diff options
Diffstat (limited to 'drivers/firmware/arm_scmi/common.h')
| -rw-r--r-- | drivers/firmware/arm_scmi/common.h | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h new file mode 100644 index 000000000000..7c35c95fddba --- /dev/null +++ b/drivers/firmware/arm_scmi/common.h @@ -0,0 +1,529 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * System Control and Management Interface (SCMI) Message Protocol + * driver common header file containing some definitions, structures + * and function prototypes used in all the different SCMI protocols. + * + * Copyright (C) 2018-2024 ARM Ltd. + */ +#ifndef _SCMI_COMMON_H +#define _SCMI_COMMON_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 <linux/unaligned.h> + +#include "protocols.h" +#include "notify.h" + +#define SCMI_MAX_CHANNELS 256 + +#define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC) + +#define SCMI_SHMEM_MAX_PAYLOAD_SIZE 104 + +enum scmi_error_codes { + SCMI_SUCCESS = 0, /* Success */ + SCMI_ERR_SUPPORT = -1, /* Not supported */ + SCMI_ERR_PARAMS = -2, /* Invalid Parameters */ + SCMI_ERR_ACCESS = -3, /* Invalid access/permission denied */ + SCMI_ERR_ENTRY = -4, /* Not found */ + SCMI_ERR_RANGE = -5, /* Value out of range */ + SCMI_ERR_BUSY = -6, /* Device busy */ + SCMI_ERR_COMMS = -7, /* Communication Error */ + SCMI_ERR_GENERIC = -8, /* Generic Error */ + SCMI_ERR_HARDWARE = -9, /* Hardware Error */ + SCMI_ERR_PROTOCOL = -10,/* Protocol Error */ +}; + +static const int scmi_linux_errmap[] = { + /* better than switch case as long as return value is continuous */ + 0, /* SCMI_SUCCESS */ + -EOPNOTSUPP, /* SCMI_ERR_SUPPORT */ + -EINVAL, /* SCMI_ERR_PARAM */ + -EACCES, /* SCMI_ERR_ACCESS */ + -ENOENT, /* SCMI_ERR_ENTRY */ + -ERANGE, /* SCMI_ERR_RANGE */ + -EBUSY, /* SCMI_ERR_BUSY */ + -ECOMM, /* SCMI_ERR_COMMS */ + -EIO, /* SCMI_ERR_GENERIC */ + -EREMOTEIO, /* SCMI_ERR_HARDWARE */ + -EPROTO, /* SCMI_ERR_PROTOCOL */ +}; + +static inline int scmi_to_linux_errno(int errno) +{ + int err_idx = -errno; + + if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap)) + return scmi_linux_errmap[err_idx]; + return -EIO; +} + +#define MSG_ID_MASK GENMASK(7, 0) +#define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr)) +#define MSG_TYPE_MASK GENMASK(9, 8) +#define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr)) +#define MSG_TYPE_COMMAND 0 +#define MSG_TYPE_DELAYED_RESP 2 +#define MSG_TYPE_NOTIFICATION 3 +#define MSG_PROTOCOL_ID_MASK GENMASK(17, 10) +#define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr)) +#define MSG_TOKEN_ID_MASK GENMASK(27, 18) +#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 + +/** + * pack_scmi_header() - packs and returns 32-bit header + * + * @hdr: pointer to header containing all the information on message 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); +} + +/** + * unpack_scmi_header() - unpacks and records message and protocol id + * + * @msg_hdr: 32-bit packed message header sent from the platform + * @hdr: pointer to header to fetch message and protocol id. + */ +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); +} + +/* + * 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_revision_info * +scmi_revision_area_get(const struct scmi_protocol_handle *ph); +void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, + u8 *prot_imp); + +extern const struct bus_type scmi_bus_type; + +#define SCMI_BUS_NOTIFY_DEVICE_REQUEST 0 +#define SCMI_BUS_NOTIFY_DEVICE_UNREQUEST 1 +extern struct blocking_notifier_head scmi_requested_devices_nh; + +struct scmi_device *scmi_device_create(struct device_node *np, + struct device *parent, int protocol, + const char *name); +void scmi_device_destroy(struct device *parent, int protocol, const char *name); + +int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id); +void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id); + +/* SCMI Transport */ +/** + * struct scmi_chan_info - Structure representing a SCMI channel information + * + * @id: An identifier for this channel: this matches the protocol number + * used to initialize this channel + * @dev: Reference to device in the SCMI hierarchy corresponding to this + * channel + * @is_p2a: A flag to identify a channel as P2A (RX) + * @rx_timeout_ms: The configured RX timeout in milliseconds. + * @max_msg_size: Maximum size of message payload. + * @handle: Pointer to SCMI entity handle + * @no_completion_irq: Flag to indicate that this channel has no completion + * interrupt mechanism for synchronous commands. + * This can be dynamically set by transports at run-time + * inside their provided .chan_setup(). + * @transport_info: Transport layer related information + */ +struct scmi_chan_info { + int id; + struct device *dev; + bool is_p2a; + unsigned int rx_timeout_ms; + unsigned int max_msg_size; + struct scmi_handle *handle; + bool no_completion_irq; + void *transport_info; +}; + +/** + * struct scmi_transport_ops - Structure representing a SCMI transport ops + * + * @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 + * @fetch_notification: Callback to fetch notification + * @clear_channel: Callback to clear a channel + * @poll_done: Callback to poll transfer status + */ +struct scmi_transport_ops { + bool (*chan_available)(struct device_node *of_node, 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_xfer *xfer); + void (*fetch_response)(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer); + void (*fetch_notification)(struct scmi_chan_info *cinfo, + size_t max_len, struct scmi_xfer *xfer); + void (*clear_channel)(struct scmi_chan_info *cinfo); + bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); +}; + +/** + * struct scmi_desc - Description of SoC integration + * + * @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 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 payload per message that can be handled. + * @atomic_threshold: Optional system wide DT-configured threshold, expressed + * in microseconds, for atomic operations. + * Only SCMI synchronous commands reported by the platform + * to have an execution latency lesser-equal to the threshold + * should be considered for atomic mode operation: such + * decision is finally left up to the SCMI drivers. + * @force_polling: Flag to force this whole transport to use SCMI core polling + * mechanism instead of completion interrupts even if available. + * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures + * synchronous-command messages are atomically + * completed on .send_message: no need to poll + * actively waiting for a response. + * Used by core internally only when polling is + * selected as a waiting for reply method: i.e. + * if a completion irq was found use that anyway. + * @atomic_enabled: Flag to indicate that this transport, which is assured not + * to sleep anywhere on the TX path, can be used in atomic mode + * when requested. + */ +struct scmi_desc { + const struct scmi_transport_ops *ops; + int max_rx_timeout_ms; + int max_msg; + int max_msg_size; + unsigned int atomic_threshold; + const bool force_polling; + const bool sync_cmds_completed_on_ret; + const bool atomic_enabled; +}; + +static inline bool is_polling_required(struct scmi_chan_info *cinfo, + const struct scmi_desc *desc) +{ + return cinfo->no_completion_irq || desc->force_polling; +} + +static inline bool is_transport_polling_capable(const struct scmi_desc *desc) +{ + return desc->ops->poll_done || desc->sync_cmds_completed_on_ret; +} + +static inline bool is_polling_enabled(struct scmi_chan_info *cinfo, + const struct scmi_desc *desc) +{ + return is_polling_required(cinfo, desc) && + is_transport_polling_capable(desc); +} + +void scmi_xfer_raw_put(const struct scmi_handle *handle, + struct scmi_xfer *xfer); +struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle); +struct scmi_chan_info * +scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id); + +int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle, + struct scmi_xfer *xfer); + +int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer, + unsigned int timeout_ms); + +enum debug_counters { + SENT_OK, + SENT_FAIL, + SENT_FAIL_POLLING_UNSUPPORTED, + SENT_FAIL_CHANNEL_NOT_FOUND, + RESPONSE_OK, + NOTIFICATION_OK, + DELAYED_RESPONSE_OK, + XFERS_RESPONSE_TIMEOUT, + XFERS_RESPONSE_POLLED_TIMEOUT, + RESPONSE_POLLED_OK, + ERR_MSG_UNEXPECTED, + ERR_MSG_INVALID, + ERR_MSG_NOMEM, + ERR_PROTOCOL, + XFERS_INFLIGHT, + SCMI_DEBUG_COUNTERS_LAST +}; + +/** + * struct scmi_debug_info - Debug common info + * @top_dentry: A reference to the top debugfs dentry + * @name: Name of this SCMI instance + * @type: Type of this SCMI instance + * @is_atomic: Flag to state if the transport of this instance is atomic + * @counters: An array of atomic_c's used for tracking statistics (if enabled) + */ +struct scmi_debug_info { + struct dentry *top_dentry; + const char *name; + const char *type; + bool is_atomic; + atomic_t counters[SCMI_DEBUG_COUNTERS_LAST]; +}; + +static inline void scmi_inc_count(struct scmi_debug_info *dbg, int stat) +{ + if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) { + if (dbg) + atomic_inc(&dbg->counters[stat]); + } +} + +static inline void scmi_dec_count(struct scmi_debug_info *dbg, int stat) +{ + if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) { + if (dbg) + atomic_dec(&dbg->counters[stat]); + } +} + +enum scmi_bad_msg { + MSG_UNEXPECTED = -1, + MSG_INVALID = -2, + MSG_UNKNOWN = -3, + MSG_NOMEM = -4, + MSG_MBOX_SPURIOUS = -5, +}; + +/* Used for compactness and signature validation of the function pointers being + * passed. + */ +typedef void (*shmem_copy_toio_t)(void __iomem *to, const void *from, + size_t count); +typedef void (*shmem_copy_fromio_t)(void *to, const void __iomem *from, + size_t count); + +/** + * struct scmi_shmem_io_ops - I/O operations to read from/write to + * Shared Memory + * + * @toio: Copy data to the shared memory area + * @fromio: Copy data from the shared memory area + */ +struct scmi_shmem_io_ops { + shmem_copy_fromio_t fromio; + shmem_copy_toio_t toio; +}; + +/* shmem related declarations */ +struct scmi_shared_mem; + +/** + * struct scmi_shared_mem_operations - Transport core operations for + * Shared Memory + * + * @tx_prepare: Prepare the @xfer message for transmission on the chosen @shmem + * @read_header: Read header of the message currently hold in @shmem + * @fetch_response: Copy the message response from @shmem into @xfer + * @fetch_notification: Copy the message notification from @shmem into @xfer + * @clear_channel: Clear the @shmem channel busy flag + * @poll_done: Check if poll has completed for @xfer on @shmem + * @channel_free: Check if @shmem channel is marked as free + * @channel_intr_enabled: Check is @shmem channel has requested a completion irq + * @setup_iomap: Setup IO shared memory for channel @cinfo + */ +struct scmi_shared_mem_operations { + void (*tx_prepare)(struct scmi_shared_mem __iomem *shmem, + struct scmi_xfer *xfer, + struct scmi_chan_info *cinfo, + shmem_copy_toio_t toio); + u32 (*read_header)(struct scmi_shared_mem __iomem *shmem); + + void (*fetch_response)(struct scmi_shared_mem __iomem *shmem, + struct scmi_xfer *xfer, + shmem_copy_fromio_t fromio); + void (*fetch_notification)(struct scmi_shared_mem __iomem *shmem, + size_t max_len, struct scmi_xfer *xfer, + shmem_copy_fromio_t fromio); + void (*clear_channel)(struct scmi_shared_mem __iomem *shmem); + bool (*poll_done)(struct scmi_shared_mem __iomem *shmem, + struct scmi_xfer *xfer); + bool (*channel_free)(struct scmi_shared_mem __iomem *shmem); + bool (*channel_intr_enabled)(struct scmi_shared_mem __iomem *shmem); + void __iomem *(*setup_iomap)(struct scmi_chan_info *cinfo, + struct device *dev, + bool tx, struct resource *res, + struct scmi_shmem_io_ops **ops); +}; + +const struct scmi_shared_mem_operations *scmi_shared_mem_operations_get(void); + +/* 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)) + +/** + * struct scmi_message_operations - Transport core operations for Message + * + * @response_size: Get calculated response size for @xfer + * @command_size: Get calculated command size for @xfer + * @tx_prepare: Prepare the @xfer message for transmission on the provided @msg + * @read_header: Read header of the message currently hold in @msg + * @fetch_response: Copy the message response from @msg into @xfer + * @fetch_notification: Copy the message notification from @msg into @xfer + */ +struct scmi_message_operations { + size_t (*response_size)(struct scmi_xfer *xfer); + size_t (*command_size)(struct scmi_xfer *xfer); + void (*tx_prepare)(struct scmi_msg_payld *msg, struct scmi_xfer *xfer); + u32 (*read_header)(struct scmi_msg_payld *msg); + void (*fetch_response)(struct scmi_msg_payld *msg, size_t len, + struct scmi_xfer *xfer); + void (*fetch_notification)(struct scmi_msg_payld *msg, size_t len, + size_t max_len, struct scmi_xfer *xfer); +}; + +const struct scmi_message_operations *scmi_message_operations_get(void); + +/** + * struct scmi_transport_core_operations - Transpoert core operations + * + * @bad_message_trace: An helper to report a malformed/unexpected message + * @rx_callback: Callback to report received messages + * @shmem: Datagram operations for shared memory based transports + * @msg: Datagram operations for message based transports + */ +struct scmi_transport_core_operations { + void (*bad_message_trace)(struct scmi_chan_info *cinfo, + u32 msg_hdr, enum scmi_bad_msg err); + void (*rx_callback)(struct scmi_chan_info *cinfo, u32 msg_hdr, + void *priv); + const struct scmi_shared_mem_operations *shmem; + const struct scmi_message_operations *msg; +}; + +/** + * struct scmi_transport - A structure representing a configured transport + * + * @supplier: Device representing the transport and acting as a supplier for + * the core SCMI stack + * @desc: Transport descriptor + * @core_ops: A pointer to a pointer used by the core SCMI stack to make the + * core transport operations accessible to the transports. + */ +struct scmi_transport { + struct device *supplier; + struct scmi_desc desc; + struct scmi_transport_core_operations **core_ops; +}; + +#define DEFINE_SCMI_TRANSPORT_DRIVER(__tag, __drv, __desc, __match, __core_ops)\ +static void __tag##_dev_free(void *data) \ +{ \ + struct platform_device *spdev = data; \ + \ + platform_device_unregister(spdev); \ +} \ + \ +static int __tag##_probe(struct platform_device *pdev) \ +{ \ + struct device *dev = &pdev->dev; \ + struct platform_device *spdev; \ + struct scmi_transport strans; \ + int ret; \ + \ + spdev = platform_device_alloc("arm-scmi", PLATFORM_DEVID_AUTO); \ + if (!spdev) \ + return -ENOMEM; \ + \ + device_set_of_node_from_dev(&spdev->dev, dev); \ + \ + strans.supplier = dev; \ + memcpy(&strans.desc, &(__desc), sizeof(strans.desc)); \ + strans.core_ops = &(__core_ops); \ + \ + ret = platform_device_add_data(spdev, &strans, sizeof(strans)); \ + if (ret) \ + goto err; \ + \ + spdev->dev.parent = dev; \ + ret = platform_device_add(spdev); \ + if (ret) \ + goto err; \ + \ + return devm_add_action_or_reset(dev, __tag##_dev_free, spdev); \ + \ +err: \ + platform_device_put(spdev); \ + return ret; \ +} \ + \ +static struct platform_driver __drv = { \ + .driver = { \ + .name = #__tag "_transport", \ + .of_match_table = __match, \ + }, \ + .probe = __tag##_probe, \ +} + +void scmi_notification_instance_data_set(const struct scmi_handle *handle, + void *priv); +void *scmi_notification_instance_data_get(const struct scmi_handle *handle); +int scmi_inflight_count(const struct scmi_handle *handle); +#endif /* _SCMI_COMMON_H */ |