diff options
Diffstat (limited to 'drivers/firmware/arm_scmi/common.h')
| -rw-r--r-- | drivers/firmware/arm_scmi/common.h | 113 |
1 files changed, 107 insertions, 6 deletions
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 8685619d38f9..dea1bfbe1052 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -14,8 +14,12 @@ #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> @@ -65,11 +69,22 @@ struct scmi_msg_resp_prot_version { #define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr)) #define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1) +/* + * Size of @pending_xfers hashtable included in @scmi_xfers_info; ideally, in + * order to minimize space and collisions, this should equal max_msg, i.e. the + * maximum number of in-flight messages on a specific platform, but such value + * is only available at runtime while kernel hashtables are statically sized: + * pick instead as a fixed static size the maximum number of entries that can + * fit the whole table into one 4k page. + */ +#define SCMI_PENDING_XFERS_HT_ORDER_SZ 9 + /** * 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 @@ -80,6 +95,7 @@ struct scmi_msg_resp_prot_version { struct scmi_msg_hdr { u8 id; u8 protocol_id; + u8 type; u16 seq; u32 status; bool poll_completion; @@ -89,13 +105,14 @@ struct scmi_msg_hdr { * pack_scmi_header() - packs and returns 32-bit header * * @hdr: pointer to header containing all the information on message id, - * protocol id and sequence id. + * protocol id, sequence id and type. * * Return: 32-bit packed message header to be sent to the platform. */ static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr) { return FIELD_PREP(MSG_ID_MASK, hdr->id) | + FIELD_PREP(MSG_TYPE_MASK, hdr->type) | FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) | FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id); } @@ -110,6 +127,7 @@ static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr) { hdr->id = MSG_XTRACT_ID(msg_hdr); hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr); + hdr->type = MSG_XTRACT_TYPE(msg_hdr); } /** @@ -134,6 +152,27 @@ struct scmi_msg { * 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; @@ -142,8 +181,36 @@ struct scmi_xfer { 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; }; +/* + * An helper macro to lookup an xfer from the @pending_xfers hashtable + * using the message sequence number token as a key. + */ +#define XFER_FIND(__ht, __k) \ +({ \ + typeof(__k) k_ = __k; \ + struct scmi_xfer *xfer_ = NULL; \ + \ + hash_for_each_possible((__ht), xfer_, node, k_) \ + if (xfer_->hdr.seq == k_) \ + break; \ + xfer_; \ +}) + struct scmi_xfer_ops; /** @@ -283,9 +350,13 @@ struct scmi_chan_info { /** * struct scmi_transport_ops - Structure representing a SCMI transport ops * + * @link_supplier: Optional callback to add link to a supplier device * @chan_available: Callback to check if channel is available or not * @chan_setup: Callback to allocate and setup a channel * @chan_free: Callback to free a channel + * @get_max_msg: Optional callback to provide max_msg dynamically + * Returns the maximum number of messages for the channel type + * (tx or rx) that can be pending simultaneously in the system * @send_message: Callback to send a message * @mark_txdone: Callback to mark tx as done * @fetch_response: Callback to fetch response @@ -294,10 +365,12 @@ struct scmi_chan_info { * @poll_done: Callback to poll transfer status */ struct scmi_transport_ops { + int (*link_supplier)(struct device *dev); bool (*chan_available)(struct device *dev, int idx); int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev, bool tx); int (*chan_free)(int id, void *p, void *data); + unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo); int (*send_message)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret); @@ -317,25 +390,39 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, /** * struct scmi_desc - Description of SoC integration * + * @transport_init: An optional function that a transport can provide to + * initialize some transport-specific setup during SCMI core + * initialization, so ahead of SCMI core probing. + * @transport_exit: An optional function that a transport can provide to + * de-initialize some transport-specific setup during SCMI core + * de-initialization, so after SCMI core removal. * @ops: Pointer to the transport specific ops structure * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds) - * @max_msg: Maximum number of messages that can be pending - * simultaneously in the system + * @max_msg: Maximum number of messages for a channel type (tx or rx) that can + * be pending simultaneously in the system. May be overridden by the + * get_max_msg op. * @max_msg_size: Maximum size of data per message that can be handled. */ struct scmi_desc { + int (*transport_init)(void); + void (*transport_exit)(void); const struct scmi_transport_ops *ops; int max_rx_timeout_ms; int max_msg; int max_msg_size; }; +#ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX extern const struct scmi_desc scmi_mailbox_desc; -#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY +#endif +#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC extern const struct scmi_desc scmi_smc_desc; #endif +#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO +extern const struct scmi_desc scmi_virtio_desc; +#endif -void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr); +void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv); void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id); /* shmem related declarations */ @@ -352,8 +439,22 @@ void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem); bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem, struct scmi_xfer *xfer); +/* declarations for message passing transports */ +struct scmi_msg_payld; + +/* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */ +#define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32)) + +size_t msg_response_size(struct scmi_xfer *xfer); +size_t msg_command_size(struct scmi_xfer *xfer); +void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer); +u32 msg_read_header(struct scmi_msg_payld *msg); +void msg_fetch_response(struct scmi_msg_payld *msg, size_t len, + struct scmi_xfer *xfer); +void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len, + size_t max_len, struct scmi_xfer *xfer); + void scmi_notification_instance_data_set(const struct scmi_handle *handle, void *priv); void *scmi_notification_instance_data_get(const struct scmi_handle *handle); - #endif /* _SCMI_COMMON_H */ |