Commit b260fccaeb ("firmware: arm_scmi: Add SCMI v3.1 protocol extended
names support") moved all the name string buffers to use the extended buffer
size of 64 instead of the required 16 bytes. While that should be fine if
the firmware terminates the string before 16 bytes, there is possibility
of copying random data if the name is not NULL terminated by the firmware.
SCMI base protocol agent_name/vendor_id/sub_vendor_id are defined by the
specification as NULL-terminated ASCII strings up to 16-bytes in length.
The underlying buffers and message descriptors are currently bigger than
needed; resize them to fit only the strictly needed 16 bytes to avoid
any possible leaks when reading data from the firmware.
Change the size argument of strlcpy to use SCMI_SHORT_NAME_MAX_SIZE always
when dealing with short domain names, so as to limit the possibility that
an ill-formed non-NULL terminated short reply from the SCMI platform
firmware can leak stale content laying in the underlying transport shared
memory area.
While at that, convert all strings handling routines to use the preferred
strscpy.
Link: https://lore.kernel.org/r/20220608095530.497879-1-cristian.marussi@arm.com
Fixes: b260fccaeb ("firmware: arm_scmi: Add SCMI v3.1 protocol extended names support")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Add SCMI v3.1 voltage protocol support for asynchronous VOLTAGE_LEVEL_SET
command.
Note that, if a voltage domain is advertised to support the asynchronous
version of VOLTAGE_LEVEL_SET, the command will be issued asynchronously
unless explicitly requested to use the synchronous version by setting the
mode to SCMI_VOLTAGE_LEVEL_SET_SYNC when calling voltage_ops->level_set.
The SCMI regulator driver level_set invocation has been left unchanged
so that it will transparently use the asynchronous version if available.
Link: https://lore.kernel.org/r/20220330150551.2573938-21-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
An SCMI agent can be configured system-wide with a well-defined atomic
threshold: only SCMI synchronous command whose latency has been advertised
by the SCMI platform to be lower or equal to this configured threshold will
be considered for atomic operations, when requested and if supported by the
underlying transport at all.
Link: https://lore.kernel.org/r/20220217131234.50328-6-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
An SCMI transport can be configured as .atomic_enabled in order to signal
to the SCMI core that all its TX path is executed in atomic context and
that, when requested, polling mode should be used while waiting for command
responses.
When a specific platform configuration had properly configured such a
transport as .atomic_enabled, the SCMI core will also take care not to
sleep in the corresponding RX path while waiting for a response if that
specific command transaction was requested as atomic using polling mode.
Asynchronous commands should not be used in an atomic context and so a
warning is emitted if polling was requested for an asynchronous command.
Add also a method to check, from the SCMI drivers, if the underlying SCMI
transport is currently configured to support atomic transactions: this will
be used by upper layers to determine if atomic requests can be supported at
all on this SCMI instance.
Link: https://lore.kernel.org/r/20211220195646.44498-7-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Kernel doc validation script is unhappy and complains with the below set
of warnings.
| Function parameter or member 'fast_switch_possible' not described in 'scmi_perf_proto_ops'
| Function parameter or member 'power_scale_mw_get' not described in 'scmi_perf_proto_ops'
| cannot understand function prototype: 'struct scmi_sensor_reading '
| cannot understand function prototype: 'struct scmi_range_attrs '
| cannot understand function prototype: 'struct scmi_sensor_axis_info '
| cannot understand function prototype: 'struct scmi_sensor_intervals_info '
Fix them adding appropriate documents or missing keywords.
Link: https://lore.kernel.org/r/20210712130801.2436492-2-sudeep.holla@arm.com
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
