/* 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)
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
* @rx_timeout_ms: The configured RX timeout in milliseconds.
* @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;
unsigned int rx_timeout_ms;
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 per message that can be handled.
* @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;
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,
SCMI_DEBUG_COUNTERS_LAST
};
static inline void scmi_inc_count(atomic_t *arr, int stat)
{
if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS))
atomic_inc(&arr[stat]);
}
enum scmi_bad_msg {
MSG_UNEXPECTED = -1,
MSG_INVALID = -2,
MSG_UNKNOWN = -3,
MSG_NOMEM = -4,
MSG_MBOX_SPURIOUS = -5,
};
/* 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);
u32 (*read_header)(struct scmi_shared_mem __iomem *shmem);
void (*fetch_response)(struct scmi_shared_mem __iomem *shmem,
struct scmi_xfer *xfer);
void (*fetch_notification)(struct scmi_shared_mem __iomem *shmem,
size_t max_len, struct scmi_xfer *xfer);
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);
};
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; \
strans.desc = &(__desc); \
strans.core_ops = &(__core_ops); \
\
ret = platform_device_add_data(spdev, &strans, sizeof(strans)); \
if (ret) \
goto err; \
\
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);
#endif /* _SCMI_COMMON_H */
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