[PATCH v5 0/14] Introduce a unified API for SCMI Server testing

[PATCH v5 0/14] 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.

In V4 it has been added the support for transports lacking a completion_irq
or configured forcibly in polled mode.

In V5 it has been added:

 - support for possibly multiple SCMI instances is introduced and as a
   consequence the API is now rooted at /sys/kernel/debug/scmi_raw/0/
   (with any additional SCMI insance Raw accessors rooted at scmi_raw/1/..
    scmi_raw/2/... etc)

 - a new COEXISTENCE mode is added that can be enabled with
   CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX=y

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/0/message

	# READING BACK THE REPLY...
	root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/0/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/0/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/0/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/0/
├── errors
├── instance_name
├── 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.
 - instance_name: can be used to identify the SCMI instance that you are
   using through this Raw accessors: it corresponds to the SCMI DT top node
   full name of the underlying SCMI instance

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
...merge requests are in progress...for now it is just a mean for me to
test the testing API ... O_o)

The V5 series is based on sudeep/for-next/scmi [3] on top of commit:

commit 729371745c53 ("hwmon: (scmi) Register explicitly with Thermal Framework")

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

Thanks,
Cristian

---
v4 --> v5
- rebased on sudeep/for-next/scmi
- added multiple SCMI instances support
- added optional Raw full-cohexistence mode
- use custom tags to distinguish Raw msg_dump traces
- add circular handling of raw buffers queues for errors and notifications

V3 --> v4
- rebased on v6.1-rc1
- addedd missing support for 'polled' transports and transport lacking a
  completion_irq (like smc/optee)
- removed a few inlines
- refactored SCMI Raw RX patch to make use more extensively of the regular
  non-Raw RX path
- fix handling of O_NONBLOCK raw_mode read requests

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/tests/scmi-tests/-/commits/raw_mode_support_devel/
[3]: https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/log/?h=for-next/scmi

Cristian Marussi (14):
  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: Refactor polling helpers
  firmware: arm_scmi: Refactor scmi_wait_for_message_response
  firmware: arm_scmi: Add is_raw flag to xfer
  firmware: arm_scmi: Add xfer Raw helpers
  firmware: arm_scmi: Move errors defs and code to common.h
  firmware: arm_scmi: Add core 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: Create Raw debugfs root dentry
  firmware: arm_scmi: Call Raw mode hooks from the core stack
  firmware: arm_scmi: Add Raw mode coexistence support

 Documentation/ABI/testing/debugfs-scmi-raw |   98 ++
 drivers/firmware/arm_scmi/Kconfig          |   23 +
 drivers/firmware/arm_scmi/Makefile         |    1 +
 drivers/firmware/arm_scmi/common.h         |   72 +-
 drivers/firmware/arm_scmi/driver.c         |  557 +++++---
 drivers/firmware/arm_scmi/mailbox.c        |    4 +-
 drivers/firmware/arm_scmi/optee.c          |    4 +-
 drivers/firmware/arm_scmi/protocols.h      |    2 +
 drivers/firmware/arm_scmi/raw_mode.c       | 1340 ++++++++++++++++++++
 drivers/firmware/arm_scmi/raw_mode.h       |   30 +
 drivers/firmware/arm_scmi/smc.c            |    4 +-
 drivers/firmware/arm_scmi/virtio.c         |    2 +-
 12 files changed, 1980 insertions(+), 157 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

-- 
2.34.1


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[PATCH v5 01/14] 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 f818d00bb2c6..c16fd3a4d8ca 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;
-- 
2.34.1


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[PATCH v5 02/14] 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;
all it needs is a DT node to operate upon, not necessarily a full blown
device.

Simplify the helper to receive in input a reference to a device_node
instead of a device carrying a pointer to such device_node.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
v3 --> v4
- fixes in commmit message
---
 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 a1c0154c31c6..16db1e177123 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -153,7 +153,7 @@ 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 c16fd3a4d8ca..474fec4c0b3a 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 1e40cb035044..c33dcadafea8 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 2a7aeab40e54..5a11091c72da 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 87a7b13cf868..122128d56d2f 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 33c9b81a55cd..46c5ea3c8f54 100644
--- a/drivers/firmware/arm_scmi/virtio.c
+++ b/drivers/firmware/arm_scmi/virtio.c
@@ -386,7 +386,7 @@ 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;
 
-- 
2.34.1


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[PATCH v5 03/14] 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>
---
v4 --> v5
- fixed missing of_put as reported by
	Reported-by: kernel test robot <lkp@intel.com>
	Reported-by: Julia Lawall <julia.lawall@lip6.fr>
v3 --> v4
- fix missing devm_kfree on failpath in scmi_chan_setup
---
 drivers/firmware/arm_scmi/driver.c | 99 ++++++++++++++++++++++--------
 1 file changed, 75 insertions(+), 24 deletions(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 474fec4c0b3a..cbc1418014b7 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;
@@ -2046,27 +2043,45 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
 	if (!cinfo)
 		return -ENOMEM;
 
-	cinfo->dev = dev;
 	cinfo->rx_timeout_ms = info->desc->max_rx_timeout_ms;
 
+	/* 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);
+			devm_kfree(info->dev, cinfo);
+		}
 		return ret;
 	}
 
@@ -2075,13 +2090,14 @@ 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, report only memory errors */
-		ret = scmi_chan_setup(info, dev, prot_id, false);
+		ret = scmi_chan_setup(info, of_node, prot_id, false);
 		if (ret && ret != -ENOMEM)
 			ret = 0;
 	}
@@ -2089,6 +2105,48 @@ scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
 	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) {
+			of_node_put(child);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 /**
  * scmi_get_protocol_device  - Helper to get/create an SCMI device.
  *
@@ -2138,14 +2196,6 @@ 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;
 
@@ -2443,7 +2493,8 @@ 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;
 
-- 
2.34.1


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[PATCH v5 04/14] firmware: arm_scmi: Refactor polling helpers

[Cristian Marussi]

Refactor polling helpers to receive scmi_desc directly as a parameter and
move all of them to common.h.

No functional change.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/common.h | 18 ++++++++++++++++
 drivers/firmware/arm_scmi/driver.c | 34 ++++++++----------------------
 2 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 16db1e177123..b8ab2397d807 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -215,6 +215,24 @@ struct scmi_desc {
 	const bool atomic_enabled;
 };
 
+static inline bool is_polling_required(struct scmi_chan_info *cinfo,
+				       const struct scmi_desc *desc)
+{
+	return cinfo->no_completion_irq || desc->force_polling;
+}
+
+static inline bool is_transport_polling_capable(const struct scmi_desc *desc)
+{
+	return desc->ops->poll_done || desc->sync_cmds_completed_on_ret;
+}
+
+static inline bool is_polling_enabled(struct scmi_chan_info *cinfo,
+				      const struct scmi_desc *desc)
+{
+	return is_polling_required(cinfo, desc) &&
+		is_transport_polling_capable(desc);
+}
+
 #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 cbc1418014b7..080e0d4e921b 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -648,25 +648,6 @@ static inline void scmi_clear_channel(struct scmi_info *info,
 		info->desc->ops->clear_channel(cinfo);
 }
 
-static inline bool is_polling_required(struct scmi_chan_info *cinfo,
-				       struct scmi_info *info)
-{
-	return cinfo->no_completion_irq || info->desc->force_polling;
-}
-
-static inline bool is_transport_polling_capable(struct scmi_info *info)
-{
-	return info->desc->ops->poll_done ||
-		info->desc->sync_cmds_completed_on_ret;
-}
-
-static inline bool is_polling_enabled(struct scmi_chan_info *cinfo,
-				      struct scmi_info *info)
-{
-	return is_polling_required(cinfo, info) &&
-		is_transport_polling_capable(info);
-}
-
 static void scmi_handle_notification(struct scmi_chan_info *cinfo,
 				     u32 msg_hdr, void *priv)
 {
@@ -909,7 +890,8 @@ static int do_xfer(const struct scmi_protocol_handle *ph,
 	struct scmi_chan_info *cinfo;
 
 	/* Check for polling request on custom command xfers at first */
-	if (xfer->hdr.poll_completion && !is_transport_polling_capable(info)) {
+	if (xfer->hdr.poll_completion &&
+	    !is_transport_polling_capable(info->desc)) {
 		dev_warn_once(dev,
 			      "Polling mode is not supported by transport.\n");
 		return -EINVAL;
@@ -920,7 +902,7 @@ static int do_xfer(const struct scmi_protocol_handle *ph,
 		return -EINVAL;
 
 	/* True ONLY if also supported by transport. */
-	if (is_polling_enabled(cinfo, info))
+	if (is_polling_enabled(cinfo, info->desc))
 		xfer->hdr.poll_completion = true;
 
 	/*
@@ -1854,7 +1836,8 @@ static bool scmi_is_transport_atomic(const struct scmi_handle *handle,
 	bool ret;
 	struct scmi_info *info = handle_to_scmi_info(handle);
 
-	ret = info->desc->atomic_enabled && is_transport_polling_capable(info);
+	ret = info->desc->atomic_enabled &&
+		is_transport_polling_capable(info->desc);
 	if (ret && atomic_threshold)
 		*atomic_threshold = info->atomic_threshold;
 
@@ -2063,8 +2046,8 @@ static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node,
 		return ret;
 	}
 
-	if (tx && is_polling_required(cinfo, info)) {
-		if (is_transport_polling_capable(info))
+	if (tx && is_polling_required(cinfo, info->desc)) {
+		if (is_transport_polling_capable(info->desc))
 			dev_info(&tdev->dev,
 				 "Enabled polling mode TX channel - prot_id:%d\n",
 				 prot_id);
@@ -2505,7 +2488,8 @@ static int scmi_probe(struct platform_device *pdev)
 	if (scmi_notification_init(handle))
 		dev_err(dev, "SCMI Notifications NOT available.\n");
 
-	if (info->desc->atomic_enabled && !is_transport_polling_capable(info))
+	if (info->desc->atomic_enabled &&
+	    !is_transport_polling_capable(info->desc))
 		dev_err(dev,
 			"Transport is not polling capable. Atomic mode not supported.\n");
 
-- 
2.34.1


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[PATCH v5 05/14] firmware: arm_scmi: Refactor scmi_wait_for_message_response

[Cristian Marussi]

Refactor scmi_wait_for_message_response() to use a internal helper to
carry out its main duties; while doing that  make it accept directly an
scmi_desc parameter to interact with the configured transport.

No functional change.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 57 +++++++++++++++++-------------
 1 file changed, 33 insertions(+), 24 deletions(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 080e0d4e921b..33b123da3053 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -791,36 +791,18 @@ static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo,
 	       ktime_after(ktime_get(), stop);
 }
 
-/**
- * scmi_wait_for_message_response  - An helper to group all the possible ways of
- * waiting for a synchronous message response.
- *
- * @cinfo: SCMI channel info
- * @xfer: Reference to the transfer being waited for.
- *
- * Chooses waiting strategy (sleep-waiting vs busy-waiting) depending on
- * configuration flags like xfer->hdr.poll_completion.
- *
- * Return: 0 on Success, error otherwise.
- */
-static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo,
-					  struct scmi_xfer *xfer)
+static int scmi_wait_for_reply(struct device *dev, const struct scmi_desc *desc,
+			       struct scmi_chan_info *cinfo,
+			       struct scmi_xfer *xfer, unsigned int timeout_ms)
 {
-	struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
-	struct device *dev = info->dev;
-	int ret = 0, timeout_ms = info->desc->max_rx_timeout_ms;
-
-	trace_scmi_xfer_response_wait(xfer->transfer_id, xfer->hdr.id,
-				      xfer->hdr.protocol_id, xfer->hdr.seq,
-				      timeout_ms,
-				      xfer->hdr.poll_completion);
+	int ret = 0;
 
 	if (xfer->hdr.poll_completion) {
 		/*
 		 * Real polling is needed only if transport has NOT declared
 		 * itself to support synchronous commands replies.
 		 */
-		if (!info->desc->sync_cmds_completed_on_ret) {
+		if (!desc->sync_cmds_completed_on_ret) {
 			/*
 			 * Poll on xfer using transport provided .poll_done();
 			 * assumes no completion interrupt was available.
@@ -846,7 +828,7 @@ static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo,
 			 */
 			spin_lock_irqsave(&xfer->lock, flags);
 			if (xfer->state == SCMI_XFER_SENT_OK) {
-				info->desc->ops->fetch_response(cinfo, xfer);
+				desc->ops->fetch_response(cinfo, xfer);
 				xfer->state = SCMI_XFER_RESP_OK;
 			}
 			spin_unlock_irqrestore(&xfer->lock, flags);
@@ -870,6 +852,33 @@ static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo,
 	return ret;
 }
 
+/**
+ * scmi_wait_for_message_response  - An helper to group all the possible ways of
+ * waiting for a synchronous message response.
+ *
+ * @cinfo: SCMI channel info
+ * @xfer: Reference to the transfer being waited for.
+ *
+ * Chooses waiting strategy (sleep-waiting vs busy-waiting) depending on
+ * configuration flags like xfer->hdr.poll_completion.
+ *
+ * Return: 0 on Success, error otherwise.
+ */
+static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo,
+					  struct scmi_xfer *xfer)
+{
+	struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
+	struct device *dev = info->dev;
+
+	trace_scmi_xfer_response_wait(xfer->transfer_id, xfer->hdr.id,
+				      xfer->hdr.protocol_id, xfer->hdr.seq,
+				      info->desc->max_rx_timeout_ms,
+				      xfer->hdr.poll_completion);
+
+	return scmi_wait_for_reply(dev, info->desc, cinfo, xfer,
+				   info->desc->max_rx_timeout_ms);
+}
+
 /**
  * do_xfer() - Do one transfer
  *
-- 
2.34.1


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[PATCH v5 06/14] firmware: arm_scmi: Add is_raw flag to xfer

[Cristian Marussi]

Add a flag to easily identify xfers originated from Raw transmissions.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/protocols.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h
index 2f3bf691db7c..70a48adcc320 100644
--- a/drivers/firmware/arm_scmi/protocols.h
+++ b/drivers/firmware/arm_scmi/protocols.h
@@ -88,6 +88,7 @@ struct scmi_msg_hdr {
 /**
  * struct scmi_xfer - Structure representing a message flow
  *
+ * @is_raw: Flag to state if this xfer has been generated by RAW mode
  * @transfer_id: Unique ID for debug & profiling purpose
  * @hdr: Transmit message header
  * @tx: Transmit message
@@ -119,6 +120,7 @@ struct scmi_msg_hdr {
  * @priv: A pointer for transport private usage.
  */
 struct scmi_xfer {
+	bool is_raw;
 	int transfer_id;
 	struct scmi_msg_hdr hdr;
 	struct scmi_msg tx;
-- 
2.34.1


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[PATCH v5 07/14] 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>
---
v4 --> v5
- add handling of xfer->is_raw flag
v3 --> v4
- add scmi_xfer_raw_wait_for_response helper
- fixed typos in comments
v2 --> v3
- allow for DT-unknown protocols to get a channel
v1 --> v2
- added scmi_xfer_raw_channel_get
---
 drivers/firmware/arm_scmi/common.h |  12 +++
 drivers/firmware/arm_scmi/driver.c | 147 +++++++++++++++++++++++++++++
 2 files changed, 159 insertions(+)

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index b8ab2397d807..2a08c2c50bf8 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -233,6 +233,18 @@ static inline bool is_polling_enabled(struct scmi_chan_info *cinfo,
 		is_transport_polling_capable(desc);
 }
 
+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);
+
+int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
+					    struct scmi_xfer *xfer,
+					    unsigned int timeout_ms);
 #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 33b123da3053..c4fd29f81b1e 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 channel, 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 +472,63 @@ 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_xfer *xfer;
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	xfer = scmi_xfer_get(handle, &info->tx_minfo);
+	if (!IS_ERR(xfer))
+		xfer->is_raw = true;
+
+	return xfer;
+}
+
+/**
+ * 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, re-using 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 +557,23 @@ __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);
+
+	xfer->is_raw = false;
+	return __scmi_xfer_put(&info->tx_minfo, xfer);
+}
+
 /**
  * scmi_xfer_lookup_unlocked  -  Helper to lookup an xfer_id
  *
@@ -879,6 +1000,32 @@ static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo,
 				   info->desc->max_rx_timeout_ms);
 }
 
+/**
+ * scmi_xfer_raw_wait_for_message_response  - An helper to wait for a message
+ * reply to an xfer raw request on a specific channel for the required timeout.
+ *
+ * @cinfo: SCMI channel info
+ * @xfer: Reference to the transfer being waited for.
+ * @timeout_ms: The maximum timeout in milliseconds
+ *
+ * Return: 0 on Success, error otherwise.
+ */
+int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
+					    struct scmi_xfer *xfer,
+					    unsigned int timeout_ms)
+{
+	int ret;
+	struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
+	struct device *dev = info->dev;
+
+	ret = scmi_wait_for_reply(dev, info->desc, cinfo, xfer, timeout_ms);
+	if (ret)
+		dev_dbg(dev, "timed out in RAW response - HDR:%08X\n",
+			pack_scmi_header(&xfer->hdr));
+
+	return ret;
+}
+
 /**
  * do_xfer() - Do one transfer
  *
-- 
2.34.1


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[PATCH v5 08/14] 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 2a08c2c50bf8..bb0763197ad6 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 c4fd29f81b1e..9dcfe096cb2b 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)
 {
@@ -1115,8 +1077,6 @@ 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
-- 
2.34.1


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[PATCH v5 09/14] firmware: arm_scmi: Add core 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>
---
v4 --> v5
- avoid using raw_buffers in scmi_raw_error_report, prefer
  dynalloc GFP_ATOMIC
- use custom tags for Raw msg_dump traces
- use xfer->is_raw to enforce segregation of Raw transactions
- add multiple SCMI server instance support. New Raw debugfs is at
	<debugfs>/scmi_raw/0/...
- fix possible race in scmi_raw_message_dequeue between list_empty
  check and effective dequeuing.
- add circular handling of raw buffers queues for errors and
  notifications
v3 --> v4
- fix handling of O_NONBLOCK raw_mode read requests
- add support for polled/nocomnpletion_irq transports
- removed inlines
v2 --> v3
- changed to dev_dbg when retrying inflight reg
- refactored and simplfiied waiters deferred worker
- fixed sparse errors about LE and __poll_t
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
---
 drivers/firmware/arm_scmi/Kconfig    |   13 +
 drivers/firmware/arm_scmi/Makefile   |    1 +
 drivers/firmware/arm_scmi/driver.c   |    5 +-
 drivers/firmware/arm_scmi/raw_mode.c | 1337 ++++++++++++++++++++++++++
 drivers/firmware/arm_scmi/raw_mode.h |   30 +
 5 files changed, 1384 insertions(+), 2 deletions(-)
 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/driver.c b/drivers/firmware/arm_scmi/driver.c
index 9dcfe096cb2b..7c7f1a666d93 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -796,7 +796,8 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo,
 
 	trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id,
 			    xfer->hdr.type == MSG_TYPE_DELAYED_RESP ?
-			    "DLYD" : "RESP",
+			    (!xfer->is_raw ? "DLYD" : "dlyd") :
+			    (!xfer->is_raw ? "RESP" : "resp"),
 			    xfer->hdr.seq, xfer->hdr.status,
 			    xfer->rx.buf, xfer->rx.len);
 
@@ -918,7 +919,7 @@ static int scmi_wait_for_reply(struct device *dev, const struct scmi_desc *desc,
 
 			/* Trace polled replies. */
 			trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id,
-					    "RESP",
+					    !xfer->is_raw ? "RESP" : "resp",
 					    xfer->hdr.seq, xfer->hdr.status,
 					    xfer->rx.buf, xfer->rx.len);
 		}
diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
new file mode 100644
index 000000000000..deb345c740c5
--- /dev/null
+++ b/drivers/firmware/arm_scmi/raw_mode.c
@@ -0,0 +1,1337 @@
+// 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 deployments.
+ *
+ * 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.
+ * All defined SCMI instances are rooted under a common top scmi_raw debugfs
+ * entry with each instance, in turn, rooted under a sequentially numbered
+ * containing subdirectory like:
+ *
+ *	/sys/kernel/debug/scmi_raw/0/
+ *	|-- errors
+ *	|-- instance_name
+ *	|-- 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
+ *  - instance_name: used to identify the underlying SCMI instance which is
+ *		     accessed by this Raw accessors; it corresponds to the
+ *		     full_name of the top SCMI DT node under which the SCMI
+ *		     instance is rooted.
+ *  - 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/atomic.h>
+#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/of.h>
+#include <linux/slab.h>
+
+#include "common.h"
+
+#include "raw_mode.h"
+
+#include <trace/events/scmi.h>
+
+#define SCMI_XFER_RAW_MAX_RETRIES	10
+
+static atomic_t scmi_raw_instance_counter = ATOMIC_INIT(-1);
+
+/**
+ * struct scmi_raw_mode_info  - Structure holding SCMI Raw instance data
+ *
+ * @id: Sequential Raw instance ID.
+ * @name: Full name of the DT node associated to the SCMI instance which is
+ *	  represented by this Raw instance.
+ * @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 {
+	unsigned int id;
+	const char *name;
+	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 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 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 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 struct scmi_raw_buffer*
+scmi_raw_buffer_dequeue_unlocked(struct scmi_raw_mode_info *raw,
+				 unsigned int idx)
+{
+	struct scmi_raw_buffer *rb = NULL;
+
+	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);
+	}
+
+	return rb;
+}
+
+static 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;
+
+	spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	rb = scmi_raw_buffer_dequeue_unlocked(raw, idx);
+	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 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 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 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 int timeout_ms;
+		unsigned long aging;
+		struct scmi_xfer *xfer;
+		struct scmi_xfer_raw_waiter *rw;
+		struct scmi_chan_info *cinfo;
+
+		rw = scmi_xfer_raw_waiter_dequeue(raw);
+		if (!rw)
+			return;
+
+		cinfo = rw->cinfo;
+		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): for this reason a 1 ms timeout is used for already
+		 * expired/aged xfers.
+		 */
+		aging = jiffies - rw->start_jiffies;
+		timeout_ms = max_tmo > aging ?
+			jiffies_to_msecs(max_tmo - aging) : 1;
+
+		ret = scmi_xfer_raw_wait_for_message_response(cinfo, xfer,
+							      timeout_ms);
+		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) {
+			unsigned long 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;
+	}
+
+	/* True ONLY if also supported by transport. */
+	if (is_polling_enabled(cinfo, raw->desc))
+		xfer->hdr.poll_completion = true;
+
+	reinit_completion(&xfer->done);
+	/* Make sure xfer state update is visible before sending */
+	smp_store_mb(xfer->state, SCMI_XFER_SENT_OK);
+
+	trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id,
+			      xfer->hdr.protocol_id, xfer->hdr.seq,
+			      xfer->hdr.poll_completion);
+
+	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,
+			 bool o_nonblock)
+{
+	unsigned long flags;
+	struct scmi_raw_buffer *rb;
+
+	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 (o_nonblock)
+			return ERR_PTR(-EAGAIN);
+
+		if (wait_event_interruptible(raw->wqs[idx],
+					     !list_empty(&raw->msg_q[idx])))
+			return ERR_PTR(-ERESTARTSYS);
+
+		spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	}
+
+	rb = scmi_raw_buffer_dequeue_unlocked(raw, idx);
+
+	spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+	return rb;
+}
+
+/**
+ * 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.
+ * @o_nonblock: A flag to request a non-blocking message dequeue.
+ *
+ * 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,
+				    bool o_nonblock)
+{
+	int ret = 0;
+	struct scmi_raw_buffer *rb;
+
+	rb = scmi_raw_message_dequeue(raw, idx, o_nonblock);
+	if (IS_ERR(rb)) {
+		dev_dbg(raw->handle->dev, "RAW - No message available!\n");
+		return PTR_ERR(rb);
+	}
+
+	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 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,
+					       filp->f_flags & O_NONBLOCK);
+		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 __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, raw->id);
+	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
+ * @raw_top_dentry: A reference to the top Raw debugfs dentry
+ * @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,
+			 struct dentry *raw_top_dentry,
+			 const struct scmi_desc *desc, int tx_max_msg)
+{
+	int ret;
+	char instance_dir[8];
+	struct scmi_raw_mode_info *raw;
+	struct device *dev;
+
+	if (!handle || !desc || !raw_top_dentry)
+		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;
+	raw->id = atomic_inc_return(&scmi_raw_instance_counter);
+	raw->name = kstrdup(of_node_full_name(dev->of_node), GFP_KERNEL);
+	if (!raw->name) {
+		devm_kfree(dev, raw);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = scmi_raw_mode_setup(raw);
+	if (ret) {
+		kfree(raw->name);
+		devm_kfree(dev, raw);
+		atomic_dec(&scmi_raw_instance_counter);
+		return ERR_PTR(ret);
+	}
+
+	snprintf(instance_dir, 8, "%u", raw->id);
+	raw->dentry = debugfs_create_dir(instance_dir, raw_top_dentry);
+	if (IS_ERR(raw->dentry)) {
+		ret = PTR_ERR(raw->dentry);
+		devres_release_group(dev, raw->gid);
+		kfree(raw->name);
+		devm_kfree(dev, raw);
+		atomic_dec(&scmi_raw_instance_counter);
+		return ERR_PTR(ret);
+	}
+
+	debugfs_create_str("instance_name", 0400, raw->dentry,
+			   (char **)&raw->name);
+
+	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);
+
+	dev_info(dev, "SCMI RAW Mode initialized for instance %d - (%s)\n",
+		 raw->id, raw->name);
+
+	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);
+
+	kfree(raw->name);
+}
+
+static int scmi_xfer_raw_collect(void *msg, size_t *msg_len,
+				 struct scmi_xfer *xfer)
+{
+	__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;
+	unsigned long flags;
+	struct scmi_raw_buffer *rb;
+	struct device *dev;
+	struct scmi_raw_mode_info *raw = r;
+
+	if (!raw || (idx == SCMI_RAW_REPLY_QUEUE && !xfer->is_raw))
+		return;
+
+	dev = raw->handle->dev;
+
+	/*
+	 * Grab the msg_q_lock upfront to avoid a possible race between
+	 * realizing the free list was empty and effectively picking the next
+	 * buffer to use from the oldest one enqueued and still unread on this
+	 * msg_q.
+	 *
+	 * Note that nowhere else these locks are taken together, so no risk of
+	 * deadlocks du eto inversion.
+	 */
+	spin_lock_irqsave(&raw->msg_q_lock[idx], flags);
+	rb = scmi_raw_buffer_get(raw, idx);
+	if (!rb) {
+		/*
+		 * Immediate and delayed replies to previously injected Raw
+		 * commands MUST be read back from userspace to free the buffers:
+		 * if this is not happening something is seriously broken and
+		 * must be fixed at the application level: complain loudly.
+		 */
+		if (idx == SCMI_RAW_REPLY_QUEUE) {
+			spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+			dev_warn(dev,
+				 "RAW[%d] - Buffers exhausted. Dropping report.\n",
+				 idx);
+			return;
+		}
+
+		/*
+		 * Notifications and errors queues are instead handled in a
+		 * circular manner: unread old buffers are just overwritten by
+		 * newer ones.
+		 *
+		 * The main reason for this is that notifications originated
+		 * by Raw requests cannot be distinguished from normal ones, so
+		 * your Raw buffers queues risk to be flooded and depleted by
+		 * notifications if you left it mistakenly enabled or when in
+		 * coexistence mode.
+		 */
+		rb = scmi_raw_buffer_dequeue_unlocked(raw, idx);
+		if (WARN_ON(!rb)) {
+			spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+			return;
+		}
+
+		/* Reset to full buffer length */
+		rb->msg.len = rb->max_len;
+
+		dev_warn_once(dev,
+			      "RAW[%d] - Buffers exhausted. Re-using oldest.\n",
+			      idx);
+	}
+	spin_unlock_irqrestore(&raw->msg_q_lock[idx], flags);
+
+	ret = scmi_xfer_raw_collect(rb->msg.buf, &rb->msg.len, xfer);
+	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_mode_info *raw = r;
+
+	if (!raw)
+		return;
+
+	xfer.rx.len = raw->desc->max_msg_size;
+	xfer.rx.buf = kzalloc(xfer.rx.len, GFP_ATOMIC);
+	if (!xfer.rx.buf) {
+		dev_info(raw->handle->dev,
+			 "Cannot report Raw error for HDR:0x%X - ENOMEM\n",
+			 msg_hdr);
+		return;
+	}
+
+	/* Any transport-provided priv must be passed back down to transport */
+	if (priv)
+		/* Ensure priv is visible */
+		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);
+
+	kfree(xfer.rx.buf);
+}
diff --git a/drivers/firmware/arm_scmi/raw_mode.h b/drivers/firmware/arm_scmi/raw_mode.h
new file mode 100644
index 000000000000..ca5018c35c2e
--- /dev/null
+++ b/drivers/firmware/arm_scmi/raw_mode.h
@@ -0,0 +1,30 @@
+/* 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,
+			 struct dentry *raw_top_dentry,
+			 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 */
-- 
2.34.1


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[PATCH v5 10/14] 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>
---
v4 --> v5
- updated ABI description for multiple SCMI instances support
---
 Documentation/ABI/testing/debugfs-scmi-raw | 98 ++++++++++++++++++++++
 1 file changed, 98 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..f50fead5d2a8
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-scmi-raw
@@ -0,0 +1,98 @@
+What:		/sys/kernel/debug/scmi_raw/<n>/instance_name
+Date:		December 2022
+KernelVersion:	6.2
+Contact:	cristian.marussi@arm.com
+Description:	The name of the underlying SCMI instance accessed by this Raw
+		interface accessors expressed as the full name of the top DT
+		SCMI node under which the SCMI instance is rooted.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/<n>/transport_max_msg_size
+Date:		December 2022
+KernelVersion:	6.2
+Contact:	cristian.marussi@arm.com
+Description:	Max message size of allowed SCMI messages for the currently
+		configured SCMI transport for instance <n>.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/<n>/transport_tx_max_msg
+Date:		December 2022
+KernelVersion:	6.2
+Contact:	cristian.marussi@arm.com
+Description:	Max number of concurrently allowed in-flight SCMI messages for
+		the currently configured SCMI transport for instance <n>.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/<n>/transport_rx_timeout_ms
+Date:		December 2022
+KernelVersion:	6.2
+Contact:	cristian.marussi@arm.com
+Description:	Timeout in milliseconds allowed for SCMI synchronous replies
+		for the currently configured SCMI transport for instance <n>.
+Users:		Debugging, any userspace test suite
+
+What:		/sys/kernel/debug/scmi_raw/<n>/message
+Date:		December 2022
+KernelVersion:	6.2
+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 for instance <n>.
+		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/<n>/message_async
+Date:		December 2022
+KernelVersion:	6.2
+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 for instance <n>.
+		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/<n>/errors
+Date:		December 2022
+KernelVersion:	6.2
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw message errors facility; any kind of timed-out or
+		generally unexpectedly received SCMI message, for instance <n>,
+		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/<n>/notification
+Date:		December 2022
+KernelVersion:	6.2
+Contact:	cristian.marussi@arm.com
+Description:	SCMI Raw notification snooping facility; any notification
+		emitted by the backend SCMI server, for instance <n>, 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/<n>/reset
+Date:		December 2022
+KernelVersion:	6.2
+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, for instance <n>.
+		Can be used to reset and clean the SCMI Raw stack between to
+		different test-run.
+Users:		Debugging, any userspace test suite
-- 
2.34.1


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[PATCH v5 11/14] 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 7c7f1a666d93..c5bc67a9c103 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2380,6 +2380,12 @@ 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.
-- 
2.34.1


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[PATCH v5 12/14] firmware: arm_scmi: Create Raw debugfs root dentry

[Cristian Marussi]

Create common root debugfs dentry at driver initialization time.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/driver.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index c5bc67a9c103..bbb43b65cbfd 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -14,8 +14,11 @@
  * Copyright (C) 2018-2021 ARM Ltd.
  */
 
+#define pr_fmt(fmt) "SCMI - " fmt
+
 #include <linux/bitmap.h>
 #include <linux/device.h>
+#include <linux/debugfs.h>
 #include <linux/export.h>
 #include <linux/idr.h>
 #include <linux/io.h>
@@ -154,6 +157,8 @@ struct scmi_info {
 	int users;
 };
 
+static struct dentry *scmi_raw_top_dentry;
+
 #define handle_to_scmi_info(h)	container_of(h, struct scmi_info, handle)
 
 void scmi_notification_instance_data_set(const struct scmi_handle *handle,
@@ -2839,6 +2844,14 @@ static int __init scmi_driver_init(void)
 	if (WARN_ON(!IS_ENABLED(CONFIG_ARM_SCMI_HAVE_TRANSPORT)))
 		return -EINVAL;
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		scmi_raw_top_dentry = debugfs_create_dir("scmi_raw", NULL);
+		if (IS_ERR(scmi_raw_top_dentry)) {
+			pr_err("Could NOT create RAW top dentry.\n");
+			scmi_raw_top_dentry = NULL;
+		}
+	}
+
 	scmi_bus_init();
 
 	/* Initialize any compiled-in transport which provided an init/exit */
@@ -2863,6 +2876,9 @@ subsys_initcall(scmi_driver_init);
 
 static void __exit scmi_driver_exit(void)
 {
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
+		debugfs_remove_recursive(scmi_raw_top_dentry);
+
 	scmi_base_unregister();
 
 	scmi_clock_unregister();
-- 
2.34.1


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[PATCH v5 13/14] 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>
---
v4 --> v5
- rework to use multiple SCMI instances
v3 --> v4
- add call hooks to support polled transports
v1 --> v2
- fixes need to use multiple cinfo if available
---
 drivers/firmware/arm_scmi/driver.c | 45 ++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index bbb43b65cbfd..9f8e5d42c7aa 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -37,6 +37,8 @@
 #include "common.h"
 #include "notify.h"
 
+#include "raw_mode.h"
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/scmi.h>
 
@@ -136,6 +138,7 @@ 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;
@@ -155,6 +158,7 @@ struct scmi_info {
 	void *notify_priv;
 	struct list_head node;
 	int users;
+	void *raw;
 };
 
 static struct dentry *scmi_raw_top_dentry;
@@ -772,6 +776,11 @@ 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);
@@ -785,6 +794,9 @@ 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;
@@ -817,6 +829,16 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo,
 		complete(&xfer->done);
 	}
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		/*
+		 * When in polling mode avoid to queue the Raw xfer on the IRQ
+		 * RX path since it will be already queued at the end of the TX
+		 * poll loop.
+		 */
+		if (!xfer->hdr.poll_completion)
+			scmi_raw_message_report(info->raw, xfer, SCMI_RAW_REPLY_QUEUE);
+	}
+
 	scmi_xfer_command_release(info, xfer);
 }
 
@@ -927,6 +949,14 @@ static int scmi_wait_for_reply(struct device *dev, const struct scmi_desc *desc,
 					    !xfer->is_raw ? "RESP" : "resp",
 					    xfer->hdr.seq, xfer->hdr.status,
 					    xfer->rx.buf, xfer->rx.len);
+
+			if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+				struct scmi_info *info =
+					handle_to_scmi_info(cinfo->handle);
+
+				scmi_raw_message_report(info->raw, xfer,
+							SCMI_RAW_REPLY_QUEUE);
+			}
 		}
 	} else {
 		/* And we wait for the response. */
@@ -2613,6 +2643,18 @@ 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, scmi_raw_top_dentry,
+					       info->desc,
+					       info->tx_minfo.max_msg);
+		if (IS_ERR(info->raw)) {
+			dev_err(dev, "Failed to initialize SCMI RAW Mode !\n");
+			return PTR_ERR(info->raw);
+		}
+
+		return 0;
+	}
+
 	if (scmi_notification_init(handle))
 		dev_err(dev, "SCMI Notifications NOT available.\n");
 
@@ -2687,6 +2729,9 @@ 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)
 		dev_warn(&pdev->dev,
-- 
2.34.1


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[PATCH v5 14/14] firmware: arm_scmi: Add Raw mode coexistence support

[Cristian Marussi]

When Raw support is enabled and configured in coexistence mode the normal
SCMI drivers are allowed to register with the SCMI core and operate as
usual alongside the Raw operations.

SCMI Normal and Raw messages will be kept segregated from each other, but
only at the transaction level: any further possible interference at the
protocol layer will have instead to be handled by the user to attain
reliable results while using Raw transactions.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/Kconfig    | 10 ++++++++++
 drivers/firmware/arm_scmi/driver.c   | 12 +++++++++---
 drivers/firmware/arm_scmi/raw_mode.c |  5 ++++-
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index ab726a92ac2f..743f53fbe2f8 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig
@@ -36,6 +36,16 @@ config ARM_SCMI_RAW_MODE_SUPPORT
 	  order to avoid unexpected interactions with the SCMI Raw message
 	  flow. If unsure say N.
 
+config ARM_SCMI_RAW_MODE_SUPPORT_COEX
+	bool "Allow SCMI Raw mode coexistence with normal SCMI stack"
+	depends on ARM_SCMI_RAW_MODE_SUPPORT
+	help
+	  Allow SCMI Raw transmission mode to coexist with normal SCMI stack.
+
+	  This will allow regular SCMI drivers to register with the core and
+	  operate normally, thing which could make an SCMI test suite using the
+	  SCMI Raw mode support unreliable. If unsure, say N.
+
 config ARM_SCMI_HAVE_TRANSPORT
 	bool
 	help
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 9f8e5d42c7aa..9a5bd8526738 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2415,7 +2415,8 @@ 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)) {
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) &&
+	    !IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX)) {
 		pr_warn("SCMI Raw mode active. Rejecting '%s'/0x%02X\n",
 			id_table->name, id_table->protocol_id);
 		return -EINVAL;
@@ -2644,15 +2645,20 @@ static int scmi_probe(struct platform_device *pdev)
 		goto clear_txrx_setup;
 
 	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		int ret = 0;
+
 		info->raw = scmi_raw_mode_init(handle, scmi_raw_top_dentry,
 					       info->desc,
 					       info->tx_minfo.max_msg);
 		if (IS_ERR(info->raw)) {
 			dev_err(dev, "Failed to initialize SCMI RAW Mode !\n");
-			return PTR_ERR(info->raw);
+			ret = PTR_ERR(info->raw);
 		}
 
-		return 0;
+		if (!IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX))
+			return ret;
+
+		dev_info(dev, "SCMI RAW Mode COEX enabled !\n");
 	}
 
 	if (scmi_notification_init(handle))
diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
index deb345c740c5..edab6158f81e 100644
--- a/drivers/firmware/arm_scmi/raw_mode.c
+++ b/drivers/firmware/arm_scmi/raw_mode.c
@@ -26,7 +26,10 @@
  * 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.
+ * inhibited, unless CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX is enabled: in this
+ * latter case the regular SCMI stack drivers will be loaded as usual and it is
+ * up to the user of this interface to take care of manually inhibiting the
+ * regular SCMI drivers in order to avoid interferences during the test runs.
  *
  * The exposed API is as follows.
  * All defined SCMI instances are rooted under a common top scmi_raw debugfs
-- 
2.34.1


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