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| author | Cristian Marussi <cristian.marussi@arm.com> | 2023-12-01 13:58:58 +0000 |
|---|---|---|
| committer | Sudeep Holla <sudeep.holla@arm.com> | 2023-12-01 16:46:10 +0000 |
| commit | b5efc28a754d2e90b9d52ba5aaa051cc24a5c85d (patch) | |
| tree | 4d8be46e4eb0b1298b8d1f85db303d53481d5cbb /drivers/firmware/arm_scmi/base.c | |
| parent | c3f17d5f89fc72d7b170beaf393a8687ae938b19 (diff) | |
| download | linux-stable-b5efc28a754d2e90b9d52ba5aaa051cc24a5c85d.tar.gz linux-stable-b5efc28a754d2e90b9d52ba5aaa051cc24a5c85d.tar.bz2 linux-stable-b5efc28a754d2e90b9d52ba5aaa051cc24a5c85d.zip | |
firmware: arm_scmi: Add protocol versioning checks
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 <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20231201135858.2367651-1-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Diffstat (limited to 'drivers/firmware/arm_scmi/base.c')
| -rw-r--r-- | drivers/firmware/arm_scmi/base.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c index a52f084a6a87..97254de35ab0 100644 --- a/drivers/firmware/arm_scmi/base.c +++ b/drivers/firmware/arm_scmi/base.c @@ -13,6 +13,9 @@ #include "common.h" #include "notify.h" +/* Updated only after ALL the mandatory features for that version are merged */ +#define SCMI_PROTOCOL_SUPPORTED_VERSION 0x20000 + #define SCMI_BASE_NUM_SOURCES 1 #define SCMI_BASE_MAX_CMD_ERR_COUNT 1024 @@ -385,7 +388,7 @@ static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph) rev->major_ver = PROTOCOL_REV_MAJOR(version), rev->minor_ver = PROTOCOL_REV_MINOR(version); - ph->set_priv(ph, rev); + ph->set_priv(ph, rev, version); ret = scmi_base_attributes_get(ph); if (ret) @@ -423,6 +426,7 @@ static const struct scmi_protocol scmi_base = { .instance_init = &scmi_base_protocol_init, .ops = NULL, .events = &base_protocol_events, + .supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION, }; DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base) |