rpmsg: qcom_smd: Use qcom_smem_is_available()

Rather than looking up a dummy item from SMEM, use the new
qcom_smem_is_available() function to make the code more clear
(and reduce the overhead slightly).

Add the same check to qcom_smd_register_edge() as well to ensure that
it only succeeds if SMEM is already available - if a driver calls the
function and SMEM is not available yet then the initial state will be
read incorrectly and the RPMSG devices might never become available.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20230531-rpm-rproc-v3-8-a07dcdefd918@gerhold.net
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

rpmsg: qcom_smd: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

qcom_smd_remove() always returned zero, though that isn't completely
trivial to see. So explain that in a comment and convert to
.remove_new().

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230321154039.355098-4-u.kleine-koenig@pengutronix.de

rpmsg: qcom_smd: Make qcom_smd_unregister_edge() return void

This function returned zero unconditionally. Convert it to return no
value instead. This makes it more obvious what happens in the callers.

One caller is converted to return zero explicitly. The only other caller
(smd_subdev_stop() in drivers/remoteproc/qcom_common.c) already ignored
the return value before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230321154039.355098-2-u.kleine-koenig@pengutronix.de

rpmsg: qcom_smd: Fix refcount leak in qcom_smd_parse_edge

of_parse_phandle() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.

Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220511120737.57374-1-linmq006@gmail.com

rpmsg: qcom: correct kerneldoc

Correct kerneldoc warnings like:

drivers/rpmsg/qcom_glink_ssr.c:45:
warning: expecting prototype for G(). Prototype was for GLINK_SSR_DO_CLEANUP() instead

Also fix meaning of 'flag' argument.

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/20220519073330.7187-3-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: qcom_smd: Fix returning 0 if irq_of_parse_and_map() fails

irq_of_parse_and_map() returns 0 on failure, so this should not be
passed further as error return code.

Fixes: 1a358d350664 ("rpmsg: qcom_smd: Fix irq_of_parse_and_map() return value")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220423093932.32136-1-krzysztof.kozlowski@linaro.org

rpmsg: qcom_smd: Fix irq_of_parse_and_map() return value

The irq_of_parse_and_map() returns 0 on failure, not a negative ERRNO.

Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220422105326.78713-1-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: qcom_smd: Fix redundant channel->registered assignment

In qcom_channel_state_worker(), we are setting channel->registered
to true when registering a channel, but this is getting repeated both
before and after re-locking the channels_lock spinlock, which is
obviously a typo.
Remove the assignment done out of the spinlock to fix this redundancy.

Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220114133259.247726-1-angelogioacchino.delregno@collabora.com

rpmsg: smd: allow opening rpm_requests even if already opened

On msm8953 the channel seems to be already opened when booting Linux but
we still need to open it for communication with regulators etc.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220220201909.445468-6-luca@z3ntu.xyz

rpmsg: qcom_smd: Promote to arch_initcall

qcom_smd's only child, smd-rpm uses arch_initcall and both have to be up
before almost anything else to ensure the MSM SoCs will work fine and
nothing will have to resort to probe defering, as this is the main pillar
of all things DVFS on these machines. Promote it to arch_initcall to avoid
such issues.

Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211230023253.1123142-1-konrad.dybcio@somainline.org

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: 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: smd: Fix a kobj leak in in qcom_smd_parse_edge()

We need to call of_node_put(node) on the error paths for this function.

Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200908071841.GA294938@mwanda
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: smd: fix memory leak on channel create

Currently a failed allocation of channel->name leads to an
immediate return without freeing channel. Fix this by setting
ret to -ENOMEM and jumping to an exit path that kfree's channel.

Detected by CoverityScan, CID#1473692 ("Resource Leak")

Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
Cc: stable@vger.kernel.org
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: Convert to using %pOFn instead of device_node.name

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: linux-remoteproc@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: smd: fix kerneldoc warnings

This patch fixes below kerneldoc warnings

qcom_smd.c:141: warning: Function parameter or member 'dev' not described in 'qcom_smd_edge'
qcom_smd.c:141: warning: Function parameter or member 'name' not described in 'qcom_smd_edge'
qcom_smd.c:141: warning: Function parameter or member 'new_channel_event' not described in 'qcom_smd_edge'
qcom_smd.c:222: warning: Function parameter or member 'qsept' not described in 'qcom_smd_channel'
qcom_smd.c:222: warning: Function parameter or member 'registered' not described in 'qcom_smd_channel'
qcom_smd.c:222: warning: Function parameter or member 'state_change_event' not described in 'qcom_smd_channel'
qcom_smd.c:222: warning: Function parameter or member 'drvdata' not described in 'qcom_smd_channel'
qcom_smd.c:737: warning: Function parameter or member 'wait' not described in '__qcom_smd_send'

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

rpmsg: smd: Add missing include of sizes.h

Add missing include of sizes.h.

drivers/rpmsg/qcom_smd.c: In function ‘qcom_smd_channel_open’:
drivers/rpmsg/qcom_smd.c:809:36: error: ‘SZ_4K’ undeclared (first use in this function)
bb_size = min(channel->fifo_size, SZ_4K);
^~~~~

Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: smd: do not use mananged resources for endpoints and channels

All the managed resources would be freed by the time release function
is invoked. Handling such memory in qcom_smd_edge_release() would do
bad things.

Found this issue while testing Audio usecase where the dsp is started up
and shutdown in a loop.

This patch fixes this issue by using simple kzalloc for allocating
channel->name and channel which is then freed in qcom_smd_edge_release().

Without this patch restarting a remoteproc would crash the system.
Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
Cc: <stable@vger.kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: smd: Switch to SPDX license identifier

Use the appropriate SPDX license identifier in the rpmsg SMD backend
driver source file 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: qcom_smd: Access APCS through mailbox framework

Attempt to acquire the APCS IPC through the mailbox framework and fall
back to the old syscon based approach, to allow us to move away from
using the syscon.

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

rpmsg: smd: Use announce_create to process any receive work

It is possible that incoming data arrives before the client driver has
reached a point in the probe method where adequate context for handling
the incoming message has been established.

In the event that the client's callback function returns an error the
message will be left on the FIFO and by invoking the receive handler
after the device has been probed the message will be picked off the FIFO
and the callback invoked again.

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

rpmsg: smd: Fix container_of macros

The container_of macros should not use the same name for the parameter
as the member to use for lookup, as this will result in a compilation
error unless the passed parameter has the same name as the member.

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

Revert "rpmsg: smd: Create device for all channels"

In an effort to pick up channels that are in a funky state we
optimistically tried to open all channels that we found, with the
addition that we failed if the other side did not handshake the opening.

But as we're starting the modem a second time all channels are found -
in a "funky" state - and we try to open them. But the modem firmware
requires the IPCRTR to be up in order to initialize. So any channels we
try to open before that will fail and will not be opened again.

This takes care of the regression, at the cost of reintroducing the
previous behavior of handling of channels with "funky" states.

Reverts commit c12fc4519f60 ("rpmsg: smd: Create device for all channels")

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

rpmsg: smd: Use spinlock in tx path

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

The mutex was interruptable as it was previously held for the duration
of some client waiting for available space in the FIFO, but this was
recently changed to only be held temporarily - allowing us to replace it
with a spinlock.

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

rpmsg: smd: use put_device() if device_register fail

if device_register() returned an error! Always use put_device()
to give up the reference initialized. unregister device for
other return error.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

vfs: do bulk POLL* -> EPOLL* replacement

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rpmsg: smd: Fix double unlock in __qcom_smd_send()

We're not holding the lock here, so we shouldn't unlock.

Fixes: 178f3f75bb4e ("rpmsg: smd: Don't hold the tx lock during wait")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[bjorn: renamed "out" label to further distinguish the two exit paths]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: smd: Don't hold the tx lock during wait

Holding the tx lock while waiting for tx-drain events from the remote
side blocks try_send requests from failing quickly, so temporarily drop
the tx lock while waiting.

While this allows try_send to fail quickly it also could allow a
subsequent send to succeed putting a smaller packet in the FIFO while
we're waiting for room for our large packet. But as this lock is per
channel we expect that clients with ordering concerns implements their
own ordering mechanism.

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

rpmsg: smd: Fail send on a closed channel

Move the check for a closed channel out from the tx-full loop to fail
any send request on a non-open channel.

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

rpmsg: smd: Wake up all waiters

It's possible to have multiple contexts waiting for new channel events
and with an upcoming change it's possible to have multiple contexts
waiting for a full FIFO. As such we need to wake them all up.

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

rpmsg: smd: Create device for all channels

Rather than selectively creating devices only for the channels that the
remote have moved to "opening" state let's create devices for all
channels found. The driver model will match drivers to the ones we care
about and attempt to open these.

The one case where this fails is if the user loads a firmware that lacks
a particular channel of the previous firmware that was running, in which
case we would find the old channel and attempt to probe it. The channel
opening handshake will ensure this will result in a graceful failure.

The result of this patch is that we will actively open the RPM channel
even though it's left in a state other than "opening" after the boot
loader's closing of the channel.

Tested-by: Will Newton <will.newton@gmail.com>
Reported-by: Jeremy McNicoll <jmcnicol@redhat.com>
Reported-by: Will Newton <will.newton@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: smd: Perform handshake during open

Validate the the remote side is opening the channel that we've found by
performing a handshake when opening the channel.

Tested-by: Will Newton <will.newton@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

the rest of drivers/*: annotate ->poll() instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

rpmsg: qcom_smd: add of_node node to edge device

This patch assigns the device node to the edge device, so that the edge
device drivers could read required device tree properties.

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

rpmsg: Release rpmsg devices in backends

The rpmsg devices are allocated in the backends and as such must be
freed there as well.

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

rpmsg: smd: Register rpmsg user space interface for edges

Create and register a rpmsg device for use with the rpmsg user space
interface, allowing user space to access SMD channels.

Also provide the "rpmsg_name" device attribute to expose the edge name
in sysfs, allowing the user to write udev rules for specific rpmsg
devices and their children.

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

rpmsg: qcom_smd: Implement endpoint "poll"

Add support for polling the status of the write buffer so that user
space can use rpmsg character devices in non-blocking mode.

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

rpmsg: qcom_smd: Add support for "label" property

Add support for the "label" property, used to give the edge a name other
than the one of the DT node. This allows the implementor to provide
consistently named edges when using the rpmsg character device.

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

rpmsg: qcom_smd: Correct return value for O_NONBLOCK

qcom_smd_send() should return -EAGAIN for non-blocking channels with
insufficient space, so that we can propagate this event to user space.

Fixes: 53e2822e56c7 ("rpmsg: Introduce Qualcomm SMD backend")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

rpmsg: smd: Expose edge registration functions

The edge registration functions is to be used from a remoteproc driver
to register and unregister an edge as the remote processor comes and
goes.

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

rpmsg: smd: Reduce restrictions when finding channel

SMD channels are created by the remotes in "opening" state, but
sometimes as we close and try to reopen them they linger in closing
state.

Following the search for a matching channel the create_ept() will verify
that the channel is in a suitable state, so we can lax the restrictions
of the search function to work around above difference in behaviour.

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

rpmsg: Introduce Qualcomm SMD backend

This introduces a new rpmsg backend for the Qualcomm SMD system,
allowing communication with various remote processors found in Qualcomm
platforms. The implementation is based on, and intends to replace,
drivers/soc/qcom/smd.c with the necessary adaptions for fitting with the
rpmsg core.

Based on original work by Sricharan R <sricharan@codeaurora.org>

Cc: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>