1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * System Control and Management Interface (SCMI) Message Protocol 4 * driver common header file containing some definitions, structures 5 * and function prototypes used in all the different SCMI protocols. 6 * 7 * Copyright (C) 2018-2024 ARM Ltd. 8 */ 9 #ifndef _SCMI_COMMON_H 10 #define _SCMI_COMMON_H 11 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 256 31 32 #define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC) 33 34 enum 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 48 static 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 63 static 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 0 77 #define MSG_TYPE_DELAYED_RESP 2 78 #define MSG_TYPE_NOTIFICATION 3 79 #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, in 87 * order to minimize space and collisions, this should equal max_msg, i.e. the 88 * maximum number of in-flight messages on a specific platform, but such value 89 * 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 can 91 * fit the whole table into one 4k page. 92 */ 93 #define SCMI_PENDING_XFERS_HT_ORDER_SZ 9 94 95 /** 96 * pack_scmi_header() - packs and returns 32-bit header 97 * 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 */ 103 static 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 id 113 * 114 * @msg_hdr: 32-bit packed message header sent from the platform 115 * @hdr: pointer to header to fetch message and protocol id. 116 */ 117 static 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 hashtable 126 * 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 }) 138 139 struct scmi_revision_info * 140 scmi_revision_area_get(const struct scmi_protocol_handle *ph); 141 void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, 142 u8 *prot_imp); 143 144 extern const struct bus_type scmi_bus_type; 145 146 #define SCMI_BUS_NOTIFY_DEVICE_REQUEST 0 147 #define SCMI_BUS_NOTIFY_DEVICE_UNREQUEST 1 148 extern struct blocking_notifier_head scmi_requested_devices_nh; 149 150 struct scmi_device *scmi_device_create(struct device_node *np, 151 struct device *parent, int protocol, 152 const char *name); 153 void scmi_device_destroy(struct device *parent, int protocol, const char *name); 154 155 int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id); 156 void 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 information 161 * 162 * @id: An identifier for this channel: this matches the protocol number 163 * used to initialize this channel 164 * @dev: Reference to device in the SCMI hierarchy corresponding to this 165 * channel 166 * @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 handle 169 * @no_completion_irq: Flag to indicate that this channel has no completion 170 * interrupt mechanism for synchronous commands. 171 * This can be dynamically set by transports at run-time 172 * inside their provided .chan_setup(). 173 * @transport_info: Transport layer related information 174 */ 175 struct 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 ops 187 * 188 * @chan_available: Callback to check if channel is available or not 189 * @chan_setup: Callback to allocate and setup a channel 190 * @chan_free: Callback to free a channel 191 * @get_max_msg: Optional callback to provide max_msg dynamically 192 * Returns the maximum number of messages for the channel type 193 * (tx or rx) that can be pending simultaneously in the system 194 * @send_message: Callback to send a message 195 * @mark_txdone: Callback to mark tx as done 196 * @fetch_response: Callback to fetch response 197 * @fetch_notification: Callback to fetch notification 198 * @clear_channel: Callback to clear a channel 199 * @poll_done: Callback to poll transfer status 200 */ 201 struct 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 integration 221 * 222 * @ops: Pointer to the transport specific ops structure 223 * @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 can 225 * be pending simultaneously in the system. May be overridden by the 226 * 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 polling 229 * mechanism instead of completion interrupts even if available. 230 * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures 231 * synchronous-command messages are atomically 232 * completed on .send_message: no need to poll 233 * actively waiting for a response. 234 * Used by core internally only when polling is 235 * 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 not 238 * to sleep anywhere on the TX path, can be used in atomic mode 239 * when requested. 240 */ 241 struct 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 }; 250 251 static 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 } 256 257 static 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 } 261 262 static 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 } 268 269 void scmi_xfer_raw_put(const struct scmi_handle *handle, 270 struct scmi_xfer *xfer); 271 struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle); 272 struct scmi_chan_info * 273 scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id); 274 275 int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle, 276 struct scmi_xfer *xfer); 277 278 int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo, 279 struct scmi_xfer *xfer, 280 unsigned int timeout_ms); 281 282 enum 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_LAST 298 }; 299 300 static 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 } 305 306 enum 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 */ 315 struct scmi_shared_mem; 316 317 /** 318 * struct scmi_shared_mem_operations - Transport core operations for 319 * Shared Memory 320 * 321 * @tx_prepare: Prepare the @xfer message for transmission on the chosen @shmem 322 * @read_header: Read header of the message currently hold in @shmem 323 * @fetch_response: Copy the message response from @shmem into @xfer 324 * @fetch_notification: Copy the message notification from @shmem into @xfer 325 * @clear_channel: Clear the @shmem channel busy flag 326 * @poll_done: Check if poll has completed for @xfer on @shmem 327 * @channel_free: Check if @shmem channel is marked as free 328 * @channel_intr_enabled: Check is @shmem channel has requested a completion irq 329 * @setup_iomap: Setup IO shared memory for channel @cinfo 330 */ 331 struct 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 }; 350 351 const struct scmi_shared_mem_operations *scmi_shared_mem_operations_get(void); 352 353 /* declarations for message passing transports */ 354 struct 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 Message 361 * 362 * @response_size: Get calculated response size for @xfer 363 * @command_size: Get calculated command size for @xfer 364 * @tx_prepare: Prepare the @xfer message for transmission on the provided @msg 365 * @read_header: Read header of the message currently hold in @msg 366 * @fetch_response: Copy the message response from @msg into @xfer 367 * @fetch_notification: Copy the message notification from @msg into @xfer 368 */ 369 struct 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 }; 379 380 const struct scmi_message_operations *scmi_message_operations_get(void); 381 382 /** 383 * struct scmi_transport_core_operations - Transpoert core operations 384 * 385 * @bad_message_trace: An helper to report a malformed/unexpected message 386 * @rx_callback: Callback to report received messages 387 * @shmem: Datagram operations for shared memory based transports 388 * @msg: Datagram operations for message based transports 389 */ 390 struct 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 transport 401 * 402 * @supplier: Device representing the transport and acting as a supplier for 403 * the core SCMI stack 404 * @desc: Transport descriptor 405 * @core_ops: A pointer to a pointer used by the core SCMI stack to make the 406 * core transport operations accessible to the transports. 407 */ 408 struct 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)\ 415 static void __tag##_dev_free(void *data) \ 416 { \ 417 struct platform_device *spdev = data; \ 418 \ 419 platform_device_unregister(spdev); \ 420 } \ 421 \ 422 static 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 \ 449 err: \ 450 platform_device_put(spdev); \ 451 return ret; \ 452 } \ 453 \ 454 static struct platform_driver __drv = { \ 455 .driver = { \ 456 .name = #__tag "_transport", \ 457 .of_match_table = __match, \ 458 }, \ 459 .probe = __tag##_probe, \ 460 } 461 462 void scmi_notification_instance_data_set(const struct scmi_handle *handle, 463 void *priv); 464 void *scmi_notification_instance_data_get(const struct scmi_handle *handle); 465 #endif /* _SCMI_COMMON_H */ 466