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 * @rx_timeout_ms: The configured RX timeout in milliseconds. 167 * @handle: Pointer to SCMI entity handle 168 * @no_completion_irq: Flag to indicate that this channel has no completion 169 * interrupt mechanism for synchronous commands. 170 * This can be dynamically set by transports at run-time 171 * inside their provided .chan_setup(). 172 * @transport_info: Transport layer related information 173 */ 174 struct scmi_chan_info { 175 int id; 176 struct device *dev; 177 unsigned int rx_timeout_ms; 178 struct scmi_handle *handle; 179 bool no_completion_irq; 180 void *transport_info; 181 }; 182 183 /** 184 * struct scmi_transport_ops - Structure representing a SCMI transport ops 185 * 186 * @chan_available: Callback to check if channel is available or not 187 * @chan_setup: Callback to allocate and setup a channel 188 * @chan_free: Callback to free a channel 189 * @get_max_msg: Optional callback to provide max_msg dynamically 190 * Returns the maximum number of messages for the channel type 191 * (tx or rx) that can be pending simultaneously in the system 192 * @send_message: Callback to send a message 193 * @mark_txdone: Callback to mark tx as done 194 * @fetch_response: Callback to fetch response 195 * @fetch_notification: Callback to fetch notification 196 * @clear_channel: Callback to clear a channel 197 * @poll_done: Callback to poll transfer status 198 */ 199 struct scmi_transport_ops { 200 bool (*chan_available)(struct device_node *of_node, int idx); 201 int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev, 202 bool tx); 203 int (*chan_free)(int id, void *p, void *data); 204 unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo); 205 int (*send_message)(struct scmi_chan_info *cinfo, 206 struct scmi_xfer *xfer); 207 void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret, 208 struct scmi_xfer *xfer); 209 void (*fetch_response)(struct scmi_chan_info *cinfo, 210 struct scmi_xfer *xfer); 211 void (*fetch_notification)(struct scmi_chan_info *cinfo, 212 size_t max_len, struct scmi_xfer *xfer); 213 void (*clear_channel)(struct scmi_chan_info *cinfo); 214 bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); 215 }; 216 217 /** 218 * struct scmi_desc - Description of SoC integration 219 * 220 * @ops: Pointer to the transport specific ops structure 221 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds) 222 * @max_msg: Maximum number of messages for a channel type (tx or rx) that can 223 * be pending simultaneously in the system. May be overridden by the 224 * get_max_msg op. 225 * @max_msg_size: Maximum size of data per message that can be handled. 226 * @force_polling: Flag to force this whole transport to use SCMI core polling 227 * mechanism instead of completion interrupts even if available. 228 * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures 229 * synchronous-command messages are atomically 230 * completed on .send_message: no need to poll 231 * actively waiting for a response. 232 * Used by core internally only when polling is 233 * selected as a waiting for reply method: i.e. 234 * if a completion irq was found use that anyway. 235 * @atomic_enabled: Flag to indicate that this transport, which is assured not 236 * to sleep anywhere on the TX path, can be used in atomic mode 237 * when requested. 238 */ 239 struct scmi_desc { 240 const struct scmi_transport_ops *ops; 241 int max_rx_timeout_ms; 242 int max_msg; 243 int max_msg_size; 244 const bool force_polling; 245 const bool sync_cmds_completed_on_ret; 246 const bool atomic_enabled; 247 }; 248 249 static inline bool is_polling_required(struct scmi_chan_info *cinfo, 250 const struct scmi_desc *desc) 251 { 252 return cinfo->no_completion_irq || desc->force_polling; 253 } 254 255 static inline bool is_transport_polling_capable(const struct scmi_desc *desc) 256 { 257 return desc->ops->poll_done || desc->sync_cmds_completed_on_ret; 258 } 259 260 static inline bool is_polling_enabled(struct scmi_chan_info *cinfo, 261 const struct scmi_desc *desc) 262 { 263 return is_polling_required(cinfo, desc) && 264 is_transport_polling_capable(desc); 265 } 266 267 void scmi_xfer_raw_put(const struct scmi_handle *handle, 268 struct scmi_xfer *xfer); 269 struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle); 270 struct scmi_chan_info * 271 scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id); 272 273 int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle, 274 struct scmi_xfer *xfer); 275 276 int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo, 277 struct scmi_xfer *xfer, 278 unsigned int timeout_ms); 279 280 enum debug_counters { 281 SENT_OK, 282 SENT_FAIL, 283 SENT_FAIL_POLLING_UNSUPPORTED, 284 SENT_FAIL_CHANNEL_NOT_FOUND, 285 RESPONSE_OK, 286 NOTIFICATION_OK, 287 DELAYED_RESPONSE_OK, 288 XFERS_RESPONSE_TIMEOUT, 289 XFERS_RESPONSE_POLLED_TIMEOUT, 290 RESPONSE_POLLED_OK, 291 ERR_MSG_UNEXPECTED, 292 ERR_MSG_INVALID, 293 ERR_MSG_NOMEM, 294 ERR_PROTOCOL, 295 SCMI_DEBUG_COUNTERS_LAST 296 }; 297 298 static inline void scmi_inc_count(atomic_t *arr, int stat) 299 { 300 if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) 301 atomic_inc(&arr[stat]); 302 } 303 304 enum scmi_bad_msg { 305 MSG_UNEXPECTED = -1, 306 MSG_INVALID = -2, 307 MSG_UNKNOWN = -3, 308 MSG_NOMEM = -4, 309 MSG_MBOX_SPURIOUS = -5, 310 }; 311 312 /* shmem related declarations */ 313 struct scmi_shared_mem; 314 315 /** 316 * struct scmi_shared_mem_operations - Transport core operations for 317 * Shared Memory 318 * 319 * @tx_prepare: Prepare the @xfer message for transmission on the chosen @shmem 320 * @read_header: Read header of the message currently hold in @shmem 321 * @fetch_response: Copy the message response from @shmem into @xfer 322 * @fetch_notification: Copy the message notification from @shmem into @xfer 323 * @clear_channel: Clear the @shmem channel busy flag 324 * @poll_done: Check if poll has completed for @xfer on @shmem 325 * @channel_free: Check if @shmem channel is marked as free 326 * @channel_intr_enabled: Check is @shmem channel has requested a completion irq 327 * @setup_iomap: Setup IO shared memory for channel @cinfo 328 */ 329 struct scmi_shared_mem_operations { 330 void (*tx_prepare)(struct scmi_shared_mem __iomem *shmem, 331 struct scmi_xfer *xfer, 332 struct scmi_chan_info *cinfo); 333 u32 (*read_header)(struct scmi_shared_mem __iomem *shmem); 334 335 void (*fetch_response)(struct scmi_shared_mem __iomem *shmem, 336 struct scmi_xfer *xfer); 337 void (*fetch_notification)(struct scmi_shared_mem __iomem *shmem, 338 size_t max_len, struct scmi_xfer *xfer); 339 void (*clear_channel)(struct scmi_shared_mem __iomem *shmem); 340 bool (*poll_done)(struct scmi_shared_mem __iomem *shmem, 341 struct scmi_xfer *xfer); 342 bool (*channel_free)(struct scmi_shared_mem __iomem *shmem); 343 bool (*channel_intr_enabled)(struct scmi_shared_mem __iomem *shmem); 344 void __iomem *(*setup_iomap)(struct scmi_chan_info *cinfo, 345 struct device *dev, 346 bool tx, struct resource *res); 347 }; 348 349 const struct scmi_shared_mem_operations *scmi_shared_mem_operations_get(void); 350 351 /* declarations for message passing transports */ 352 struct scmi_msg_payld; 353 354 /* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */ 355 #define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32)) 356 357 /** 358 * struct scmi_message_operations - Transport core operations for Message 359 * 360 * @response_size: Get calculated response size for @xfer 361 * @command_size: Get calculated command size for @xfer 362 * @tx_prepare: Prepare the @xfer message for transmission on the provided @msg 363 * @read_header: Read header of the message currently hold in @msg 364 * @fetch_response: Copy the message response from @msg into @xfer 365 * @fetch_notification: Copy the message notification from @msg into @xfer 366 */ 367 struct scmi_message_operations { 368 size_t (*response_size)(struct scmi_xfer *xfer); 369 size_t (*command_size)(struct scmi_xfer *xfer); 370 void (*tx_prepare)(struct scmi_msg_payld *msg, struct scmi_xfer *xfer); 371 u32 (*read_header)(struct scmi_msg_payld *msg); 372 void (*fetch_response)(struct scmi_msg_payld *msg, size_t len, 373 struct scmi_xfer *xfer); 374 void (*fetch_notification)(struct scmi_msg_payld *msg, size_t len, 375 size_t max_len, struct scmi_xfer *xfer); 376 }; 377 378 const struct scmi_message_operations *scmi_message_operations_get(void); 379 380 /** 381 * struct scmi_transport_core_operations - Transpoert core operations 382 * 383 * @bad_message_trace: An helper to report a malformed/unexpected message 384 * @rx_callback: Callback to report received messages 385 * @shmem: Datagram operations for shared memory based transports 386 * @msg: Datagram operations for message based transports 387 */ 388 struct scmi_transport_core_operations { 389 void (*bad_message_trace)(struct scmi_chan_info *cinfo, 390 u32 msg_hdr, enum scmi_bad_msg err); 391 void (*rx_callback)(struct scmi_chan_info *cinfo, u32 msg_hdr, 392 void *priv); 393 const struct scmi_shared_mem_operations *shmem; 394 const struct scmi_message_operations *msg; 395 }; 396 397 /** 398 * struct scmi_transport - A structure representing a configured transport 399 * 400 * @supplier: Device representing the transport and acting as a supplier for 401 * the core SCMI stack 402 * @desc: Transport descriptor 403 * @core_ops: A pointer to a pointer used by the core SCMI stack to make the 404 * core transport operations accessible to the transports. 405 */ 406 struct scmi_transport { 407 struct device *supplier; 408 struct scmi_desc *desc; 409 struct scmi_transport_core_operations **core_ops; 410 }; 411 412 #define DEFINE_SCMI_TRANSPORT_DRIVER(__tag, __drv, __desc, __match, __core_ops)\ 413 static void __tag##_dev_free(void *data) \ 414 { \ 415 struct platform_device *spdev = data; \ 416 \ 417 platform_device_unregister(spdev); \ 418 } \ 419 \ 420 static int __tag##_probe(struct platform_device *pdev) \ 421 { \ 422 struct device *dev = &pdev->dev; \ 423 struct platform_device *spdev; \ 424 struct scmi_transport strans; \ 425 int ret; \ 426 \ 427 spdev = platform_device_alloc("arm-scmi", PLATFORM_DEVID_AUTO); \ 428 if (!spdev) \ 429 return -ENOMEM; \ 430 \ 431 device_set_of_node_from_dev(&spdev->dev, dev); \ 432 \ 433 strans.supplier = dev; \ 434 strans.desc = &(__desc); \ 435 strans.core_ops = &(__core_ops); \ 436 \ 437 ret = platform_device_add_data(spdev, &strans, sizeof(strans)); \ 438 if (ret) \ 439 goto err; \ 440 \ 441 ret = platform_device_add(spdev); \ 442 if (ret) \ 443 goto err; \ 444 \ 445 return devm_add_action_or_reset(dev, __tag##_dev_free, spdev); \ 446 \ 447 err: \ 448 platform_device_put(spdev); \ 449 return ret; \ 450 } \ 451 \ 452 static struct platform_driver __drv = { \ 453 .driver = { \ 454 .name = #__tag "_transport", \ 455 .of_match_table = __match, \ 456 }, \ 457 .probe = __tag##_probe, \ 458 } 459 460 void scmi_notification_instance_data_set(const struct scmi_handle *handle, 461 void *priv); 462 void *scmi_notification_instance_data_get(const struct scmi_handle *handle); 463 #endif /* _SCMI_COMMON_H */ 464