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 * @force_polling: Flag to force this whole transport to use SCMI core polling 239 * mechanism instead of completion interrupts even if available. 240 * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures 241 * synchronous-command messages are atomically 242 * completed on .send_message: no need to poll 243 * actively waiting for a response. 244 * Used by core internally only when polling is 245 * selected as a waiting for reply method: i.e. 246 * if a completion irq was found use that anyway. 247 * @atomic_enabled: Flag to indicate that this transport, which is assured not 248 * to sleep anywhere on the TX path, can be used in atomic mode 249 * when requested. 250 */ 251 struct scmi_desc { 252 const struct scmi_transport_ops *ops; 253 int max_rx_timeout_ms; 254 int max_msg; 255 int max_msg_size; 256 unsigned int atomic_threshold; 257 const bool force_polling; 258 const bool sync_cmds_completed_on_ret; 259 const bool atomic_enabled; 260 }; 261 262 static inline bool is_polling_required(struct scmi_chan_info *cinfo, 263 const struct scmi_desc *desc) 264 { 265 return cinfo->no_completion_irq || desc->force_polling; 266 } 267 268 static inline bool is_transport_polling_capable(const struct scmi_desc *desc) 269 { 270 return desc->ops->poll_done || desc->sync_cmds_completed_on_ret; 271 } 272 273 static inline bool is_polling_enabled(struct scmi_chan_info *cinfo, 274 const struct scmi_desc *desc) 275 { 276 return is_polling_required(cinfo, desc) && 277 is_transport_polling_capable(desc); 278 } 279 280 void scmi_xfer_raw_put(const struct scmi_handle *handle, 281 struct scmi_xfer *xfer); 282 struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle); 283 struct scmi_chan_info * 284 scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id); 285 286 int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle, 287 struct scmi_xfer *xfer); 288 289 int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo, 290 struct scmi_xfer *xfer, 291 unsigned int timeout_ms); 292 293 enum debug_counters { 294 SENT_OK, 295 SENT_FAIL, 296 SENT_FAIL_POLLING_UNSUPPORTED, 297 SENT_FAIL_CHANNEL_NOT_FOUND, 298 RESPONSE_OK, 299 NOTIFICATION_OK, 300 DELAYED_RESPONSE_OK, 301 XFERS_RESPONSE_TIMEOUT, 302 XFERS_RESPONSE_POLLED_TIMEOUT, 303 RESPONSE_POLLED_OK, 304 ERR_MSG_UNEXPECTED, 305 ERR_MSG_INVALID, 306 ERR_MSG_NOMEM, 307 ERR_PROTOCOL, 308 SCMI_DEBUG_COUNTERS_LAST 309 }; 310 311 static inline void scmi_inc_count(atomic_t *arr, int stat) 312 { 313 if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) 314 atomic_inc(&arr[stat]); 315 } 316 317 enum scmi_bad_msg { 318 MSG_UNEXPECTED = -1, 319 MSG_INVALID = -2, 320 MSG_UNKNOWN = -3, 321 MSG_NOMEM = -4, 322 MSG_MBOX_SPURIOUS = -5, 323 }; 324 325 /* Used for compactness and signature validation of the function pointers being 326 * passed. 327 */ 328 typedef void (*shmem_copy_toio_t)(void __iomem *to, const void *from, 329 size_t count); 330 typedef void (*shmem_copy_fromio_t)(void *to, const void __iomem *from, 331 size_t count); 332 333 /** 334 * struct scmi_shmem_io_ops - I/O operations to read from/write to 335 * Shared Memory 336 * 337 * @toio: Copy data to the shared memory area 338 * @fromio: Copy data from the shared memory area 339 */ 340 struct scmi_shmem_io_ops { 341 shmem_copy_fromio_t fromio; 342 shmem_copy_toio_t toio; 343 }; 344 345 /* shmem related declarations */ 346 struct scmi_shared_mem; 347 348 /** 349 * struct scmi_shared_mem_operations - Transport core operations for 350 * Shared Memory 351 * 352 * @tx_prepare: Prepare the @xfer message for transmission on the chosen @shmem 353 * @read_header: Read header of the message currently hold in @shmem 354 * @fetch_response: Copy the message response from @shmem into @xfer 355 * @fetch_notification: Copy the message notification from @shmem into @xfer 356 * @clear_channel: Clear the @shmem channel busy flag 357 * @poll_done: Check if poll has completed for @xfer on @shmem 358 * @channel_free: Check if @shmem channel is marked as free 359 * @channel_intr_enabled: Check is @shmem channel has requested a completion irq 360 * @setup_iomap: Setup IO shared memory for channel @cinfo 361 */ 362 struct scmi_shared_mem_operations { 363 void (*tx_prepare)(struct scmi_shared_mem __iomem *shmem, 364 struct scmi_xfer *xfer, 365 struct scmi_chan_info *cinfo, 366 shmem_copy_toio_t toio); 367 u32 (*read_header)(struct scmi_shared_mem __iomem *shmem); 368 369 void (*fetch_response)(struct scmi_shared_mem __iomem *shmem, 370 struct scmi_xfer *xfer, 371 shmem_copy_fromio_t fromio); 372 void (*fetch_notification)(struct scmi_shared_mem __iomem *shmem, 373 size_t max_len, struct scmi_xfer *xfer, 374 shmem_copy_fromio_t fromio); 375 void (*clear_channel)(struct scmi_shared_mem __iomem *shmem); 376 bool (*poll_done)(struct scmi_shared_mem __iomem *shmem, 377 struct scmi_xfer *xfer); 378 bool (*channel_free)(struct scmi_shared_mem __iomem *shmem); 379 bool (*channel_intr_enabled)(struct scmi_shared_mem __iomem *shmem); 380 void __iomem *(*setup_iomap)(struct scmi_chan_info *cinfo, 381 struct device *dev, 382 bool tx, struct resource *res, 383 struct scmi_shmem_io_ops **ops); 384 }; 385 386 const struct scmi_shared_mem_operations *scmi_shared_mem_operations_get(void); 387 388 /* declarations for message passing transports */ 389 struct scmi_msg_payld; 390 391 /* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */ 392 #define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32)) 393 394 /** 395 * struct scmi_message_operations - Transport core operations for Message 396 * 397 * @response_size: Get calculated response size for @xfer 398 * @command_size: Get calculated command size for @xfer 399 * @tx_prepare: Prepare the @xfer message for transmission on the provided @msg 400 * @read_header: Read header of the message currently hold in @msg 401 * @fetch_response: Copy the message response from @msg into @xfer 402 * @fetch_notification: Copy the message notification from @msg into @xfer 403 */ 404 struct scmi_message_operations { 405 size_t (*response_size)(struct scmi_xfer *xfer); 406 size_t (*command_size)(struct scmi_xfer *xfer); 407 void (*tx_prepare)(struct scmi_msg_payld *msg, struct scmi_xfer *xfer); 408 u32 (*read_header)(struct scmi_msg_payld *msg); 409 void (*fetch_response)(struct scmi_msg_payld *msg, size_t len, 410 struct scmi_xfer *xfer); 411 void (*fetch_notification)(struct scmi_msg_payld *msg, size_t len, 412 size_t max_len, struct scmi_xfer *xfer); 413 }; 414 415 const struct scmi_message_operations *scmi_message_operations_get(void); 416 417 /** 418 * struct scmi_transport_core_operations - Transpoert core operations 419 * 420 * @bad_message_trace: An helper to report a malformed/unexpected message 421 * @rx_callback: Callback to report received messages 422 * @shmem: Datagram operations for shared memory based transports 423 * @msg: Datagram operations for message based transports 424 */ 425 struct scmi_transport_core_operations { 426 void (*bad_message_trace)(struct scmi_chan_info *cinfo, 427 u32 msg_hdr, enum scmi_bad_msg err); 428 void (*rx_callback)(struct scmi_chan_info *cinfo, u32 msg_hdr, 429 void *priv); 430 const struct scmi_shared_mem_operations *shmem; 431 const struct scmi_message_operations *msg; 432 }; 433 434 /** 435 * struct scmi_transport - A structure representing a configured transport 436 * 437 * @supplier: Device representing the transport and acting as a supplier for 438 * the core SCMI stack 439 * @desc: Transport descriptor 440 * @core_ops: A pointer to a pointer used by the core SCMI stack to make the 441 * core transport operations accessible to the transports. 442 */ 443 struct scmi_transport { 444 struct device *supplier; 445 struct scmi_desc *desc; 446 struct scmi_transport_core_operations **core_ops; 447 }; 448 449 #define DEFINE_SCMI_TRANSPORT_DRIVER(__tag, __drv, __desc, __match, __core_ops)\ 450 static void __tag##_dev_free(void *data) \ 451 { \ 452 struct platform_device *spdev = data; \ 453 \ 454 platform_device_unregister(spdev); \ 455 } \ 456 \ 457 static int __tag##_probe(struct platform_device *pdev) \ 458 { \ 459 struct device *dev = &pdev->dev; \ 460 struct platform_device *spdev; \ 461 struct scmi_transport strans; \ 462 int ret; \ 463 \ 464 spdev = platform_device_alloc("arm-scmi", PLATFORM_DEVID_AUTO); \ 465 if (!spdev) \ 466 return -ENOMEM; \ 467 \ 468 device_set_of_node_from_dev(&spdev->dev, dev); \ 469 \ 470 strans.supplier = dev; \ 471 strans.desc = &(__desc); \ 472 strans.core_ops = &(__core_ops); \ 473 \ 474 ret = platform_device_add_data(spdev, &strans, sizeof(strans)); \ 475 if (ret) \ 476 goto err; \ 477 \ 478 ret = platform_device_add(spdev); \ 479 if (ret) \ 480 goto err; \ 481 \ 482 return devm_add_action_or_reset(dev, __tag##_dev_free, spdev); \ 483 \ 484 err: \ 485 platform_device_put(spdev); \ 486 return ret; \ 487 } \ 488 \ 489 static struct platform_driver __drv = { \ 490 .driver = { \ 491 .name = #__tag "_transport", \ 492 .of_match_table = __match, \ 493 }, \ 494 .probe = __tag##_probe, \ 495 } 496 497 void scmi_notification_instance_data_set(const struct scmi_handle *handle, 498 void *priv); 499 void *scmi_notification_instance_data_get(const struct scmi_handle *handle); 500 #endif /* _SCMI_COMMON_H */ 501