Merge tag 'scmi-updates-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/drivers

Arm SCMI firmware driver updates/fixes for v5.19

The main theme for most of the changes this time is around the addition
of the support for SCMI v3.1 specification changes. Though one of the main
addition in the specification is the powercap protocol, that is still
work in progress and this set includes all other changes bit and pieces
scattered all around the different parts of the specification. There are
few bugs discovered during the process and associated fixes and some
refactoring to simplify the addition of v3.1 support. It mainly includes
the support for extended names, few newly added notifications and async
command support.

Apart from v3.1 SCMI changes, OPTEE transport gets support for dynamic
shared memory.

* tag 'scmi-updates-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux: (24 commits)
  firmware: arm_scmi: Fix late checks on pointer dereference
  firmware: arm_scmi: Support optee shared memory in the optee transport
  firmware: arm_scmi: Add SCMI v3.1 VOLTAGE_LEVEL_SET_COMPLETE
  firmware: arm_scmi: Add SCMI v3.1 clock notifications
  firmware: arm_scmi: Add checks for min/max limits in PERFORMANCE_LIMITS_SET
  firmware: arm_scmi: Add SCMI v3.1 perf power-cost in microwatts
  firmware: arm_scmi: Use common iterators in the perf protocol
  firmware: arm_scmi: Use common iterators in the voltage protocol
  firmware: arm_scmi: Use common iterators in the clock protocol
  firmware: arm_scmi: Add SCMI v3.1 SENSOR_AXIS_NAME_GET support
  firmware: arm_scmi: Use common iterators in the sensor protocol
  firmware: arm_scmi: Add iterators for multi-part commands
  firmware: arm_scmi: Parse clock_enable_latency conditionally
  firmware: arm_scmi: Set clock latency to U32_MAX if it is not supported
  firmware: arm_scmi: Add SCMI v3.1 protocol extended names support
  firmware: arm_scmi: Introduce a common SCMI v3.1 .extended_name_get helper
  firmware: arm_scmi: Split protocol specific definitions in a dedicated header
  firmware: arm_scmi: Remove unneeded NULL termination of clk name
  firmware: arm_scmi: Check CLOCK_RATE_SET_COMPLETE async response
  firmware: arm_scmi: Make name_get operations return a const
  ...

Link: https://lore.kernel.org/r/20220504112906.3491985-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 318 insertions, 0 deletions

diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h
new file mode 100644
index 000000000000..73304af5ec4a
--- /dev/null
+++ b/drivers/firmware/arm_scmi/protocols.h
@@ -0,0 +1,318 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol
+ * protocols common header file containing some definitions, structures
+ * and function prototypes used in all the different SCMI protocols.
+ *
+ * Copyright (C) 2022 ARM Ltd.
+ */
+#ifndef _SCMI_PROTOCOLS_H
+#define _SCMI_PROTOCOLS_H
+
+#include <linux/bitfield.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/hashtable.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/refcount.h>
+#include <linux/scmi_protocol.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/unaligned.h>
+
+#define SCMI_SHORT_NAME_MAX_SIZE	16
+
+#define PROTOCOL_REV_MINOR_MASK	GENMASK(15, 0)
+#define PROTOCOL_REV_MAJOR_MASK	GENMASK(31, 16)
+#define PROTOCOL_REV_MAJOR(x)	((u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x))))
+#define PROTOCOL_REV_MINOR(x)	((u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x))))
+
+enum scmi_common_cmd {
+	PROTOCOL_VERSION = 0x0,
+	PROTOCOL_ATTRIBUTES = 0x1,
+	PROTOCOL_MESSAGE_ATTRIBUTES = 0x2,
+};
+
+/**
+ * struct scmi_msg_resp_prot_version - Response for a message
+ *
+ * @minor_version: Minor version of the ABI that firmware supports
+ * @major_version: Major version of the ABI that firmware supports
+ *
+ * In general, ABI version changes follow the rule that minor version increments
+ * are backward compatible. Major revision changes in ABI may not be
+ * backward compatible.
+ *
+ * Response to a generic message with message type SCMI_MSG_VERSION
+ */
+struct scmi_msg_resp_prot_version {
+	__le16 minor_version;
+	__le16 major_version;
+};
+
+/**
+ * struct scmi_msg - Message(Tx/Rx) structure
+ *
+ * @buf: Buffer pointer
+ * @len: Length of data in the Buffer
+ */
+struct scmi_msg {
+	void *buf;
+	size_t len;
+};
+
+/**
+ * struct scmi_msg_hdr - Message(Tx/Rx) header
+ *
+ * @id: The identifier of the message being sent
+ * @protocol_id: The identifier of the protocol used to send @id message
+ * @type: The SCMI type for this message
+ * @seq: The token to identify the message. When a message returns, the
+ *	platform returns the whole message header unmodified including the
+ *	token
+ * @status: Status of the transfer once it's complete
+ * @poll_completion: Indicate if the transfer needs to be polled for
+ *	completion or interrupt mode is used
+ */
+struct scmi_msg_hdr {
+	u8 id;
+	u8 protocol_id;
+	u8 type;
+	u16 seq;
+	u32 status;
+	bool poll_completion;
+};
+
+/**
+ * struct scmi_xfer - Structure representing a message flow
+ *
+ * @transfer_id: Unique ID for debug & profiling purpose
+ * @hdr: Transmit message header
+ * @tx: Transmit message
+ * @rx: Receive message, the buffer should be pre-allocated to store
+ *	message. If request-ACK protocol is used, we can reuse the same
+ *	buffer for the rx path as we use for the tx path.
+ * @done: command message transmit completion event
+ * @async_done: pointer to delayed response message received event completion
+ * @pending: True for xfers added to @pending_xfers hashtable
+ * @node: An hlist_node reference used to store this xfer, alternatively, on
+ *	  the free list @free_xfers or in the @pending_xfers hashtable
+ * @users: A refcount to track the active users for this xfer.
+ *	   This is meant to protect against the possibility that, when a command
+ *	   transaction times out concurrently with the reception of a valid
+ *	   response message, the xfer could be finally put on the TX path, and
+ *	   so vanish, while on the RX path scmi_rx_callback() is still
+ *	   processing it: in such a case this refcounting will ensure that, even
+ *	   though the timed-out transaction will anyway cause the command
+ *	   request to be reported as failed by time-out, the underlying xfer
+ *	   cannot be discarded and possibly reused until the last one user on
+ *	   the RX path has released it.
+ * @busy: An atomic flag to ensure exclusive write access to this xfer
+ * @state: The current state of this transfer, with states transitions deemed
+ *	   valid being:
+ *	    - SCMI_XFER_SENT_OK -> SCMI_XFER_RESP_OK [ -> SCMI_XFER_DRESP_OK ]
+ *	    - SCMI_XFER_SENT_OK -> SCMI_XFER_DRESP_OK
+ *	      (Missing synchronous response is assumed OK and ignored)
+ * @lock: A spinlock to protect state and busy fields.
+ * @priv: A pointer for transport private usage.
+ */
+struct scmi_xfer {
+	int transfer_id;
+	struct scmi_msg_hdr hdr;
+	struct scmi_msg tx;
+	struct scmi_msg rx;
+	struct completion done;
+	struct completion *async_done;
+	bool pending;
+	struct hlist_node node;
+	refcount_t users;
+#define SCMI_XFER_FREE		0
+#define SCMI_XFER_BUSY		1
+	atomic_t busy;
+#define SCMI_XFER_SENT_OK	0
+#define SCMI_XFER_RESP_OK	1
+#define SCMI_XFER_DRESP_OK	2
+	int state;
+	/* A lock to protect state and busy fields */
+	spinlock_t lock;
+	void *priv;
+};
+
+struct scmi_xfer_ops;
+struct scmi_proto_helpers_ops;
+
+/**
+ * struct scmi_protocol_handle  - Reference to an initialized protocol instance
+ *
+ * @dev: A reference to the associated SCMI instance device (handle->dev).
+ * @xops: A reference to a struct holding refs to the core xfer operations that
+ *	  can be used by the protocol implementation to generate SCMI messages.
+ * @set_priv: A method to set protocol private data for this instance.
+ * @get_priv: A method to get protocol private data previously set.
+ *
+ * This structure represents a protocol initialized against specific SCMI
+ * instance and it will be used as follows:
+ * - as a parameter fed from the core to the protocol initialization code so
+ *   that it can access the core xfer operations to build and generate SCMI
+ *   messages exclusively for the specific underlying protocol instance.
+ * - as an opaque handle fed by an SCMI driver user when it tries to access
+ *   this protocol through its own protocol operations.
+ *   In this case this handle will be returned as an opaque object together
+ *   with the related protocol operations when the SCMI driver tries to access
+ *   the protocol.
+ */
+struct scmi_protocol_handle {
+	struct device *dev;
+	const struct scmi_xfer_ops *xops;
+	const struct scmi_proto_helpers_ops *hops;
+	int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv);
+	void *(*get_priv)(const struct scmi_protocol_handle *ph);
+};
+
+/**
+ * struct scmi_iterator_state  - Iterator current state descriptor
+ * @desc_index: Starting index for the current mulit-part request.
+ * @num_returned: Number of returned items in the last multi-part reply.
+ * @num_remaining: Number of remaining items in the multi-part message.
+ * @max_resources: Maximum acceptable number of items, configured by the caller
+ *		   depending on the underlying resources that it is querying.
+ * @loop_idx: The iterator loop index in the current multi-part reply.
+ * @priv: Optional pointer to some additional state-related private data setup
+ *	  by the caller during the iterations.
+ */
+struct scmi_iterator_state {
+	unsigned int desc_index;
+	unsigned int num_returned;
+	unsigned int num_remaining;
+	unsigned int max_resources;
+	unsigned int loop_idx;
+	void *priv;
+};
+
+/**
+ * struct scmi_iterator_ops  - Custom iterator operations
+ * @prepare_message: An operation to provide the custom logic to fill in the
+ *		     SCMI command request pointed by @message. @desc_index is
+ *		     a reference to the next index to use in the multi-part
+ *		     request.
+ * @update_state: An operation to provide the custom logic to update the
+ *		  iterator state from the actual message response.
+ * @process_response: An operation to provide the custom logic needed to process
+ *		      each chunk of the multi-part message.
+ */
+struct scmi_iterator_ops {
+	void (*prepare_message)(void *message, unsigned int desc_index,
+				const void *priv);
+	int (*update_state)(struct scmi_iterator_state *st,
+			    const void *response, void *priv);
+	int (*process_response)(const struct scmi_protocol_handle *ph,
+				const void *response,
+				struct scmi_iterator_state *st, void *priv);
+};
+
+/**
+ * struct scmi_proto_helpers_ops  - References to common protocol helpers
+ * @extended_name_get: A common helper function to retrieve extended naming
+ *		       for the specified resource using the specified command.
+ *		       Result is returned as a NULL terminated string in the
+ *		       pre-allocated area pointed to by @name with maximum
+ *		       capacity of @len bytes.
+ * @iter_response_init: A common helper to initialize a generic iterator to
+ *			parse multi-message responses: when run the iterator
+ *			will take care to send the initial command request as
+ *			specified by @msg_id and @tx_size and then to parse the
+ *			multi-part responses using the custom operations
+ *			provided in @ops.
+ * @iter_response_run: A common helper to trigger the run of a previously
+ *		       initialized iterator.
+ */
+struct scmi_proto_helpers_ops {
+	int (*extended_name_get)(const struct scmi_protocol_handle *ph,
+				 u8 cmd_id, u32 res_id, char *name, size_t len);
+	void *(*iter_response_init)(const struct scmi_protocol_handle *ph,
+				    struct scmi_iterator_ops *ops,
+				    unsigned int max_resources, u8 msg_id,
+				    size_t tx_size, void *priv);
+	int (*iter_response_run)(void *iter);
+};
+
+/**
+ * struct scmi_xfer_ops  - References to the core SCMI xfer operations.
+ * @version_get: Get this version protocol.
+ * @xfer_get_init: Initialize one struct xfer if any xfer slot is free.
+ * @reset_rx_to_maxsz: Reset rx size to max transport size.
+ * @do_xfer: Do the SCMI transfer.
+ * @do_xfer_with_response: Do the SCMI transfer waiting for a response.
+ * @xfer_put: Free the xfer slot.
+ *
+ * Note that all this operations expect a protocol handle as first parameter;
+ * they then internally use it to infer the underlying protocol number: this
+ * way is not possible for a protocol implementation to forge messages for
+ * another protocol.
+ */
+struct scmi_xfer_ops {
+	int (*version_get)(const struct scmi_protocol_handle *ph, u32 *version);
+	int (*xfer_get_init)(const struct scmi_protocol_handle *ph, u8 msg_id,
+			     size_t tx_size, size_t rx_size,
+			     struct scmi_xfer **p);
+	void (*reset_rx_to_maxsz)(const struct scmi_protocol_handle *ph,
+				  struct scmi_xfer *xfer);
+	int (*do_xfer)(const struct scmi_protocol_handle *ph,
+		       struct scmi_xfer *xfer);
+	int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph,
+				     struct scmi_xfer *xfer);
+	void (*xfer_put)(const struct scmi_protocol_handle *ph,
+			 struct scmi_xfer *xfer);
+};
+
+typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *);
+
+/**
+ * struct scmi_protocol  - Protocol descriptor
+ * @id: Protocol ID.
+ * @owner: Module reference if any.
+ * @instance_init: Mandatory protocol initialization function.
+ * @instance_deinit: Optional protocol de-initialization function.
+ * @ops: Optional reference to the operations provided by the protocol and
+ *	 exposed in scmi_protocol.h.
+ * @events: An optional reference to the events supported by this protocol.
+ */
+struct scmi_protocol {
+	const u8				id;
+	struct module				*owner;
+	const scmi_prot_init_ph_fn_t		instance_init;
+	const scmi_prot_init_ph_fn_t		instance_deinit;
+	const void				*ops;
+	const struct scmi_protocol_events	*events;
+};
+
+#define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto)	\
+static const struct scmi_protocol *__this_proto = &(proto);	\
+								\
+int __init scmi_##name##_register(void)				\
+{								\
+	return scmi_protocol_register(__this_proto);		\
+}								\
+								\
+void __exit scmi_##name##_unregister(void)			\
+{								\
+	scmi_protocol_unregister(__this_proto);			\
+}
+
+#define DECLARE_SCMI_REGISTER_UNREGISTER(func)		\
+	int __init scmi_##func##_register(void);	\
+	void __exit scmi_##func##_unregister(void)
+DECLARE_SCMI_REGISTER_UNREGISTER(base);
+DECLARE_SCMI_REGISTER_UNREGISTER(clock);
+DECLARE_SCMI_REGISTER_UNREGISTER(perf);
+DECLARE_SCMI_REGISTER_UNREGISTER(power);
+DECLARE_SCMI_REGISTER_UNREGISTER(reset);
+DECLARE_SCMI_REGISTER_UNREGISTER(sensors);
+DECLARE_SCMI_REGISTER_UNREGISTER(voltage);
+DECLARE_SCMI_REGISTER_UNREGISTER(system);
+
+#endif /* _SCMI_PROTOCOLS_H */