A reply to CLOCK_DESCRIBE_RATES issued against a non rate-discrete clock
should be composed of a triplet of rates descriptors (min/max/step)
returned all in one reply message.
This is not always the case when dealing with some SCMI server deployed in
the wild: relax such constraint while maintaining memory safety by checking
carefully the returned payload size.
While at that cleanup a stale debug printout.
Link: https://lore.kernel.org/r/20220616170347.2800771-1-cristian.marussi@arm.com
Fixes: 7bc7caafe6 ("firmware: arm_scmi: Use common iterators in the clock protocol")
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
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>
While using SCMI iterators helpers a few local automatic variables are
defined but then used only as input for sizeof operators.
cppcheck is fooled to complain about this with:
| drivers/firmware/arm_scmi/sensors.c:341:48: warning: Variable 'msg' is
| not assigned a value. [unassignedVariable]
| struct scmi_msg_sensor_list_update_intervals *msg;
Even though this is an innocuos warning, since the uninitialized variable
is at the end never used in the reported cases, fix these occurences all
over SCMI stack to avoid keeping unneeded objects on the stack.
Link: https://lore.kernel.org/r/20220530115237.277077-1-cristian.marussi@arm.com
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
As per the spec, the clock_enable_delay is the worst case latency
incurred by the platform to enable the clock. The value of 0 indicates
that the platform doesn't support the same and must be considered as
maximum latency for practical purposes.
Currently the value of 0 is assigned as is and is propogated to the clock
framework which can assume that the clock can support atomic enable operation.
Link: https://lore.kernel.org/r/20220428122913.1654821-1-sudeep.holla@arm.com
Fixes: 18f295b758 ("firmware: arm_scmi: Add support for clock_enable_latency")
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Move some SCMI protocol specific definitions from common.h into a the new
dedicated protocols.h header so that SCMI protocols core code can include
only what it needs; this is going to be useful to avoid the risk of growing
indefinitely the dimension of common.h, especially when introducing some
common protocols helper functions.
Header common.h will continue to be included by SCMI core and transport
layers.
Link: https://lore.kernel.org/r/20220330150551.2573938-10-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
The string array 'name' inside struct scmi_clock_info holds the clock name
which was successfully retrieved by querying the SCMI platform, unless the
related underlying SCMI command failed.
Anyway, such scmi_clock_info structure is allocated using devm_kcalloc()
which in turn internally appends a __GFP_ZERO flag to its invocation:
as a consequence the string 'name' field does not need to be zeroed when
we fail to get the clock name via SCMI, it is already NULL terminated.
Remove unneeded explicit NULL termination.
Link: https://lore.kernel.org/r/20220330150551.2573938-9-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
When CLOCK_RATE_SET command is issued in asynchronous mode the delayed
response CLOCK_RATE_SET_COMPLETE comes back once the SCMI platform has
effectively operated the requested change: such delayed response carries
also the clock ID and the final clock rate that has been set.
As an aid to debug issues, check that the clock ID in the delayed
response matches the expected one and debug print the rate value.
Link: https://lore.kernel.org/r/20220330150551.2573938-8-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
During SCMI Clock protocol initialization, after having retrieved from the
SCMI platform all the available discrete rates for a specific clock, the
clock rates array is sorted, unfortunately using a pointer to its end as
a base instead of its start, so that sorting does not work.
Fix invocation of sort() passing as base a pointer to the start of the
retrieved clock rates array.
Link: https://lore.kernel.org/r/20220318092813.49283-1-cristian.marussi@arm.com
Fixes: dccec73de9 ("firmware: arm_scmi: Keep the discrete clock rates sorted")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Extend common protocol registration routines and provide some new generic
protocols get/put helpers that can track protocols usage and automatically
perform the proper initialization and de-initialization on demand when
required.
Convert all standard protocols to use this new registration scheme while
keeping them all still using the usual initialization logic bound to SCMI
devices probing.
Link: https://lore.kernel.org/r/20210316124903.35011-2-cristian.marussi@arm.com
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Few commands provide the list of description partially and require
to be called consecutively until all the descriptors are fetched
completely. In such cases, we don't release the buffers and reuse
them for consecutive transmits.
However, currently we don't reset the Rx size which will be set as
per the response for the last transmit. This may result in incorrect
response size being interpretted as the firmware may repond with size
greater than the one set but we read only upto the size set by previous
response.
Let us reset the receive buffer size to max possible in such cases as
we don't know the exact size of the response.
Link: https://lore.kernel.org/r/20201012141746.32575-1-sudeep.holla@arm.com
Fixes: b6f20ff8bd ("firmware: arm_scmi: add common infrastructure and support for base protocol")
Reported-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
In preparation to enable building SCMI as a single module, let us move
the SCMI protocol registration call into the driver. This enables us
to also add unregistration of the SCMI protocols.
The main reason for this is to keep it simple instead of maintaining
it as separate modules and dealing with all possible initcall races
and deferred probe handling. We can move it as separate modules if
needed in future.
Link: https://lore.kernel.org/r/20200907195046.56615-4-sudeep.holla@arm.com
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
In order to avoid querying the individual protocol versions multiple
time with more that one device created for each protocol, we can simple
store the copy in the protocol specific private data and use them whenever
required.
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Instead of type-casting the {tx,rx}.buf all over the place while
accessing them to read/write __le{32,64} from/to the firmware, let's
use the existing {get,put}_unaligned_le{32,64} accessors to hide all
the type cast ugliness.
Suggested-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
CLOCK_PROTOCOL_ATTRIBUTES provides attributes to indicate the maximum
number of pending asynchronous clock rate changes supported by the
platform. If it's non-zero, then we should be able to use asynchronous
clock rate set for any clocks until the maximum limit is reached.
Tracking the current count of pending asynchronous clock set rate
requests, we can decide if the incoming/new request for clock set rate
can be handled asynchronously or not until the maximum limit is
reached.
Cc: linux-clk@vger.kernel.org
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
CLOCK_PROTOCOL_ATTRIBUTES provides attributes to indicate the maximum
number of pending asynchronous clock rate changes supported by the
platform. If it's non-zero, then we should be able to use asynchronous
clock rate set for any clocks until the maximum limit is reached.
In order to add that support, let's drop the config flag passed to
clk_ops->rate_set and handle the asynchronous requests dynamically.
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
The boolean rate_discrete needs to be assigned to clk->rate_discrete,
so that clock driver can distinguish between the continuous range and
discrete rates. It uses this in scmi_clk_round_rate could get the
rounded value if it's a continuous range.
Fixes: 5f6c6430e9 ("firmware: arm_scmi: add initial support for clock protocol")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
[sudeep.holla: updated commit message]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Replace all the memcpy() for copying name strings from the firmware with
strlcpy() to make sure we are bounded by the source buffer size and we
also always have NULL-terminated strings.
This is needed to avoid out of bounds accesses if the firmware returns
a non-terminated string.
Reported-by: Olof Johansson <olof@lixom.net>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
SCMI cleanups for v4.18
This contains all of the trivial review comments that were not
addressed as the series was already queued up for v4.17 and were not
critical to go as fixes.
They generally just improve code readability, fix kernel-docs, remove
unused/unnecessary code, follow standard function naming and simplifies
certain exit paths.
* tag 'scmi-updates-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
firmware: arm_scmi: simplify exit path by returning on error
firmware: arm_scmi: improve exit paths and code readability
firmware: arm_scmi: remove unnecessary bitmap_zero
firmware: arm_scmi: drop unused `con_priv` structure member
firmware: arm_scmi: rename scmi_xfer_{init,get,put}
firmware: arm_scmi: rename get_transition_latency and add_opps_to_device
firmware: arm_scmi: fix kernel-docs documentation
firmware: arm_scmi: improve code readability using bitfield accessor macros
Signed-off-by: Olof Johansson <olof@lixom.net>
Just after the initial patches were queued, Jonathan Cameron mentioned
that scmi_one_xfer_{get_put} were not very clear and suggested to use
scmi_xfer_{alloc,free}. While I agree to some extent, the reason not to
have alloc/free as these are preallocated buffers and these functions
just returns a reference to free slot in that preallocated array.
However it was agreed to drop "_one" as it's implicit that we are always
dealing with one slot anyways.
This patch updates the name accordingly dropping "_one" in both {get,put}
functions. Also scmi_one_xfer_init is renamed as scmi_xfer_get_init to
reflect the fact that it gets the free slots and then initialise it.
Reported-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
The null check on clk->name is redundant since name is a char array
and can never be null, so the check is always true. Remove it.
Detected by CoverityScan, CID#1466117 ("Array compared against 0")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
gcc-5.3 and earlier warns that rate_discrete maybe-uninitialized
../drivers/firmware/arm_scmi/clock.c:185:5: warning: 'rate_discrete'
may be used uninitialized in this function [-Wmaybe-uninitialized]
if (rate_discrete)
^
../drivers/firmware/arm_scmi/clock.c:128:7: note:
'rate_discrete' was declared here
bool rate_discrete;
^
This patch fixing the warning by initialising rate_discrete and also using
goto label for the error path.
Fixes: 5f6c6430e9 ("firmware: arm_scmi: add initial support for clock protocol")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
[sudeep.holla: added one line description to the commit message]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
The clock protocol is intended for management of clocks. It is used to
enable or disable clocks, and to set and get the clock rates. This
protocol provides commands to describe the protocol version, discover
various implementation specific attributes, describe a clock, enable
and disable a clock and get/set the rate of the clock synchronously or
asynchronously.
This patch adds initial support for the clock protocol.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
