
+ * case of errors to save and enqueue the bad message payload carried by the
+ * message that has just been received.
+ *
+ * Note that we have to manually fetch any available payload into a temporary
+ * xfer to be able to save and enqueue the message, since the regular RX error
+ * path which had called this would have not fetched the message payload having
+ * classified it as an error.
+ */
+void scmi_raw_error_report(void *r, struct scmi_chan_info *cinfo,
+			   u32 msg_hdr, void *priv)
+{
+	struct scmi_xfer xfer;
+	struct scmi_raw_buffer *rb;
+	struct scmi_raw_mode_info *raw = r;
+
+	if (!raw)
+		return;
+
+	rb = scmi_raw_buffer_get(raw, SCMI_RAW_ERRS_QUEUE);
+	if (!rb) {
+		dev_warn(raw->handle->dev,
+			 "RAW[%d] - Cannot get a free RAW buffer\n",
+			 SCMI_RAW_ERRS_QUEUE);
+		return;
+	}
+
+	/* Use a raw buffer to provide rx space to the temp xfer */
+	xfer.rx.buf = rb->msg.buf;
+	/*
+	 * Allow max_msg_size...note that allocated rx.buf length is
+	 * max_msg_size + sizeof(u32).
+	 */
+	xfer.rx.len = raw->desc->max_msg_size;
+	if (priv)
+		/*
+		 * Any transport-provided priv must be passed back down
+		 * to transport
+		 */
+		smp_store_mb(xfer.priv, priv);
+
+	scmi_xfer_raw_fill(raw, cinfo, &xfer, msg_hdr);
+	scmi_raw_message_report(raw, &xfer, SCMI_RAW_ERRS_QUEUE);
+
+	scmi_raw_buffer_put(raw, rb, SCMI_RAW_ERRS_QUEUE);
+}
diff --git a/drivers/firmware/arm_scmi/raw_mode.h b/drivers/firmware/arm_scmi/raw_mode.h
new file mode 100644
index 000000000000..e2d8672e1f8b
--- /dev/null
+++ b/drivers/firmware/arm_scmi/raw_mode.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol
+ * Raw mode support header.
+ *
+ * Copyright (C) 2022 ARM Ltd.
+ */
+#ifndef _SCMI_RAW_MODE_H
+#define _SCMI_RAW_MODE_H
+
+#include "common.h"
+
+enum {
+	SCMI_RAW_REPLY_QUEUE,
+	SCMI_RAW_NOTIF_QUEUE,
+	SCMI_RAW_ERRS_QUEUE,
+	SCMI_RAW_MAX_QUEUE
+};
+
+void *scmi_raw_mode_init(const struct scmi_handle *handle,
+			 const struct scmi_desc *desc, int tx_max_msg);
+void scmi_raw_mode_cleanup(void *raw);
+
+void scmi_raw_message_report(void *raw, struct scmi_xfer *xfer,
+			     unsigned int idx);
+void scmi_raw_error_report(void *raw, struct scmi_chan_info *cinfo,
+			   u32 msg_hdr, void *priv);
+
+#endif /* _SCMI_RAW_MODE_H */
-- 
2.32.0

[PATCH v3 6/9] firmware: arm_scmi: Add raw transmission support

[Cristian Marussi]

Add SCMI Raw mode support which exposes a userspace interface to allow for
bare SCMI command injection and snooping from userspace.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
v1 --> v2
- make use of proper channel depending on protocol at hand (using
  scmi_xfer_raw_channel_get to lookup related DT config)
- refactored scmi_inflight_register call
- added debugfs docs and comments
v2 --> v3
- changed to dev_dbg when retrying inflight reg
- refactored and simplfiied waiters deferred worker
- fixed sparse errors about LE and __poll_t
---
 drivers/firmware/arm_scmi/Kconfig    |   13 +
 drivers/firmware/arm_scmi/Makefile   |    1 +
 drivers/firmware/arm_scmi/raw_mode.c | 1235 ++++++++++++++++++++++++++
 drivers/firmware/arm_scmi/raw_mode.h |   29 +
 4 files changed, 1278 insertions(+)
 create mode 100644 drivers/firmware/arm_scmi/raw_mode.c
 create mode 100644 drivers/firmware/arm_scmi/raw_mode.h

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index a14f65444b35..ab726a92ac2f 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig
@@ -23,6 +23,19 @@ config ARM_SCMI_PROTOCOL
 
 if ARM_SCMI_PROTOCOL
 
+config ARM_SCMI_RAW_MODE_SUPPORT
+	bool "Enable support for SCMI Raw transmission mode"
+	help
+	  Enable support for SCMI Raw transmission mode.
+
+	  If enabled allows the direct injection and snooping of SCMI bare
+	  messages through a dedicated debugfs interface.
+	  It is meant to be used by SCMI compliance/testing suites.
+
+	  When enabled regular SCMI drivers interactions are inhibited in
+	  order to avoid unexpected interactions with the SCMI Raw message
+	  flow. If unsure say N.
+
 config ARM_SCMI_HAVE_TRANSPORT
 	bool
 	help
diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 9ea86f8cc8f7..7c1aca60c8ce 100644
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 scmi-bus-y = bus.o
 scmi-driver-y = driver.o notify.o
+scmi-driver-$(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) += raw_mode.o
 scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o
 scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += mailbox.o
 scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) += smc.o
diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
new file mode 100644
index 000000000000..3ff333874724
--- /dev/null
+++ b/drivers/firmware/arm_scmi/raw_mode.c
@@ -0,0 +1,1235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Raw mode support
+ *
+ * Copyright (C) 2022 ARM Ltd.
+ */
+/**
+ * DOC: Theory of operation
+ *
+ * When enabled the SCMI Raw mode support exposes a userspace API which allows
+ * to send and receive SCMI commands, replies and notifications from a user
+ * application through injection and snooping of bare SCMI messages in binary
+ * little-endian format.
+ *
+ * Such injected SCMI transactions will then be routed through the SCMI core
+ * stack towards the SCMI backend server using whatever SCMI transport is
+ * currently configured on the system under test.
+ *
+ * It is meant to help in running any sort of SCMI backend server testing, no
+ * matter where the server is placed, as long as it is normally reachable via
+ * the transport configured on the system.
+ *
+ * It is activated by a Kernel configuration option since it is NOT meant to
+ * be used in production but only during development and in CI deployements.
+ *
+ * In order to avoid possible interferences between the SCMI Raw transactions
+ * originated from a test-suite and the normal operations of the SCMI drivers,
+ * when Raw mode is enabled, by default, all the regular SCMI drivers are
+ * inhibited.
+ *
+ * The exposed API is as follows:
+ *
+ *	/sys/kernel/debug/scmi_raw/
+ *	|-- errors
+ *	|-- message
+ *	|-- message_async
+ *	|-- notification
+ *	|-- reset
+ *	|-- transport_max_msg_size
+ *	|-- transport_rx_timeout_ms
+ *	|-- transport_tx_max_msg
+ *
+ * where:
+ *
+ *  - errors: used to read back timed-out and unexpected replies
+ *  - message*: used to send sync/async commands and read back immediate and
+ *		delayed reponses (if any)
+ *  - notification: used to read any notification being emitted by the system
+ *		    (if previously enabled by the user app)
+ *  - reset: used to flush the queues of messages (of any kind) still pending
+ *	     to be read; this is useful at test-suite start/stop to get
+ *	     rid of any unread messages from the previous run.
+ *  - transport*: a bunch of configurations useful to setup the user
+ *		  application expectations in terms of timeouts and message
+ *		  characteristics.
+ *
+ * Each write to the message* entries causes one command request to be built
+ * and sent while the replies or delayed response are read back from those same
+ * entries one message at time (receiving an EOF at each message boundary).
+ *
+ * The user application running the test is in charge of handling timeouts
+ * on replies and properly choosing SCMI sequence numbers for the outgoing
+ * requests (using the same sequence number is supported but discouraged).
+ *
+ * Injection of multiple in-flight requests is supported as long as the user
+ * application uses properly distinct sequence numbers for concurrent requests
+ * and takes care to properly manage all the related issues about concurrency
+ * and command/reply pairing. Keep in mind that, anyway, the real level of
+ * parallelism attainable in such scenario is dependent on the characteristics
+ * of the underlying transport being used.
+ *
+ * Since the SCMI core regular stack is partially used to deliver and collect
+ * the messages, late replies arrived after timeouts and any other sort of
+ * unexpected message can be identified by the SCMI core as usual and they will
+ * be reported as messages under "errors" for later analysis.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/idr.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+
+#include "common.h"
+
+#include "raw_mode.h"
+
+#include <trace/events/scmi.h>
+
+#define SCMI_XFER_RAW_MAX_RETRIES	10
+
+/**
+ * struct scmi_raw_mode_info  - Structure holding SCMI Raw instance data
+ *
+ * @handle: Pointer to SCMI entity handle to use
+ * @desc: Pointer to the transport descriptor to use
+ * @tx_max_msg: Maximum number of concurrent TX in-flight messages
+ * @free_raw_bufs: An array of freelists heads used to keep unused raw buffers
+ * @free_bufs_lock: Spinlocks used to protect access to each @free_raw_bufs
+ * @msg_q: An array of lists to queue snooped messages waiting to be read out
+ * @msg_q_lock: Spinlocks used to protect access to each @msg_q
+ * @wqs: An array of waitqueues used to wait and poll on related @msg_q
+ * @free_waiters: Head of freelist for unused waiters
+ * @free_mtx: A mutex to protect the waiters freelist
+ * @active_waiters: Head of list for currently active and used waiters
+ * @active_mtx: A mutex to protect the active waiters list
+ * @waiters_work: A work descriptor to be used with the workqueue machinery
+ * @wait_wq: A workqueue reference to the created workqueue
+ * @dentry: Top debugfs root dentry for SCMI Raw
+ * @gid: A group ID used for devres accounting
+ *
+ * Note that this descriptor is passed back to the core after SCMI Raw is
+ * initialized as an opaque handle to use by subsequent SCMI Raw call hooks.
+ *
+ */
+struct scmi_raw_mode_info {
+	const struct scmi_handle *handle;
+	const struct scmi_desc *desc;
+	int tx_max_msg;
+	struct list_head free_raw_bufs[SCMI_RAW_MAX_QUEUE];
+	/* Protect free_raw_bufs[] lists */
+	spinlock_t free_bufs_lock[SCMI_RAW_MAX_QUEUE];
+	struct list_head msg_q[SCMI_RAW_MAX_QUEUE];
+	/* Protect msg_q[] lists */
+	spinlock_t msg_q_lock[SCMI_RAW_MAX_QUEUE];
+	wait_queue_head_t wqs[SCMI_RAW_MAX_QUEUE];
+	struct list_head free_waiters;
+	/* Protect free_waiters list */
+	struct mutex free_mtx;
+	struct list_head active_waiters;
+	/* Protect active_waiters list */
+	struct mutex active_mtx;
+	struct work_struct waiters_work;
+	struct workqueue_struct	*wait_wq;
+	struct dentry *dentry;
+	void *gid;
+};
+
+/**
+ * struct scmi_xfer_raw_waiter  - Structure to describe an xfer to be waited for
+ *
+ * @start_jiffies: The timestamp in jiffies of when this structure was queued.
+ * @cinfo: A reference to the channel to use for this transaction
+ * @xfer: A reference to the xfer to be waited for
+ * @async_response: A completion to be, optionally, used for async waits: it
+ *		    will be setup by @scmi_do_xfer_raw_start, if needed, to be
+ *		    pointed at by xfer->async_done.
+ * @node: A list node.
+ */
+struct scmi_xfer_raw_waiter {
+	unsigned long start_jiffies;
+	struct scmi_chan_info *cinfo;
+	struct scmi_xfer *xfer;
+	struct completion async_response;
+	struct list_head node;
+};
+
+/**
+ * struct scmi_raw_buffer  - Structure to hold a full SCMI message
+ *
+ * @max_len: The maximum allowed message size (header included) that can be
+ *	     stored into @msg
+ * @msg: A message buffer used to collect a full message grabbed from an xfer.
+ * @node: A list node.
+ */
+struct scmi_raw_buffer {
+	size_t max_len;
+	struct scmi_msg msg;
+	struct list_head node;
+};
+
+/**
+ * struct scmi_dbg_raw_data  - Structure holding data needed by the debugfs
+ * layer
+ *
+ * @raw: A reference to the Raw instance.
+ * @tx: A message buffer used to collect TX message on write.
+ * @tx_size: The effective size of the TX message.
+ * @tx_req_size: The final expected size of the complete TX message.
+ * @rx: A message buffer to collect RX message on read.
+ * @rx_size: The effective size of the RX message.
+ */
+struct scmi_dbg_raw_data {
+	struct scmi_raw_mode_info *raw;
+	struct scmi_msg tx;
+	size_t tx_size;
+	size_t tx_req_size;
+	struct scmi_msg rx;
+	size_t rx_size;
+};
+
+static inline
+struct scmi_raw_buffer *scmi_raw_buffer_get(struct scmi_raw_mode_info *raw,
+					    unsigned int idx)
+{
+	unsigned long flags;
+	struct scmi_raw_buffer *rb = NULL;
+	struct list_head *head = &raw->free_raw_bufs[idx];
+
+	spin_lock_irqsave(&raw->free_bufs_lock[idx], flags);
+	if (!list_empty(head)) {
+		rb = list_first_entry(head, struct scmi_raw_buffer, node);
+		list_del_init(&rb->node);
+	}
+	spin_unlock_irqrestore(&raw->free_bufs_lock[idx], flags);
+
+	return rb;
+}
+
+static inline void scmi_raw_buffer_put(struct scmi_raw_mode_info *raw,
+				       struct scmi_raw_buffer *rb,
+				       unsigned int idx)
+{
+	unsigned long flags;
+
+	/* Reset to full buffer length */
+	rb->msg.len = rb->max_len;
+
+	spin_lock_irqsave(&raw->free_bufs_lock[idx], flags);
+	list_add_tail(&rb->node, &raw->free_raw_bufs[idx]);
+	spin_unlock_irqrestore(&raw->free_bufs_lock[idx], flags);
+}
+
+static inline void scmi_raw_buffer_enqueue(struct scmi_raw_mode_info *raw,
+					   struct scmi_raw_buffer *rb,
+					   unsigned int idx)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	list_add_tail(&rb->node, &raw->msg_q[idx]);
+	spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+	wake_up_interruptible(&raw->wqs[idx]);
+}
+
+static inline struct scmi_raw_buffer*
+scmi_raw_buffer_dequeue(struct scmi_raw_mode_info *raw, unsigned int idx)
+{
+	unsigned long flags;
+	struct scmi_raw_buffer *rb = NULL;
+
+	spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	if (!list_empty(&raw->msg_q[idx])) {
+		rb = list_first_entry(&raw->msg_q[idx],
+				      struct scmi_raw_buffer, node);
+		list_del_init(&rb->node);
+	}
+	spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+	return rb;
+}
+
+static void scmi_raw_buffer_queue_flush(struct scmi_raw_mode_info *raw,
+					unsigned int idx)
+{
+	struct scmi_raw_buffer *rb;
+
+	do {
+		rb = scmi_raw_buffer_dequeue(raw, idx);
+		if (rb)
+			scmi_raw_buffer_put(raw, rb, idx);
+	} while (rb);
+}
+
+static inline struct scmi_xfer_raw_waiter *
+scmi_xfer_raw_waiter_get(struct scmi_raw_mode_info *raw, struct scmi_xfer *xfer,
+			 struct scmi_chan_info *cinfo, bool async)
+{
+	struct scmi_xfer_raw_waiter *rw = NULL;
+
+	mutex_lock(&raw->free_mtx);
+	if (!list_empty(&raw->free_waiters)) {
+		rw = list_first_entry(&raw->free_waiters,
+				      struct scmi_xfer_raw_waiter, node);
+		list_del_init(&rw->node);
+
+		if (async) {
+			reinit_completion(&rw->async_response);
+			xfer->async_done = &rw->async_response;
+		}
+
+		rw->cinfo = cinfo;
+		rw->xfer = xfer;
+	}
+	mutex_unlock(&raw->free_mtx);
+
+	return rw;
+}
+
+static inline void scmi_xfer_raw_waiter_put(struct scmi_raw_mode_info *raw,
+					    struct scmi_xfer_raw_waiter *rw)
+{
+	if (rw->xfer) {
+		rw->xfer->async_done = NULL;
+		rw->xfer = NULL;
+	}
+
+	mutex_lock(&raw->free_mtx);
+	list_add_tail(&rw->node, &raw->free_waiters);
+	mutex_unlock(&raw->free_mtx);
+}
+
+static inline void scmi_xfer_raw_waiter_enqueue(struct scmi_raw_mode_info *raw,
+						struct scmi_xfer_raw_waiter *rw)
+{
+	/* A timestamp for the deferred worker to know how much this has aged */
+	rw->start_jiffies = jiffies;
+
+	trace_scmi_xfer_response_wait(rw->xfer->transfer_id, rw->xfer->hdr.id,
+				      rw->xfer->hdr.protocol_id,
+				      rw->xfer->hdr.seq,
+				      raw->desc->max_rx_timeout_ms,
+				      rw->xfer->hdr.poll_completion);
+
+	mutex_lock(&raw->active_mtx);
+	list_add_tail(&rw->node, &raw->active_waiters);
+	mutex_unlock(&raw->active_mtx);
+	/* kick waiter work */
+	queue_work(raw->wait_wq, &raw->waiters_work);
+}
+
+static struct scmi_xfer_raw_waiter*
+scmi_xfer_raw_waiter_dequeue(struct scmi_raw_mode_info *raw)
+{
+	struct scmi_xfer_raw_waiter *rw = NULL;
+
+	mutex_lock(&raw->active_mtx);
+	if (!list_empty(&raw->active_waiters)) {
+		rw = list_first_entry(&raw->active_waiters,
+				      struct scmi_xfer_raw_waiter, node);
+		list_del_init(&rw->node);
+	}
+	mutex_unlock(&raw->active_mtx);
+
+	return rw;
+}
+
+/**
+ * scmi_xfer_raw_worker  - Work function to wait for Raw xfers completions
+ *
+ * @work: A reference to the work.
+ *
+ * In SCMI Raw mode, once a user-provided injected SCMI message is sent, we
+ * cannot wait to receive its response (if any) in the context of the injection
+ * routines so as not to leave the userspace write syscall, which delivered the
+ * SCMI message to send, pending till eventually a reply is received.
+ * Userspace should and will poll/wait instead on the read syscalls which will
+ * be in charge of reading a received reply (if any).
+ *
+ * Even though reply messages are collected and reported into the SCMI Raw layer
+ * on the RX path, nonetheless we have to properly wait for their completion as
+ * usual (and async_completion too if needed) in order to properly release the
+ * xfer structure at the end: to do this out of the context of the write/send
+ * these waiting jobs are delegated to this deferred worker.
+ *
+ * Any sent xfer, to be waited for, is timestamped and queued for later
+ * consumption by this worker: queue aging is accounted for while choosing a
+ * timeout for the completion, BUT we do not really care here if we end up
+ * accidentally waiting for a bit too long.
+ */
+static void scmi_xfer_raw_worker(struct work_struct *work)
+{
+	struct scmi_raw_mode_info *raw;
+	struct device *dev;
+	unsigned long max_tmo;
+
+	raw = container_of(work, struct scmi_raw_mode_info, waiters_work);
+	dev = raw->handle->dev;
+	max_tmo = msecs_to_jiffies(raw->desc->max_rx_timeout_ms);
+
+	do {
+		int ret = 0;
+		unsigned long aging, tmo;
+		struct scmi_xfer *xfer;
+		struct scmi_xfer_raw_waiter *rw;
+
+		rw = scmi_xfer_raw_waiter_dequeue(raw);
+		if (!rw)
+			return;
+
+		xfer = rw->xfer;
+
+		/*
+		 * Waiters are queued by wait-deadline at the end, so some of
+		 * them could have been already expired when processed, BUT we
+		 * have to check the completion status anyway just in case a
+		 * virtually expired (aged) transaction was indeed completed
+		 * fine and we'll have to wait for the asynchronous part (if
+		 * any).
+		 */
+		aging = jiffies - rw->start_jiffies;
+		tmo = max_tmo > aging ? max_tmo - aging : 0;
+
+		if ((tmo && !wait_for_completion_timeout(&xfer->done, tmo)) ||
+		    (!tmo && !try_wait_for_completion(&xfer->done))) {
+			dev_err(dev, "timed out in RAW response - HDR:%08X\n",
+				pack_scmi_header(&xfer->hdr));
+			ret = -ETIMEDOUT;
+		}
+
+		/* Avoid unneeded async waits */
+		if (!ret && xfer->hdr.status)
+			ret = scmi_to_linux_errno(xfer->hdr.status);
+
+		if (raw->desc->ops->mark_txdone)
+			raw->desc->ops->mark_txdone(rw->cinfo, ret, xfer);
+
+		trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id,
+				    xfer->hdr.protocol_id, xfer->hdr.seq, ret);
+
+		/* Wait also for an async delayed response if needed */
+		if (!ret && xfer->async_done) {
+			tmo = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT);
+			if (!wait_for_completion_timeout(xfer->async_done, tmo))
+				dev_err(dev,
+					"timed out in RAW delayed resp - HDR:%08X\n",
+					pack_scmi_header(&xfer->hdr));
+		}
+
+		/* Release waiter and xfer */
+		scmi_xfer_raw_put(raw->handle, xfer);
+		scmi_xfer_raw_waiter_put(raw, rw);
+	} while (1);
+}
+
+static void scmi_xfer_raw_reset(struct scmi_raw_mode_info *raw)
+{
+	int i;
+
+	dev_info(raw->handle->dev, "Resetting SCMI Raw stack.\n");
+
+	for (i = 0; i < SCMI_RAW_MAX_QUEUE; i++)
+		scmi_raw_buffer_queue_flush(raw, i);
+}
+
+/**
+ * scmi_xfer_raw_get_init  - An helper to build a valid xfer from the provided
+ * bare SCMI message.
+ *
+ * @raw: A reference to the Raw instance.
+ * @buf: A buffer containing the whole SCMI message to send (including the
+ *	 header) in little-endian binary formmat.
+ * @len: Length of the message in @buf.
+ * @p: A pointer to return the initialized Raw xfer.
+ *
+ * After an xfer is picked from the TX pool and filled in with the message
+ * content, the xfer is registered as pending with the core in the usual way
+ * using the original sequence number provided by the user with the message.
+ *
+ * Note that, in case the testing user application is NOT using distinct
+ * sequence-numbers between successive SCMI messages such registration could
+ * fail temporarily if the previous message, using the same sequence number,
+ * had still not released; in such a case we just wait and retry.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_xfer_raw_get_init(struct scmi_raw_mode_info *raw, void *buf,
+				  size_t len, struct scmi_xfer **p)
+{
+	u32 msg_hdr;
+	size_t tx_size;
+	struct scmi_xfer *xfer;
+	int ret, retry = SCMI_XFER_RAW_MAX_RETRIES;
+	struct device *dev = raw->handle->dev;
+
+	if (!buf || len < sizeof(u32))
+		return -EINVAL;
+
+	tx_size = len - sizeof(u32);
+	/* Ensure we have sane transfer sizes */
+	if (tx_size > raw->desc->max_msg_size)
+		return -ERANGE;
+
+	xfer = scmi_xfer_raw_get(raw->handle);
+	if (IS_ERR(xfer)) {
+		dev_warn(dev, "RAW - Cannot get a free RAW xfer !\n");
+		return PTR_ERR(xfer);
+	}
+
+	/* Build xfer from the provided SCMI bare LE message */
+	msg_hdr = le32_to_cpu(*((__le32 *)buf));
+	unpack_scmi_header(msg_hdr, &xfer->hdr);
+	xfer->hdr.seq = (u16)MSG_XTRACT_TOKEN(msg_hdr);
+	/* Polling not supported */
+	xfer->hdr.poll_completion = false;
+	xfer->hdr.status = SCMI_SUCCESS;
+	xfer->tx.len = tx_size;
+	xfer->rx.len = raw->desc->max_msg_size;
+	/* Clear the whole TX buffer */
+	memset(xfer->tx.buf, 0x00, raw->desc->max_msg_size);
+	if (xfer->tx.len)
+		memcpy(xfer->tx.buf, (u8 *)buf + sizeof(msg_hdr), xfer->tx.len);
+	*p = xfer;
+
+	/*
+	 * In flight registration can temporarily fail in case of Raw messages
+	 * if the user injects messages without using monotonically increasing
+	 * sequence numbers since, in Raw mode, the xfer (and the token) is
+	 * finally released later by a deferred worker. Just retry for a while.
+	 */
+	do {
+		ret = scmi_xfer_raw_inflight_register(raw->handle, xfer);
+		if (ret) {
+			dev_dbg(dev,
+				"...retrying[%d] inflight registration\n",
+				retry);
+			msleep(raw->desc->max_rx_timeout_ms /
+			       SCMI_XFER_RAW_MAX_RETRIES);
+		}
+	} while (ret && --retry);
+
+	if (ret) {
+		dev_warn(dev,
+			 "RAW - Could NOT register xfer %d in-flight HDR:0x%08X\n",
+			 xfer->hdr.seq, msg_hdr);
+		scmi_xfer_raw_put(raw->handle, xfer);
+	}
+
+	return ret;
+}
+
+/**
+ * scmi_do_xfer_raw_start  - An helper to send a valid raw xfer
+ *
+ * @raw: A reference to the Raw instance.
+ * @xfer: The xfer to send
+ * @async: A flag stating if an asynchronous command is required.
+ *
+ * This function send a previously built raw xfer using an appropriate channel
+ * and queues the related waiting work.
+ *
+ * Note that we need to know explicitly if the required command is meant to be
+ * asynchronous in kind since we have to properly setup the waiter.
+ * (and deducing this from the payload is weak and do not scale given there is
+ *  NOT a common header-flag stating if the command is asynchronous or not)
+ *
+ * Return: 0 on Success
+ */
+static int scmi_do_xfer_raw_start(struct scmi_raw_mode_info *raw,
+				  struct scmi_xfer *xfer, bool async)
+{
+	int ret;
+	struct scmi_chan_info *cinfo;
+	struct scmi_xfer_raw_waiter *rw;
+	struct device *dev = raw->handle->dev;
+
+	cinfo = scmi_xfer_raw_channel_get(raw->handle, xfer->hdr.protocol_id);
+	if (IS_ERR(cinfo))
+		return PTR_ERR(cinfo);
+
+	rw = scmi_xfer_raw_waiter_get(raw, xfer, cinfo, async);
+	if (!rw) {
+		dev_warn(dev, "RAW - Cannot get a free waiter !\n");
+		return -ENOMEM;
+	}
+
+	trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id,
+			      xfer->hdr.protocol_id, xfer->hdr.seq,
+			      xfer->hdr.poll_completion);
+
+	reinit_completion(&xfer->done);
+	/* Make sure xfer state update is visible before sending */
+	smp_store_mb(xfer->state, SCMI_XFER_SENT_OK);
+
+	ret = raw->desc->ops->send_message(rw->cinfo, xfer);
+	if (ret) {
+		dev_err(dev, "Failed to send RAW message %d\n", ret);
+		scmi_xfer_raw_waiter_put(raw, rw);
+		return ret;
+	}
+
+	trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id, "CMND",
+			    xfer->hdr.seq, xfer->hdr.status,
+			    xfer->tx.buf, xfer->tx.len);
+
+	scmi_xfer_raw_waiter_enqueue(raw, rw);
+
+	return ret;
+}
+
+/**
+ * scmi_raw_message_send  - An helper to build and send an SCMI command using
+ * the provided SCMI bare message buffer
+ *
+ * @raw: A reference to the Raw instance.
+ * @buf: A buffer containing the whole SCMI message to send (including the
+ *	 header) in little-endian binary format.
+ * @len: Length of the message in @buf.
+ * @async: A flag stating if an asynchronous command is required.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_raw_message_send(struct scmi_raw_mode_info *raw,
+				 void *buf, size_t len, bool async)
+{
+	int ret;
+	struct scmi_xfer *xfer;
+
+	ret = scmi_xfer_raw_get_init(raw, buf, len, &xfer);
+	if (ret)
+		return ret;
+
+	ret = scmi_do_xfer_raw_start(raw, xfer, async);
+	if (ret)
+		scmi_xfer_raw_put(raw->handle, xfer);
+
+	return ret;
+}
+
+static struct scmi_raw_buffer *
+scmi_raw_message_dequeue(struct scmi_raw_mode_info *raw, unsigned int idx)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	while (list_empty(&raw->msg_q[idx])) {
+		spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+		if (wait_event_interruptible(raw->wqs[idx],
+					     !list_empty(&raw->msg_q[idx])))
+			return NULL;
+
+		spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	}
+	spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+	return scmi_raw_buffer_dequeue(raw, idx);
+}
+
+/**
+ * scmi_raw_message_receive  - An helper to dequeue and report the next
+ * available enqueued raw message payload that has been collected.
+ *
+ * @raw: A reference to the Raw instance.
+ * @buf: A buffer to get hold of the whole SCMI message received and represented
+ *	 in little-endian binary format.
+ * @len: Length of @buf.
+ * @size: The effective size of the message copied into @buf
+ * @idx: The index of the queue to pick the next queued message from.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_raw_message_receive(struct scmi_raw_mode_info *raw,
+				    void *buf, size_t len, size_t *size,
+				    unsigned int idx)
+{
+	int ret = 0;
+	struct scmi_raw_buffer *rb;
+
+	rb = scmi_raw_message_dequeue(raw, idx);
+	if (!rb) {
+		dev_dbg(raw->handle->dev, "RAW - No message available!\n");
+		return -ENODEV;
+	}
+
+	if (rb->msg.len <= len) {
+		memcpy(buf, rb->msg.buf, rb->msg.len);
+		*size = rb->msg.len;
+	} else {
+		ret = -ENOSPC;
+	}
+
+	scmi_raw_buffer_put(raw, rb, idx);
+
+	return ret;
+}
+
+/* SCMI Raw debugfs helpers */
+
+static inline ssize_t scmi_dbg_raw_mode_common_read(struct file *filp,
+						    char __user *buf,
+						    size_t count, loff_t *ppos,
+						    unsigned int idx)
+{
+	ssize_t cnt;
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+
+	if (!rd->rx_size) {
+		int ret;
+
+		ret = scmi_raw_message_receive(rd->raw, rd->rx.buf, rd->rx.len,
+					       &rd->rx_size, idx);
+		if (ret) {
+			rd->rx_size = 0;
+			return ret;
+		}
+
+		/* Reset any previous filepos change, including writes */
+		*ppos = 0;
+	} else if (*ppos == rd->rx_size) {
+		/* Return EOF once all the message has been read-out */
+		rd->rx_size = 0;
+		return 0;
+	}
+
+	cnt = simple_read_from_buffer(buf, count, ppos,
+				      rd->rx.buf, rd->rx_size);
+
+	return cnt;
+}
+
+static ssize_t scmi_dbg_raw_mode_common_write(struct file *filp,
+					      const char __user *buf,
+					      size_t count, loff_t *ppos,
+					      bool async)
+{
+	int ret;
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+
+	if (count > rd->tx.len - rd->tx_size)
+		return -ENOSPC;
+
+	/* On first write attempt @count carries the total full message size. */
+	if (!rd->tx_size)
+		rd->tx_req_size = count;
+
+	/*
+	 * Gather a full message, possibly across multiple interrupted wrrtes,
+	 * before sending it with a single RAW xfer.
+	 */
+	if (rd->tx_size < rd->tx_req_size) {
+		size_t cnt;
+
+		cnt = simple_write_to_buffer(rd->tx.buf, rd->tx.len, ppos,
+					     buf, count);
+		rd->tx_size += cnt;
+		if (cnt < count)
+			return cnt;
+	}
+
+	ret = scmi_raw_message_send(rd->raw, rd->tx.buf, rd->tx_size, async);
+
+	/* Reset ppos for next message ... */
+	rd->tx_size = 0;
+
+	return ret ?: count;
+}
+
+static inline __poll_t
+scmi_test_dbg_raw_common_poll(struct file *filp, struct poll_table_struct *wait,
+			      unsigned int idx)
+{
+	unsigned long flags;
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+	__poll_t mask = 0;
+
+	poll_wait(filp, &rd->raw->wqs[idx], wait);
+
+	spin_lock_irqsave(&rd->raw->msg_q_lock[idx], flags);
+	if (!list_empty(&rd->raw->msg_q[idx]))
+		mask = EPOLLIN | EPOLLRDNORM;
+	spin_unlock_irqrestore(&rd->raw->msg_q_lock[idx], flags);
+
+	return mask;
+}
+
+static ssize_t scmi_dbg_raw_mode_message_read(struct file *filp,
+					      char __user *buf,
+					      size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_read(filp, buf, count, ppos,
+					     SCMI_RAW_REPLY_QUEUE);
+}
+
+static ssize_t scmi_dbg_raw_mode_message_write(struct file *filp,
+					       const char __user *buf,
+					       size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, false);
+}
+
+static __poll_t scmi_dbg_raw_mode_message_poll(struct file *filp,
+					       struct poll_table_struct *wait)
+{
+	return scmi_test_dbg_raw_common_poll(filp, wait, SCMI_RAW_REPLY_QUEUE);
+}
+
+static int scmi_dbg_raw_mode_open(struct inode *inode, struct file *filp)
+{
+	struct scmi_raw_mode_info *raw;
+	struct scmi_dbg_raw_data *rd;
+
+	if (!inode->i_private)
+		return -ENODEV;
+
+	raw = inode->i_private;
+	rd = kzalloc(sizeof(*rd), GFP_KERNEL);
+	if (!rd)
+		return -ENOMEM;
+
+	rd->rx.len = raw->desc->max_msg_size + sizeof(u32);
+	rd->rx.buf = kzalloc(rd->rx.len, GFP_KERNEL);
+	if (!rd->rx.buf) {
+		kfree(rd);
+		return -ENOMEM;
+	}
+
+	rd->tx.len = raw->desc->max_msg_size + sizeof(u32);
+	rd->tx.buf = kzalloc(rd->tx.len, GFP_KERNEL);
+	if (!rd->tx.buf) {
+		kfree(rd->rx.buf);
+		kfree(rd);
+		return -ENOMEM;
+	}
+
+	rd->raw = raw;
+	filp->private_data = rd;
+
+	return 0;
+}
+
+static int scmi_dbg_raw_mode_release(struct inode *inode, struct file *filp)
+{
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+
+	kfree(rd->rx.buf);
+	kfree(rd->tx.buf);
+	kfree(rd);
+
+	return 0;
+}
+
+static ssize_t scmi_dbg_raw_mode_reset_write(struct file *filp,
+					     const char __user *buf,
+					     size_t count, loff_t *ppos)
+{
+	struct scmi_dbg_raw_data *rd = filp->private_data;
+
+	scmi_xfer_raw_reset(rd->raw);
+
+	return count;
+}
+
+static const struct file_operations scmi_dbg_raw_mode_reset_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.write = scmi_dbg_raw_mode_reset_write,
+	.owner = THIS_MODULE,
+};
+
+static const struct file_operations scmi_dbg_raw_mode_message_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_dbg_raw_mode_message_read,
+	.write = scmi_dbg_raw_mode_message_write,
+	.poll = scmi_dbg_raw_mode_message_poll,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t scmi_dbg_raw_mode_message_async_write(struct file *filp,
+						     const char __user *buf,
+						     size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_write(filp, buf, count, ppos, true);
+}
+
+static const struct file_operations scmi_dbg_raw_mode_message_async_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_dbg_raw_mode_message_read,
+	.write = scmi_dbg_raw_mode_message_async_write,
+	.poll = scmi_dbg_raw_mode_message_poll,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t scmi_test_dbg_raw_mode_notif_read(struct file *filp,
+						 char __user *buf,
+						 size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_read(filp, buf, count, ppos,
+					     SCMI_RAW_NOTIF_QUEUE);
+}
+
+static __poll_t scmi_test_dbg_raw_mode_notif_poll(struct file *filp,
+						  struct poll_table_struct *wait)
+{
+	return scmi_test_dbg_raw_common_poll(filp, wait, SCMI_RAW_NOTIF_QUEUE);
+}
+
+static const struct file_operations scmi_dbg_raw_mode_notification_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_test_dbg_raw_mode_notif_read,
+	.poll = scmi_test_dbg_raw_mode_notif_poll,
+	.owner = THIS_MODULE,
+};
+
+static ssize_t scmi_test_dbg_raw_mode_errors_read(struct file *filp,
+						  char __user *buf,
+						  size_t count, loff_t *ppos)
+{
+	return scmi_dbg_raw_mode_common_read(filp, buf, count, ppos,
+					     SCMI_RAW_ERRS_QUEUE);
+}
+
+static __poll_t scmi_test_dbg_raw_mode_errors_poll(struct file *filp,
+						   struct poll_table_struct *wait)
+{
+	return scmi_test_dbg_raw_common_poll(filp, wait, SCMI_RAW_ERRS_QUEUE);
+}
+
+static const struct file_operations scmi_dbg_raw_mode_errors_fops = {
+	.open = scmi_dbg_raw_mode_open,
+	.release = scmi_dbg_raw_mode_release,
+	.read = scmi_test_dbg_raw_mode_errors_read,
+	.poll = scmi_test_dbg_raw_mode_errors_poll,
+	.owner = THIS_MODULE,
+};
+
+static int scmi_xfer_raw_free_bufs_init(struct scmi_raw_mode_info *raw, int idx)
+{
+	int i;
+	struct scmi_raw_buffer *rb;
+	struct device *dev = raw->handle->dev;
+
+	rb = devm_kcalloc(dev, raw->tx_max_msg, sizeof(*rb), GFP_KERNEL);
+	if (!rb)
+		return -ENOMEM;
+
+	spin_lock_init(&raw->free_bufs_lock[idx]);
+	INIT_LIST_HEAD(&raw->free_raw_bufs[idx]);
+	for (i = 0; i < raw->tx_max_msg; i++, rb++) {
+		rb->max_len = raw->desc->max_msg_size + sizeof(u32);
+		rb->msg.buf = devm_kzalloc(dev, rb->max_len, GFP_KERNEL);
+		if (!rb->msg.buf)
+			return -ENOMEM;
+		scmi_raw_buffer_put(raw, rb, idx);
+	}
+
+	spin_lock_init(&raw->msg_q_lock[idx]);
+	INIT_LIST_HEAD(&raw->msg_q[idx]);
+	init_waitqueue_head(&raw->wqs[idx]);
+
+	return 0;
+}
+
+static int scmi_xfer_raw_worker_init(struct scmi_raw_mode_info *raw)
+{
+	int i;
+	struct scmi_xfer_raw_waiter *rw;
+	struct device *dev = raw->handle->dev;
+
+	rw = devm_kcalloc(dev, raw->tx_max_msg, sizeof(*rw), GFP_KERNEL);
+	if (!rw)
+		return -ENOMEM;
+
+	raw->wait_wq = alloc_workqueue("scmi-raw-wait-wq-%d",
+				       WQ_UNBOUND | WQ_FREEZABLE |
+				       WQ_HIGHPRI, WQ_SYSFS, 0);
+	if (!raw->wait_wq)
+		return -ENOMEM;
+
+	mutex_init(&raw->free_mtx);
+	INIT_LIST_HEAD(&raw->free_waiters);
+	mutex_init(&raw->active_mtx);
+	INIT_LIST_HEAD(&raw->active_waiters);
+
+	for (i = 0; i < raw->tx_max_msg; i++, rw++) {
+		init_completion(&rw->async_response);
+		scmi_xfer_raw_waiter_put(raw, rw);
+	}
+	INIT_WORK(&raw->waiters_work, scmi_xfer_raw_worker);
+
+	return 0;
+}
+
+static int scmi_raw_mode_setup(struct scmi_raw_mode_info *raw)
+{
+	int ret, idx;
+	void *gid;
+	struct device *dev = raw->handle->dev;
+
+	gid = devres_open_group(dev, NULL, GFP_KERNEL);
+	if (!gid)
+		return -ENOMEM;
+
+	for (idx = 0; idx < SCMI_RAW_MAX_QUEUE; idx++) {
+		ret = scmi_xfer_raw_free_bufs_init(raw, idx);
+		if (ret)
+			goto err;
+	}
+
+	ret = scmi_xfer_raw_worker_init(raw);
+	if (ret)
+		goto err;
+
+	devres_close_group(dev, gid);
+	raw->gid = gid;
+
+	return 0;
+
+err:
+	devres_release_group(dev, gid);
+	return ret;
+}
+
+/**
+ * scmi_raw_mode_init  - Function to initialize the SCMI Raw stack
+ *
+ * @handle: Pointer to SCMI entity handle
+ * @desc: Reference to the transport operations
+ * @tx_max_msg: Max number of in-flight messages allowed by the transport
+ *
+ * This function prepare the SCMI Raw stack and creates the debugfs API.
+ *
+ * Return: An opaque handle to the Raw instance on Success, an ERR_PTR otherwise
+ */
+void *scmi_raw_mode_init(const struct scmi_handle *handle,
+			 const struct scmi_desc *desc, int tx_max_msg)
+{
+	int ret;
+	struct scmi_raw_mode_info *raw;
+	struct device *dev;
+
+	if (!handle || !desc)
+		return ERR_PTR(-EINVAL);
+
+	dev = handle->dev;
+	raw = devm_kzalloc(dev, sizeof(*raw), GFP_KERNEL);
+	if (!raw)
+		return ERR_PTR(-ENOMEM);
+
+	raw->handle = handle;
+	raw->desc = desc;
+	raw->tx_max_msg = tx_max_msg;
+
+	ret = scmi_raw_mode_setup(raw);
+	if (ret) {
+		devm_kfree(dev, raw);
+		return ERR_PTR(ret);
+	}
+
+	raw->dentry = debugfs_create_dir("scmi_raw", NULL);
+	if (IS_ERR(raw->dentry)) {
+		ret = PTR_ERR(raw->dentry);
+		devres_release_group(dev, raw->gid);
+		devm_kfree(dev, raw);
+		return ERR_PTR(ret);
+	}
+
+	debugfs_create_file("reset", 0200, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_reset_fops);
+
+	debugfs_create_u32("transport_rx_timeout_ms", 0400, raw->dentry,
+			   (u32 *)&raw->desc->max_rx_timeout_ms);
+
+	debugfs_create_u32("transport_max_msg_size", 0400, raw->dentry,
+			   (u32 *)&raw->desc->max_msg_size);
+
+	debugfs_create_u32("transport_tx_max_msg", 0400, raw->dentry,
+			   (u32 *)&raw->tx_max_msg);
+
+	debugfs_create_file("message", 0600, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_message_fops);
+
+	debugfs_create_file("message_async", 0600, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_message_async_fops);
+
+	debugfs_create_file("notification", 0400, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_notification_fops);
+
+	debugfs_create_file("errors", 0400, raw->dentry, raw,
+			    &scmi_dbg_raw_mode_errors_fops);
+
+	return raw;
+}
+
+/**
+ * scmi_raw_mode_cleanup  - Function to cleanup the SCMI Raw stack
+ *
+ * @r: An opaque handle to an initialized SCMI Raw instance
+ */
+void scmi_raw_mode_cleanup(void *r)
+{
+	struct scmi_raw_mode_info *raw = r;
+
+	if (!raw)
+		return;
+
+	debugfs_remove_recursive(raw->dentry);
+
+	cancel_work_sync(&raw->waiters_work);
+	destroy_workqueue(raw->wait_wq);
+}
+
+static int scmi_xfer_raw_collect(struct scmi_xfer *xfer,
+				 void *msg, size_t *msg_len)
+{
+	__le32 *m;
+	size_t msg_size;
+
+	if (!xfer || !msg || !msg_len)
+		return -EINVAL;
+
+	/* Account for hdr ...*/
+	msg_size = xfer->rx.len + sizeof(u32);
+	/* ... and status if needed */
+	if (xfer->hdr.type != MSG_TYPE_NOTIFICATION)
+		msg_size += sizeof(u32);
+
+	if (msg_size > *msg_len)
+		return -ENOSPC;
+
+	m = msg;
+	*m = cpu_to_le32(pack_scmi_header(&xfer->hdr));
+	if (xfer->hdr.type != MSG_TYPE_NOTIFICATION)
+		*++m = cpu_to_le32(xfer->hdr.status);
+
+	memcpy(++m, xfer->rx.buf, xfer->rx.len);
+
+	*msg_len = msg_size;
+
+	return 0;
+}
+
+/**
+ * scmi_raw_message_report  - Helper to report back valid reponses/notifications
+ * to raw message requests.
+ *
+ * @r: An opaque reference to the raw instance configuration
+ * @xfer: The xfer containing the message to be reported
+ * @idx: The index of the queue.
+ *
+ * If Raw mode is enabled, this is called from the SCMI core on the regular RX
+ * path to save and enqueue the response/notification payload carried by this
+ * xfer into a dedicated scmi_raw_buffer for later consumption by the user.
+ *
+ * This way the caller can free the related xfer immediately afterwards and the
+ * user can read back the raw message payload at its own pace (if ever) without
+ * holding an xfer for too long.
+ */
+void scmi_raw_message_report(void *r, struct scmi_xfer *xfer, unsigned int idx)
+{
+	int ret;
+	struct scmi_raw_buffer *rb;
+	struct device *dev;
+	struct scmi_raw_mode_info *raw = r;
+
+	if (!raw)
+		return;
+
+	dev = raw->handle->dev;
+	rb = scmi_raw_buffer_get(raw, idx);
+	if (!rb) {
+		dev_warn(dev, "RAW[%d] - Cannot get a free RAW buffer\n", idx);
+		return;
+	}
+
+	ret = scmi_xfer_raw_collect(xfer, rb->msg.buf, &rb->msg.len);
+	if (ret) {
+		dev_warn(dev, "RAW - Cannot collect xfer into buffer !\n");
+		scmi_raw_buffer_put(raw, rb, idx);
+		return;
+	}
+
+	scmi_raw_buffer_enqueue(raw, rb, idx);
+}
+
+static void scmi_xfer_raw_fill(struct scmi_raw_mode_info *raw,
+			       struct scmi_chan_info *cinfo,
+			       struct scmi_xfer *xfer, u32 msg_hdr)
+{
+	/* Unpack received HDR as it is */
+	unpack_scmi_header(msg_hdr, &xfer->hdr);
+	xfer->hdr.seq = MSG_XTRACT_TOKEN(msg_hdr);
+
+	memset(xfer->rx.buf, 0x00, xfer->rx.len);
+
+	raw->desc->ops->fetch_response(cinfo, xfer);
+}
+
+/**
+ * scmi_raw_error_report  - Helper to report back timed-out or generally
+ * unexpected replies.
+ *
+ * @r: An opaque reference to the raw instance configuration
+ * @cinfo: A reference to the channel to use to retrieve the broken xfer
+ * @msg_hdr: The SCMI message header of the message to fetch and report
+ * @priv: Any private data related to the xfer.
+ *
+ * If Raw mode is enabled, this is called from the SCMI core on the RX path in
+ * case of errors to save and enqueue the bad message payload carried by the
+ * message that has just been received.
+ *
+ * Note that we have to manually fetch any available payload into a temporary
+ * xfer to be able to save and enqueue the message, since the regular RX error
+ * path which had called this would have not fetched the message payload having
+ * classified it as an error.
+ */
+void scmi_raw_error_report(void *r, struct scmi_chan_info *cinfo,
+			   u32 msg_hdr, void *priv)
+{
+	struct scmi_xfer xfer;
+	struct scmi_raw_buffer *rb;
+	struct scmi_raw_mode_info *raw = r;
+
+	if (!raw)
+		return;
+
+	rb = scmi_raw_buffer_get(raw, SCMI_RAW_ERRS_QUEUE);
+	if (!rb) {
+		dev_warn(raw->handle->dev,
+			 "RAW[%d] - Cannot get a free RAW buffer\n",
+			 SCMI_RAW_ERRS_QUEUE);
+		return;
+	}
+
+	/* Use a raw buffer to provide rx space to the temp xfer */
+	xfer.rx.buf = rb->msg.buf;
+	/*
+	 * Allow max_msg_size...note that allocated rx.buf length is
+	 * max_msg_size + sizeof(u32).
+	 */
+	xfer.rx.len = raw->desc->max_msg_size;
+	if (priv)
+		/*
+		 * Any transport-provided priv must be passed back down
+		 * to transport
+		 */
+		smp_store_mb(xfer.priv, priv);
+
+	scmi_xfer_raw_fill(raw, cinfo, &xfer, msg_hdr);
+	scmi_raw_message_report(raw, &xfer, SCMI_RAW_ERRS_QUEUE);
+
+	scmi_raw_buffer_put(raw, rb, SCMI_RAW_ERRS_QUEUE);
+}
diff --git a/drivers/firmware/arm_scmi/raw_mode.h b/drivers/firmware/arm_scmi/raw_mode.h
new file mode 100644
index 000000000000..e2d8672e1f8b
--- /dev/null
+++ b/drivers/firmware/arm_scmi/raw_mode.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol
+ * Raw mode support header.
+ *
+ * Copyright (C) 2022 ARM Ltd.
+ */
+#ifndef _SCMI_RAW_MODE_H
+#define _SCMI_RAW_MODE_H
+
+#include "common.h"
+
+enum {
+	SCMI_RAW_REPLY_QUEUE,
+	SCMI_RAW_NOTIF_QUEUE,
+	SCMI_RAW_ERRS_QUEUE,
+	SCMI_RAW_MAX_QUEUE
+};
+
+void *scmi_raw_mode_init(const struct scmi_handle *handle,
+			 const struct scmi_desc *desc, int tx_max_msg);
+void scmi_raw_mode_cleanup(void *raw);
+
+void scmi_raw_message_report(void *raw, struct scmi_xfer *xfer,
+			     unsigned int idx);
+void scmi_raw_error_report(void *raw, struct scmi_chan_info *cinfo,
+			   u32 msg_hdr, void *priv);
+
+#endif /* _SCMI_RAW_MODE_H */
-- 
2.32.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v3 7/9] firmware: arm_scmi: Add debugfs ABI documentation for Raw mode

[Cristian Marussi]

Add description of the debugfs SCMI Raw ABI.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 Documentation/ABI/testing/debugfs-scmi-raw | 88 ++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 Documentation/ABI/testing/debugfs-scmi-raw

diff --git a/Documentation/ABI/testing/debugfs-scmi-raw b/Documentation/ABI/testing/debugfs-scmi-raw
new file mode 100644
index 000000000000..183ec678cb3e
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-scmi-raw
@@ -0,0 +1,88 @@
+What:		/sys/kernel/debug/scmi_raw/transport_max_msg_size
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	Max message size of allowed SCMI messages for the currently
+		configured SCMI transport.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/transport_tx_max_msg
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	Max number of concurrently allowed in-flight SCMI messages for
+		the currently configured SCMI transport.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/transport_rx_timeout_ms
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	Timeout in milliseconds allowed for SCMI synchronous replies
+		for the currently configured SCMI transport.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/message
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw synchronous message injection/snooping facility; write
+		a complete SCMI synchronous command message (header included)
+		in little-endian binary format to have it sent to the configured
+		backend SCMI server.
+		Any subsequently received response can be read from this same
+		entry if it arrived within the configured timeout.
+		Each write to the entry causes one command request to be built
+		and sent while the replies are read back one message at time
+		(receiving an EOF at each message boundary).
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/message_async
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw asynchronous message injection/snooping facility; write
+		a complete SCMI asynchronous command message (header included)
+		in little-endian binary format to have it sent to the configured
+		backend SCMI server.
+		Any subsequently received response can be read from this same
+		entry if it arrived within the configured timeout.
+		Any additional delayed response received afterwards can be read
+		from this same entry too if it arrived within the configured
+		timeout.
+		Each write to the entry causes one command request to be built
+		and sent while the replies are read back one message at time
+		(receiving an EOF at each message boundary).
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/errors
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw message errors facility; any kind of timed-out or
+		generally unexpectedly received SCMI message can be read from
+		this entry.
+		Each read gives back one message at time (receiving an EOF at
+		each message boundary).
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/notification
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw notification snooping facility; any notification
+		emitted by the backend SCMI server can be read from this entry.
+		Each read gives back one message at time (receiving an EOF at
+		each message boundary).
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/reset
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw stack reset facility; writing a value to this entry
+		causes the internal queues of any kind of received message,
+		still pending to be read out, to be flushed.
+		Can be used to reset and clean the SCMI Raw stack between to
+		different test-run.
+Users:		Debugging, any userspace test suite
-- 
2.32.0

[PATCH v3 7/9] firmware: arm_scmi: Add debugfs ABI documentation for Raw mode

[Cristian Marussi]

Add description of the debugfs SCMI Raw ABI.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 Documentation/ABI/testing/debugfs-scmi-raw | 88 ++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 Documentation/ABI/testing/debugfs-scmi-raw

diff --git a/Documentation/ABI/testing/debugfs-scmi-raw b/Documentation/ABI/testing/debugfs-scmi-raw
new file mode 100644
index 000000000000..183ec678cb3e
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-scmi-raw
@@ -0,0 +1,88 @@
+What:		/sys/kernel/debug/scmi_raw/transport_max_msg_size
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	Max message size of allowed SCMI messages for the currently
+		configured SCMI transport.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/transport_tx_max_msg
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	Max number of concurrently allowed in-flight SCMI messages for
+		the currently configured SCMI transport.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/transport_rx_timeout_ms
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	Timeout in milliseconds allowed for SCMI synchronous replies
+		for the currently configured SCMI transport.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/message
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw synchronous message injection/snooping facility; write
+		a complete SCMI synchronous command message (header included)
+		in little-endian binary format to have it sent to the configured
+		backend SCMI server.
+		Any subsequently received response can be read from this same
+		entry if it arrived within the configured timeout.
+		Each write to the entry causes one command request to be built
+		and sent while the replies are read back one message at time
+		(receiving an EOF at each message boundary).
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/message_async
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw asynchronous message injection/snooping facility; write
+		a complete SCMI asynchronous command message (header included)
+		in little-endian binary format to have it sent to the configured
+		backend SCMI server.
+		Any subsequently received response can be read from this same
+		entry if it arrived within the configured timeout.
+		Any additional delayed response received afterwards can be read
+		from this same entry too if it arrived within the configured
+		timeout.
+		Each write to the entry causes one command request to be built
+		and sent while the replies are read back one message at time
+		(receiving an EOF at each message boundary).
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/errors
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw message errors facility; any kind of timed-out or
+		generally unexpectedly received SCMI message can be read from
+		this entry.
+		Each read gives back one message at time (receiving an EOF at
+		each message boundary).
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/notification
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw notification snooping facility; any notification
+		emitted by the backend SCMI server can be read from this entry.
+		Each read gives back one message at time (receiving an EOF at
+		each message boundary).
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/reset
+Date:		December 2022
+KernelVersion:	6.1
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw stack reset facility; writing a value to this entry
+		causes the internal queues of any kind of received message,
+		still pending to be read out, to be flushed.
+		Can be used to reset and clean the SCMI Raw stack between to
+		different test-run.
+Users:		Debugging, any userspace test suite
-- 
2.32.0


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[PATCH v3 8/9] firmware: arm_scmi: Reject SCMI drivers while in Raw mode

[Cristian Marussi]

Reject SCMI driver registration when SCMI Raw mode support is configured,
so as to avoid interferences between the SCMI Raw mode transactions and the
normal SCMI stack operations.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 056796b2dcae..78879e23fef8 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2345,6 +2345,12 @@ int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 	pr_debug("Requesting SCMI device (%s) for protocol %x\n",
 		 id_table->name, id_table->protocol_id);
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		pr_warn("SCMI Raw mode active. Rejecting '%s'/0x%02X\n",
+			id_table->name, id_table->protocol_id);
+		return -EINVAL;
+	}
+
 	/*
 	 * Search for the matching protocol rdev list and then search
 	 * of any existent equally named device...fails if any duplicate found.
-- 
2.32.0

[PATCH v3 8/9] firmware: arm_scmi: Reject SCMI drivers while in Raw mode

[Cristian Marussi]

Reject SCMI driver registration when SCMI Raw mode support is configured,
so as to avoid interferences between the SCMI Raw mode transactions and the
normal SCMI stack operations.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 056796b2dcae..78879e23fef8 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2345,6 +2345,12 @@ int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 	pr_debug("Requesting SCMI device (%s) for protocol %x\n",
 		 id_table->name, id_table->protocol_id);
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		pr_warn("SCMI Raw mode active. Rejecting '%s'/0x%02X\n",
+			id_table->name, id_table->protocol_id);
+		return -EINVAL;
+	}
+
 	/*
 	 * Search for the matching protocol rdev list and then search
 	 * of any existent equally named device...fails if any duplicate found.
-- 
2.32.0


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[PATCH v3 9/9] firmware: arm_scmi: Call Raw mode hooks from the core stack

[Cristian Marussi]

Add a few call sites where, if SCMI Raw mode access had been enabled in
Kconfig, the needed SCMI Raw initialization and hooks are called.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
v1 --> v2
- fixes need to use multiple cinfo if available
---
 drivers/firmware/arm_scmi/driver.c | 32 ++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 78879e23fef8..fd4f3ac54077 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -23,10 +23,12 @@
 #include <linux/kernel.h>
 #include <linux/ktime.h>
 #include <linux/hashtable.h>
+#include <linux/fs.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
+#include <linux/poll.h>
 #include <linux/processor.h>
 #include <linux/refcount.h>
 #include <linux/slab.h>
@@ -34,6 +36,8 @@
 #include "common.h"
 #include "notify.h"
 
+#include "raw_mode.h"
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/scmi.h>
 
@@ -133,6 +137,7 @@ struct scmi_protocol_instance {
  * @notify_priv: Pointer to private data structure specific to notifications.
  * @node: List head
  * @users: Number of users of this instance
+ * @raw: An opaque reference handle used by SCMI Raw mode.
  */
 struct scmi_info {
 	struct device *dev;
@@ -152,6 +157,7 @@ struct scmi_info {
 	void *notify_priv;
 	struct list_head node;
 	int users;
+	void *raw;
 };
 
 #define handle_to_scmi_info(h)	container_of(h, struct scmi_info, handle)
@@ -780,6 +786,11 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo,
 			   xfer->hdr.protocol_id, xfer->hdr.seq,
 			   MSG_TYPE_NOTIFICATION);
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		xfer->hdr.seq = MSG_XTRACT_TOKEN(msg_hdr);
+		scmi_raw_message_report(info->raw, xfer, SCMI_RAW_NOTIF_QUEUE);
+	}
+
 	__scmi_xfer_put(minfo, xfer);
 
 	scmi_clear_channel(info, cinfo);
@@ -793,6 +804,9 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo,
 
 	xfer = scmi_xfer_command_acquire(cinfo, msg_hdr);
 	if (IS_ERR(xfer)) {
+		if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
+			scmi_raw_error_report(info->raw, cinfo, msg_hdr, priv);
+
 		if (MSG_XTRACT_TYPE(msg_hdr) == MSG_TYPE_DELAYED_RESP)
 			scmi_clear_channel(info, cinfo);
 		return;
@@ -824,6 +838,9 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo,
 		complete(&xfer->done);
 	}
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
+		scmi_raw_message_report(info->raw, xfer, SCMI_RAW_REPLY_QUEUE);
+
 	scmi_xfer_command_release(info, xfer);
 }
 
@@ -2567,6 +2584,18 @@ static int scmi_probe(struct platform_device *pdev)
 	if (ret)
 		goto clear_txrx_setup;
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		info->raw = scmi_raw_mode_init(handle, info->desc,
+					       info->tx_minfo.max_msg);
+		if (!IS_ERR(info->raw)) {
+			dev_info(dev, "SCMI RAW Mode initialized.\n");
+			return 0;
+		}
+
+		dev_err(dev, "Failed to initialize SCMI RAW Mode !\n");
+		info->raw = NULL;
+	}
+
 	if (scmi_notification_init(handle))
 		dev_err(dev, "SCMI Notifications NOT available.\n");
 
@@ -2640,6 +2669,9 @@ static int scmi_remove(struct platform_device *pdev)
 	struct scmi_info *info = platform_get_drvdata(pdev);
 	struct device_node *child;
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
+		scmi_raw_mode_cleanup(info->raw);
+
 	mutex_lock(&scmi_list_mutex);
 	if (info->users)
 		ret = -EBUSY;
-- 
2.32.0

[PATCH v3 9/9] firmware: arm_scmi: Call Raw mode hooks from the core stack

[Cristian Marussi]

Add a few call sites where, if SCMI Raw mode access had been enabled in
Kconfig, the needed SCMI Raw initialization and hooks are called.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
v1 --> v2
- fixes need to use multiple cinfo if available
---
 drivers/firmware/arm_scmi/driver.c | 32 ++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 78879e23fef8..fd4f3ac54077 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -23,10 +23,12 @@
 #include <linux/kernel.h>
 #include <linux/ktime.h>
 #include <linux/hashtable.h>
+#include <linux/fs.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
+#include <linux/poll.h>
 #include <linux/processor.h>
 #include <linux/refcount.h>
 #include <linux/slab.h>
@@ -34,6 +36,8 @@
 #include "common.h"
 #include "notify.h"
 
+#include "raw_mode.h"
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/scmi.h>
 
@@ -133,6 +137,7 @@ struct scmi_protocol_instance {
  * @notify_priv: Pointer to private data structure specific to notifications.
  * @node: List head
  * @users: Number of users of this instance
+ * @raw: An opaque reference handle used by SCMI Raw mode.
  */
 struct scmi_info {
 	struct device *dev;
@@ -152,6 +157,7 @@ struct scmi_info {
 	void *notify_priv;
 	struct list_head node;
 	int users;
+	void *raw;
 };
 
 #define handle_to_scmi_info(h)	container_of(h, struct scmi_info, handle)
@@ -780,6 +786,11 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo,
 			   xfer->hdr.protocol_id, xfer->hdr.seq,
 			   MSG_TYPE_NOTIFICATION);
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		xfer->hdr.seq = MSG_XTRACT_TOKEN(msg_hdr);
+		scmi_raw_message_report(info->raw, xfer, SCMI_RAW_NOTIF_QUEUE);
+	}
+
 	__scmi_xfer_put(minfo, xfer);
 
 	scmi_clear_channel(info, cinfo);
@@ -793,6 +804,9 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo,
 
 	xfer = scmi_xfer_command_acquire(cinfo, msg_hdr);
 	if (IS_ERR(xfer)) {
+		if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
+			scmi_raw_error_report(info->raw, cinfo, msg_hdr, priv);
+
 		if (MSG_XTRACT_TYPE(msg_hdr) == MSG_TYPE_DELAYED_RESP)
 			scmi_clear_channel(info, cinfo);
 		return;
@@ -824,6 +838,9 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo,
 		complete(&xfer->done);
 	}
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
+		scmi_raw_message_report(info->raw, xfer, SCMI_RAW_REPLY_QUEUE);
+
 	scmi_xfer_command_release(info, xfer);
 }
 
@@ -2567,6 +2584,18 @@ static int scmi_probe(struct platform_device *pdev)
 	if (ret)
 		goto clear_txrx_setup;
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		info->raw = scmi_raw_mode_init(handle, info->desc,
+					       info->tx_minfo.max_msg);
+		if (!IS_ERR(info->raw)) {
+			dev_info(dev, "SCMI RAW Mode initialized.\n");
+			return 0;
+		}
+
+		dev_err(dev, "Failed to initialize SCMI RAW Mode !\n");
+		info->raw = NULL;
+	}
+
 	if (scmi_notification_init(handle))
 		dev_err(dev, "SCMI Notifications NOT available.\n");
 
@@ -2640,6 +2669,9 @@ static int scmi_remove(struct platform_device *pdev)
 	struct scmi_info *info = platform_get_drvdata(pdev);
 	struct device_node *child;
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
+		scmi_raw_mode_cleanup(info->raw);
+
 	mutex_lock(&scmi_list_mutex);
 	if (info->users)
 		ret = -EBUSY;
-- 
2.32.0


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Re: [PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Vincent Guittot]

Hi Cristian,

On Sat, 3 Sept 2022 at 20:31, Cristian Marussi <cristian.marussi@arm.com> wrote:
>
> Hi all,
>
> This series aims to introduce a new SCMI unified userspace interface meant
> to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
> from the perspective of the OSPM agent (non-secure world only ...)
>
> It is proposed as a testing/development facility, it is NOT meant to be a
> feature to use in production, but only enabled in Kconfig for test
> deployments.
>
> Currently an SCMI Compliance Suite like the one at [1] can only work by
> injecting SCMI messages at the SCMI transport layer using the mailbox test
> driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
> the related replies from the SCMI backend Server.
>

...

>
> In V2 the runtime enable/disable switching capability has been removed
> (for now) since still not deemed to be stable/reliable enough: as a
> consequence when SCMI Raw support is compiled in, the regular SCMI stack
> drivers are now inhibited permanently for that Kernel.
>
> A quick and trivial example from the shell...reading from a sensor
> injecting a properly crafted packet in raw mode:
>
>         # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
>         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message

I have tried your patchset with an SCMI server using an optee-os
transport channel but I have a timed out error when trying your
example above to read sensor1

#  echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
> /sys/kernel/debug/scmi_raw/message
# [   93.306690] arm-scmi firmware:scmi0: timed out in RAW response -
HDR:00005406

and there no response available when trying to read it with
# cat /sys/kernel/debug/scmi_raw/message


The sensor 1 can be successfully read in normal mode:
# cat /sys/class/hwmon/hwmon0/temp1_input
25000
#

In both case, the SCMI server received the requests and replied successfully

Could it be that you process the answer differently in case of raw mode ?

>
>         # READING BACK THE REPLY...
>         root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4
>         0000000 00005406 00000000 00000335 00000000
>         0000020
>
> while doing that, since Raw mode makes (partial) use of the regular SCMI
> stack, you can observe the messages going through the SCMI stack with the
> usual traces:
>
>               bash-329     [000] ..... 14183.446808: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000000000000
>    irq/35-mhu_db_l-81      [000] ..... 14183.447809: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=0 pyld=3503000000000000
>
>
> ..trying to read in async when the backend server does NOT supports asyncs:
>
>         # AN ASYNC SENSOR READING REQUEST...
>         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x01\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message_async
>
>               bash-329     [000] ..... 16415.938739: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000001000000
>    irq/35-mhu_db_l-81      [000] ..... 16415.944129: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=-1 pyld=
>
>         # RETURNS A STATUS -1 FROM THE SERVER NOT SUPPORTING IT
>         root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4
>         0000000 00005406 ffffffff
>         0000010
>
> Note that this was on a JUNO, BUT exactly the same steps can be used to
> reach an SCMI Server living on a VM reachable via virtio as long as the
> system under test if properly configured to work with a virtio transport.
>
> In a nutshell the exposed API is as follows:
>
> /sys/kernel/debug/scmi_raw/
> ├── errors
> ├── message
> ├── message_async
> ├── notification
> ├── reset
> ├── transport_max_msg_size
> ├── transport_rx_timeout_ms
> └── transport_tx_max_msg
>
> where:
>
>  - message*: used to send sync/async commands and read back immediate and
>    delayed responses (if any)
>  - errors: used to report timeout and unexpected replies
>  - reset: used to reset the SCMI Raw stack, flushing all queues from
>    received messages still pending to be read out (useful to be sure to
>    cleanup between test suite runs...)
>  - notification: used to read any notification being spit by the system
>    (if previously enabled by the user app)
>  - transport*: a bunch of configuration useful to setup the user
>    application expectations in terms of timeouts and message
>    characteristics.
>
> Each write corresponds to one command request and the replies or delayed
> response are read back one message at time (receiving an EOF at each
> message boundary).
>
> The user application running the test is in charge of handling timeouts
> and properly choosing SCMI sequence numbers for the outgoing requests: note
> that the same fixed number can be re-used (...though discouraged...) as
> long as the suite does NOT expect to send multiple in-flight commands
> concurrently.
>
> Since the SCMI core regular stack is partially used to deliver and collect
> the messages, late replies after timeouts and any other sort of unexpected
> message sent by the SCMI server platform back can be identified by the SCMI
> core as usual and it will be reported under /errors for later analysis.
> (a userspace test-app will have anyway properly detected the timeout on
>  /message* ...)
>
> All of the above has been roughly tested against a standard JUNO SCP SCMI
> Server (mailbox trans) and an emulated SCMI Server living in a VM (virtio
> trans) using a custom experimental version of the scmi-tests Compliance
> suite patched to support Raw mode and posted at [2]. (still in development
> ...certainly not up for review as of now...it is just a mean for me to
> test the testing API ... O_o)
>
> The series is based on sudeep/for-next/scmi [3] on top of:
>
> commit 40d30cf680cb ("firmware: arm_scmi: Harmonize SCMI tracing message format")
>
> Still todo:
>
> - needs more complete testing, ideally running to completion at least the full
>   SCMI compliance suite at [2] to use it as a reference
> - more feedback on the API
>
> Having said that (in such a concise and brief way :P) ...
>
> ...any feedback/comments are welcome !
>
> Thanks,
> Cristian
>
> ---
> v2 --> v3
> - fixed some sparse warning on LE and __poll_t
> - reworked and simplified deferred worker in charge of xfer delayed waiting
> - allow for injection of DT-unknown protocols messages when in Raw mode
>   (needed for any kind of fuzzing...)
>
> v1 --> v2
> - added comments and debugfs docs
> - added dedicated transport devices for channels initialization
> - better channels handling in Raw mode
> - removed runtime enable, moved to static compile time exclusion
>   of SCMI regular stack
>
> [1]: https://gitlab.arm.com/tests/scmi-tests
> [2]: https://gitlab.arm.com/linux-arm/scmi-tests-cm/-/commits/raw_mode_support_V3/
> [3]: https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/log/?h=for-next/scmi
>
> Cristian Marussi (9):
>   firmware: arm_scmi: Refactor xfer in-flight registration routines
>   firmware: arm_scmi: Simplify chan_available transport operation
>   firmware: arm_scmi: Use dedicated devices to initialize channels
>   firmware: arm_scmi: Add xfer raw helpers
>   firmware: arm_scmi: Move errors defs and code to common.h
>   firmware: arm_scmi: Add raw transmission support
>   firmware: arm_scmi: Add debugfs ABI documentation for Raw mode
>   firmware: arm_scmi: Reject SCMI drivers while in Raw mode
>   firmware: arm_scmi: Call Raw mode hooks from the core stack
>
>  Documentation/ABI/testing/debugfs-scmi-raw |   88 ++
>  drivers/firmware/arm_scmi/Kconfig          |   13 +
>  drivers/firmware/arm_scmi/Makefile         |    1 +
>  drivers/firmware/arm_scmi/common.h         |   51 +-
>  drivers/firmware/arm_scmi/driver.c         |  389 ++++--
>  drivers/firmware/arm_scmi/mailbox.c        |    4 +-
>  drivers/firmware/arm_scmi/optee.c          |    4 +-
>  drivers/firmware/arm_scmi/raw_mode.c       | 1235 ++++++++++++++++++++
>  drivers/firmware/arm_scmi/raw_mode.h       |   29 +
>  drivers/firmware/arm_scmi/smc.c            |    4 +-
>  drivers/firmware/arm_scmi/virtio.c         |    2 +-
>  11 files changed, 1714 insertions(+), 106 deletions(-)
>  create mode 100644 Documentation/ABI/testing/debugfs-scmi-raw
>  create mode 100644 drivers/firmware/arm_scmi/raw_mode.c
>  create mode 100644 drivers/firmware/arm_scmi/raw_mode.h
>
> --
> 2.32.0
>

Re: [PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Vincent Guittot]

Hi Cristian,

On Sat, 3 Sept 2022 at 20:31, Cristian Marussi <cristian.marussi@arm.com> wrote:
>
> Hi all,
>
> This series aims to introduce a new SCMI unified userspace interface meant
> to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
> from the perspective of the OSPM agent (non-secure world only ...)
>
> It is proposed as a testing/development facility, it is NOT meant to be a
> feature to use in production, but only enabled in Kconfig for test
> deployments.
>
> Currently an SCMI Compliance Suite like the one at [1] can only work by
> injecting SCMI messages at the SCMI transport layer using the mailbox test
> driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
> the related replies from the SCMI backend Server.
>

...

>
> In V2 the runtime enable/disable switching capability has been removed
> (for now) since still not deemed to be stable/reliable enough: as a
> consequence when SCMI Raw support is compiled in, the regular SCMI stack
> drivers are now inhibited permanently for that Kernel.
>
> A quick and trivial example from the shell...reading from a sensor
> injecting a properly crafted packet in raw mode:
>
>         # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
>         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message

I have tried your patchset with an SCMI server using an optee-os
transport channel but I have a timed out error when trying your
example above to read sensor1

#  echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
> /sys/kernel/debug/scmi_raw/message
# [   93.306690] arm-scmi firmware:scmi0: timed out in RAW response -
HDR:00005406

and there no response available when trying to read it with
# cat /sys/kernel/debug/scmi_raw/message


The sensor 1 can be successfully read in normal mode:
# cat /sys/class/hwmon/hwmon0/temp1_input
25000
#

In both case, the SCMI server received the requests and replied successfully

Could it be that you process the answer differently in case of raw mode ?

>
>         # READING BACK THE REPLY...
>         root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4
>         0000000 00005406 00000000 00000335 00000000
>         0000020
>
> while doing that, since Raw mode makes (partial) use of the regular SCMI
> stack, you can observe the messages going through the SCMI stack with the
> usual traces:
>
>               bash-329     [000] ..... 14183.446808: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000000000000
>    irq/35-mhu_db_l-81      [000] ..... 14183.447809: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=0 pyld=3503000000000000
>
>
> ..trying to read in async when the backend server does NOT supports asyncs:
>
>         # AN ASYNC SENSOR READING REQUEST...
>         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x01\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message_async
>
>               bash-329     [000] ..... 16415.938739: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000001000000
>    irq/35-mhu_db_l-81      [000] ..... 16415.944129: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=-1 pyld=
>
>         # RETURNS A STATUS -1 FROM THE SERVER NOT SUPPORTING IT
>         root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4
>         0000000 00005406 ffffffff
>         0000010
>
> Note that this was on a JUNO, BUT exactly the same steps can be used to
> reach an SCMI Server living on a VM reachable via virtio as long as the
> system under test if properly configured to work with a virtio transport.
>
> In a nutshell the exposed API is as follows:
>
> /sys/kernel/debug/scmi_raw/
> ├── errors
> ├── message
> ├── message_async
> ├── notification
> ├── reset
> ├── transport_max_msg_size
> ├── transport_rx_timeout_ms
> └── transport_tx_max_msg
>
> where:
>
>  - message*: used to send sync/async commands and read back immediate and
>    delayed responses (if any)
>  - errors: used to report timeout and unexpected replies
>  - reset: used to reset the SCMI Raw stack, flushing all queues from
>    received messages still pending to be read out (useful to be sure to
>    cleanup between test suite runs...)
>  - notification: used to read any notification being spit by the system
>    (if previously enabled by the user app)
>  - transport*: a bunch of configuration useful to setup the user
>    application expectations in terms of timeouts and message
>    characteristics.
>
> Each write corresponds to one command request and the replies or delayed
> response are read back one message at time (receiving an EOF at each
> message boundary).
>
> The user application running the test is in charge of handling timeouts
> and properly choosing SCMI sequence numbers for the outgoing requests: note
> that the same fixed number can be re-used (...though discouraged...) as
> long as the suite does NOT expect to send multiple in-flight commands
> concurrently.
>
> Since the SCMI core regular stack is partially used to deliver and collect
> the messages, late replies after timeouts and any other sort of unexpected
> message sent by the SCMI server platform back can be identified by the SCMI
> core as usual and it will be reported under /errors for later analysis.
> (a userspace test-app will have anyway properly detected the timeout on
>  /message* ...)
>
> All of the above has been roughly tested against a standard JUNO SCP SCMI
> Server (mailbox trans) and an emulated SCMI Server living in a VM (virtio
> trans) using a custom experimental version of the scmi-tests Compliance
> suite patched to support Raw mode and posted at [2]. (still in development
> ...certainly not up for review as of now...it is just a mean for me to
> test the testing API ... O_o)
>
> The series is based on sudeep/for-next/scmi [3] on top of:
>
> commit 40d30cf680cb ("firmware: arm_scmi: Harmonize SCMI tracing message format")
>
> Still todo:
>
> - needs more complete testing, ideally running to completion at least the full
>   SCMI compliance suite at [2] to use it as a reference
> - more feedback on the API
>
> Having said that (in such a concise and brief way :P) ...
>
> ...any feedback/comments are welcome !
>
> Thanks,
> Cristian
>
> ---
> v2 --> v3
> - fixed some sparse warning on LE and __poll_t
> - reworked and simplified deferred worker in charge of xfer delayed waiting
> - allow for injection of DT-unknown protocols messages when in Raw mode
>   (needed for any kind of fuzzing...)
>
> v1 --> v2
> - added comments and debugfs docs
> - added dedicated transport devices for channels initialization
> - better channels handling in Raw mode
> - removed runtime enable, moved to static compile time exclusion
>   of SCMI regular stack
>
> [1]: https://gitlab.arm.com/tests/scmi-tests
> [2]: https://gitlab.arm.com/linux-arm/scmi-tests-cm/-/commits/raw_mode_support_V3/
> [3]: https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/log/?h=for-next/scmi
>
> Cristian Marussi (9):
>   firmware: arm_scmi: Refactor xfer in-flight registration routines
>   firmware: arm_scmi: Simplify chan_available transport operation
>   firmware: arm_scmi: Use dedicated devices to initialize channels
>   firmware: arm_scmi: Add xfer raw helpers
>   firmware: arm_scmi: Move errors defs and code to common.h
>   firmware: arm_scmi: Add raw transmission support
>   firmware: arm_scmi: Add debugfs ABI documentation for Raw mode
>   firmware: arm_scmi: Reject SCMI drivers while in Raw mode
>   firmware: arm_scmi: Call Raw mode hooks from the core stack
>
>  Documentation/ABI/testing/debugfs-scmi-raw |   88 ++
>  drivers/firmware/arm_scmi/Kconfig          |   13 +
>  drivers/firmware/arm_scmi/Makefile         |    1 +
>  drivers/firmware/arm_scmi/common.h         |   51 +-
>  drivers/firmware/arm_scmi/driver.c         |  389 ++++--
>  drivers/firmware/arm_scmi/mailbox.c        |    4 +-
>  drivers/firmware/arm_scmi/optee.c          |    4 +-
>  drivers/firmware/arm_scmi/raw_mode.c       | 1235 ++++++++++++++++++++
>  drivers/firmware/arm_scmi/raw_mode.h       |   29 +
>  drivers/firmware/arm_scmi/smc.c            |    4 +-
>  drivers/firmware/arm_scmi/virtio.c         |    2 +-
>  11 files changed, 1714 insertions(+), 106 deletions(-)
>  create mode 100644 Documentation/ABI/testing/debugfs-scmi-raw
>  create mode 100644 drivers/firmware/arm_scmi/raw_mode.c
>  create mode 100644 drivers/firmware/arm_scmi/raw_mode.h
>
> --
> 2.32.0
>

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Re: [PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Cristian Marussi]

On Fri, Oct 07, 2022 at 04:23:33PM +0200, Vincent Guittot wrote:
> Hi Cristian,
> 

Hi Vincent

thanks for give it a try !

> On Sat, 3 Sept 2022 at 20:31, Cristian Marussi <cristian.marussi@arm.com> wrote:
> >
> > Hi all,
> >
> > This series aims to introduce a new SCMI unified userspace interface meant
> > to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
> > from the perspective of the OSPM agent (non-secure world only ...)
> >
> > It is proposed as a testing/development facility, it is NOT meant to be a
> > feature to use in production, but only enabled in Kconfig for test
> > deployments.
> >
> > Currently an SCMI Compliance Suite like the one at [1] can only work by
> > injecting SCMI messages at the SCMI transport layer using the mailbox test
> > driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
> > the related replies from the SCMI backend Server.
> >
> 
> ...
> 
> >
> > In V2 the runtime enable/disable switching capability has been removed
> > (for now) since still not deemed to be stable/reliable enough: as a
> > consequence when SCMI Raw support is compiled in, the regular SCMI stack
> > drivers are now inhibited permanently for that Kernel.
> >
> > A quick and trivial example from the shell...reading from a sensor
> > injecting a properly crafted packet in raw mode:
> >
> >         # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
> >         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message
> 
> I have tried your patchset with an SCMI server using an optee-os
> transport channel but I have a timed out error when trying your
> example above to read sensor1
> 
> #  echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
> > /sys/kernel/debug/scmi_raw/message
> # [   93.306690] arm-scmi firmware:scmi0: timed out in RAW response -
> HDR:00005406
> 
> and there no response available when trying to read it with
> # cat /sys/kernel/debug/scmi_raw/message
> 

is there anything cat'ting /sys/kernel/debug/scmi_raw/errors ?

> 
> The sensor 1 can be successfully read in normal mode:
> # cat /sys/class/hwmon/hwmon0/temp1_input
> 25000
> #
> 
> In both case, the SCMI server received the requests and replied successfully
> 
> Could it be that you process the answer differently in case of raw mode ?
> 

Well, absolutely, when in raw mode the reply is picked up directly into
the RX path and copied in a message queue to be read from asyncrhnously
later via debugfs.

... mmm I think I found the problem...the reply is picked up on the RX *IRQ*
path as of now...but in optee/SMC there is no interrupt (sometime there is in
SMC) and the reply is instead read back straight away (transport is marked as
sync_cmds_completed_on_ret=true in fact).... so this is the issue probably ...
I have NOT tested on anything but mailbox and virtio till now...and I
missed this possibility that this NO-irq reply was a thing even when NOT
in polling mode (which I do not support)...my bad :<

Ok, next week I'll rework the series to fix this big_BUG and some other minor
things...in the meantime if you want to try this snippet down below...

... this won't definitely be the final patch but it could let you experiment
more (only build tested though )

Thanks for testing !
Cristian

--->8-------

diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
index 13eeebe4b7a8..b9fcb66a1b6a 100644
--- a/drivers/firmware/arm_scmi/raw_mode.c
+++ b/drivers/firmware/arm_scmi/raw_mode.c
@@ -197,6 +197,8 @@ struct scmi_dbg_raw_data {
        size_t rx_size;
 };
 
+void scmi_raw_message_report(void *r, struct scmi_xfer *xfer, unsigned int idx);
+
 static inline
 struct scmi_raw_buffer *scmi_raw_buffer_get(struct scmi_raw_mode_info *raw,
                                            unsigned int idx)
@@ -389,22 +391,34 @@ static void scmi_xfer_raw_worker(struct work_struct *work)
 
                xfer = rw->xfer;
 
-               /*
-                * Waiters are queued by wait-deadline at the end, so some of
-                * them could have been already expired when processed, BUT we
-                * have to check the completion status anyway just in case a
-                * virtually expired (aged) transaction was indeed completed
-                * fine and we'll have to wait for the asynchronous part (if
-                * any).
-                */
-               aging = jiffies - rw->start_jiffies;
-               tmo = max_tmo > aging ? max_tmo - aging : 0;
-
-               if ((tmo && !wait_for_completion_timeout(&xfer->done, tmo)) ||
-                   (!tmo && !try_wait_for_completion(&xfer->done))) {
-                       dev_err(dev, "timed out in RAW response - HDR:%08X\n",
-                               pack_scmi_header(&xfer->hdr));
-                       ret = -ETIMEDOUT;
+               if (!raw->desc->sync_cmds_completed_on_ret) {
+                       /*
+                        * Waiters are queued by wait-deadline at the end, so some of
+                        * them could have been already expired when processed, BUT we
+                        * have to check the completion status anyway just in case a
+                        * virtually expired (aged) transaction was indeed completed
+                        * fine and we'll have to wait for the asynchronous part (if
+                        * any).
+                        */
+                       aging = jiffies - rw->start_jiffies;
+                       tmo = max_tmo > aging ? max_tmo - aging : 0;
+
+                       if ((tmo &&
+                            !wait_for_completion_timeout(&xfer->done, tmo)) ||
+                            (!tmo && !try_wait_for_completion(&xfer->done))) {
+                               dev_err(dev,
+                                       "timed out in RAW response - HDR:%08X\n",
+                                       pack_scmi_header(&xfer->hdr));
+                               ret = -ETIMEDOUT;
+                       }
+               } else {
+                       raw->desc->ops->fetch_response(rw->cinfo, xfer);
+                       /* Trace polled replies. */
+                       trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id,
+                                           "RESP",
+                                           xfer->hdr.seq, xfer->hdr.status,
+                                           xfer->rx.buf, xfer->rx.len);
+                       scmi_raw_message_report(raw, xfer, SCMI_RAW_REPLY_QUEUE);
                }
 
                /* Avoid unneeded async waits */


---8<-------

Re: [PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Cristian Marussi]

On Fri, Oct 07, 2022 at 04:23:33PM +0200, Vincent Guittot wrote:
> Hi Cristian,
> 

Hi Vincent

thanks for give it a try !

> On Sat, 3 Sept 2022 at 20:31, Cristian Marussi <cristian.marussi@arm.com> wrote:
> >
> > Hi all,
> >
> > This series aims to introduce a new SCMI unified userspace interface meant
> > to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
> > from the perspective of the OSPM agent (non-secure world only ...)
> >
> > It is proposed as a testing/development facility, it is NOT meant to be a
> > feature to use in production, but only enabled in Kconfig for test
> > deployments.
> >
> > Currently an SCMI Compliance Suite like the one at [1] can only work by
> > injecting SCMI messages at the SCMI transport layer using the mailbox test
> > driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
> > the related replies from the SCMI backend Server.
> >
> 
> ...
> 
> >
> > In V2 the runtime enable/disable switching capability has been removed
> > (for now) since still not deemed to be stable/reliable enough: as a
> > consequence when SCMI Raw support is compiled in, the regular SCMI stack
> > drivers are now inhibited permanently for that Kernel.
> >
> > A quick and trivial example from the shell...reading from a sensor
> > injecting a properly crafted packet in raw mode:
> >
> >         # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
> >         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message
> 
> I have tried your patchset with an SCMI server using an optee-os
> transport channel but I have a timed out error when trying your
> example above to read sensor1
> 
> #  echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
> > /sys/kernel/debug/scmi_raw/message
> # [   93.306690] arm-scmi firmware:scmi0: timed out in RAW response -
> HDR:00005406
> 
> and there no response available when trying to read it with
> # cat /sys/kernel/debug/scmi_raw/message
> 

is there anything cat'ting /sys/kernel/debug/scmi_raw/errors ?

> 
> The sensor 1 can be successfully read in normal mode:
> # cat /sys/class/hwmon/hwmon0/temp1_input
> 25000
> #
> 
> In both case, the SCMI server received the requests and replied successfully
> 
> Could it be that you process the answer differently in case of raw mode ?
> 

Well, absolutely, when in raw mode the reply is picked up directly into
the RX path and copied in a message queue to be read from asyncrhnously
later via debugfs.

... mmm I think I found the problem...the reply is picked up on the RX *IRQ*
path as of now...but in optee/SMC there is no interrupt (sometime there is in
SMC) and the reply is instead read back straight away (transport is marked as
sync_cmds_completed_on_ret=true in fact).... so this is the issue probably ...
I have NOT tested on anything but mailbox and virtio till now...and I
missed this possibility that this NO-irq reply was a thing even when NOT
in polling mode (which I do not support)...my bad :<

Ok, next week I'll rework the series to fix this big_BUG and some other minor
things...in the meantime if you want to try this snippet down below...

... this won't definitely be the final patch but it could let you experiment
more (only build tested though )

Thanks for testing !
Cristian

--->8-------

diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
index 13eeebe4b7a8..b9fcb66a1b6a 100644
--- a/drivers/firmware/arm_scmi/raw_mode.c
+++ b/drivers/firmware/arm_scmi/raw_mode.c
@@ -197,6 +197,8 @@ struct scmi_dbg_raw_data {
        size_t rx_size;
 };
 
+void scmi_raw_message_report(void *r, struct scmi_xfer *xfer, unsigned int idx);
+
 static inline
 struct scmi_raw_buffer *scmi_raw_buffer_get(struct scmi_raw_mode_info *raw,
                                            unsigned int idx)
@@ -389,22 +391,34 @@ static void scmi_xfer_raw_worker(struct work_struct *work)
 
                xfer = rw->xfer;
 
-               /*
-                * Waiters are queued by wait-deadline at the end, so some of
-                * them could have been already expired when processed, BUT we
-                * have to check the completion status anyway just in case a
-                * virtually expired (aged) transaction was indeed completed
-                * fine and we'll have to wait for the asynchronous part (if
-                * any).
-                */
-               aging = jiffies - rw->start_jiffies;
-               tmo = max_tmo > aging ? max_tmo - aging : 0;
-
-               if ((tmo && !wait_for_completion_timeout(&xfer->done, tmo)) ||
-                   (!tmo && !try_wait_for_completion(&xfer->done))) {
-                       dev_err(dev, "timed out in RAW response - HDR:%08X\n",
-                               pack_scmi_header(&xfer->hdr));
-                       ret = -ETIMEDOUT;
+               if (!raw->desc->sync_cmds_completed_on_ret) {
+                       /*
+                        * Waiters are queued by wait-deadline at the end, so some of
+                        * them could have been already expired when processed, BUT we
+                        * have to check the completion status anyway just in case a
+                        * virtually expired (aged) transaction was indeed completed
+                        * fine and we'll have to wait for the asynchronous part (if
+                        * any).
+                        */
+                       aging = jiffies - rw->start_jiffies;
+                       tmo = max_tmo > aging ? max_tmo - aging : 0;
+
+                       if ((tmo &&
+                            !wait_for_completion_timeout(&xfer->done, tmo)) ||
+                            (!tmo && !try_wait_for_completion(&xfer->done))) {
+                               dev_err(dev,
+                                       "timed out in RAW response - HDR:%08X\n",
+                                       pack_scmi_header(&xfer->hdr));
+                               ret = -ETIMEDOUT;
+                       }
+               } else {
+                       raw->desc->ops->fetch_response(rw->cinfo, xfer);
+                       /* Trace polled replies. */
+                       trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id,
+                                           "RESP",
+                                           xfer->hdr.seq, xfer->hdr.status,
+                                           xfer->rx.buf, xfer->rx.len);
+                       scmi_raw_message_report(raw, xfer, SCMI_RAW_REPLY_QUEUE);
                }
 
                /* Avoid unneeded async waits */


---8<-------


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Re: [PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Vincent Guittot]

On Fri, 7 Oct 2022 at 17:37, Cristian Marussi <cristian.marussi@arm.com> wrote:
>
> On Fri, Oct 07, 2022 at 04:23:33PM +0200, Vincent Guittot wrote:
> > Hi Cristian,
> >
>
> Hi Vincent
>
> thanks for give it a try !
>
> > On Sat, 3 Sept 2022 at 20:31, Cristian Marussi <cristian.marussi@arm.com> wrote:
> > >
> > > Hi all,
> > >
> > > This series aims to introduce a new SCMI unified userspace interface meant
> > > to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
> > > from the perspective of the OSPM agent (non-secure world only ...)
> > >
> > > It is proposed as a testing/development facility, it is NOT meant to be a
> > > feature to use in production, but only enabled in Kconfig for test
> > > deployments.
> > >
> > > Currently an SCMI Compliance Suite like the one at [1] can only work by
> > > injecting SCMI messages at the SCMI transport layer using the mailbox test
> > > driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
> > > the related replies from the SCMI backend Server.
> > >
> >
> > ...
> >
> > >
> > > In V2 the runtime enable/disable switching capability has been removed
> > > (for now) since still not deemed to be stable/reliable enough: as a
> > > consequence when SCMI Raw support is compiled in, the regular SCMI stack
> > > drivers are now inhibited permanently for that Kernel.
> > >
> > > A quick and trivial example from the shell...reading from a sensor
> > > injecting a properly crafted packet in raw mode:
> > >
> > >         # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
> > >         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message
> >
> > I have tried your patchset with an SCMI server using an optee-os
> > transport channel but I have a timed out error when trying your
> > example above to read sensor1
> >
> > #  echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
> > > /sys/kernel/debug/scmi_raw/message
> > # [   93.306690] arm-scmi firmware:scmi0: timed out in RAW response -
> > HDR:00005406
> >
> > and there no response available when trying to read it with
> > # cat /sys/kernel/debug/scmi_raw/message
> >
>
> is there anything cat'ting /sys/kernel/debug/scmi_raw/errors ?

It was empty

>
> >
> > The sensor 1 can be successfully read in normal mode:
> > # cat /sys/class/hwmon/hwmon0/temp1_input
> > 25000
> > #
> >
> > In both case, the SCMI server received the requests and replied successfully
> >
> > Could it be that you process the answer differently in case of raw mode ?
> >
>
> Well, absolutely, when in raw mode the reply is picked up directly into
> the RX path and copied in a message queue to be read from asyncrhnously
> later via debugfs.
>
> ... mmm I think I found the problem...the reply is picked up on the RX *IRQ*
> path as of now...but in optee/SMC there is no interrupt (sometime there is in
> SMC) and the reply is instead read back straight away (transport is marked as
> sync_cmds_completed_on_ret=true in fact).... so this is the issue probably ...
> I have NOT tested on anything but mailbox and virtio till now...and I
> missed this possibility that this NO-irq reply was a thing even when NOT
> in polling mode (which I do not support)...my bad :<
>
> Ok, next week I'll rework the series to fix this big_BUG and some other minor
> things...in the meantime if you want to try this snippet down below...
>
> ... this won't definitely be the final patch but it could let you experiment
> more (only build tested though )

Thanks.
The patch below fixes my problem with optee transport layer

>
> Thanks for testing !
> Cristian
>
> --->8-------
>
> diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
> index 13eeebe4b7a8..b9fcb66a1b6a 100644
> --- a/drivers/firmware/arm_scmi/raw_mode.c
> +++ b/drivers/firmware/arm_scmi/raw_mode.c
> @@ -197,6 +197,8 @@ struct scmi_dbg_raw_data {
>         size_t rx_size;
>  };
>
> +void scmi_raw_message_report(void *r, struct scmi_xfer *xfer, unsigned int idx);
> +
>  static inline
>  struct scmi_raw_buffer *scmi_raw_buffer_get(struct scmi_raw_mode_info *raw,
>                                             unsigned int idx)
> @@ -389,22 +391,34 @@ static void scmi_xfer_raw_worker(struct work_struct *work)
>
>                 xfer = rw->xfer;
>
> -               /*
> -                * Waiters are queued by wait-deadline at the end, so some of
> -                * them could have been already expired when processed, BUT we
> -                * have to check the completion status anyway just in case a
> -                * virtually expired (aged) transaction was indeed completed
> -                * fine and we'll have to wait for the asynchronous part (if
> -                * any).
> -                */
> -               aging = jiffies - rw->start_jiffies;
> -               tmo = max_tmo > aging ? max_tmo - aging : 0;
> -
> -               if ((tmo && !wait_for_completion_timeout(&xfer->done, tmo)) ||
> -                   (!tmo && !try_wait_for_completion(&xfer->done))) {
> -                       dev_err(dev, "timed out in RAW response - HDR:%08X\n",
> -                               pack_scmi_header(&xfer->hdr));
> -                       ret = -ETIMEDOUT;
> +               if (!raw->desc->sync_cmds_completed_on_ret) {
> +                       /*
> +                        * Waiters are queued by wait-deadline at the end, so some of
> +                        * them could have been already expired when processed, BUT we
> +                        * have to check the completion status anyway just in case a
> +                        * virtually expired (aged) transaction was indeed completed
> +                        * fine and we'll have to wait for the asynchronous part (if
> +                        * any).
> +                        */
> +                       aging = jiffies - rw->start_jiffies;
> +                       tmo = max_tmo > aging ? max_tmo - aging : 0;
> +
> +                       if ((tmo &&
> +                            !wait_for_completion_timeout(&xfer->done, tmo)) ||
> +                            (!tmo && !try_wait_for_completion(&xfer->done))) {
> +                               dev_err(dev,
> +                                       "timed out in RAW response - HDR:%08X\n",
> +                                       pack_scmi_header(&xfer->hdr));
> +                               ret = -ETIMEDOUT;
> +                       }
> +               } else {
> +                       raw->desc->ops->fetch_response(rw->cinfo, xfer);
> +                       /* Trace polled replies. */
> +                       trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id,
> +                                           "RESP",
> +                                           xfer->hdr.seq, xfer->hdr.status,
> +                                           xfer->rx.buf, xfer->rx.len);
> +                       scmi_raw_message_report(raw, xfer, SCMI_RAW_REPLY_QUEUE);
>                 }
>
>                 /* Avoid unneeded async waits */
>
>
> ---8<-------
>

Re: [PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Vincent Guittot]

On Fri, 7 Oct 2022 at 17:37, Cristian Marussi <cristian.marussi@arm.com> wrote:
>
> On Fri, Oct 07, 2022 at 04:23:33PM +0200, Vincent Guittot wrote:
> > Hi Cristian,
> >
>
> Hi Vincent
>
> thanks for give it a try !
>
> > On Sat, 3 Sept 2022 at 20:31, Cristian Marussi <cristian.marussi@arm.com> wrote:
> > >
> > > Hi all,
> > >
> > > This series aims to introduce a new SCMI unified userspace interface meant
> > > to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
> > > from the perspective of the OSPM agent (non-secure world only ...)
> > >
> > > It is proposed as a testing/development facility, it is NOT meant to be a
> > > feature to use in production, but only enabled in Kconfig for test
> > > deployments.
> > >
> > > Currently an SCMI Compliance Suite like the one at [1] can only work by
> > > injecting SCMI messages at the SCMI transport layer using the mailbox test
> > > driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
> > > the related replies from the SCMI backend Server.
> > >
> >
> > ...
> >
> > >
> > > In V2 the runtime enable/disable switching capability has been removed
> > > (for now) since still not deemed to be stable/reliable enough: as a
> > > consequence when SCMI Raw support is compiled in, the regular SCMI stack
> > > drivers are now inhibited permanently for that Kernel.
> > >
> > > A quick and trivial example from the shell...reading from a sensor
> > > injecting a properly crafted packet in raw mode:
> > >
> > >         # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
> > >         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message
> >
> > I have tried your patchset with an SCMI server using an optee-os
> > transport channel but I have a timed out error when trying your
> > example above to read sensor1
> >
> > #  echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
> > > /sys/kernel/debug/scmi_raw/message
> > # [   93.306690] arm-scmi firmware:scmi0: timed out in RAW response -
> > HDR:00005406
> >
> > and there no response available when trying to read it with
> > # cat /sys/kernel/debug/scmi_raw/message
> >
>
> is there anything cat'ting /sys/kernel/debug/scmi_raw/errors ?

It was empty

>
> >
> > The sensor 1 can be successfully read in normal mode:
> > # cat /sys/class/hwmon/hwmon0/temp1_input
> > 25000
> > #
> >
> > In both case, the SCMI server received the requests and replied successfully
> >
> > Could it be that you process the answer differently in case of raw mode ?
> >
>
> Well, absolutely, when in raw mode the reply is picked up directly into
> the RX path and copied in a message queue to be read from asyncrhnously
> later via debugfs.
>
> ... mmm I think I found the problem...the reply is picked up on the RX *IRQ*
> path as of now...but in optee/SMC there is no interrupt (sometime there is in
> SMC) and the reply is instead read back straight away (transport is marked as
> sync_cmds_completed_on_ret=true in fact).... so this is the issue probably ...
> I have NOT tested on anything but mailbox and virtio till now...and I
> missed this possibility that this NO-irq reply was a thing even when NOT
> in polling mode (which I do not support)...my bad :<
>
> Ok, next week I'll rework the series to fix this big_BUG and some other minor
> things...in the meantime if you want to try this snippet down below...
>
> ... this won't definitely be the final patch but it could let you experiment
> more (only build tested though )

Thanks.
The patch below fixes my problem with optee transport layer

>
> Thanks for testing !
> Cristian
>
> --->8-------
>
> diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
> index 13eeebe4b7a8..b9fcb66a1b6a 100644
> --- a/drivers/firmware/arm_scmi/raw_mode.c
> +++ b/drivers/firmware/arm_scmi/raw_mode.c
> @@ -197,6 +197,8 @@ struct scmi_dbg_raw_data {
>         size_t rx_size;
>  };
>
> +void scmi_raw_message_report(void *r, struct scmi_xfer *xfer, unsigned int idx);
> +
>  static inline
>  struct scmi_raw_buffer *scmi_raw_buffer_get(struct scmi_raw_mode_info *raw,
>                                             unsigned int idx)
> @@ -389,22 +391,34 @@ static void scmi_xfer_raw_worker(struct work_struct *work)
>
>                 xfer = rw->xfer;
>
> -               /*
> -                * Waiters are queued by wait-deadline at the end, so some of
> -                * them could have been already expired when processed, BUT we
> -                * have to check the completion status anyway just in case a
> -                * virtually expired (aged) transaction was indeed completed
> -                * fine and we'll have to wait for the asynchronous part (if
> -                * any).
> -                */
> -               aging = jiffies - rw->start_jiffies;
> -               tmo = max_tmo > aging ? max_tmo - aging : 0;
> -
> -               if ((tmo && !wait_for_completion_timeout(&xfer->done, tmo)) ||
> -                   (!tmo && !try_wait_for_completion(&xfer->done))) {
> -                       dev_err(dev, "timed out in RAW response - HDR:%08X\n",
> -                               pack_scmi_header(&xfer->hdr));
> -                       ret = -ETIMEDOUT;
> +               if (!raw->desc->sync_cmds_completed_on_ret) {
> +                       /*
> +                        * Waiters are queued by wait-deadline at the end, so some of
> +                        * them could have been already expired when processed, BUT we
> +                        * have to check the completion status anyway just in case a
> +                        * virtually expired (aged) transaction was indeed completed
> +                        * fine and we'll have to wait for the asynchronous part (if
> +                        * any).
> +                        */
> +                       aging = jiffies - rw->start_jiffies;
> +                       tmo = max_tmo > aging ? max_tmo - aging : 0;
> +
> +                       if ((tmo &&
> +                            !wait_for_completion_timeout(&xfer->done, tmo)) ||
> +                            (!tmo && !try_wait_for_completion(&xfer->done))) {
> +                               dev_err(dev,
> +                                       "timed out in RAW response - HDR:%08X\n",
> +                                       pack_scmi_header(&xfer->hdr));
> +                               ret = -ETIMEDOUT;
> +                       }
> +               } else {
> +                       raw->desc->ops->fetch_response(rw->cinfo, xfer);
> +                       /* Trace polled replies. */
> +                       trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id,
> +                                           "RESP",
> +                                           xfer->hdr.seq, xfer->hdr.status,
> +                                           xfer->rx.buf, xfer->rx.len);
> +                       scmi_raw_message_report(raw, xfer, SCMI_RAW_REPLY_QUEUE);
>                 }
>
>                 /* Avoid unneeded async waits */
>
>
> ---8<-------
>

_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Cristian Marussi]

On Fri, Oct 07, 2022 at 05:58:59PM +0200, Vincent Guittot wrote:
> On Fri, 7 Oct 2022 at 17:37, Cristian Marussi <cristian.marussi@arm.com> wrote:
> >
> > On Fri, Oct 07, 2022 at 04:23:33PM +0200, Vincent Guittot wrote:
> > > Hi Cristian,
> > >
> >
> > Hi Vincent
> >
> > thanks for give it a try !
> >
> > > On Sat, 3 Sept 2022 at 20:31, Cristian Marussi <cristian.marussi@arm.com> wrote:
> > > >
> > > > Hi all,
> > > >
> > > > This series aims to introduce a new SCMI unified userspace interface meant
> > > > to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
> > > > from the perspective of the OSPM agent (non-secure world only ...)
> > > >
> > > > It is proposed as a testing/development facility, it is NOT meant to be a
> > > > feature to use in production, but only enabled in Kconfig for test
> > > > deployments.
> > > >
> > > > Currently an SCMI Compliance Suite like the one at [1] can only work by
> > > > injecting SCMI messages at the SCMI transport layer using the mailbox test
> > > > driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
> > > > the related replies from the SCMI backend Server.
> > > >
> > >
> > > ...
> > >
> > > >
> > > > In V2 the runtime enable/disable switching capability has been removed
> > > > (for now) since still not deemed to be stable/reliable enough: as a
> > > > consequence when SCMI Raw support is compiled in, the regular SCMI stack
> > > > drivers are now inhibited permanently for that Kernel.
> > > >
> > > > A quick and trivial example from the shell...reading from a sensor
> > > > injecting a properly crafted packet in raw mode:
> > > >
> > > >         # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
> > > >         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message
> > >
> > > I have tried your patchset with an SCMI server using an optee-os
> > > transport channel but I have a timed out error when trying your
> > > example above to read sensor1
> > >
> > > #  echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
> > > > /sys/kernel/debug/scmi_raw/message
> > > # [   93.306690] arm-scmi firmware:scmi0: timed out in RAW response -
> > > HDR:00005406
> > >
> > > and there no response available when trying to read it with
> > > # cat /sys/kernel/debug/scmi_raw/message
> > >
> >
> > is there anything cat'ting /sys/kernel/debug/scmi_raw/errors ?
> 
> It was empty
> 
> >
> > >
> > > The sensor 1 can be successfully read in normal mode:
> > > # cat /sys/class/hwmon/hwmon0/temp1_input
> > > 25000
> > > #
> > >
> > > In both case, the SCMI server received the requests and replied successfully
> > >
> > > Could it be that you process the answer differently in case of raw mode ?
> > >
> >
> > Well, absolutely, when in raw mode the reply is picked up directly into
> > the RX path and copied in a message queue to be read from asyncrhnously
> > later via debugfs.
> >
> > ... mmm I think I found the problem...the reply is picked up on the RX *IRQ*
> > path as of now...but in optee/SMC there is no interrupt (sometime there is in
> > SMC) and the reply is instead read back straight away (transport is marked as
> > sync_cmds_completed_on_ret=true in fact).... so this is the issue probably ...
> > I have NOT tested on anything but mailbox and virtio till now...and I
> > missed this possibility that this NO-irq reply was a thing even when NOT
> > in polling mode (which I do not support)...my bad :<
> >
> > Ok, next week I'll rework the series to fix this big_BUG and some other minor
> > things...in the meantime if you want to try this snippet down below...
> >
> > ... this won't definitely be the final patch but it could let you experiment
> > more (only build tested though )
> 
> Thanks.
> The patch below fixes my problem with optee transport layer
> 

Good, thanks for the patience.

Thanks,
Cristian

> >
> > Thanks for testing !
> > Cristian
> >
> > --->8-------
> >
> > diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
> > index 13eeebe4b7a8..b9fcb66a1b6a 100644
> > --- a/drivers/firmware/arm_scmi/raw_mode.c
> > +++ b/drivers/firmware/arm_scmi/raw_mode.c
> > @@ -197,6 +197,8 @@ struct scmi_dbg_raw_data {
> >         size_t rx_size;
> >  };
> >
> > +void scmi_raw_message_report(void *r, struct scmi_xfer *xfer, unsigned int idx);
> > +
> >  static inline
> >  struct scmi_raw_buffer *scmi_raw_buffer_get(struct scmi_raw_mode_info *raw,
> >                                             unsigned int idx)
> > @@ -389,22 +391,34 @@ static void scmi_xfer_raw_worker(struct work_struct *work)
> >
> >                 xfer = rw->xfer;
> >
> > -               /*
> > -                * Waiters are queued by wait-deadline at the end, so some of
> > -                * them could have been already expired when processed, BUT we
> > -                * have to check the completion status anyway just in case a
> > -                * virtually expired (aged) transaction was indeed completed
> > -                * fine and we'll have to wait for the asynchronous part (if
> > -                * any).
> > -                */
> > -               aging = jiffies - rw->start_jiffies;
> > -               tmo = max_tmo > aging ? max_tmo - aging : 0;
> > -
> > -               if ((tmo && !wait_for_completion_timeout(&xfer->done, tmo)) ||
> > -                   (!tmo && !try_wait_for_completion(&xfer->done))) {
> > -                       dev_err(dev, "timed out in RAW response - HDR:%08X\n",
> > -                               pack_scmi_header(&xfer->hdr));
> > -                       ret = -ETIMEDOUT;
> > +               if (!raw->desc->sync_cmds_completed_on_ret) {
> > +                       /*
> > +                        * Waiters are queued by wait-deadline at the end, so some of
> > +                        * them could have been already expired when processed, BUT we
> > +                        * have to check the completion status anyway just in case a
> > +                        * virtually expired (aged) transaction was indeed completed
> > +                        * fine and we'll have to wait for the asynchronous part (if
> > +                        * any).
> > +                        */
> > +                       aging = jiffies - rw->start_jiffies;
> > +                       tmo = max_tmo > aging ? max_tmo - aging : 0;
> > +
> > +                       if ((tmo &&
> > +                            !wait_for_completion_timeout(&xfer->done, tmo)) ||
> > +                            (!tmo && !try_wait_for_completion(&xfer->done))) {
> > +                               dev_err(dev,
> > +                                       "timed out in RAW response - HDR:%08X\n",
> > +                                       pack_scmi_header(&xfer->hdr));
> > +                               ret = -ETIMEDOUT;
> > +                       }
> > +               } else {
> > +                       raw->desc->ops->fetch_response(rw->cinfo, xfer);
> > +                       /* Trace polled replies. */
> > +                       trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id,
> > +                                           "RESP",
> > +                                           xfer->hdr.seq, xfer->hdr.status,
> > +                                           xfer->rx.buf, xfer->rx.len);
> > +                       scmi_raw_message_report(raw, xfer, SCMI_RAW_REPLY_QUEUE);
> >                 }
> >
> >                 /* Avoid unneeded async waits */
> >
> >
> > ---8<-------
> >

Re: [PATCH v3 0/9] Introduce a unified API for SCMI Server testing

[Cristian Marussi]

On Fri, Oct 07, 2022 at 05:58:59PM +0200, Vincent Guittot wrote:
> On Fri, 7 Oct 2022 at 17:37, Cristian Marussi <cristian.marussi@arm.com> wrote:
> >
> > On Fri, Oct 07, 2022 at 04:23:33PM +0200, Vincent Guittot wrote:
> > > Hi Cristian,
> > >
> >
> > Hi Vincent
> >
> > thanks for give it a try !
> >
> > > On Sat, 3 Sept 2022 at 20:31, Cristian Marussi <cristian.marussi@arm.com> wrote:
> > > >
> > > > Hi all,
> > > >
> > > > This series aims to introduce a new SCMI unified userspace interface meant
> > > > to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
> > > > from the perspective of the OSPM agent (non-secure world only ...)
> > > >
> > > > It is proposed as a testing/development facility, it is NOT meant to be a
> > > > feature to use in production, but only enabled in Kconfig for test
> > > > deployments.
> > > >
> > > > Currently an SCMI Compliance Suite like the one at [1] can only work by
> > > > injecting SCMI messages at the SCMI transport layer using the mailbox test
> > > > driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
> > > > the related replies from the SCMI backend Server.
> > > >
> > >
> > > ...
> > >
> > > >
> > > > In V2 the runtime enable/disable switching capability has been removed
> > > > (for now) since still not deemed to be stable/reliable enough: as a
> > > > consequence when SCMI Raw support is compiled in, the regular SCMI stack
> > > > drivers are now inhibited permanently for that Kernel.
> > > >
> > > > A quick and trivial example from the shell...reading from a sensor
> > > > injecting a properly crafted packet in raw mode:
> > > >
> > > >         # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
> > > >         root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message
> > >
> > > I have tried your patchset with an SCMI server using an optee-os
> > > transport channel but I have a timed out error when trying your
> > > example above to read sensor1
> > >
> > > #  echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
> > > > /sys/kernel/debug/scmi_raw/message
> > > # [   93.306690] arm-scmi firmware:scmi0: timed out in RAW response -
> > > HDR:00005406
> > >
> > > and there no response available when trying to read it with
> > > # cat /sys/kernel/debug/scmi_raw/message
> > >
> >
> > is there anything cat'ting /sys/kernel/debug/scmi_raw/errors ?
> 
> It was empty
> 
> >
> > >
> > > The sensor 1 can be successfully read in normal mode:
> > > # cat /sys/class/hwmon/hwmon0/temp1_input
> > > 25000
> > > #
> > >
> > > In both case, the SCMI server received the requests and replied successfully
> > >
> > > Could it be that you process the answer differently in case of raw mode ?
> > >
> >
> > Well, absolutely, when in raw mode the reply is picked up directly into
> > the RX path and copied in a message queue to be read from asyncrhnously
> > later via debugfs.
> >
> > ... mmm I think I found the problem...the reply is picked up on the RX *IRQ*
> > path as of now...but in optee/SMC there is no interrupt (sometime there is in
> > SMC) and the reply is instead read back straight away (transport is marked as
> > sync_cmds_completed_on_ret=true in fact).... so this is the issue probably ...
> > I have NOT tested on anything but mailbox and virtio till now...and I
> > missed this possibility that this NO-irq reply was a thing even when NOT
> > in polling mode (which I do not support)...my bad :<
> >
> > Ok, next week I'll rework the series to fix this big_BUG and some other minor
> > things...in the meantime if you want to try this snippet down below...
> >
> > ... this won't definitely be the final patch but it could let you experiment
> > more (only build tested though )
> 
> Thanks.
> The patch below fixes my problem with optee transport layer
> 

Good, thanks for the patience.

Thanks,
Cristian

> >
> > Thanks for testing !
> > Cristian
> >
> > --->8-------
> >
> > diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
> > index 13eeebe4b7a8..b9fcb66a1b6a 100644
> > --- a/drivers/firmware/arm_scmi/raw_mode.c
> > +++ b/drivers/firmware/arm_scmi/raw_mode.c
> > @@ -197,6 +197,8 @@ struct scmi_dbg_raw_data {
> >         size_t rx_size;
> >  };
> >
> > +void scmi_raw_message_report(void *r, struct scmi_xfer *xfer, unsigned int idx);
> > +
> >  static inline
> >  struct scmi_raw_buffer *scmi_raw_buffer_get(struct scmi_raw_mode_info *raw,
> >                                             unsigned int idx)
> > @@ -389,22 +391,34 @@ static void scmi_xfer_raw_worker(struct work_struct *work)
> >
> >                 xfer = rw->xfer;
> >
> > -               /*
> > -                * Waiters are queued by wait-deadline at the end, so some of
> > -                * them could have been already expired when processed, BUT we
> > -                * have to check the completion status anyway just in case a
> > -                * virtually expired (aged) transaction was indeed completed
> > -                * fine and we'll have to wait for the asynchronous part (if
> > -                * any).
> > -                */
> > -               aging = jiffies - rw->start_jiffies;
> > -               tmo = max_tmo > aging ? max_tmo - aging : 0;
> > -
> > -               if ((tmo && !wait_for_completion_timeout(&xfer->done, tmo)) ||
> > -                   (!tmo && !try_wait_for_completion(&xfer->done))) {
> > -                       dev_err(dev, "timed out in RAW response - HDR:%08X\n",
> > -                               pack_scmi_header(&xfer->hdr));
> > -                       ret = -ETIMEDOUT;
> > +               if (!raw->desc->sync_cmds_completed_on_ret) {
> > +                       /*
> > +                        * Waiters are queued by wait-deadline at the end, so some of
> > +                        * them could have been already expired when processed, BUT we
> > +                        * have to check the completion status anyway just in case a
> > +                        * virtually expired (aged) transaction was indeed completed
> > +                        * fine and we'll have to wait for the asynchronous part (if
> > +                        * any).
> > +                        */
> > +                       aging = jiffies - rw->start_jiffies;
> > +                       tmo = max_tmo > aging ? max_tmo - aging : 0;
> > +
> > +                       if ((tmo &&
> > +                            !wait_for_completion_timeout(&xfer->done, tmo)) ||
> > +                            (!tmo && !try_wait_for_completion(&xfer->done))) {
> > +                               dev_err(dev,
> > +                                       "timed out in RAW response - HDR:%08X\n",
> > +                                       pack_scmi_header(&xfer->hdr));
> > +                               ret = -ETIMEDOUT;
> > +                       }
> > +               } else {
> > +                       raw->desc->ops->fetch_response(rw->cinfo, xfer);
> > +                       /* Trace polled replies. */
> > +                       trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id,
> > +                                           "RESP",
> > +                                           xfer->hdr.seq, xfer->hdr.status,
> > +                                           xfer->rx.buf, xfer->rx.len);
> > +                       scmi_raw_message_report(raw, xfer, SCMI_RAW_REPLY_QUEUE);
> >                 }
> >
> >                 /* Avoid unneeded async waits */
> >
> >
> > ---8<-------
> >

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