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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * System Control and Management Interface (SCMI) Message Protocol4 * driver common header file containing some definitions, structures5 * and function prototypes used in all the different SCMI protocols.6 *7 * Copyright (C) 2018-2024 ARM Ltd.8 */9#ifndef _SCMI_COMMON_H10#define _SCMI_COMMON_H11 12#include <linux/bitfield.h>13#include <linux/completion.h>14#include <linux/device.h>15#include <linux/errno.h>16#include <linux/kernel.h>17#include <linux/hashtable.h>18#include <linux/list.h>19#include <linux/module.h>20#include <linux/refcount.h>21#include <linux/scmi_protocol.h>22#include <linux/spinlock.h>23#include <linux/types.h>24 25#include <linux/unaligned.h>26 27#include "protocols.h"28#include "notify.h"29 30#define SCMI_MAX_CHANNELS 25631 32#define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC)33 34enum scmi_error_codes {35 SCMI_SUCCESS = 0, /* Success */36 SCMI_ERR_SUPPORT = -1, /* Not supported */37 SCMI_ERR_PARAMS = -2, /* Invalid Parameters */38 SCMI_ERR_ACCESS = -3, /* Invalid access/permission denied */39 SCMI_ERR_ENTRY = -4, /* Not found */40 SCMI_ERR_RANGE = -5, /* Value out of range */41 SCMI_ERR_BUSY = -6, /* Device busy */42 SCMI_ERR_COMMS = -7, /* Communication Error */43 SCMI_ERR_GENERIC = -8, /* Generic Error */44 SCMI_ERR_HARDWARE = -9, /* Hardware Error */45 SCMI_ERR_PROTOCOL = -10,/* Protocol Error */46};47 48static const int scmi_linux_errmap[] = {49 /* better than switch case as long as return value is continuous */50 0, /* SCMI_SUCCESS */51 -EOPNOTSUPP, /* SCMI_ERR_SUPPORT */52 -EINVAL, /* SCMI_ERR_PARAM */53 -EACCES, /* SCMI_ERR_ACCESS */54 -ENOENT, /* SCMI_ERR_ENTRY */55 -ERANGE, /* SCMI_ERR_RANGE */56 -EBUSY, /* SCMI_ERR_BUSY */57 -ECOMM, /* SCMI_ERR_COMMS */58 -EIO, /* SCMI_ERR_GENERIC */59 -EREMOTEIO, /* SCMI_ERR_HARDWARE */60 -EPROTO, /* SCMI_ERR_PROTOCOL */61};62 63static inline int scmi_to_linux_errno(int errno)64{65 int err_idx = -errno;66 67 if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap))68 return scmi_linux_errmap[err_idx];69 return -EIO;70}71 72#define MSG_ID_MASK GENMASK(7, 0)73#define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr))74#define MSG_TYPE_MASK GENMASK(9, 8)75#define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr))76#define MSG_TYPE_COMMAND 077#define MSG_TYPE_DELAYED_RESP 278#define MSG_TYPE_NOTIFICATION 379#define MSG_PROTOCOL_ID_MASK GENMASK(17, 10)80#define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))81#define MSG_TOKEN_ID_MASK GENMASK(27, 18)82#define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))83#define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)84 85/*86 * Size of @pending_xfers hashtable included in @scmi_xfers_info; ideally, in87 * order to minimize space and collisions, this should equal max_msg, i.e. the88 * maximum number of in-flight messages on a specific platform, but such value89 * is only available at runtime while kernel hashtables are statically sized:90 * pick instead as a fixed static size the maximum number of entries that can91 * fit the whole table into one 4k page.92 */93#define SCMI_PENDING_XFERS_HT_ORDER_SZ 994 95/**96 * pack_scmi_header() - packs and returns 32-bit header97 *98 * @hdr: pointer to header containing all the information on message id,99 * protocol id, sequence id and type.100 *101 * Return: 32-bit packed message header to be sent to the platform.102 */103static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)104{105 return FIELD_PREP(MSG_ID_MASK, hdr->id) |106 FIELD_PREP(MSG_TYPE_MASK, hdr->type) |107 FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |108 FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);109}110 111/**112 * unpack_scmi_header() - unpacks and records message and protocol id113 *114 * @msg_hdr: 32-bit packed message header sent from the platform115 * @hdr: pointer to header to fetch message and protocol id.116 */117static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)118{119 hdr->id = MSG_XTRACT_ID(msg_hdr);120 hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);121 hdr->type = MSG_XTRACT_TYPE(msg_hdr);122}123 124/*125 * An helper macro to lookup an xfer from the @pending_xfers hashtable126 * using the message sequence number token as a key.127 */128#define XFER_FIND(__ht, __k) \129({ \130 typeof(__k) k_ = __k; \131 struct scmi_xfer *xfer_ = NULL; \132 \133 hash_for_each_possible((__ht), xfer_, node, k_) \134 if (xfer_->hdr.seq == k_) \135 break; \136 xfer_; \137})138 139struct scmi_revision_info *140scmi_revision_area_get(const struct scmi_protocol_handle *ph);141void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,142 u8 *prot_imp);143 144extern const struct bus_type scmi_bus_type;145 146#define SCMI_BUS_NOTIFY_DEVICE_REQUEST 0147#define SCMI_BUS_NOTIFY_DEVICE_UNREQUEST 1148extern struct blocking_notifier_head scmi_requested_devices_nh;149 150struct scmi_device *scmi_device_create(struct device_node *np,151 struct device *parent, int protocol,152 const char *name);153void scmi_device_destroy(struct device *parent, int protocol, const char *name);154 155int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);156void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);157 158/* SCMI Transport */159/**160 * struct scmi_chan_info - Structure representing a SCMI channel information161 *162 * @id: An identifier for this channel: this matches the protocol number163 * used to initialize this channel164 * @dev: Reference to device in the SCMI hierarchy corresponding to this165 * channel166 * @is_p2a: A flag to identify a channel as P2A (RX)167 * @rx_timeout_ms: The configured RX timeout in milliseconds.168 * @handle: Pointer to SCMI entity handle169 * @no_completion_irq: Flag to indicate that this channel has no completion170 * interrupt mechanism for synchronous commands.171 * This can be dynamically set by transports at run-time172 * inside their provided .chan_setup().173 * @transport_info: Transport layer related information174 */175struct scmi_chan_info {176 int id;177 struct device *dev;178 bool is_p2a;179 unsigned int rx_timeout_ms;180 struct scmi_handle *handle;181 bool no_completion_irq;182 void *transport_info;183};184 185/**186 * struct scmi_transport_ops - Structure representing a SCMI transport ops187 *188 * @chan_available: Callback to check if channel is available or not189 * @chan_setup: Callback to allocate and setup a channel190 * @chan_free: Callback to free a channel191 * @get_max_msg: Optional callback to provide max_msg dynamically192 * Returns the maximum number of messages for the channel type193 * (tx or rx) that can be pending simultaneously in the system194 * @send_message: Callback to send a message195 * @mark_txdone: Callback to mark tx as done196 * @fetch_response: Callback to fetch response197 * @fetch_notification: Callback to fetch notification198 * @clear_channel: Callback to clear a channel199 * @poll_done: Callback to poll transfer status200 */201struct scmi_transport_ops {202 bool (*chan_available)(struct device_node *of_node, int idx);203 int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,204 bool tx);205 int (*chan_free)(int id, void *p, void *data);206 unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo);207 int (*send_message)(struct scmi_chan_info *cinfo,208 struct scmi_xfer *xfer);209 void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret,210 struct scmi_xfer *xfer);211 void (*fetch_response)(struct scmi_chan_info *cinfo,212 struct scmi_xfer *xfer);213 void (*fetch_notification)(struct scmi_chan_info *cinfo,214 size_t max_len, struct scmi_xfer *xfer);215 void (*clear_channel)(struct scmi_chan_info *cinfo);216 bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);217};218 219/**220 * struct scmi_desc - Description of SoC integration221 *222 * @ops: Pointer to the transport specific ops structure223 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)224 * @max_msg: Maximum number of messages for a channel type (tx or rx) that can225 * be pending simultaneously in the system. May be overridden by the226 * get_max_msg op.227 * @max_msg_size: Maximum size of data per message that can be handled.228 * @force_polling: Flag to force this whole transport to use SCMI core polling229 * mechanism instead of completion interrupts even if available.230 * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures231 * synchronous-command messages are atomically232 * completed on .send_message: no need to poll233 * actively waiting for a response.234 * Used by core internally only when polling is235 * selected as a waiting for reply method: i.e.236 * if a completion irq was found use that anyway.237 * @atomic_enabled: Flag to indicate that this transport, which is assured not238 * to sleep anywhere on the TX path, can be used in atomic mode239 * when requested.240 */241struct scmi_desc {242 const struct scmi_transport_ops *ops;243 int max_rx_timeout_ms;244 int max_msg;245 int max_msg_size;246 const bool force_polling;247 const bool sync_cmds_completed_on_ret;248 const bool atomic_enabled;249};250 251static inline bool is_polling_required(struct scmi_chan_info *cinfo,252 const struct scmi_desc *desc)253{254 return cinfo->no_completion_irq || desc->force_polling;255}256 257static inline bool is_transport_polling_capable(const struct scmi_desc *desc)258{259 return desc->ops->poll_done || desc->sync_cmds_completed_on_ret;260}261 262static inline bool is_polling_enabled(struct scmi_chan_info *cinfo,263 const struct scmi_desc *desc)264{265 return is_polling_required(cinfo, desc) &&266 is_transport_polling_capable(desc);267}268 269void scmi_xfer_raw_put(const struct scmi_handle *handle,270 struct scmi_xfer *xfer);271struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle);272struct scmi_chan_info *273scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id);274 275int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,276 struct scmi_xfer *xfer);277 278int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,279 struct scmi_xfer *xfer,280 unsigned int timeout_ms);281 282enum debug_counters {283 SENT_OK,284 SENT_FAIL,285 SENT_FAIL_POLLING_UNSUPPORTED,286 SENT_FAIL_CHANNEL_NOT_FOUND,287 RESPONSE_OK,288 NOTIFICATION_OK,289 DELAYED_RESPONSE_OK,290 XFERS_RESPONSE_TIMEOUT,291 XFERS_RESPONSE_POLLED_TIMEOUT,292 RESPONSE_POLLED_OK,293 ERR_MSG_UNEXPECTED,294 ERR_MSG_INVALID,295 ERR_MSG_NOMEM,296 ERR_PROTOCOL,297 SCMI_DEBUG_COUNTERS_LAST298};299 300static inline void scmi_inc_count(atomic_t *arr, int stat)301{302 if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS))303 atomic_inc(&arr[stat]);304}305 306enum scmi_bad_msg {307 MSG_UNEXPECTED = -1,308 MSG_INVALID = -2,309 MSG_UNKNOWN = -3,310 MSG_NOMEM = -4,311 MSG_MBOX_SPURIOUS = -5,312};313 314/* shmem related declarations */315struct scmi_shared_mem;316 317/**318 * struct scmi_shared_mem_operations - Transport core operations for319 * Shared Memory320 *321 * @tx_prepare: Prepare the @xfer message for transmission on the chosen @shmem322 * @read_header: Read header of the message currently hold in @shmem323 * @fetch_response: Copy the message response from @shmem into @xfer324 * @fetch_notification: Copy the message notification from @shmem into @xfer325 * @clear_channel: Clear the @shmem channel busy flag326 * @poll_done: Check if poll has completed for @xfer on @shmem327 * @channel_free: Check if @shmem channel is marked as free328 * @channel_intr_enabled: Check is @shmem channel has requested a completion irq329 * @setup_iomap: Setup IO shared memory for channel @cinfo330 */331struct scmi_shared_mem_operations {332 void (*tx_prepare)(struct scmi_shared_mem __iomem *shmem,333 struct scmi_xfer *xfer,334 struct scmi_chan_info *cinfo);335 u32 (*read_header)(struct scmi_shared_mem __iomem *shmem);336 337 void (*fetch_response)(struct scmi_shared_mem __iomem *shmem,338 struct scmi_xfer *xfer);339 void (*fetch_notification)(struct scmi_shared_mem __iomem *shmem,340 size_t max_len, struct scmi_xfer *xfer);341 void (*clear_channel)(struct scmi_shared_mem __iomem *shmem);342 bool (*poll_done)(struct scmi_shared_mem __iomem *shmem,343 struct scmi_xfer *xfer);344 bool (*channel_free)(struct scmi_shared_mem __iomem *shmem);345 bool (*channel_intr_enabled)(struct scmi_shared_mem __iomem *shmem);346 void __iomem *(*setup_iomap)(struct scmi_chan_info *cinfo,347 struct device *dev,348 bool tx, struct resource *res);349};350 351const struct scmi_shared_mem_operations *scmi_shared_mem_operations_get(void);352 353/* declarations for message passing transports */354struct scmi_msg_payld;355 356/* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */357#define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32))358 359/**360 * struct scmi_message_operations - Transport core operations for Message361 *362 * @response_size: Get calculated response size for @xfer363 * @command_size: Get calculated command size for @xfer364 * @tx_prepare: Prepare the @xfer message for transmission on the provided @msg365 * @read_header: Read header of the message currently hold in @msg366 * @fetch_response: Copy the message response from @msg into @xfer367 * @fetch_notification: Copy the message notification from @msg into @xfer368 */369struct scmi_message_operations {370 size_t (*response_size)(struct scmi_xfer *xfer);371 size_t (*command_size)(struct scmi_xfer *xfer);372 void (*tx_prepare)(struct scmi_msg_payld *msg, struct scmi_xfer *xfer);373 u32 (*read_header)(struct scmi_msg_payld *msg);374 void (*fetch_response)(struct scmi_msg_payld *msg, size_t len,375 struct scmi_xfer *xfer);376 void (*fetch_notification)(struct scmi_msg_payld *msg, size_t len,377 size_t max_len, struct scmi_xfer *xfer);378};379 380const struct scmi_message_operations *scmi_message_operations_get(void);381 382/**383 * struct scmi_transport_core_operations - Transpoert core operations384 *385 * @bad_message_trace: An helper to report a malformed/unexpected message386 * @rx_callback: Callback to report received messages387 * @shmem: Datagram operations for shared memory based transports388 * @msg: Datagram operations for message based transports389 */390struct scmi_transport_core_operations {391 void (*bad_message_trace)(struct scmi_chan_info *cinfo,392 u32 msg_hdr, enum scmi_bad_msg err);393 void (*rx_callback)(struct scmi_chan_info *cinfo, u32 msg_hdr,394 void *priv);395 const struct scmi_shared_mem_operations *shmem;396 const struct scmi_message_operations *msg;397};398 399/**400 * struct scmi_transport - A structure representing a configured transport401 *402 * @supplier: Device representing the transport and acting as a supplier for403 * the core SCMI stack404 * @desc: Transport descriptor405 * @core_ops: A pointer to a pointer used by the core SCMI stack to make the406 * core transport operations accessible to the transports.407 */408struct scmi_transport {409 struct device *supplier;410 struct scmi_desc *desc;411 struct scmi_transport_core_operations **core_ops;412};413 414#define DEFINE_SCMI_TRANSPORT_DRIVER(__tag, __drv, __desc, __match, __core_ops)\415static void __tag##_dev_free(void *data) \416{ \417 struct platform_device *spdev = data; \418 \419 platform_device_unregister(spdev); \420} \421 \422static int __tag##_probe(struct platform_device *pdev) \423{ \424 struct device *dev = &pdev->dev; \425 struct platform_device *spdev; \426 struct scmi_transport strans; \427 int ret; \428 \429 spdev = platform_device_alloc("arm-scmi", PLATFORM_DEVID_AUTO); \430 if (!spdev) \431 return -ENOMEM; \432 \433 device_set_of_node_from_dev(&spdev->dev, dev); \434 \435 strans.supplier = dev; \436 strans.desc = &(__desc); \437 strans.core_ops = &(__core_ops); \438 \439 ret = platform_device_add_data(spdev, &strans, sizeof(strans)); \440 if (ret) \441 goto err; \442 \443 ret = platform_device_add(spdev); \444 if (ret) \445 goto err; \446 \447 return devm_add_action_or_reset(dev, __tag##_dev_free, spdev); \448 \449err: \450 platform_device_put(spdev); \451 return ret; \452} \453 \454static struct platform_driver __drv = { \455 .driver = { \456 .name = #__tag "_transport", \457 .of_match_table = __match, \458 }, \459 .probe = __tag##_probe, \460}461 462void scmi_notification_instance_data_set(const struct scmi_handle *handle,463 void *priv);464void *scmi_notification_instance_data_get(const struct scmi_handle *handle);465#endif /* _SCMI_COMMON_H */466