Add a mailbox controller driver for the Axiado AX3005 SoC.
The controller provides communication channels between
the host CPU and the coprocessor.

The hardware provides 8 TX channels and 8 RX channels
through separate register regions. RX channels use
per-channel interrupts, while TX completion is detected by
polling the FIFO status.

Add the driver path to the existing Axiado mailbox entry in
MAINTAINERS.

Signed-off-by: Swark Yang <syang@axiado.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

cix_mbox_probe() logged property error messages referencing
"cix,mbox_dir" (with an underscore) instead of the actual DT property
string "cix,mbox-dir".

Fix the DT property string in error log messages and convert probe error
paths to dev_err_probe().

Signed-off-by: Surendra Singh Chouhan <kr494167@gmail.com>
Reviewed-by: Guomin Chen <Guomin.Chen@cixtech.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

The SBI return value controls how many bytes are copied from shared
memory into the RPMI notification buffer. It is not validated against
the negotiated shared-memory size before that copy. The event walker
also uses a reversed loop condition and can inspect a short event record.

Validate the complete notification length before copying it, iterate only
while a full event header remains, and stop when a declared event payload
extends beyond the copied notification data.

Fixes: bf3022a4eb11 ("mailbox: Add RISC-V SBI message proxy (MPXY) based mailbox driver")
Assisted-by: Codex:gpt-5
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

Replace irq_of_parse_and_map() with platform_get_irq() for the mailbox
interrupt lookup, and move IRQ and MMIO resource acquisition to the top
of the probe function before any memory allocation.

Simplify error handling throughout: use direct return of platform_get_irq
and PTR_ERR values, remove the redundant platform_set_drvdata and
dev_info log, and inline the final return.

Assisted-by: Opencode:Big-Pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

The IPCC of_xlate() both scans for a free mailbox channel and checks
for duplicate references to the same underlying IPCC channel. When a
channel has been shutdown it might have left a hole in the channel
list, which would terminate the search without considering duplicates
later in the list.

Continue the traversal of the channel list to detect and reject
duplicates, while keeping track of the first free channel.

Fixes: d6fbfdbc1274 ("mailbox: qcom-ipcc: Fix IPCC mbox channel exhaustion")
Cc: stable@vger.kernel.org
Signed-off-by: Anup Vishwakarma <anup.vishwakarma@oss.qualcomm.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

Add a check to see if devm_kasprintf() is not NULL in
mchp_ipc_get_cluster_aggr_irq(), returning -ENOMEM if the function
failed.

Assisted-by: gkh_clanker_t1000
CC: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Griffin Kroah-Hartman <griffin@kroah.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

Since commit 55b48e23f5c4 ("genirq/devres: Add error handling in
devm_request_*_irq()"), devm_request_irq() and devm_request_threaded_irq()
automatically log detailed error messages on failure. Remove the
now-redundant driver-specific dev_err() and dev_err_probe() calls.

Signed-off-by: Pan Chuang <panchuang@vivo.com>
Acked-by: Chen-Yu Tsai <wens@kernel.org>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

Exynos850-based platforms support ACPM and has similar workflow
of communicating with ACPM via mailbox, however mailbox controller
registers are located at different offsets and writes/reads could be
different. To distinguish between such different behaviours,
the registers offsets for Exynos850 and the platform-specific data
structs are introduced and configuration is described in such structs
for gs101 and exynos850 based SoCs. Probe routine now selects the
corresponding platform-specific data via device_get_match_data().

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

PCC command execution can time out when a fast platform completes a
transaction and signals the platform interrupt before pcc_send_data()
marks the channel as in use. For shared platform interrupts, the type 3
handler uses chan_in_use to decide whether the interrupt belongs to the
channel. If it observes false, it ignores the completion and the caller
waits until timeout.

Publish chan_in_use before ringing the doorbell. Use WRITE_ONCE() for
the lockless flag updates and READ_ONCE() in the interrupt handler. The
following ordered I/O accessor orders the flag store before the platform
is notified.

Clear chan_in_use if ringing the doorbell fails. Otherwise, leave it set
until the interrupt handler completes the transaction, clearing it before
the mailbox core can submit another transfer.

Fixes: 3db174e478cb ("mailbox: pcc: Support shared interrupt for multiple subspaces")
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>
Tested-by: Adam Young <admiyo@os.amperecomputing.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

ACPI 6.6 Tables 14.9 and 14.12 define the PCC shared memory
signature as the bitwise OR of 0x50434300 and the PCC subspace ID.
They also clarify that the signature is populated by the platform and
verified by OSPM. The signature is at byte offset 0 in the generic,
extended and reduced PCC shared memory layouts.

Check the signature when a client requests a PCC mailbox channel,
after mapping shared memory and before binding the mailbox client.
This keeps the check in the PCC mailbox controller instead of
duplicating it in individual clients.

Treat a signature mismatch as a warning rather than rejecting the
channel request. Making this newly added check fatal could break
existing systems whose firmware did not populate the signature
correctly even though PCC communication works. Continue to reject
shared memory that is too small to contain a signature because it
cannot be inspected safely.

Cc: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>
Tested_by: Adam Young <admiyo@os.amperecomputing.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>