kernel/linux.git/drivers/firmware/arm_scmi/base.c, branch linux-7.1.y

firmware: arm_scmi: Use round_up() for base protocol list size calculation

2026-03-08T13:12:00+00:00

Replace the open-coded size rounding logic with the kernel's round_up() helper to improve readability and align with common kernel practices. The original expression: (1 + (loop_num_ret - 1) / sizeof(u32)) * sizeof(u32) is equivalent to rounding up loop_num_ret to the nearest multiple of sizeof(u32), which is exactly what round_up() does. No functional change. Signed-off-by: Peng Fan Reviewed-by: Cristian Marussi Message-Id: <20260228-scmi-check-v1-1-4935b58bb2db@nxp.com> Signed-off-by: Sudeep Holla

firmware: arm_scmi: Remove legacy protocol versioning logic

2025-12-27T20:09:30+00:00

Protocol version negotiation logic is centralized in the SCMI core stack so that most of the legacy per-protocol versioning logic is redundant and can be removed. Remove protocol-specific versioning code and refactor all the protocols to use the new simplified centralized logic. Signed-off-by: Cristian Marussi Message-Id: <20251227164132.1311988-3-cristian.marussi@arm.com> Signed-off-by: Sudeep Holla

firmware: arm_scmi: Replace comma with the semicolon

2024-08-28T16:16:25+00:00

Replace the typo comma with the semicolon. No functional change. Message-Id: <20240827143838.1465913-4-sudeep.holla@arm.com> Signed-off-by: Sudeep Holla

firmware: arm_scmi: Fix trivial whitespace/coding style issues

2024-08-28T16:16:25+00:00

Fix couple of unnecessary multiple blank lines and spaces instead of tabs. No functional change. Message-Id: <20240827143838.1465913-2-sudeep.holla@arm.com> Signed-off-by: Sudeep Holla

firmware: arm_scmi: Update various protocols versions

2024-08-16T09:26:58+00:00

A few protocol versions had been increased with SCMI v3.2. Update accordingly the supported version define in the kernel stack, since all the mandatory base commands are indeed already supported. Signed-off-by: Cristian Marussi Message-Id: <20240812174027.3931160-1-cristian.marussi@arm.com> Reviewed-by: Dhruva Gole Signed-off-by: Sudeep Holla

firmware: arm_scmi: Add protocol versioning checks

2023-12-01T16:46:10+00:00

Platform and agent supported protocols versions do not necessarily match. When talking to an older SCMI platform, supporting only older protocol versions, the kernel SCMI agent will downgrade the version of the used protocol to match the platform and avoid compatibility issues. In the case where the kernel/OSPM agent happens to communicate with a newer platform which can support newer protocol versions unknown to the agent, and potentially backward incompatible, the agent currently carries on, silently, in a best-effort approach. Note that the SCMI specification doesn't provide means to explicitly detect the protocol versions used by the agents, neither it is required to support multiple, older, protocol versions. Add an explicit protocol version check to let the agent detect when this version mismatch happens and warn the user about this condition. Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20231201135858.2367651-1-cristian.marussi@arm.com Signed-off-by: Sudeep Holla

firmware: arm_scmi: Avoid using extended string-buffers sizes if not necessary

2022-06-10T16:55:29+00:00

Commit b260fccaebdc2 ("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: b260fccaebdc2 ("firmware: arm_scmi: Add SCMI v3.1 protocol extended names support") Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Relax base protocol sanity checks on the protocol list

2022-06-06T14:46:35+00:00

Even though malformed replies from firmware must be treated carefully to avoid memory corruption in the kernel, some out-of-spec SCMI replies can be tolerated to avoid breaking existing deployed system, as long as they won't cause memory issues. Relax the sanity checks on the recieved protocol list in the base protocol to avoid breaking one of the deployed platform whose firmware is not easily upgradable currently. Link: https://lore.kernel.org/r/20220523171559.472112-1-cristian.marussi@arm.com Cc: Etienne Carriere Cc: Sudeep Holla Reported-by: Nicolas Frattaroli Tested-By: Frank Wunderlich Acked-by: Michael Riesch Acked-by: Etienne Carriere Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Dynamically allocate implemented protocols array

2022-04-28T17:22:51+00:00

Move away from a statically allocated array for holding the current set of protocols implemented by the platform in favour of allocating it dynamically based on the number of protocols effectively advertised by the platform via BASE protocol exchanges. While at that, rectify the BASE_DISCOVER_LIST_PROTOCOLS loop iterations to terminate only when a number of protocols equal to the advertised ones has been received, instead of looping till the platform returns no more protocols descriptors. This new behaviour is better compliant with the specification and it has been tested to work equally well against an SCMI stack running on top of an official SCP firmware on a JUNO board. Link: https://lore.kernel.org/r/20220330150551.2573938-6-cristian.marussi@arm.com Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla

firmware: arm_scmi: Validate BASE_DISCOVER_LIST_PROTOCOLS response

2022-04-28T17:22:50+00:00

Do not blindly trust SCMI platform response about list of implemented protocols, instead validate the reported length of the list of protocols against the real payload size of the message reply. Link: https://lore.kernel.org/r/20220330150551.2573938-5-cristian.marussi@arm.com Fixes: b6f20ff8bd94 ("firmware: arm_scmi: add common infrastructure and support for base protocol") Signed-off-by: Cristian Marussi [sudeep.holla: Added early break if loop_num_ret = 0 and simplified calc_list_sz calculation] Signed-off-by: Sudeep Holla