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 #define SCMI_SHMEM_MAX_PAYLOAD_SIZE 104 35 36 enum scmi_error_codes { 37 SCMI_SUCCESS = 0, /* Success */ 38 SCMI_ERR_SUPPORT = -1, /* Not supported */ 39 SCMI_ERR_PARAMS = -2, /* Invalid Parameters */ 40 SCMI_ERR_ACCESS = -3, /* Invalid access/permission denied */ 41 SCMI_ERR_ENTRY = -4, /* Not found */ 42 SCMI_ERR_RANGE = -5, /* Value out of range */ 43 SCMI_ERR_BUSY = -6, /* Device busy */ 44 SCMI_ERR_COMMS = -7, /* Communication Error */ 45 SCMI_ERR_GENERIC = -8, /* Generic Error */ 46 SCMI_ERR_HARDWARE = -9, /* Hardware Error */ 47 SCMI_ERR_PROTOCOL = -10,/* Protocol Error */ 48 }; 49 50 static const int scmi_linux_errmap[] = { 51 /* better than switch case as long as return value is continuous */ 52 0, /* SCMI_SUCCESS */ 53 -EOPNOTSUPP, /* SCMI_ERR_SUPPORT */ 54 -EINVAL, /* SCMI_ERR_PARAM */ 55 -EACCES, /* SCMI_ERR_ACCESS */ 56 -ENOENT, /* SCMI_ERR_ENTRY */ 57 -ERANGE, /* SCMI_ERR_RANGE */ 58 -EBUSY, /* SCMI_ERR_BUSY */ 59 -ECOMM, /* SCMI_ERR_COMMS */ 60 -EIO, /* SCMI_ERR_GENERIC */ 61 -EREMOTEIO, /* SCMI_ERR_HARDWARE */ 62 -EPROTO, /* SCMI_ERR_PROTOCOL */ 63 }; 64 65 static inline int scmi_to_linux_errno(int errno) 66 { 67 int err_idx = -errno; 68 69 if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap)) 70 return scmi_linux_errmap[err_idx]; 71 return -EIO; 72 } 73 74 #define MSG_ID_MASK GENMASK(7, 0) 75 #define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr)) 76 #define MSG_TYPE_MASK GENMASK(9, 8) 77 #define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr)) 78 #define MSG_TYPE_COMMAND 0 79 #define MSG_TYPE_DELAYED_RESP 2 80 #define MSG_TYPE_NOTIFICATION 3 81 #define MSG_PROTOCOL_ID_MASK GENMASK(17, 10) 82 #define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr)) 83 #define MSG_TOKEN_ID_MASK GENMASK(27, 18) 84 #define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr)) 85 #define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1) 86 87 /* 88 * Size of @pending_xfers hashtable included in @scmi_xfers_info; ideally, in 89 * order to minimize space and collisions, this should equal max_msg, i.e. the 90 * maximum number of in-flight messages on a specific platform, but such value 91 * is only available at runtime while kernel hashtables are statically sized: 92 * pick instead as a fixed static size the maximum number of entries that can 93 * fit the whole table into one 4k page. 94 */ 95 #define SCMI_PENDING_XFERS_HT_ORDER_SZ 9 96 97 /** 98 * pack_scmi_header() - packs and returns 32-bit header 99 * 100 * @hdr: pointer to header containing all the information on message id, 101 * protocol id, sequence id and type. 102 * 103 * Return: 32-bit packed message header to be sent to the platform. 104 */ 105 static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr) 106 { 107 return FIELD_PREP(MSG_ID_MASK, hdr->id) | 108 FIELD_PREP(MSG_TYPE_MASK, hdr->type) | 109 FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) | 110 FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id); 111 } 112 113 /** 114 * unpack_scmi_header() - unpacks and records message and protocol id 115 * 116 * @msg_hdr: 32-bit packed message header sent from the platform 117 * @hdr: pointer to header to fetch message and protocol id. 118 */ 119 static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr) 120 { 121 hdr->id = MSG_XTRACT_ID(msg_hdr); 122 hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr); 123 hdr->type = MSG_XTRACT_TYPE(msg_hdr); 124 } 125 126 /* 127 * An helper macro to lookup an xfer from the @pending_xfers hashtable 128 * using the message sequence number token as a key. 129 */ 130 #define XFER_FIND(__ht, __k) \ 131 ({ \ 132 typeof(__k) k_ = __k; \ 133 struct scmi_xfer *xfer_ = NULL; \ 134 \ 135 hash_for_each_possible((__ht), xfer_, node, k_) \ 136 if (xfer_->hdr.seq == k_) \ 137 break; \ 138 xfer_; \ 139 }) 140 141 struct scmi_revision_info * 142 scmi_revision_area_get(const struct scmi_protocol_handle *ph); 143 void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, 144 u8 *prot_imp); 145 146 extern const struct bus_type scmi_bus_type; 147 148 #define SCMI_BUS_NOTIFY_DEVICE_REQUEST 0 149 #define SCMI_BUS_NOTIFY_DEVICE_UNREQUEST 1 150 extern struct blocking_notifier_head scmi_requested_devices_nh; 151 152 struct scmi_device *scmi_device_create(struct device_node *np, 153 struct device *parent, int protocol, 154 const char *name); 155 void scmi_device_destroy(struct device *parent, int protocol, const char *name); 156 157 int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id); 158 void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id); 159 160 /* SCMI Transport */ 161 /** 162 * struct scmi_chan_info - Structure representing a SCMI channel information 163 * 164 * @id: An identifier for this channel: this matches the protocol number 165 * used to initialize this channel 166 * @dev: Reference to device in the SCMI hierarchy corresponding to this 167 * channel 168 * @is_p2a: A flag to identify a channel as P2A (RX) 169 * @rx_timeout_ms: The configured RX timeout in milliseconds. 170 * @max_msg_size: Maximum size of message payload. 171 * @handle: Pointer to SCMI entity handle 172 * @no_completion_irq: Flag to indicate that this channel has no completion 173 * interrupt mechanism for synchronous commands. 174 * This can be dynamically set by transports at run-time 175 * inside their provided .chan_setup(). 176 * @transport_info: Transport layer related information 177 */ 178 struct scmi_chan_info { 179 int id; 180 struct device *dev; 181 bool is_p2a; 182 unsigned int rx_timeout_ms; 183 unsigned int max_msg_size; 184 struct scmi_handle *handle; 185 bool no_completion_irq; 186 void *transport_info; 187 }; 188 189 /** 190 * struct scmi_transport_ops - Structure representing a SCMI transport ops 191 * 192 * @chan_available: Callback to check if channel is available or not 193 * @chan_setup: Callback to allocate and setup a channel 194 * @chan_free: Callback to free a channel 195 * @get_max_msg: Optional callback to provide max_msg dynamically 196 * Returns the maximum number of messages for the channel type 197 * (tx or rx) that can be pending simultaneously in the system 198 * @send_message: Callback to send a message 199 * @mark_txdone: Callback to mark tx as done 200 * @fetch_response: Callback to fetch response 201 * @fetch_notification: Callback to fetch notification 202 * @clear_channel: Callback to clear a channel 203 * @poll_done: Callback to poll transfer status 204 */ 205 struct scmi_transport_ops { 206 bool (*chan_available)(struct device_node *of_node, int idx); 207 int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev, 208 bool tx); 209 int (*chan_free)(int id, void *p, void *data); 210 unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo); 211 int (*send_message)(struct scmi_chan_info *cinfo, 212 struct scmi_xfer *xfer); 213 void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret, 214 struct scmi_xfer *xfer); 215 void (*fetch_response)(struct scmi_chan_info *cinfo, 216 struct scmi_xfer *xfer); 217 void (*fetch_notification)(struct scmi_chan_info *cinfo, 218 size_t max_len, struct scmi_xfer *xfer); 219 void (*clear_channel)(struct scmi_chan_info *cinfo); 220 bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); 221 }; 222 223 /** 224 * struct scmi_desc - Description of SoC integration 225 * 226 * @ops: Pointer to the transport specific ops structure 227 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds) 228 * @max_msg: Maximum number of messages for a channel type (tx or rx) that can 229 * be pending simultaneously in the system. May be overridden by the 230 * get_max_msg op. 231 * @max_msg_size: Maximum size of data payload per message that can be handled. 232 * @atomic_threshold: Optional system wide DT-configured threshold, expressed 233 * in microseconds, for atomic operations. 234 * Only SCMI synchronous commands reported by the platform 235 * to have an execution latency lesser-equal to the threshold 236 * should be considered for atomic mode operation: such 237 * decision is finally left up to the SCMI drivers. 238 * @no_completion_irq: Flag to indicate that this transport has no completion 239 * interrupt and has to be polled. This is similar to the 240 * force_polling below, except this is set via DT property. 241 * @force_polling: Flag to force this whole transport to use SCMI core polling 242 * mechanism instead of completion interrupts even if available. 243 * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures 244 * synchronous-command messages are atomically 245 * completed on .send_message: no need to poll 246 * actively waiting for a response. 247 * Used by core internally only when polling is 248 * selected as a waiting for reply method: i.e. 249 * if a completion irq was found use that anyway. 250 * @atomic_enabled: Flag to indicate that this transport, which is assured not 251 * to sleep anywhere on the TX path, can be used in atomic mode 252 * when requested. 253 */ 254 struct scmi_desc { 255 const struct scmi_transport_ops *ops; 256 int max_rx_timeout_ms; 257 int max_msg; 258 int max_msg_size; 259 unsigned int atomic_threshold; 260 bool no_completion_irq; 261 const bool force_polling; 262 const bool sync_cmds_completed_on_ret; 263 const bool atomic_enabled; 264 }; 265 266 static inline bool is_polling_required(struct scmi_chan_info *cinfo, 267 const struct scmi_desc *desc) 268 { 269 return cinfo->no_completion_irq || desc->force_polling; 270 } 271 272 static inline bool is_transport_polling_capable(const struct scmi_desc *desc) 273 { 274 return desc->ops->poll_done || desc->sync_cmds_completed_on_ret; 275 } 276 277 static inline bool is_polling_enabled(struct scmi_chan_info *cinfo, 278 const struct scmi_desc *desc) 279 { 280 return is_polling_required(cinfo, desc) && 281 is_transport_polling_capable(desc); 282 } 283 284 void scmi_xfer_raw_put(const struct scmi_handle *handle, 285 struct scmi_xfer *xfer); 286 struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle); 287 struct scmi_chan_info * 288 scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id); 289 290 int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle, 291 struct scmi_xfer *xfer); 292 293 int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo, 294 struct scmi_xfer *xfer, 295 unsigned int timeout_ms); 296 297 enum debug_counters { 298 SENT_OK, 299 SENT_FAIL, 300 SENT_FAIL_POLLING_UNSUPPORTED, 301 SENT_FAIL_CHANNEL_NOT_FOUND, 302 RESPONSE_OK, 303 NOTIFICATION_OK, 304 DELAYED_RESPONSE_OK, 305 XFERS_RESPONSE_TIMEOUT, 306 XFERS_RESPONSE_POLLED_TIMEOUT, 307 RESPONSE_POLLED_OK, 308 ERR_MSG_UNEXPECTED, 309 ERR_MSG_INVALID, 310 ERR_MSG_NOMEM, 311 ERR_PROTOCOL, 312 XFERS_INFLIGHT, 313 SCMI_DEBUG_COUNTERS_LAST 314 }; 315 316 /** 317 * struct scmi_debug_info - Debug common info 318 * @top_dentry: A reference to the top debugfs dentry 319 * @name: Name of this SCMI instance 320 * @type: Type of this SCMI instance 321 * @is_atomic: Flag to state if the transport of this instance is atomic 322 * @counters: An array of atomic_c's used for tracking statistics (if enabled) 323 */ 324 struct scmi_debug_info { 325 struct dentry *top_dentry; 326 const char *name; 327 const char *type; 328 bool is_atomic; 329 atomic_t counters[SCMI_DEBUG_COUNTERS_LAST]; 330 }; 331 332 static inline void scmi_inc_count(struct scmi_debug_info *dbg, int stat) 333 { 334 if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) { 335 if (dbg) 336 atomic_inc(&dbg->counters[stat]); 337 } 338 } 339 340 static inline void scmi_dec_count(struct scmi_debug_info *dbg, int stat) 341 { 342 if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) { 343 if (dbg) 344 atomic_dec(&dbg->counters[stat]); 345 } 346 } 347 348 enum scmi_bad_msg { 349 MSG_UNEXPECTED = -1, 350 MSG_INVALID = -2, 351 MSG_UNKNOWN = -3, 352 MSG_NOMEM = -4, 353 MSG_MBOX_SPURIOUS = -5, 354 }; 355 356 /* Used for compactness and signature validation of the function pointers being 357 * passed. 358 */ 359 typedef void (*shmem_copy_toio_t)(void __iomem *to, const void *from, 360 size_t count); 361 typedef void (*shmem_copy_fromio_t)(void *to, const void __iomem *from, 362 size_t count); 363 364 /** 365 * struct scmi_shmem_io_ops - I/O operations to read from/write to 366 * Shared Memory 367 * 368 * @toio: Copy data to the shared memory area 369 * @fromio: Copy data from the shared memory area 370 */ 371 struct scmi_shmem_io_ops { 372 shmem_copy_fromio_t fromio; 373 shmem_copy_toio_t toio; 374 }; 375 376 /* shmem related declarations */ 377 struct scmi_shared_mem; 378 379 /** 380 * struct scmi_shared_mem_operations - Transport core operations for 381 * Shared Memory 382 * 383 * @tx_prepare: Prepare the @xfer message for transmission on the chosen @shmem 384 * @read_header: Read header of the message currently hold in @shmem 385 * @fetch_response: Copy the message response from @shmem into @xfer 386 * @fetch_notification: Copy the message notification from @shmem into @xfer 387 * @clear_channel: Clear the @shmem channel busy flag 388 * @poll_done: Check if poll has completed for @xfer on @shmem 389 * @channel_free: Check if @shmem channel is marked as free 390 * @channel_intr_enabled: Check is @shmem channel has requested a completion irq 391 * @setup_iomap: Setup IO shared memory for channel @cinfo 392 */ 393 struct scmi_shared_mem_operations { 394 void (*tx_prepare)(struct scmi_shared_mem __iomem *shmem, 395 struct scmi_xfer *xfer, 396 struct scmi_chan_info *cinfo, 397 shmem_copy_toio_t toio); 398 u32 (*read_header)(struct scmi_shared_mem __iomem *shmem); 399 400 void (*fetch_response)(struct scmi_shared_mem __iomem *shmem, 401 struct scmi_xfer *xfer, 402 shmem_copy_fromio_t fromio); 403 void (*fetch_notification)(struct scmi_shared_mem __iomem *shmem, 404 size_t max_len, struct scmi_xfer *xfer, 405 shmem_copy_fromio_t fromio); 406 void (*clear_channel)(struct scmi_shared_mem __iomem *shmem); 407 bool (*poll_done)(struct scmi_shared_mem __iomem *shmem, 408 struct scmi_xfer *xfer); 409 bool (*channel_free)(struct scmi_shared_mem __iomem *shmem); 410 bool (*channel_intr_enabled)(struct scmi_shared_mem __iomem *shmem); 411 void __iomem *(*setup_iomap)(struct scmi_chan_info *cinfo, 412 struct device *dev, 413 bool tx, struct resource *res, 414 struct scmi_shmem_io_ops **ops); 415 }; 416 417 const struct scmi_shared_mem_operations *scmi_shared_mem_operations_get(void); 418 419 /* declarations for message passing transports */ 420 struct scmi_msg_payld; 421 422 /* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */ 423 #define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32)) 424 425 /** 426 * struct scmi_message_operations - Transport core operations for Message 427 * 428 * @response_size: Get calculated response size for @xfer 429 * @command_size: Get calculated command size for @xfer 430 * @tx_prepare: Prepare the @xfer message for transmission on the provided @msg 431 * @read_header: Read header of the message currently hold in @msg 432 * @fetch_response: Copy the message response from @msg into @xfer 433 * @fetch_notification: Copy the message notification from @msg into @xfer 434 */ 435 struct scmi_message_operations { 436 size_t (*response_size)(struct scmi_xfer *xfer); 437 size_t (*command_size)(struct scmi_xfer *xfer); 438 void (*tx_prepare)(struct scmi_msg_payld *msg, struct scmi_xfer *xfer); 439 u32 (*read_header)(struct scmi_msg_payld *msg); 440 void (*fetch_response)(struct scmi_msg_payld *msg, size_t len, 441 struct scmi_xfer *xfer); 442 void (*fetch_notification)(struct scmi_msg_payld *msg, size_t len, 443 size_t max_len, struct scmi_xfer *xfer); 444 }; 445 446 const struct scmi_message_operations *scmi_message_operations_get(void); 447 448 /** 449 * struct scmi_transport_core_operations - Transpoert core operations 450 * 451 * @bad_message_trace: An helper to report a malformed/unexpected message 452 * @rx_callback: Callback to report received messages 453 * @shmem: Datagram operations for shared memory based transports 454 * @msg: Datagram operations for message based transports 455 */ 456 struct scmi_transport_core_operations { 457 void (*bad_message_trace)(struct scmi_chan_info *cinfo, 458 u32 msg_hdr, enum scmi_bad_msg err); 459 void (*rx_callback)(struct scmi_chan_info *cinfo, u32 msg_hdr, 460 void *priv); 461 const struct scmi_shared_mem_operations *shmem; 462 const struct scmi_message_operations *msg; 463 }; 464 465 /** 466 * struct scmi_transport - A structure representing a configured transport 467 * 468 * @supplier: Device representing the transport and acting as a supplier for 469 * the core SCMI stack 470 * @desc: Transport descriptor 471 * @core_ops: A pointer to a pointer used by the core SCMI stack to make the 472 * core transport operations accessible to the transports. 473 */ 474 struct scmi_transport { 475 struct device *supplier; 476 struct scmi_desc desc; 477 struct scmi_transport_core_operations **core_ops; 478 }; 479 480 #define DEFINE_SCMI_TRANSPORT_DRIVER(__tag, __drv, __desc, __match, __core_ops)\ 481 static void __tag##_dev_free(void *data) \ 482 { \ 483 struct platform_device *spdev = data; \ 484 \ 485 platform_device_unregister(spdev); \ 486 } \ 487 \ 488 static int __tag##_probe(struct platform_device *pdev) \ 489 { \ 490 struct device *dev = &pdev->dev; \ 491 struct platform_device *spdev; \ 492 struct scmi_transport strans; \ 493 int ret; \ 494 \ 495 spdev = platform_device_alloc("arm-scmi", PLATFORM_DEVID_AUTO); \ 496 if (!spdev) \ 497 return -ENOMEM; \ 498 \ 499 device_set_of_node_from_dev(&spdev->dev, dev); \ 500 \ 501 strans.supplier = dev; \ 502 memcpy(&strans.desc, &(__desc), sizeof(strans.desc)); \ 503 strans.core_ops = &(__core_ops); \ 504 \ 505 ret = platform_device_add_data(spdev, &strans, sizeof(strans)); \ 506 if (ret) \ 507 goto err; \ 508 \ 509 spdev->dev.parent = dev; \ 510 ret = platform_device_add(spdev); \ 511 if (ret) \ 512 goto err; \ 513 \ 514 return devm_add_action_or_reset(dev, __tag##_dev_free, spdev); \ 515 \ 516 err: \ 517 platform_device_put(spdev); \ 518 return ret; \ 519 } \ 520 \ 521 static struct platform_driver __drv = { \ 522 .driver = { \ 523 .name = #__tag "_transport", \ 524 .of_match_table = __match, \ 525 }, \ 526 .probe = __tag##_probe, \ 527 } 528 529 void scmi_notification_instance_data_set(const struct scmi_handle *handle, 530 void *priv); 531 void *scmi_notification_instance_data_get(const struct scmi_handle *handle); 532 int scmi_inflight_count(const struct scmi_handle *handle); 533 #endif /* _SCMI_COMMON_H */ 534