#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 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
struct scmi_msg_hdr {
u8 id;
u8 protocol_id;
+ u8 type;
u16 seq;
u32 status;
bool poll_completion;
* 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);
}
{
hdr->id = MSG_XTRACT_ID(msg_hdr);
hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
+ hdr->type = MSG_XTRACT_TYPE(msg_hdr);
}
/**
* 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 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;
/**
/**
* 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
* @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);
/**
* 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 */
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 */
projects / linux-2.6-microblaze.git / blobdiff