From 69255e746890274e887ba36a403019380cde0b48 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Mon, 20 Dec 2021 19:56:41 +0000 Subject: firmware: arm_scmi: Add support for atomic transports 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 Signed-off-by: Sudeep Holla --- include/linux/scmi_protocol.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/scmi_protocol.h') diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h index 80e781c51ddc..9f895cb81818 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -612,6 +612,13 @@ struct scmi_notify_ops { * @devm_protocol_get: devres managed method to acquire a protocol and get specific * operations and a dedicated protocol handler * @devm_protocol_put: devres managed method to release a protocol + * @is_transport_atomic: method to check if the underlying transport for this + * instance handle is configured to support atomic + * transactions for commands. + * Some users of the SCMI stack in the upper layers could + * be interested to know if they can assume SCMI + * command transactions associated to this handle will + * never sleep and act accordingly. * @notify_ops: pointer to set of notifications related operations */ struct scmi_handle { @@ -622,6 +629,7 @@ struct scmi_handle { (*devm_protocol_get)(struct scmi_device *sdev, u8 proto, struct scmi_protocol_handle **ph); void (*devm_protocol_put)(struct scmi_device *sdev, u8 proto); + bool (*is_transport_atomic)(const struct scmi_handle *handle); const struct scmi_notify_ops *notify_ops; }; -- cgit v1.2.3 From 05976c5f3bff8f8b5230da4b39f7cd6dfba9943e Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Thu, 17 Feb 2022 13:12:31 +0000 Subject: firmware: arm_scmi: Support optional system wide atomic-threshold-us 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 Signed-off-by: Sudeep Holla --- include/linux/scmi_protocol.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux/scmi_protocol.h') diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h index 9f895cb81818..fdf6bd83cc59 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -619,6 +619,8 @@ struct scmi_notify_ops { * be interested to know if they can assume SCMI * command transactions associated to this handle will * never sleep and act accordingly. + * An optional atomic threshold value could be returned + * where configured. * @notify_ops: pointer to set of notifications related operations */ struct scmi_handle { @@ -629,7 +631,8 @@ struct scmi_handle { (*devm_protocol_get)(struct scmi_device *sdev, u8 proto, struct scmi_protocol_handle **ph); void (*devm_protocol_put)(struct scmi_device *sdev, u8 proto); - bool (*is_transport_atomic)(const struct scmi_handle *handle); + bool (*is_transport_atomic)(const struct scmi_handle *handle, + unsigned int *atomic_threshold); const struct scmi_notify_ops *notify_ops; }; -- cgit v1.2.3 From b7bd36f2e9430a58aefdc326f8e6653e9b000243 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Thu, 17 Feb 2022 13:12:32 +0000 Subject: firmware: arm_scmi: Add atomic support to clock protocol Introduce new _atomic variant for SCMI clock protocol operations related to enable disable operations: when an atomic operation is required the xfer poll_completion flag is set for that transaction. Link: https://lore.kernel.org/r/20220217131234.50328-7-cristian.marussi@arm.com Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla --- include/linux/scmi_protocol.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/scmi_protocol.h') diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h index fdf6bd83cc59..306e576835f8 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -82,6 +82,9 @@ struct scmi_clk_proto_ops { u64 rate); int (*enable)(const struct scmi_protocol_handle *ph, u32 clk_id); int (*disable)(const struct scmi_protocol_handle *ph, u32 clk_id); + int (*enable_atomic)(const struct scmi_protocol_handle *ph, u32 clk_id); + int (*disable_atomic)(const struct scmi_protocol_handle *ph, + u32 clk_id); }; /** -- cgit v1.2.3 From 18f295b758b227857133f680a397a42e83c62f3f Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Thu, 17 Feb 2022 13:12:33 +0000 Subject: firmware: arm_scmi: Add support for clock_enable_latency An SCMI platform can optionally advertise an enable latency typically associated with a specific clock resource: add support for parsing such optional message field and export such information in the usual publicly accessible clock descriptor. Link: https://lore.kernel.org/r/20220217131234.50328-8-cristian.marussi@arm.com Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla --- include/linux/scmi_protocol.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/scmi_protocol.h') diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h index 306e576835f8..b87551f41f9f 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -42,6 +42,7 @@ struct scmi_revision_info { struct scmi_clock_info { char name[SCMI_MAX_STR_SIZE]; + unsigned int enable_latency; bool rate_discrete; union { struct { -- cgit v1.2.3