rpmsg: glink: Avoid dereferencing NULL channel

The newly introduced signal command handler checks for non-existing
channel and print an error message, but then continues on to dereference
that same channel.

Instead abort the handler when no channel is found.

Fixes: a2b73aa512a4 ("rpmsg: glink: Add support to handle signals command")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202307160800.sb7gMnL6-lkp@intel.com/
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Link: https://lore.kernel.org/r/20230717165538.1542034-1-quic_bjorande@quicinc.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

rpmsg: glink: Add check for kstrdup

Add check for the return value of kstrdup() and return the error
if it fails in order to avoid NULL pointer dereference.

Fixes: b4f8e52b89f6 ("rpmsg: Introduce Qualcomm RPM glink driver")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/20230619030631.12361-1-jiasheng@iscas.ac.cn
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

rpmsg: glink: Add support to handle signals command

Remote peripherals send signal notifications over glink with commandID 15.

Add support to send and receive the signal command and based signals
enable or disable flow control with remote host.

Signed-off-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Deepak Kumar Singh <quic_deesin@quicinc.com>
Signed-off-by: Sarannya S <quic_sarannya@quicinc.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Link: https://lore.kernel.org/r/1688679698-31274-3-git-send-email-quic_sarannya@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

rpmsg: glink: Consolidate TX_DATA and TX_DATA_CONT

Rather than duplicating most of the code for constructing the initial
TX_DATA and subsequent TX_DATA_CONT packets, roll them into a single
loop.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230418163018.785524-3-quic_bjorande@quicinc.com

rpmsg: glink: Propagate TX failures in intentless mode as well

As support for splitting transmission over several messages using
TX_DATA_CONT was introduced it does not immediately return the return
value of qcom_glink_tx().

The result is that in the intentless case (i.e. intent == NULL), the
code will continue to send all additional chunks. This is wasteful, and
it's possible that the send operation could incorrectly indicate
success, if the last chunk fits in the TX fifo.

Fix the condition.

Fixes: 8956927faed3 ("rpmsg: glink: Add TX_DATA_CONT command while sending")
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230418163018.785524-2-quic_bjorande@quicinc.com

rpmsg: glink: Wait for intent, not just request ack

In some implementations of the remote firmware, an intent request
acknowledgment is sent when it's determined if the intent allocation
will be fulfilled, but then the intent is queued after the
acknowledgment.

The result is that upon receiving a granted allocation request, the
search for the newly allocated intent will fail and an additional
request will be made. This will at best waste memory, but if the second
request is rejected the transaction will be incorrectly rejected.

Take the incoming intent into account in the wait to mitigate this
problem.

The above scenario can still happen, in the case that, on that same
channel, an unrelated intent is delivered prior to the request
acknowledgment and a separate process enters the send path and picks up
the intent. Given that there's no relationship between the
acknowledgment and the delivered (or to be delivered intent), there
doesn't seem to be a solution to this problem.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
[bjorn: Fixed spelling issues pointed out by checkpatch in commit message]
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230327144617.3134175-3-quic_bjorande@quicinc.com

rpmsg: glink: Transition intent request signaling to wait queue

Transition the intent request acknowledgement to use a wait queue so
that it's possible, in the next commit, to extend the wait to also wait
for an incoming intent.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230327144617.3134175-2-quic_bjorande@quicinc.com

rpmsg: glink: Release driver_override

Upon termination of the rpmsg_device, driver_override needs to be freed
to avoid leaking the potentially assigned string.

Fixes: 42cd402b8fd4 ("rpmsg: Fix kfree() of static memory on setting driver_override")
Fixes: 39e47767ec9b ("rpmsg: Add driver_override device attribute for rpmsg_device")
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109223931.1706429-1-quic_bjorande@quicinc.com

rpmsg: glink: Avoid infinite loop on intent for missing channel

In the event that an intent advertisement arrives on an unknown channel
the fifo is not advanced, resulting in the same message being handled
over and over.

Fixes: dacbb35e930f ("rpmsg: glink: Receive and store the remote intent buffers")
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230214234231.2069751-1-quic_bjorande@quicinc.com

rpmsg: glink: Fix GLINK command prefix

The upstream GLINK driver was first introduced to communicate with the
RPM on MSM8996, presumably as an artifact from that era the command
defines was prefixed RPM_CMD, while they actually are GLINK_CMDs.

Let's rename these, to keep things tidy. No functional change.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230214225933.2025595-1-quic_bjorande@quicinc.com

rpmsg: glink: Fix spelling of peek

The code is peeking into the buffers, not peaking. Fix this throughout
the glink drivers.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230214224746.1996130-1-quic_bjorande@quicinc.com

rpmsg: glink: Cancel pending intent requests at removal

During removal of the glink edge interrupts are disabled and no more
incoming messages are being serviced. In addition to the remote endpoint
being defunct that means that any outstanding requests for intents will
not be serviced, and qcom_glink_request_intent() will blindly wait for
up to 10 seconds.

Mark the intent request as not granted and complete the intent request
completion to fail the waiting client immediately.

Once the current intent request is failed, any potential clients waiting
for the intent request mutex will not enter the same wait, as the
qcom_glink_tx() call will fail fast.

Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230213155215.1237059-7-quic_bjorande@quicinc.com

rpmsg: glink: Fail qcom_glink_tx() once remove has been initiated

Upon removing the glink edge, communication is at best one-way. This
means that the very common scenario of glink requesting intents will not
be possible to serve.

Typically a successful transmission results in the client waiting for a
response, with some timeout and a mechanism for aborting that timeout.

Because of this, once the glink edge is defunct once removal is
commenced it's better to fail transmissions fast.

Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230213155215.1237059-6-quic_bjorande@quicinc.com

rpmsg: glink: Move irq and mbox handling to transports

Not all GLINK transports uses an interrupt and a mailbox instance. The
interrupt for RPM needs to be IRQF_NOSUSPEND, while it seems reasonable
for the SMEM interrupt to use irq_set_wake. The glink struct device is
constructed in the SMEM and RPM drivers but torn down in the core
driver.

Move the interrupt and kick handling into the SMEM and RPM driver, to
improve this and facilitate further improvements.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230213155215.1237059-5-quic_bjorande@quicinc.com

rpmsg: glink: Extract tx kick operation

Refactor out the tx kick operations to its own function, in preparation
for pushing the details to the individual transports.

Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230213155215.1237059-2-quic_bjorande@quicinc.com

rpmsg: convert sysfs snprintf to sysfs_emit

Fix the following coccicheck warning:
drivers/rpmsg/qcom_glink_native.c:1677:8-16:
WARNING: use scnprintf or sprintf

Signed-off-by: Xuezhi Zhang <zhangxuezhi1@coolpad.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220607120649.78436-1-zhangxuezhi1@coolpad.com

rpmsg: qcom: glink: remove unused name

The qcom_glink.name is read from DTS but never used further, never
referenced, so drop it. This also fixes kerneldoc warning:

drivers/rpmsg/qcom_glink_native.c:125:
warning: Function parameter or member 'name' not described in 'qcom_glink'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220519073330.7187-2-krzysztof.kozlowski@linaro.org

rpmsg: qcom: glink: replace strncpy() with strscpy_pad()

The use of strncpy() is considered deprecated for NUL-terminated
strings[1]. Replace strncpy() with strscpy_pad(), to keep existing
pad-behavior of strncpy, similarly to commit 08de420a8014 ("rpmsg:
glink: Replace strncpy() with strscpy_pad()"). This fixes W=1 warning:

In function ‘qcom_glink_rx_close’,
inlined from ‘qcom_glink_work’ at ../drivers/rpmsg/qcom_glink_native.c:1638:4:
drivers/rpmsg/qcom_glink_native.c:1549:17: warning: ‘strncpy’ specified bound 32 equals destination size [-Wstringop-truncation]
1549 | strncpy(chinfo.name, channel->name, sizeof(chinfo.name));

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220519073330.7187-1-krzysztof.kozlowski@linaro.org

rpmsg: Update rpmsg_chrdev_register_device function

The rpmsg_chrdev driver has been replaced by the rpmsg_ctrl driver
for the /dev/rpmsg_ctrlX devices management. The reference for the
driver override is now the rpmsg_ctrl.

Update the rpmsg_chrdev_register_device function to reflect the update,
and rename the function to use the rpmsg_ctrldev prefix.

The platform drivers are updated accordingly.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220124102524.295783-8-arnaud.pouliquen@foss.st.com

rpmsg: use struct_size over open coded arithmetic

Replace zero-length array with flexible-array member and make use
of the struct_size() helper in kzalloc(). For example:

struct glink_defer_cmd {
struct list_head node;

struct glink_msg msg;
u8 data[];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220216030720.1839503-1-chi.minghao@zte.com.cn

rpmsg: Fix documentation return formatting

kernel documentation specification:
"The return value, if any, should be described in a dedicated section
named Return."

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Link: https://lore.kernel.org/r/20211108140126.3530-1-arnaud.pouliquen@foss.st.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

rpmsg: glink: Send READ_NOTIFY command in FIFO full case

The current design sleeps unconditionally in TX FIFO full case and
wakeup only after sleep timer expires which adds random delays in
clients TX path.

Avoid sleep and use READ_NOTIFY command so that writer can be woken up
when remote notifies about read completion by sending IRQ.

Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1596086296-28529-7-git-send-email-deesin@codeaurora.org

rpmsg: glink: Remove channel decouple from rpdev release

If a channel is being rapidly restarting and the kobj release worker is
busy, there is a chance the rpdev_release function will run after the
channel struct itself has been released.

There should not be a need to decouple the channel from rpdev in the
rpdev release since that should only happen from the close commands.

Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1596086296-28529-6-git-send-email-deesin@codeaurora.org

rpmsg: glink: Remove the rpmsg dev in close_ack

Un-register and register of rpmsg driver is sending invalid open_ack
on closed channel.

To avoid sending invalid open_ack case unregister the rpmsg device
after receiving the local_close_ack from remote side.

Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
[bjorn: s/strlcpy/strscpy/]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1596086296-28529-5-git-send-email-deesin@codeaurora.org

rpmsg: glink: Add TX_DATA_CONT command while sending

With current design the transport can send packets of size upto
FIFO_SIZE which is 16k and return failure for all packets above 16k.

Add TX_DATA_CONT command to send packets greater than 16k by splitting
into 8K chunks.

Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1596086296-28529-4-git-send-email-deesin@codeaurora.org

rpmsg: glink: Replace strncpy() with strscpy_pad()

The use of strncpy() is considered deprecated for NUL-terminated
strings[1]. Replace strncpy() with strscpy_pad() (as it seems this case
expects the NUL padding to fill the allocation following the flexible
array). This additionally silences a warning seen when building under
-Warray-bounds:

./include/linux/fortify-string.h:38:30: warning: '__builtin_strncpy' offset 24 from the object at '__mptr' is out of the bounds of referenced subobject 'data' with type 'u8[]' {aka 'unsigned char[]'} at offset 24 [-Warray-bounds]
38 | #define __underlying_strncpy __builtin_strncpy
| ^
./include/linux/fortify-string.h:50:9: note: in expansion of macro '__underlying_strncpy'
50 | return __underlying_strncpy(p, q, size);
| ^~~~~~~~~~~~~~~~~~~~
drivers/rpmsg/qcom_glink_native.c: In function 'qcom_glink_work':
drivers/rpmsg/qcom_glink_native.c:36:5: note: subobject 'data' declared here
36 | u8 data[];
| ^~~~

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings

Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-remoteproc@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20210728020745.GB35706@embeddedor
Link: https://lore.kernel.org/r/20210818060533.3569517-4-keescook@chromium.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: qcom_glink_native: fix error return code of qcom_glink_rx_data()

When idr_find() returns NULL to intent, no error return code of
qcom_glink_rx_data() is assigned.
To fix this bug, ret is assigned with -ENOENT in this case.

Fixes: 64f95f87920d ("rpmsg: glink: Use the local intents when receiving data")
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Link: https://lore.kernel.org/r/20210306133624.17237-1-baijiaju1990@gmail.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: char: Use rpmsg_sendto to specify the message destination address

When the endpoint device is created by the application, a destination
address is specified in the rpmsg_channel_info structure. Since the
rpmsg_endpoint structure does not store the destination address,
this destination address must be specified when sending a message.

Replaces rpmsg_send with rpmsg_sendto to allow to specify the
destination address. This implementation is requested for compatibly with
some rpmsg backends like the virtio backend.

For this, the GLINK an SMD drivers have been updated to support the
rpmsg_sendto, even if the destination address is ignored for these
backends. For these drivers, the rpmsg_send and rpmsg_trysend ops are
preserved to avoid breaking the legacy.

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

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210311140413.31725-5-arnaud.pouliquen@foss.st.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Expose rpmsg name attr for glink

Expose the name field as an attr so clients listening to uevents for
rpmsg can identify the edge the events correspond to.

Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
Link: https://lore.kernel.org/r/1593017121-7953-5-git-send-email-deesin@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Add support for rpmsg glink chrdev

RPMSG provides a char device interface to userspace. Probe the rpmsg
chrdev channel to enable the rpmsg_ctrl device creation on glink
transports.

Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
Link: https://lore.kernel.org/r/1593017121-7953-4-git-send-email-deesin@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Use complete_all for open states

The open_req and open_ack completion variables are the state variables
to represet a remote channel as open. Use complete_all so there are no
races with waiters and using completion_done.

Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
Link: https://lore.kernel.org/r/1593017121-7953-2-git-send-email-deesin@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

rpmsg: glink: Free pending deferred work on remove

By just cancelling the deferred rx worker during GLINK instance teardown
any pending deferred commands are leaked, so free them.

Fixes: b4f8e52b89f6 ("rpmsg: Introduce Qualcomm RPM glink driver")
Cc: stable@vger.kernel.org
Acked-by: Chris Lew <clew@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Don't send pending rx_done during remove

Attempting to transmit rx_done messages after the GLINK instance is
being torn down will cause use after free and memory leaks. So cancel
the intent_work and free up the pending intents.

With this there are no concurrent accessors of the channel left during
qcom_glink_native_remove() and there is therefor no need to hold the
spinlock during this operation - which would prohibit the use of
cancel_work_sync() in the release function. So remove this.

Fixes: 1d2ea36eead9 ("rpmsg: glink: Add rx done command")
Cc: stable@vger.kernel.org
Acked-by: Chris Lew <clew@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Fix rpmsg_register_device err handling

The device release function is set before registering with rpmsg. If
rpmsg registration fails, the framework will call device_put(), which
invokes the release function. The channel create logic does not need to
free rpdev if rpmsg_register_device() fails and release is called.

Fixes: b4f8e52b89f6 ("rpmsg: Introduce Qualcomm RPM glink driver")
Cc: stable@vger.kernel.org
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Put an extra reference during cleanup

In a remote processor crash scenario, there is no guarantee the remote
processor sent close requests before it went into a bad state. Remove
the reference that is normally handled by the close command in the
so channel resources can be released.

Fixes: b4f8e52b89f6 ("rpmsg: Introduce Qualcomm RPM glink driver")
Cc: stable@vger.kernel.org
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Chris Lew <clew@codeaurora.org>
Reported-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Fix use after free in open_ack TIMEOUT case

Extra channel reference put when remote sending OPEN_ACK after timeout
causes use-after-free while handling next remote CLOSE command.

Remove extra reference put in timeout case to avoid use-after-free.

Fixes: b4f8e52b89f6 ("rpmsg: Introduce Qualcomm RPM glink driver")
Cc: stable@vger.kernel.org
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Fix reuse intents memory leak issue

Memory allocated for re-usable intents are not freed during channel
cleanup which causes memory leak in system.

Check and free all re-usable memory to avoid memory leak.

Fixes: 933b45da5d1d ("rpmsg: glink: Add support for TX intents")
Cc: stable@vger.kernel.org
Acked-By: Chris Lew <clew@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Reported-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Use struct_size() helper

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct {
...
struct intent_pair intents[];
} __packed * msg;

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

So, replace the following form:

sizeof(*msg) + sizeof(struct intent_pair) * count

with:

struct_size(msg, intents, count)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Remove chunk size word align warning

It is possible for the chunk sizes coming from the non RPM remote procs
to not be word aligned. Remove the alignment warning and continue to
read from the FIFO so execution is not stalled.

Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Store edge name for glink device

Channels may need to identify the edge their channel was probed for.
Store the edge name by reading the label property from device tree or
default to the node name.

Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Fix various kerneldoc warnings.

Fix below kerneldoc warnings while building with W=1
qcom_glink_native.c:53: warning: Function parameter or member 'data' not described in 'glink_defer_cmd'
qcom_glink_native.c:75: warning: Function parameter or member 'data' not described in 'glink_core_rx_intent'
qcom_glink_native.c:75: warning: Function parameter or member 'id' not described in 'glink_core_rx_intent'
qcom_glink_native.c:75: warning: Function parameter or member 'size' not described in 'glink_core_rx_intent'
qcom_glink_native.c:75: warning: Function parameter or member 'reuse' not described in 'glink_core_rx_intent'
qcom_glink_native.c:75: warning: Function parameter or member 'in_use' not described in 'glink_core_rx_intent'
qcom_glink_native.c:75: warning: Function parameter or member 'offset' not described in 'glink_core_rx_intent'
qcom_glink_native.c:75: warning: Function parameter or member 'node' not described in 'glink_core_rx_intent'
qcom_glink_native.c:116: warning: Function parameter or member 'features' not described in 'qcom_glink'
qcom_glink_native.c:116: warning: Function parameter or member 'intentless' not described in 'qcom_glink'
qcom_glink_native.c:524: warning: Function parameter or member 'version' not described in 'qcom_glink_receive_version'
qcom_glink_native.c:524: warning: Function parameter or member 'features' not described in 'qcom_glink_receive_version'
qcom_glink_native.c:524: warning: Excess function parameter 'r_version' description in 'qcom_glink_receive_version'
qcom_glink_native.c:524: warning: Excess function parameter 'r_features' description in 'qcom_glink_receive_version'
qcom_glink_native.c:551: warning: Function parameter or member 'version' not described in 'qcom_glink_receive_version_ack'
qcom_glink_native.c:551: warning: Function parameter or member 'features' not described in 'qcom_glink_receive_version_ack'
qcom_glink_native.c:551: warning: Excess function parameter 'r_version' description in 'qcom_glink_receive_version_ack'
qcom_glink_native.c:551: warning: Excess function parameter 'r_features' description in 'qcom_glink_receive_version_ack'
qcom_glink_native.c:570: warning: bad line: wire format and transmit
qcom_glink_native.c:604: warning: Function parameter or member 'intent' not described in 'qcom_glink_advertise_intent'
qcom_glink_native.c:604: warning: Excess function parameter 'size' description in 'qcom_glink_advertise_intent'
qcom_glink_native.c:710: warning: Function parameter or member 'glink' not described in 'qcom_glink_handle_intent_req'
qcom_glink_native.c:710: warning: Function parameter or member 'cid' not described in 'qcom_glink_handle_intent_req'
qcom_glink_native.c:710: warning: Function parameter or member 'size' not described in 'qcom_glink_handle_intent_req'

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: correctly annotate intent members

As intent structure members are not correctly annotated, leading to below warnings

qcom_glink_native.c:614:16: warning: incorrect type in assignment (different base types)
qcom_glink_native.c:614:16: expected unsigned short [unsigned] [usertype] id
qcom_glink_native.c:614:16: got restricted __le16 [usertype] <noident>
qcom_glink_native.c:615:18: warning: incorrect type in assignment (different base types)
qcom_glink_native.c:615:18: expected unsigned short [unsigned] [usertype] lcid
qcom_glink_native.c:615:18: got restricted __le16 [usertype] <noident>
qcom_glink_native.c:616:19: warning: incorrect type in assignment (different base types)
qcom_glink_native.c:616:19: expected unsigned int [unsigned] [usertype] count
qcom_glink_native.c:616:19: got restricted __le32 [usertype] <noident>
qcom_glink_native.c:617:18: warning: incorrect type in assignment (different base types)
qcom_glink_native.c:617:18: expected unsigned int [unsigned] [usertype] size
qcom_glink_native.c:617:18: got restricted __le32 [usertype] <noident>
qcom_glink_native.c:618:18: warning: incorrect type in assignment (different base types)
qcom_glink_native.c:618:18: expected unsigned int [unsigned] [usertype] liid
qcom_glink_native.c:618:18: got restricted __le32 [usertype] <noident>

Fix this by correctly annotating them.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Switch to SPDX license identifier

Use the appropriate SPDX license identifier in various rpmsg
glink driver source files and drop the previous boilerplate
license text.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Use spinlock in tx path

Switch the tx_lock to a spinlock we allow clients to use rpmsg_trysend()
from atomic context.

In order to allow clients to sleep while waiting for space in the FIFO
we release the lock temporarily around the delay; which should be
replaced by sending a READ_NOTIF and waiting for the remote to signal
us that space has been made available.

Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Fix missing mutex_init() in qcom_glink_alloc_channel()

qcom_glink_alloc_channel() allocates the mutex but not initialize it.
Use mutex_init() on it to initialize it correctly.

This is detected by Coccinelle semantic patch.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: The mbox client knows_txdone

As the GLINK driver is ticking the txdone of the mailbox channel (to
implement the doorbell) it needs to set knows_txdone.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Add missing MODULE_LICENSE

The qcom_glink_native driver is missing a MODULE_LICENSE(), correct
this.

Fixes: 835764ddd9af ("rpmsg: glink: Move the common glink protocol implementation to glink_native.c")
Cc: stable@vger.kernel.org
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Use best fit intent during tx

Intents can vary in size, try to find the best fitting remote intent
instead of first fit when sending a message to the remote proc.

Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Add support to preallocate intents

The base intents prequeued during channel creation may not satisfy a
channel's throughput requirement. Add support for intents dt-binding to
allow channels to specify the size and amount of intents to prequeue
during endpoint announcement.

Signed-off-by: Chris Lew <clew@codeaurora.org>
[bjorn: Altered how defaults are expressed]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Initialize the "intent_req_comp" completion variable

The "intent_req_comp" variable is used without initialization which
results in NULL pointer dereference in qcom_glink_request_intent().

we need to initialize the completion variable before using it.

Fixes: 27b9c5b66b23 ("rpmsg: glink: Request for intents when unavailable")
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Fix memory leak in qcom_glink_alloc_intent()

We need to free "intent" and "intent->data" on a couple error paths.

Fixes: 933b45da5d1d ("rpmsg: glink: Add support for TX intents")
Acked-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Unlock on error in qcom_glink_request_intent()

If qcom_glink_tx() fails, then we need to unlock before returning the
error code.

Fixes: 27b9c5b66b23 ("rpmsg: glink: Request for intents when unavailable")
Acked-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: initialize ret to zero to ensure error status check is correct

The new switch cases for RPM_CMD_RX_DONE, RPM_CMD_RX_DONE_W_REUSE,
RPM_CMD_RX_INTENT_REQ_ACK, RPM_CMD_INTENT and RPM_CMD_RX_INTENT_REQ from
4 recent commits are not setting ret and so a later non-zero check on ret
is testing on a garbage value in ret. Fix this by initializing ret to zero.

Detected by CoverityScan CID#1455249 ("Uninitialized scalar variable")

Fixes: 933b45da5d1d ("rpmsg: glink: Add support for TX intents)
Fixes: dacbb35e930f ("glink: Receive and store the remote intent buffers")
Fixes: 27b9c5b66b23 ("rpmsg: glink: Request for intents when unavailable")
Fixes: 88c6060f5a7f ("rpmsg: glink: Handle remote rx done command")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: fix null pointer dereference on a null intent

In the case where glink->intentless is true and the call
to qcom_glink_tx fails then we have a condition where ret is
non-zero and intent is null, causing a null pointer deference
when setting intent->in_use to false. Add an extra check to
only dereference intent if intent is non-null.

Detected by: CoverityScan CID#1455247 ("Explicit null dereferenced")

Fixes: 88c6060f5a7f ("rpmsg: glink: Handle remote rx done command")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Export symbols from common code

The common code needs to export the probe and remove symbols in order
for the SMEM and RPM drivers to access them when compiled as a module.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Release idr lock before returning on error

The idr_lock should be released in the case that we don't find the given
channel.

Fixes: 44f6df922a26 ("rpmsg: glink: Fix idr_lock from mutex to spinlock")
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Handle remote rx done command

Once the remote side sends a rx done ack, check for the intent reuse
information from it and suitably discard or reuse the remote passed
intent buffers.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Request for intents when unavailable

While sending data, we search for suitable sized intent to map and
simply fail if a intent is not found. Instead request for a intent of
required size and wait till one is alloted.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Use the intents passed by remote

While sending data, use the remote intent id buffer of suitable size
that was passed by remote previously.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Receive and store the remote intent buffers

Just like we allocating and sending intent ids to remote, remote side
allocates and sends us the intents as well. So save the intent ids and
use it later while sending data targeting the appropriate intents based
on the size.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Add announce_create ops and preallocate intents

Preallocate local intent buffers and pass the intent ids to the remote.
This way there are some default intents available for the remote to
start sending data without having to wait by sending intent requests. Do
this by adding the rpmsg announce_create ops, which gets called right
after the rpmsg device gets probed.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Add rx done command

Send RX data receive ack to remote and also inform that local intent
buffer is used and freed. This informs the remote to request for next
set of intent buffers before doing a send operation.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Make RX FIFO peak accessor to take an offset

To fully read the received rx data from FIFO both the command and data
has to be read. Currently we read command, data separately and process
them. By adding an offset parameter to RX FIFO peak accessor, command
and data can be read together, simplifying things. So introduce this.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Use the local intents when receiving data

So previously on request from remote side, we allocated local intent
buffers and passed the ids to the remote. Now when we receive data
buffers from remote directed to that intent id, copy the data to the
corresponding preallocated intent buffer.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Add support for TX intents

Intents are nothing but pre-allocated buffers of appropriate size that
are allocated on the local side and communicated to the remote side and
the remote stores the list of intent ids that it is informed.

Later when remote side is intenting to send data, it picks up a right
intent (based on the size) and sends the data buffer and the intent id.
Local side receives the data and copies it to the local intent buffer.

The whole idea is to avoid stalls on the transport for allocating
memory, used for copy based transports.

When the remote request to allocate buffers using CMD_RX_INTENT_REQ, we
allocate buffers of requested size, store the buffer id locally and also
communicate the intent id to the remote.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Fix idr_lock from mutex to spinlock

The channel members lcids, rcids synchronised using the idr_lock is
accessed in both atomic/non-atomic contexts. The readers are not
currently synchronised. That no correct, so add the readers as well
under the lock and use a spinlock.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Add support for transport version negotiation

G-link supports a version number and feature flags for each transport.
A combination of the version number and feature flags enable/disable:

(*) G-Link software updates for each edge
(*) Individual features for each edge

Endpoints negotiate both the version and the supported flags when
the transport is opened and they cannot be changed after negotiation has
been completed.

Each full implementation of G-Link must support a minimum of the current
version, the previous version, and the base negotiation version called v0.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Introduce glink smem based transport

The glink protocol supports different types of transports (shared
memory). With the core protocol remaining the same, the way the
transport's memory is probed and accessed is different. So add support
for glink's smem based transports.

Adding a new smem transport register function and the fifo accessors for
the same.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Do a mbox_free_channel in remove

mbox_request_channel is done in probe, so free the channel in remove.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Return -EAGAIN when there is no FIFO space

The TX FIFO can be full, if the remote client has not read enough data
(or) reading it slowly. So its nessecary to return -EAGAIN to the local
client to enable retry.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Allow unaligned data access

Glink protocol requires that each message is aligned on a 8 byte offset.
This is purely a restriction from glink, so in order to support clients
which do not adher to this, allow data packets of any size, but align
the head index accordingly, effectively removing the alignment
restriction.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: glink: Move the common glink protocol implementation to glink_native.c

Move the common part of glink core protocol implementation to
glink_native.c that can be shared with the smem based glink
transport in the later patches.

Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>