Fail gracefully if there is no channel array attached to the mailbox
controller. Otherwise the later dereference will cause an OOPS which
might not be seen because mailbox controllers might instantiate very
early. Remove the comment explaining the obvious while here.
Fixes: 2b6d83e2b8 ("mailbox: Introduce framework for mailbox")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
The active_req field serves double duty as both the "is a TX in
flight" flag (NULL means idle) and the storage for the in-flight
message pointer. When a client sends NULL via mbox_send_message(),
active_req is set to NULL, which the framework misinterprets as
"no active request". This breaks the TX state machine by:
- tx_tick() short-circuits on (!mssg), skipping the tx_done
callback and the tx_complete completion
- txdone_hrtimer() skips the channel entirely since active_req
is NULL, so poll-based TX-done detection never fires.
Fix this by introducing a MBOX_NO_MSG sentinel value that means
"no active request," freeing NULL to be valid message data. The
sentinel is defined in the subsystem-internal mailbox.h so that
controller drivers within drivers/mailbox/ can reference it, but
it is not exposed to clients outside the subsystem.
Fifteen in-tree callers send NULL (doorbell-style IPCs on Qualcomm,
Tegra, TI, Xilinx, i.MX, SCMI, and PCC platforms). All were
audited for regression:
- Most already work around the bug via knows_txdone=true with a
manual mbox_client_txdone() call, making the framework's
tracking irrelevant. These are unaffected.
- Poll-based callers (Xilinx zynqmp/r5) are strictly better off:
the poll timer now correctly detects NULL-active channels
instead of silently skipping them.
- irq-qcom-mpm.c was a pre-existing bug -- the only Qualcomm
caller that omitted the knows_txdone + mbox_client_txdone()
pattern. Fixed in a companion commit ("irqchip/qcom-mpm: Fix
missing mailbox TX done acknowledgment").
- No caller sets both a tx_done callback and sends NULL, nor
combines tx_block=true with NULL sends, so the newly reachable
callback/completion paths are never exercised.
Also update tegra-hsp's flush callback, which directly inspects
active_req to wait for the channel to drain: the old "!= NULL"
check becomes "!= MBOX_NO_MSG", otherwise flush spins until
timeout since the sentinel is non-NULL.
The only tradeoff is that 'MBOX_NO_MSG' can not be used as a message
by clients.
Reported-by: Joonwon Kang <joonwonkang@google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Quite some controller drivers use the defines from the internal header
already. This prevents controller drivers outside the mailbox directory.
Move the defines to the public controller header to allow this again as
the defines are not strictly internal anyhow.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Sudeep Holla <sudeep.holla@kernel.org>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Clients sometimes need to know whether the mailbox TX queue has room
before posting a new message. Rather than exposing internal queue state
through a struct field, provide a proper accessor function that returns
the number of available slots for a given channel.
This lets clients choose to back off when the queue is full instead of
hitting the -ENOBUFS error path and the misleading "Try increasing
MBOX_TX_QUEUE_LEN" warning.
Tested-by: Tanmay Shah <tanmay.shah@amd.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Although it is guided that `#mbox-cells` must be at least 1, there are
many instances of `#mbox-cells = <0>;` in the device tree. If that is
the case and the corresponding mailbox controller does not provide
`fw_xlate` and of_xlate` function pointers, `fw_mbox_index_xlate()` will
be used by default and out-of-bounds accesses could occur due to lack of
bounds check in that function.
Cc: stable@vger.kernel.org
Signed-off-by: Joonwon Kang <joonwonkang@google.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Use guard and scoped_guard for chan->lock and mbox->poll_hrt_lock to
simplify code.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Commit e898d9cdd3a9("mailbox: Add device-managed registration functions")
introduced device-managed API for mailbox, but in the past 7 years,
there is no user for devm_mbox_controller_unregister. So remove it.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
In case of_property_match_string fails, it makes more sense
to return its error value to caller, not force the value to
ERR_PTR(-EINVAL).
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
&chan->lock is not supposed to protect 'chan->mbox'.
And in __mbox_bind_client, try_module_get is also not protected
by &chan->lock. So move module_put out of the lock protected
region.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Pull mailbox updates from Jassi Brar:
"Core:
- misc rejig of header includes
- minor const fixes
Misc:
- constify amba_id table
pcc:
- cleanup and refactoring of shmem and irq handling
qcom:
- add MSM8226 compatible
fsl,mu:
- add i.MX94 compatible
mediatek:
- remove cl in struct cmdq_pkt
tegra:
- define dimensioning masks in SoC data"
* tag 'mailbox-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jassibrar/mailbox: (25 commits)
mailbox: Remove unneeded semicolon
mailbox: pcc: Refactor and simplify check_and_ack()
mailbox: pcc: Always map the shared memory communication address
mailbox: pcc: Refactor error handling in irq handler into separate function
mailbox: pcc: Use acpi_os_ioremap() instead of ioremap()
mailbox: pcc: Return early if no GAS register from pcc_mbox_cmd_complete_check
mailbox: pcc: Drop unnecessary endianness conversion of pcc_hdr.flags
mailbox: pcc: Always clear the platform ack interrupt first
mailbox: pcc: Fix the possible race in updation of chan_in_use flag
dt-bindings: mailbox: qcom: add compatible for MSM8226 SoC
dt-bindings: mailbox: fsl,mu: Add i.MX94 compatible
MAINTAINERS: add mailbox API's tree type and location
mailbox: remove unused header files
mailbox: explicitly include <linux/bits.h>
mailbox: sort headers alphabetically
mailbox: don't protect of_parse_phandle_with_args with con_mutex
mailbox: use error ret code of of_parse_phandle_with_args()
mailbox: arm_mhuv2: Constify amba_id table
mailbox: arm_mhu_db: Constify amba_id table
mailbox: arm_mhu: Constify amba_id table
...
Sorting headers alphabetically helps locating duplicates,
and makes it easier to figure out where to insert new headers.
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
There are no concurrency problems if multiple consumers parse the
phandle, don't gratuiously protect the parsing with the mutex used
for the controllers list.
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
In case of error, of_parse_phandle_with_args() returns -EINVAL when the
passed index is negative, or -ENOENT when the index is for an empty
phandle. The mailbox core overwrote the error return code with a less
precise -ENODEV. Use the error returned code from
of_parse_phandle_with_args().
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Use of_property_match_string() instead of open-coding the search. With
this, of_get_property() can be removed as there is no need to check for
"mbox-names" presence first.
This is part of a larger effort to remove callers of of_get_property()
and similar functions. of_get_property() leaks the DT property data
pointer which is a problem for dynamically allocated nodes which may
be freed.
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Support virtual mailbox controllers and clients which are not platform
devices or come from the devicetree by allowing them to match client to
channel via some other mechanism.
Tested-by: Sudeep Holla <sudeep.holla@arm.com> (pcc)
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
This reverts commit c7dacf5b0f,
"mailbox: avoid timer start from callback"
The previous commit was reverted since it lead to a race that
caused the hrtimer to not be started at all. The check for
hrtimer_active() in msg_submit() will return true if the
callback function txdone_hrtimer() is currently running. This
function could return HRTIMER_NORESTART and then the timer
will not be restarted, and also msg_submit() will not start
the timer. This will lead to a message actually being submitted
but no timer will start to check for its compleation.
The original fix that added checking hrtimer_active() was added to
avoid a warning with hrtimer_forward. Looking in the kernel
another solution to avoid this warning is to check hrtimer_is_queued()
before calling hrtimer_forward_now() instead. This however requires a
lock so the timer is not started by msg_submit() inbetween this check
and the hrtimer_forward() call.
Fixes: c7dacf5b0f ("mailbox: avoid timer start from callback")
Signed-off-by: Björn Ardö <bjorn.ardo@axis.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
If the txdone is done by polling, it is possible for msg_submit() to start
the timer while txdone_hrtimer() callback is running. If the timer needs
recheduling, it could already be enqueued by the time hrtimer_forward_now()
is called, leading hrtimer to loudly complain.
WARNING: CPU: 3 PID: 74 at kernel/time/hrtimer.c:932 hrtimer_forward+0xc4/0x110
CPU: 3 PID: 74 Comm: kworker/u8:1 Not tainted 5.9.0-rc2-00236-gd3520067d01c-dirty #5
Hardware name: Libre Computer AML-S805X-AC (DT)
Workqueue: events_freezable_power_ thermal_zone_device_check
pstate: 20000085 (nzCv daIf -PAN -UAO BTYPE=--)
pc : hrtimer_forward+0xc4/0x110
lr : txdone_hrtimer+0xf8/0x118
[...]
This can be fixed by not starting the timer from the callback path. Which
requires the timer reloading as long as any message is queued on the
channel, and not just when current tx is not done yet.
Fixes: 0cc67945ea ("mailbox: switch to hrtimer for tx_complete polling")
Reported-by: Da Xue <da@libre.computer>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Wolfram SangandJassi Brar
Joonwon KangandJassi Brar
Anup PatelandPaul Walmsley
Peng FanandJassi Brar
Linus Torvalds
Tudor AmbarusandJassi Brar
Nam CaoandThomas Gleixner
Rob Herring (Arm)andJassi Brar
Elliot BermanandJassi Brar
Björn ArdöandJassi Brar