1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * System Control and Management Interface (SCMI) Message Protocol driver 4 * 5 * SCMI Message Protocol is used between the System Control Processor(SCP) 6 * and the Application Processors(AP). The Message Handling Unit(MHU) 7 * provides a mechanism for inter-processor communication between SCP's 8 * Cortex M3 and AP. 9 * 10 * SCP offers control and management of the core/cluster power states, 11 * various power domain DVFS including the core/cluster, certain system 12 * clocks configuration, thermal sensors and many others. 13 * 14 * Copyright (C) 2018-2024 ARM Ltd. 15 */ 16 17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18 19 #include <linux/bitmap.h> 20 #include <linux/debugfs.h> 21 #include <linux/device.h> 22 #include <linux/export.h> 23 #include <linux/idr.h> 24 #include <linux/io.h> 25 #include <linux/io-64-nonatomic-hi-lo.h> 26 #include <linux/kernel.h> 27 #include <linux/ktime.h> 28 #include <linux/hashtable.h> 29 #include <linux/list.h> 30 #include <linux/module.h> 31 #include <linux/of.h> 32 #include <linux/platform_device.h> 33 #include <linux/processor.h> 34 #include <linux/refcount.h> 35 #include <linux/slab.h> 36 #include <linux/xarray.h> 37 38 #include "common.h" 39 #include "notify.h" 40 41 #include "raw_mode.h" 42 43 #define CREATE_TRACE_POINTS 44 #include <trace/events/scmi.h> 45 46 static DEFINE_IDA(scmi_id); 47 48 static DEFINE_XARRAY(scmi_protocols); 49 50 /* List of all SCMI devices active in system */ 51 static LIST_HEAD(scmi_list); 52 /* Protection for the entire list */ 53 static DEFINE_MUTEX(scmi_list_mutex); 54 /* Track the unique id for the transfers for debug & profiling purpose */ 55 static atomic_t transfer_last_id; 56 57 static struct dentry *scmi_top_dentry; 58 59 /** 60 * struct scmi_xfers_info - Structure to manage transfer information 61 * 62 * @xfer_alloc_table: Bitmap table for allocated messages. 63 * Index of this bitmap table is also used for message 64 * sequence identifier. 65 * @xfer_lock: Protection for message allocation 66 * @max_msg: Maximum number of messages that can be pending 67 * @free_xfers: A free list for available to use xfers. It is initialized with 68 * a number of xfers equal to the maximum allowed in-flight 69 * messages. 70 * @pending_xfers: An hashtable, indexed by msg_hdr.seq, used to keep all the 71 * currently in-flight messages. 72 */ 73 struct scmi_xfers_info { 74 unsigned long *xfer_alloc_table; 75 spinlock_t xfer_lock; 76 int max_msg; 77 struct hlist_head free_xfers; 78 DECLARE_HASHTABLE(pending_xfers, SCMI_PENDING_XFERS_HT_ORDER_SZ); 79 }; 80 81 /** 82 * struct scmi_protocol_instance - Describe an initialized protocol instance. 83 * @handle: Reference to the SCMI handle associated to this protocol instance. 84 * @proto: A reference to the protocol descriptor. 85 * @gid: A reference for per-protocol devres management. 86 * @users: A refcount to track effective users of this protocol. 87 * @priv: Reference for optional protocol private data. 88 * @version: Protocol version supported by the platform as detected at runtime. 89 * @negotiated_version: When the platform supports a newer protocol version, 90 * the agent will try to negotiate with the platform the 91 * usage of the newest version known to it, since 92 * backward compatibility is NOT automatically assured. 93 * This field is NON-zero when a successful negotiation 94 * has completed. 95 * @ph: An embedded protocol handle that will be passed down to protocol 96 * initialization code to identify this instance. 97 * 98 * Each protocol is initialized independently once for each SCMI platform in 99 * which is defined by DT and implemented by the SCMI server fw. 100 */ 101 struct scmi_protocol_instance { 102 const struct scmi_handle *handle; 103 const struct scmi_protocol *proto; 104 void *gid; 105 refcount_t users; 106 void *priv; 107 unsigned int version; 108 unsigned int negotiated_version; 109 struct scmi_protocol_handle ph; 110 }; 111 112 #define ph_to_pi(h) container_of(h, struct scmi_protocol_instance, ph) 113 114 /** 115 * struct scmi_debug_info - Debug common info 116 * @top_dentry: A reference to the top debugfs dentry 117 * @name: Name of this SCMI instance 118 * @type: Type of this SCMI instance 119 * @is_atomic: Flag to state if the transport of this instance is atomic 120 * @counters: An array of atomic_c's used for tracking statistics (if enabled) 121 */ 122 struct scmi_debug_info { 123 struct dentry *top_dentry; 124 const char *name; 125 const char *type; 126 bool is_atomic; 127 atomic_t counters[SCMI_DEBUG_COUNTERS_LAST]; 128 }; 129 130 /** 131 * struct scmi_info - Structure representing a SCMI instance 132 * 133 * @id: A sequence number starting from zero identifying this instance 134 * @dev: Device pointer 135 * @desc: SoC description for this instance 136 * @version: SCMI revision information containing protocol version, 137 * implementation version and (sub-)vendor identification. 138 * @handle: Instance of SCMI handle to send to clients 139 * @tx_minfo: Universal Transmit Message management info 140 * @rx_minfo: Universal Receive Message management info 141 * @tx_idr: IDR object to map protocol id to Tx channel info pointer 142 * @rx_idr: IDR object to map protocol id to Rx channel info pointer 143 * @protocols: IDR for protocols' instance descriptors initialized for 144 * this SCMI instance: populated on protocol's first attempted 145 * usage. 146 * @protocols_mtx: A mutex to protect protocols instances initialization. 147 * @protocols_imp: List of protocols implemented, currently maximum of 148 * scmi_revision_info.num_protocols elements allocated by the 149 * base protocol 150 * @active_protocols: IDR storing device_nodes for protocols actually defined 151 * in the DT and confirmed as implemented by fw. 152 * @atomic_threshold: Optional system wide DT-configured threshold, expressed 153 * in microseconds, for atomic operations. 154 * Only SCMI synchronous commands reported by the platform 155 * to have an execution latency lesser-equal to the threshold 156 * should be considered for atomic mode operation: such 157 * decision is finally left up to the SCMI drivers. 158 * @notify_priv: Pointer to private data structure specific to notifications. 159 * @node: List head 160 * @users: Number of users of this instance 161 * @bus_nb: A notifier to listen for device bind/unbind on the scmi bus 162 * @dev_req_nb: A notifier to listen for device request/unrequest on the scmi 163 * bus 164 * @devreq_mtx: A mutex to serialize device creation for this SCMI instance 165 * @dbg: A pointer to debugfs related data (if any) 166 * @raw: An opaque reference handle used by SCMI Raw mode. 167 */ 168 struct scmi_info { 169 int id; 170 struct device *dev; 171 const struct scmi_desc *desc; 172 struct scmi_revision_info version; 173 struct scmi_handle handle; 174 struct scmi_xfers_info tx_minfo; 175 struct scmi_xfers_info rx_minfo; 176 struct idr tx_idr; 177 struct idr rx_idr; 178 struct idr protocols; 179 /* Ensure mutual exclusive access to protocols instance array */ 180 struct mutex protocols_mtx; 181 u8 *protocols_imp; 182 struct idr active_protocols; 183 unsigned int atomic_threshold; 184 void *notify_priv; 185 struct list_head node; 186 int users; 187 struct notifier_block bus_nb; 188 struct notifier_block dev_req_nb; 189 /* Serialize device creation process for this instance */ 190 struct mutex devreq_mtx; 191 struct scmi_debug_info *dbg; 192 void *raw; 193 }; 194 195 #define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle) 196 #define bus_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, bus_nb) 197 #define req_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, dev_req_nb) 198 199 static void scmi_rx_callback(struct scmi_chan_info *cinfo, 200 u32 msg_hdr, void *priv); 201 static void scmi_bad_message_trace(struct scmi_chan_info *cinfo, 202 u32 msg_hdr, enum scmi_bad_msg err); 203 204 static struct scmi_transport_core_operations scmi_trans_core_ops = { 205 .bad_message_trace = scmi_bad_message_trace, 206 .rx_callback = scmi_rx_callback, 207 }; 208 209 static unsigned long 210 scmi_vendor_protocol_signature(unsigned int protocol_id, char *vendor_id, 211 char *sub_vendor_id, u32 impl_ver) 212 { 213 char *signature, *p; 214 unsigned long hash = 0; 215 216 /* vendor_id/sub_vendor_id guaranteed <= SCMI_SHORT_NAME_MAX_SIZE */ 217 signature = kasprintf(GFP_KERNEL, "%02X|%s|%s|0x%08X", protocol_id, 218 vendor_id ?: "", sub_vendor_id ?: "", impl_ver); 219 if (!signature) 220 return 0; 221 222 p = signature; 223 while (*p) 224 hash = partial_name_hash(tolower(*p++), hash); 225 hash = end_name_hash(hash); 226 227 kfree(signature); 228 229 return hash; 230 } 231 232 static unsigned long 233 scmi_protocol_key_calculate(int protocol_id, char *vendor_id, 234 char *sub_vendor_id, u32 impl_ver) 235 { 236 if (protocol_id < SCMI_PROTOCOL_VENDOR_BASE) 237 return protocol_id; 238 else 239 return scmi_vendor_protocol_signature(protocol_id, vendor_id, 240 sub_vendor_id, impl_ver); 241 } 242 243 static const struct scmi_protocol * 244 __scmi_vendor_protocol_lookup(int protocol_id, char *vendor_id, 245 char *sub_vendor_id, u32 impl_ver) 246 { 247 unsigned long key; 248 struct scmi_protocol *proto = NULL; 249 250 key = scmi_protocol_key_calculate(protocol_id, vendor_id, 251 sub_vendor_id, impl_ver); 252 if (key) 253 proto = xa_load(&scmi_protocols, key); 254 255 return proto; 256 } 257 258 static const struct scmi_protocol * 259 scmi_vendor_protocol_lookup(int protocol_id, char *vendor_id, 260 char *sub_vendor_id, u32 impl_ver) 261 { 262 const struct scmi_protocol *proto = NULL; 263 264 /* Searching for closest match ...*/ 265 proto = __scmi_vendor_protocol_lookup(protocol_id, vendor_id, 266 sub_vendor_id, impl_ver); 267 if (proto) 268 return proto; 269 270 /* Any match just on vendor/sub_vendor ? */ 271 if (impl_ver) { 272 proto = __scmi_vendor_protocol_lookup(protocol_id, vendor_id, 273 sub_vendor_id, 0); 274 if (proto) 275 return proto; 276 } 277 278 /* Any match just on the vendor ? */ 279 if (sub_vendor_id) 280 proto = __scmi_vendor_protocol_lookup(protocol_id, vendor_id, 281 NULL, 0); 282 return proto; 283 } 284 285 static const struct scmi_protocol * 286 scmi_protocol_get(int protocol_id, struct scmi_revision_info *version) 287 { 288 const struct scmi_protocol *proto = NULL; 289 290 if (protocol_id < SCMI_PROTOCOL_VENDOR_BASE) 291 proto = xa_load(&scmi_protocols, protocol_id); 292 else 293 proto = scmi_vendor_protocol_lookup(protocol_id, 294 version->vendor_id, 295 version->sub_vendor_id, 296 version->impl_ver); 297 if (!proto || !try_module_get(proto->owner)) { 298 pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id); 299 return NULL; 300 } 301 302 pr_debug("Found SCMI Protocol 0x%x\n", protocol_id); 303 304 if (protocol_id >= SCMI_PROTOCOL_VENDOR_BASE) 305 pr_info("Loaded SCMI Vendor Protocol 0x%x - %s %s %X\n", 306 protocol_id, proto->vendor_id ?: "", 307 proto->sub_vendor_id ?: "", proto->impl_ver); 308 309 return proto; 310 } 311 312 static void scmi_protocol_put(const struct scmi_protocol *proto) 313 { 314 if (proto) 315 module_put(proto->owner); 316 } 317 318 static int scmi_vendor_protocol_check(const struct scmi_protocol *proto) 319 { 320 if (!proto->vendor_id) { 321 pr_err("missing vendor_id for protocol 0x%x\n", proto->id); 322 return -EINVAL; 323 } 324 325 if (strlen(proto->vendor_id) >= SCMI_SHORT_NAME_MAX_SIZE) { 326 pr_err("malformed vendor_id for protocol 0x%x\n", proto->id); 327 return -EINVAL; 328 } 329 330 if (proto->sub_vendor_id && 331 strlen(proto->sub_vendor_id) >= SCMI_SHORT_NAME_MAX_SIZE) { 332 pr_err("malformed sub_vendor_id for protocol 0x%x\n", 333 proto->id); 334 return -EINVAL; 335 } 336 337 return 0; 338 } 339 340 int scmi_protocol_register(const struct scmi_protocol *proto) 341 { 342 int ret; 343 unsigned long key; 344 345 if (!proto) { 346 pr_err("invalid protocol\n"); 347 return -EINVAL; 348 } 349 350 if (!proto->instance_init) { 351 pr_err("missing init for protocol 0x%x\n", proto->id); 352 return -EINVAL; 353 } 354 355 if (proto->id >= SCMI_PROTOCOL_VENDOR_BASE && 356 scmi_vendor_protocol_check(proto)) 357 return -EINVAL; 358 359 /* 360 * Calculate a protocol key to register this protocol with the core; 361 * key value 0 is considered invalid. 362 */ 363 key = scmi_protocol_key_calculate(proto->id, proto->vendor_id, 364 proto->sub_vendor_id, 365 proto->impl_ver); 366 if (!key) 367 return -EINVAL; 368 369 ret = xa_insert(&scmi_protocols, key, (void *)proto, GFP_KERNEL); 370 if (ret) { 371 pr_err("unable to allocate SCMI protocol slot for 0x%x - err %d\n", 372 proto->id, ret); 373 return ret; 374 } 375 376 pr_debug("Registered SCMI Protocol 0x%x\n", proto->id); 377 378 return 0; 379 } 380 EXPORT_SYMBOL_GPL(scmi_protocol_register); 381 382 void scmi_protocol_unregister(const struct scmi_protocol *proto) 383 { 384 unsigned long key; 385 386 key = scmi_protocol_key_calculate(proto->id, proto->vendor_id, 387 proto->sub_vendor_id, 388 proto->impl_ver); 389 if (!key) 390 return; 391 392 xa_erase(&scmi_protocols, key); 393 394 pr_debug("Unregistered SCMI Protocol 0x%x\n", proto->id); 395 } 396 EXPORT_SYMBOL_GPL(scmi_protocol_unregister); 397 398 /** 399 * scmi_create_protocol_devices - Create devices for all pending requests for 400 * this SCMI instance. 401 * 402 * @np: The device node describing the protocol 403 * @info: The SCMI instance descriptor 404 * @prot_id: The protocol ID 405 * @name: The optional name of the device to be created: if not provided this 406 * call will lead to the creation of all the devices currently requested 407 * for the specified protocol. 408 */ 409 static void scmi_create_protocol_devices(struct device_node *np, 410 struct scmi_info *info, 411 int prot_id, const char *name) 412 { 413 struct scmi_device *sdev; 414 415 mutex_lock(&info->devreq_mtx); 416 sdev = scmi_device_create(np, info->dev, prot_id, name); 417 if (name && !sdev) 418 dev_err(info->dev, 419 "failed to create device for protocol 0x%X (%s)\n", 420 prot_id, name); 421 mutex_unlock(&info->devreq_mtx); 422 } 423 424 static void scmi_destroy_protocol_devices(struct scmi_info *info, 425 int prot_id, const char *name) 426 { 427 mutex_lock(&info->devreq_mtx); 428 scmi_device_destroy(info->dev, prot_id, name); 429 mutex_unlock(&info->devreq_mtx); 430 } 431 432 void scmi_notification_instance_data_set(const struct scmi_handle *handle, 433 void *priv) 434 { 435 struct scmi_info *info = handle_to_scmi_info(handle); 436 437 info->notify_priv = priv; 438 /* Ensure updated protocol private date are visible */ 439 smp_wmb(); 440 } 441 442 void *scmi_notification_instance_data_get(const struct scmi_handle *handle) 443 { 444 struct scmi_info *info = handle_to_scmi_info(handle); 445 446 /* Ensure protocols_private_data has been updated */ 447 smp_rmb(); 448 return info->notify_priv; 449 } 450 451 /** 452 * scmi_xfer_token_set - Reserve and set new token for the xfer at hand 453 * 454 * @minfo: Pointer to Tx/Rx Message management info based on channel type 455 * @xfer: The xfer to act upon 456 * 457 * Pick the next unused monotonically increasing token and set it into 458 * xfer->hdr.seq: picking a monotonically increasing value avoids immediate 459 * reuse of freshly completed or timed-out xfers, thus mitigating the risk 460 * of incorrect association of a late and expired xfer with a live in-flight 461 * transaction, both happening to re-use the same token identifier. 462 * 463 * Since platform is NOT required to answer our request in-order we should 464 * account for a few rare but possible scenarios: 465 * 466 * - exactly 'next_token' may be NOT available so pick xfer_id >= next_token 467 * using find_next_zero_bit() starting from candidate next_token bit 468 * 469 * - all tokens ahead upto (MSG_TOKEN_ID_MASK - 1) are used in-flight but we 470 * are plenty of free tokens at start, so try a second pass using 471 * find_next_zero_bit() and starting from 0. 472 * 473 * X = used in-flight 474 * 475 * Normal 476 * ------ 477 * 478 * |- xfer_id picked 479 * -----------+---------------------------------------------------------- 480 * | | |X|X|X| | | | | | ... ... ... ... ... ... ... ... ... ... ...|X|X| 481 * ---------------------------------------------------------------------- 482 * ^ 483 * |- next_token 484 * 485 * Out-of-order pending at start 486 * ----------------------------- 487 * 488 * |- xfer_id picked, last_token fixed 489 * -----+---------------------------------------------------------------- 490 * |X|X| | | | |X|X| ... ... ... ... ... ... ... ... ... ... ... ...|X| | 491 * ---------------------------------------------------------------------- 492 * ^ 493 * |- next_token 494 * 495 * 496 * Out-of-order pending at end 497 * --------------------------- 498 * 499 * |- xfer_id picked, last_token fixed 500 * -----+---------------------------------------------------------------- 501 * |X|X| | | | |X|X| ... ... ... ... ... ... ... ... ... ... |X|X|X||X|X| 502 * ---------------------------------------------------------------------- 503 * ^ 504 * |- next_token 505 * 506 * Context: Assumes to be called with @xfer_lock already acquired. 507 * 508 * Return: 0 on Success or error 509 */ 510 static int scmi_xfer_token_set(struct scmi_xfers_info *minfo, 511 struct scmi_xfer *xfer) 512 { 513 unsigned long xfer_id, next_token; 514 515 /* 516 * Pick a candidate monotonic token in range [0, MSG_TOKEN_MAX - 1] 517 * using the pre-allocated transfer_id as a base. 518 * Note that the global transfer_id is shared across all message types 519 * so there could be holes in the allocated set of monotonic sequence 520 * numbers, but that is going to limit the effectiveness of the 521 * mitigation only in very rare limit conditions. 522 */ 523 next_token = (xfer->transfer_id & (MSG_TOKEN_MAX - 1)); 524 525 /* Pick the next available xfer_id >= next_token */ 526 xfer_id = find_next_zero_bit(minfo->xfer_alloc_table, 527 MSG_TOKEN_MAX, next_token); 528 if (xfer_id == MSG_TOKEN_MAX) { 529 /* 530 * After heavily out-of-order responses, there are no free 531 * tokens ahead, but only at start of xfer_alloc_table so 532 * try again from the beginning. 533 */ 534 xfer_id = find_next_zero_bit(minfo->xfer_alloc_table, 535 MSG_TOKEN_MAX, 0); 536 /* 537 * Something is wrong if we got here since there can be a 538 * maximum number of (MSG_TOKEN_MAX - 1) in-flight messages 539 * but we have not found any free token [0, MSG_TOKEN_MAX - 1]. 540 */ 541 if (WARN_ON_ONCE(xfer_id == MSG_TOKEN_MAX)) 542 return -ENOMEM; 543 } 544 545 /* Update +/- last_token accordingly if we skipped some hole */ 546 if (xfer_id != next_token) 547 atomic_add((int)(xfer_id - next_token), &transfer_last_id); 548 549 xfer->hdr.seq = (u16)xfer_id; 550 551 return 0; 552 } 553 554 /** 555 * scmi_xfer_token_clear - Release the token 556 * 557 * @minfo: Pointer to Tx/Rx Message management info based on channel type 558 * @xfer: The xfer to act upon 559 */ 560 static inline void scmi_xfer_token_clear(struct scmi_xfers_info *minfo, 561 struct scmi_xfer *xfer) 562 { 563 clear_bit(xfer->hdr.seq, minfo->xfer_alloc_table); 564 } 565 566 /** 567 * scmi_xfer_inflight_register_unlocked - Register the xfer as in-flight 568 * 569 * @xfer: The xfer to register 570 * @minfo: Pointer to Tx/Rx Message management info based on channel type 571 * 572 * Note that this helper assumes that the xfer to be registered as in-flight 573 * had been built using an xfer sequence number which still corresponds to a 574 * free slot in the xfer_alloc_table. 575 * 576 * Context: Assumes to be called with @xfer_lock already acquired. 577 */ 578 static inline void 579 scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer, 580 struct scmi_xfers_info *minfo) 581 { 582 /* Set in-flight */ 583 set_bit(xfer->hdr.seq, minfo->xfer_alloc_table); 584 hash_add(minfo->pending_xfers, &xfer->node, xfer->hdr.seq); 585 xfer->pending = true; 586 } 587 588 /** 589 * scmi_xfer_inflight_register - Try to register an xfer as in-flight 590 * 591 * @xfer: The xfer to register 592 * @minfo: Pointer to Tx/Rx Message management info based on channel type 593 * 594 * Note that this helper does NOT assume anything about the sequence number 595 * that was baked into the provided xfer, so it checks at first if it can 596 * be mapped to a free slot and fails with an error if another xfer with the 597 * same sequence number is currently still registered as in-flight. 598 * 599 * Return: 0 on Success or -EBUSY if sequence number embedded in the xfer 600 * could not rbe mapped to a free slot in the xfer_alloc_table. 601 */ 602 static int scmi_xfer_inflight_register(struct scmi_xfer *xfer, 603 struct scmi_xfers_info *minfo) 604 { 605 int ret = 0; 606 unsigned long flags; 607 608 spin_lock_irqsave(&minfo->xfer_lock, flags); 609 if (!test_bit(xfer->hdr.seq, minfo->xfer_alloc_table)) 610 scmi_xfer_inflight_register_unlocked(xfer, minfo); 611 else 612 ret = -EBUSY; 613 spin_unlock_irqrestore(&minfo->xfer_lock, flags); 614 615 return ret; 616 } 617 618 /** 619 * scmi_xfer_raw_inflight_register - An helper to register the given xfer as in 620 * flight on the TX channel, if possible. 621 * 622 * @handle: Pointer to SCMI entity handle 623 * @xfer: The xfer to register 624 * 625 * Return: 0 on Success, error otherwise 626 */ 627 int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle, 628 struct scmi_xfer *xfer) 629 { 630 struct scmi_info *info = handle_to_scmi_info(handle); 631 632 return scmi_xfer_inflight_register(xfer, &info->tx_minfo); 633 } 634 635 /** 636 * scmi_xfer_pending_set - Pick a proper sequence number and mark the xfer 637 * as pending in-flight 638 * 639 * @xfer: The xfer to act upon 640 * @minfo: Pointer to Tx/Rx Message management info based on channel type 641 * 642 * Return: 0 on Success or error otherwise 643 */ 644 static inline int scmi_xfer_pending_set(struct scmi_xfer *xfer, 645 struct scmi_xfers_info *minfo) 646 { 647 int ret; 648 unsigned long flags; 649 650 spin_lock_irqsave(&minfo->xfer_lock, flags); 651 /* Set a new monotonic token as the xfer sequence number */ 652 ret = scmi_xfer_token_set(minfo, xfer); 653 if (!ret) 654 scmi_xfer_inflight_register_unlocked(xfer, minfo); 655 spin_unlock_irqrestore(&minfo->xfer_lock, flags); 656 657 return ret; 658 } 659 660 /** 661 * scmi_xfer_get() - Allocate one message 662 * 663 * @handle: Pointer to SCMI entity handle 664 * @minfo: Pointer to Tx/Rx Message management info based on channel type 665 * 666 * Helper function which is used by various message functions that are 667 * exposed to clients of this driver for allocating a message traffic event. 668 * 669 * Picks an xfer from the free list @free_xfers (if any available) and perform 670 * a basic initialization. 671 * 672 * Note that, at this point, still no sequence number is assigned to the 673 * allocated xfer, nor it is registered as a pending transaction. 674 * 675 * The successfully initialized xfer is refcounted. 676 * 677 * Context: Holds @xfer_lock while manipulating @free_xfers. 678 * 679 * Return: An initialized xfer if all went fine, else pointer error. 680 */ 681 static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle, 682 struct scmi_xfers_info *minfo) 683 { 684 unsigned long flags; 685 struct scmi_xfer *xfer; 686 687 spin_lock_irqsave(&minfo->xfer_lock, flags); 688 if (hlist_empty(&minfo->free_xfers)) { 689 spin_unlock_irqrestore(&minfo->xfer_lock, flags); 690 return ERR_PTR(-ENOMEM); 691 } 692 693 /* grab an xfer from the free_list */ 694 xfer = hlist_entry(minfo->free_xfers.first, struct scmi_xfer, node); 695 hlist_del_init(&xfer->node); 696 697 /* 698 * Allocate transfer_id early so that can be used also as base for 699 * monotonic sequence number generation if needed. 700 */ 701 xfer->transfer_id = atomic_inc_return(&transfer_last_id); 702 703 refcount_set(&xfer->users, 1); 704 atomic_set(&xfer->busy, SCMI_XFER_FREE); 705 spin_unlock_irqrestore(&minfo->xfer_lock, flags); 706 707 return xfer; 708 } 709 710 /** 711 * scmi_xfer_raw_get - Helper to get a bare free xfer from the TX channel 712 * 713 * @handle: Pointer to SCMI entity handle 714 * 715 * Note that xfer is taken from the TX channel structures. 716 * 717 * Return: A valid xfer on Success, or an error-pointer otherwise 718 */ 719 struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle) 720 { 721 struct scmi_xfer *xfer; 722 struct scmi_info *info = handle_to_scmi_info(handle); 723 724 xfer = scmi_xfer_get(handle, &info->tx_minfo); 725 if (!IS_ERR(xfer)) 726 xfer->flags |= SCMI_XFER_FLAG_IS_RAW; 727 728 return xfer; 729 } 730 731 /** 732 * scmi_xfer_raw_channel_get - Helper to get a reference to the proper channel 733 * to use for a specific protocol_id Raw transaction. 734 * 735 * @handle: Pointer to SCMI entity handle 736 * @protocol_id: Identifier of the protocol 737 * 738 * Note that in a regular SCMI stack, usually, a protocol has to be defined in 739 * the DT to have an associated channel and be usable; but in Raw mode any 740 * protocol in range is allowed, re-using the Base channel, so as to enable 741 * fuzzing on any protocol without the need of a fully compiled DT. 742 * 743 * Return: A reference to the channel to use, or an ERR_PTR 744 */ 745 struct scmi_chan_info * 746 scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id) 747 { 748 struct scmi_chan_info *cinfo; 749 struct scmi_info *info = handle_to_scmi_info(handle); 750 751 cinfo = idr_find(&info->tx_idr, protocol_id); 752 if (!cinfo) { 753 if (protocol_id == SCMI_PROTOCOL_BASE) 754 return ERR_PTR(-EINVAL); 755 /* Use Base channel for protocols not defined for DT */ 756 cinfo = idr_find(&info->tx_idr, SCMI_PROTOCOL_BASE); 757 if (!cinfo) 758 return ERR_PTR(-EINVAL); 759 dev_warn_once(handle->dev, 760 "Using Base channel for protocol 0x%X\n", 761 protocol_id); 762 } 763 764 return cinfo; 765 } 766 767 /** 768 * __scmi_xfer_put() - Release a message 769 * 770 * @minfo: Pointer to Tx/Rx Message management info based on channel type 771 * @xfer: message that was reserved by scmi_xfer_get 772 * 773 * After refcount check, possibly release an xfer, clearing the token slot, 774 * removing xfer from @pending_xfers and putting it back into free_xfers. 775 * 776 * This holds a spinlock to maintain integrity of internal data structures. 777 */ 778 static void 779 __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer) 780 { 781 unsigned long flags; 782 783 spin_lock_irqsave(&minfo->xfer_lock, flags); 784 if (refcount_dec_and_test(&xfer->users)) { 785 if (xfer->pending) { 786 scmi_xfer_token_clear(minfo, xfer); 787 hash_del(&xfer->node); 788 xfer->pending = false; 789 } 790 hlist_add_head(&xfer->node, &minfo->free_xfers); 791 } 792 spin_unlock_irqrestore(&minfo->xfer_lock, flags); 793 } 794 795 /** 796 * scmi_xfer_raw_put - Release an xfer that was taken by @scmi_xfer_raw_get 797 * 798 * @handle: Pointer to SCMI entity handle 799 * @xfer: A reference to the xfer to put 800 * 801 * Note that as with other xfer_put() handlers the xfer is really effectively 802 * released only if there are no more users on the system. 803 */ 804 void scmi_xfer_raw_put(const struct scmi_handle *handle, struct scmi_xfer *xfer) 805 { 806 struct scmi_info *info = handle_to_scmi_info(handle); 807 808 xfer->flags &= ~SCMI_XFER_FLAG_IS_RAW; 809 xfer->flags &= ~SCMI_XFER_FLAG_CHAN_SET; 810 return __scmi_xfer_put(&info->tx_minfo, xfer); 811 } 812 813 /** 814 * scmi_xfer_lookup_unlocked - Helper to lookup an xfer_id 815 * 816 * @minfo: Pointer to Tx/Rx Message management info based on channel type 817 * @xfer_id: Token ID to lookup in @pending_xfers 818 * 819 * Refcounting is untouched. 820 * 821 * Context: Assumes to be called with @xfer_lock already acquired. 822 * 823 * Return: A valid xfer on Success or error otherwise 824 */ 825 static struct scmi_xfer * 826 scmi_xfer_lookup_unlocked(struct scmi_xfers_info *minfo, u16 xfer_id) 827 { 828 struct scmi_xfer *xfer = NULL; 829 830 if (test_bit(xfer_id, minfo->xfer_alloc_table)) 831 xfer = XFER_FIND(minfo->pending_xfers, xfer_id); 832 833 return xfer ?: ERR_PTR(-EINVAL); 834 } 835 836 /** 837 * scmi_bad_message_trace - A helper to trace weird messages 838 * 839 * @cinfo: A reference to the channel descriptor on which the message was 840 * received 841 * @msg_hdr: Message header to track 842 * @err: A specific error code used as a status value in traces. 843 * 844 * This helper can be used to trace any kind of weird, incomplete, unexpected, 845 * timed-out message that arrives and as such, can be traced only referring to 846 * the header content, since the payload is missing/unreliable. 847 */ 848 static void scmi_bad_message_trace(struct scmi_chan_info *cinfo, u32 msg_hdr, 849 enum scmi_bad_msg err) 850 { 851 char *tag; 852 struct scmi_info *info = handle_to_scmi_info(cinfo->handle); 853 854 switch (MSG_XTRACT_TYPE(msg_hdr)) { 855 case MSG_TYPE_COMMAND: 856 tag = "!RESP"; 857 break; 858 case MSG_TYPE_DELAYED_RESP: 859 tag = "!DLYD"; 860 break; 861 case MSG_TYPE_NOTIFICATION: 862 tag = "!NOTI"; 863 break; 864 default: 865 tag = "!UNKN"; 866 break; 867 } 868 869 trace_scmi_msg_dump(info->id, cinfo->id, 870 MSG_XTRACT_PROT_ID(msg_hdr), 871 MSG_XTRACT_ID(msg_hdr), tag, 872 MSG_XTRACT_TOKEN(msg_hdr), err, NULL, 0); 873 } 874 875 /** 876 * scmi_msg_response_validate - Validate message type against state of related 877 * xfer 878 * 879 * @cinfo: A reference to the channel descriptor. 880 * @msg_type: Message type to check 881 * @xfer: A reference to the xfer to validate against @msg_type 882 * 883 * This function checks if @msg_type is congruent with the current state of 884 * a pending @xfer; if an asynchronous delayed response is received before the 885 * related synchronous response (Out-of-Order Delayed Response) the missing 886 * synchronous response is assumed to be OK and completed, carrying on with the 887 * Delayed Response: this is done to address the case in which the underlying 888 * SCMI transport can deliver such out-of-order responses. 889 * 890 * Context: Assumes to be called with xfer->lock already acquired. 891 * 892 * Return: 0 on Success, error otherwise 893 */ 894 static inline int scmi_msg_response_validate(struct scmi_chan_info *cinfo, 895 u8 msg_type, 896 struct scmi_xfer *xfer) 897 { 898 /* 899 * Even if a response was indeed expected on this slot at this point, 900 * a buggy platform could wrongly reply feeding us an unexpected 901 * delayed response we're not prepared to handle: bail-out safely 902 * blaming firmware. 903 */ 904 if (msg_type == MSG_TYPE_DELAYED_RESP && !xfer->async_done) { 905 dev_err(cinfo->dev, 906 "Delayed Response for %d not expected! Buggy F/W ?\n", 907 xfer->hdr.seq); 908 return -EINVAL; 909 } 910 911 switch (xfer->state) { 912 case SCMI_XFER_SENT_OK: 913 if (msg_type == MSG_TYPE_DELAYED_RESP) { 914 /* 915 * Delayed Response expected but delivered earlier. 916 * Assume message RESPONSE was OK and skip state. 917 */ 918 xfer->hdr.status = SCMI_SUCCESS; 919 xfer->state = SCMI_XFER_RESP_OK; 920 complete(&xfer->done); 921 dev_warn(cinfo->dev, 922 "Received valid OoO Delayed Response for %d\n", 923 xfer->hdr.seq); 924 } 925 break; 926 case SCMI_XFER_RESP_OK: 927 if (msg_type != MSG_TYPE_DELAYED_RESP) 928 return -EINVAL; 929 break; 930 case SCMI_XFER_DRESP_OK: 931 /* No further message expected once in SCMI_XFER_DRESP_OK */ 932 return -EINVAL; 933 } 934 935 return 0; 936 } 937 938 /** 939 * scmi_xfer_state_update - Update xfer state 940 * 941 * @xfer: A reference to the xfer to update 942 * @msg_type: Type of message being processed. 943 * 944 * Note that this message is assumed to have been already successfully validated 945 * by @scmi_msg_response_validate(), so here we just update the state. 946 * 947 * Context: Assumes to be called on an xfer exclusively acquired using the 948 * busy flag. 949 */ 950 static inline void scmi_xfer_state_update(struct scmi_xfer *xfer, u8 msg_type) 951 { 952 xfer->hdr.type = msg_type; 953 954 /* Unknown command types were already discarded earlier */ 955 if (xfer->hdr.type == MSG_TYPE_COMMAND) 956 xfer->state = SCMI_XFER_RESP_OK; 957 else 958 xfer->state = SCMI_XFER_DRESP_OK; 959 } 960 961 static bool scmi_xfer_acquired(struct scmi_xfer *xfer) 962 { 963 int ret; 964 965 ret = atomic_cmpxchg(&xfer->busy, SCMI_XFER_FREE, SCMI_XFER_BUSY); 966 967 return ret == SCMI_XFER_FREE; 968 } 969 970 /** 971 * scmi_xfer_command_acquire - Helper to lookup and acquire a command xfer 972 * 973 * @cinfo: A reference to the channel descriptor. 974 * @msg_hdr: A message header to use as lookup key 975 * 976 * When a valid xfer is found for the sequence number embedded in the provided 977 * msg_hdr, reference counting is properly updated and exclusive access to this 978 * xfer is granted till released with @scmi_xfer_command_release. 979 * 980 * Return: A valid @xfer on Success or error otherwise. 981 */ 982 static inline struct scmi_xfer * 983 scmi_xfer_command_acquire(struct scmi_chan_info *cinfo, u32 msg_hdr) 984 { 985 int ret; 986 unsigned long flags; 987 struct scmi_xfer *xfer; 988 struct scmi_info *info = handle_to_scmi_info(cinfo->handle); 989 struct scmi_xfers_info *minfo = &info->tx_minfo; 990 u8 msg_type = MSG_XTRACT_TYPE(msg_hdr); 991 u16 xfer_id = MSG_XTRACT_TOKEN(msg_hdr); 992 993 /* Are we even expecting this? */ 994 spin_lock_irqsave(&minfo->xfer_lock, flags); 995 xfer = scmi_xfer_lookup_unlocked(minfo, xfer_id); 996 if (IS_ERR(xfer)) { 997 dev_err(cinfo->dev, 998 "Message for %d type %d is not expected!\n", 999 xfer_id, msg_type); 1000 spin_unlock_irqrestore(&minfo->xfer_lock, flags); 1001 1002 scmi_bad_message_trace(cinfo, msg_hdr, MSG_UNEXPECTED); 1003 scmi_inc_count(info->dbg->counters, ERR_MSG_UNEXPECTED); 1004 1005 return xfer; 1006 } 1007 refcount_inc(&xfer->users); 1008 spin_unlock_irqrestore(&minfo->xfer_lock, flags); 1009 1010 spin_lock_irqsave(&xfer->lock, flags); 1011 ret = scmi_msg_response_validate(cinfo, msg_type, xfer); 1012 /* 1013 * If a pending xfer was found which was also in a congruent state with 1014 * the received message, acquire exclusive access to it setting the busy 1015 * flag. 1016 * Spins only on the rare limit condition of concurrent reception of 1017 * RESP and DRESP for the same xfer. 1018 */ 1019 if (!ret) { 1020 spin_until_cond(scmi_xfer_acquired(xfer)); 1021 scmi_xfer_state_update(xfer, msg_type); 1022 } 1023 spin_unlock_irqrestore(&xfer->lock, flags); 1024 1025 if (ret) { 1026 dev_err(cinfo->dev, 1027 "Invalid message type:%d for %d - HDR:0x%X state:%d\n", 1028 msg_type, xfer_id, msg_hdr, xfer->state); 1029 1030 scmi_bad_message_trace(cinfo, msg_hdr, MSG_INVALID); 1031 scmi_inc_count(info->dbg->counters, ERR_MSG_INVALID); 1032 1033 /* On error the refcount incremented above has to be dropped */ 1034 __scmi_xfer_put(minfo, xfer); 1035 xfer = ERR_PTR(-EINVAL); 1036 } 1037 1038 return xfer; 1039 } 1040 1041 static inline void scmi_xfer_command_release(struct scmi_info *info, 1042 struct scmi_xfer *xfer) 1043 { 1044 atomic_set(&xfer->busy, SCMI_XFER_FREE); 1045 __scmi_xfer_put(&info->tx_minfo, xfer); 1046 } 1047 1048 static inline void scmi_clear_channel(struct scmi_info *info, 1049 struct scmi_chan_info *cinfo) 1050 { 1051 if (info->desc->ops->clear_channel) 1052 info->desc->ops->clear_channel(cinfo); 1053 } 1054 1055 static void scmi_handle_notification(struct scmi_chan_info *cinfo, 1056 u32 msg_hdr, void *priv) 1057 { 1058 struct scmi_xfer *xfer; 1059 struct device *dev = cinfo->dev; 1060 struct scmi_info *info = handle_to_scmi_info(cinfo->handle); 1061 struct scmi_xfers_info *minfo = &info->rx_minfo; 1062 ktime_t ts; 1063 1064 ts = ktime_get_boottime(); 1065 xfer = scmi_xfer_get(cinfo->handle, minfo); 1066 if (IS_ERR(xfer)) { 1067 dev_err(dev, "failed to get free message slot (%ld)\n", 1068 PTR_ERR(xfer)); 1069 1070 scmi_bad_message_trace(cinfo, msg_hdr, MSG_NOMEM); 1071 scmi_inc_count(info->dbg->counters, ERR_MSG_NOMEM); 1072 1073 scmi_clear_channel(info, cinfo); 1074 return; 1075 } 1076 1077 unpack_scmi_header(msg_hdr, &xfer->hdr); 1078 if (priv) 1079 /* Ensure order between xfer->priv store and following ops */ 1080 smp_store_mb(xfer->priv, priv); 1081 info->desc->ops->fetch_notification(cinfo, info->desc->max_msg_size, 1082 xfer); 1083 1084 trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id, 1085 xfer->hdr.id, "NOTI", xfer->hdr.seq, 1086 xfer->hdr.status, xfer->rx.buf, xfer->rx.len); 1087 scmi_inc_count(info->dbg->counters, NOTIFICATION_OK); 1088 1089 scmi_notify(cinfo->handle, xfer->hdr.protocol_id, 1090 xfer->hdr.id, xfer->rx.buf, xfer->rx.len, ts); 1091 1092 trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id, 1093 xfer->hdr.protocol_id, xfer->hdr.seq, 1094 MSG_TYPE_NOTIFICATION); 1095 1096 if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { 1097 xfer->hdr.seq = MSG_XTRACT_TOKEN(msg_hdr); 1098 scmi_raw_message_report(info->raw, xfer, SCMI_RAW_NOTIF_QUEUE, 1099 cinfo->id); 1100 } 1101 1102 __scmi_xfer_put(minfo, xfer); 1103 1104 scmi_clear_channel(info, cinfo); 1105 } 1106 1107 static void scmi_handle_response(struct scmi_chan_info *cinfo, 1108 u32 msg_hdr, void *priv) 1109 { 1110 struct scmi_xfer *xfer; 1111 struct scmi_info *info = handle_to_scmi_info(cinfo->handle); 1112 1113 xfer = scmi_xfer_command_acquire(cinfo, msg_hdr); 1114 if (IS_ERR(xfer)) { 1115 if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) 1116 scmi_raw_error_report(info->raw, cinfo, msg_hdr, priv); 1117 1118 if (MSG_XTRACT_TYPE(msg_hdr) == MSG_TYPE_DELAYED_RESP) 1119 scmi_clear_channel(info, cinfo); 1120 return; 1121 } 1122 1123 /* rx.len could be shrunk in the sync do_xfer, so reset to maxsz */ 1124 if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP) 1125 xfer->rx.len = info->desc->max_msg_size; 1126 1127 if (priv) 1128 /* Ensure order between xfer->priv store and following ops */ 1129 smp_store_mb(xfer->priv, priv); 1130 info->desc->ops->fetch_response(cinfo, xfer); 1131 1132 trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id, 1133 xfer->hdr.id, 1134 xfer->hdr.type == MSG_TYPE_DELAYED_RESP ? 1135 (!SCMI_XFER_IS_RAW(xfer) ? "DLYD" : "dlyd") : 1136 (!SCMI_XFER_IS_RAW(xfer) ? "RESP" : "resp"), 1137 xfer->hdr.seq, xfer->hdr.status, 1138 xfer->rx.buf, xfer->rx.len); 1139 1140 trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id, 1141 xfer->hdr.protocol_id, xfer->hdr.seq, 1142 xfer->hdr.type); 1143 1144 if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP) { 1145 scmi_clear_channel(info, cinfo); 1146 complete(xfer->async_done); 1147 scmi_inc_count(info->dbg->counters, DELAYED_RESPONSE_OK); 1148 } else { 1149 complete(&xfer->done); 1150 scmi_inc_count(info->dbg->counters, RESPONSE_OK); 1151 } 1152 1153 if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { 1154 /* 1155 * When in polling mode avoid to queue the Raw xfer on the IRQ 1156 * RX path since it will be already queued at the end of the TX 1157 * poll loop. 1158 */ 1159 if (!xfer->hdr.poll_completion) 1160 scmi_raw_message_report(info->raw, xfer, 1161 SCMI_RAW_REPLY_QUEUE, 1162 cinfo->id); 1163 } 1164 1165 scmi_xfer_command_release(info, xfer); 1166 } 1167 1168 /** 1169 * scmi_rx_callback() - callback for receiving messages 1170 * 1171 * @cinfo: SCMI channel info 1172 * @msg_hdr: Message header 1173 * @priv: Transport specific private data. 1174 * 1175 * Processes one received message to appropriate transfer information and 1176 * signals completion of the transfer. 1177 * 1178 * NOTE: This function will be invoked in IRQ context, hence should be 1179 * as optimal as possible. 1180 */ 1181 static void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, 1182 void *priv) 1183 { 1184 u8 msg_type = MSG_XTRACT_TYPE(msg_hdr); 1185 1186 switch (msg_type) { 1187 case MSG_TYPE_NOTIFICATION: 1188 scmi_handle_notification(cinfo, msg_hdr, priv); 1189 break; 1190 case MSG_TYPE_COMMAND: 1191 case MSG_TYPE_DELAYED_RESP: 1192 scmi_handle_response(cinfo, msg_hdr, priv); 1193 break; 1194 default: 1195 WARN_ONCE(1, "received unknown msg_type:%d\n", msg_type); 1196 scmi_bad_message_trace(cinfo, msg_hdr, MSG_UNKNOWN); 1197 break; 1198 } 1199 } 1200 1201 /** 1202 * xfer_put() - Release a transmit message 1203 * 1204 * @ph: Pointer to SCMI protocol handle 1205 * @xfer: message that was reserved by xfer_get_init 1206 */ 1207 static void xfer_put(const struct scmi_protocol_handle *ph, 1208 struct scmi_xfer *xfer) 1209 { 1210 const struct scmi_protocol_instance *pi = ph_to_pi(ph); 1211 struct scmi_info *info = handle_to_scmi_info(pi->handle); 1212 1213 __scmi_xfer_put(&info->tx_minfo, xfer); 1214 } 1215 1216 static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo, 1217 struct scmi_xfer *xfer, ktime_t stop) 1218 { 1219 struct scmi_info *info = handle_to_scmi_info(cinfo->handle); 1220 1221 /* 1222 * Poll also on xfer->done so that polling can be forcibly terminated 1223 * in case of out-of-order receptions of delayed responses 1224 */ 1225 return info->desc->ops->poll_done(cinfo, xfer) || 1226 try_wait_for_completion(&xfer->done) || 1227 ktime_after(ktime_get(), stop); 1228 } 1229 1230 static int scmi_wait_for_reply(struct device *dev, const struct scmi_desc *desc, 1231 struct scmi_chan_info *cinfo, 1232 struct scmi_xfer *xfer, unsigned int timeout_ms) 1233 { 1234 int ret = 0; 1235 struct scmi_info *info = handle_to_scmi_info(cinfo->handle); 1236 1237 if (xfer->hdr.poll_completion) { 1238 /* 1239 * Real polling is needed only if transport has NOT declared 1240 * itself to support synchronous commands replies. 1241 */ 1242 if (!desc->sync_cmds_completed_on_ret) { 1243 /* 1244 * Poll on xfer using transport provided .poll_done(); 1245 * assumes no completion interrupt was available. 1246 */ 1247 ktime_t stop = ktime_add_ms(ktime_get(), timeout_ms); 1248 1249 spin_until_cond(scmi_xfer_done_no_timeout(cinfo, 1250 xfer, stop)); 1251 if (ktime_after(ktime_get(), stop)) { 1252 dev_err(dev, 1253 "timed out in resp(caller: %pS) - polling\n", 1254 (void *)_RET_IP_); 1255 ret = -ETIMEDOUT; 1256 scmi_inc_count(info->dbg->counters, XFERS_RESPONSE_POLLED_TIMEOUT); 1257 } 1258 } 1259 1260 if (!ret) { 1261 unsigned long flags; 1262 1263 /* 1264 * Do not fetch_response if an out-of-order delayed 1265 * response is being processed. 1266 */ 1267 spin_lock_irqsave(&xfer->lock, flags); 1268 if (xfer->state == SCMI_XFER_SENT_OK) { 1269 desc->ops->fetch_response(cinfo, xfer); 1270 xfer->state = SCMI_XFER_RESP_OK; 1271 } 1272 spin_unlock_irqrestore(&xfer->lock, flags); 1273 1274 /* Trace polled replies. */ 1275 trace_scmi_msg_dump(info->id, cinfo->id, 1276 xfer->hdr.protocol_id, xfer->hdr.id, 1277 !SCMI_XFER_IS_RAW(xfer) ? 1278 "RESP" : "resp", 1279 xfer->hdr.seq, xfer->hdr.status, 1280 xfer->rx.buf, xfer->rx.len); 1281 scmi_inc_count(info->dbg->counters, RESPONSE_POLLED_OK); 1282 1283 if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { 1284 scmi_raw_message_report(info->raw, xfer, 1285 SCMI_RAW_REPLY_QUEUE, 1286 cinfo->id); 1287 } 1288 } 1289 } else { 1290 /* And we wait for the response. */ 1291 if (!wait_for_completion_timeout(&xfer->done, 1292 msecs_to_jiffies(timeout_ms))) { 1293 dev_err(dev, "timed out in resp(caller: %pS)\n", 1294 (void *)_RET_IP_); 1295 ret = -ETIMEDOUT; 1296 scmi_inc_count(info->dbg->counters, XFERS_RESPONSE_TIMEOUT); 1297 } 1298 } 1299 1300 return ret; 1301 } 1302 1303 /** 1304 * scmi_wait_for_message_response - An helper to group all the possible ways of 1305 * waiting for a synchronous message response. 1306 * 1307 * @cinfo: SCMI channel info 1308 * @xfer: Reference to the transfer being waited for. 1309 * 1310 * Chooses waiting strategy (sleep-waiting vs busy-waiting) depending on 1311 * configuration flags like xfer->hdr.poll_completion. 1312 * 1313 * Return: 0 on Success, error otherwise. 1314 */ 1315 static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo, 1316 struct scmi_xfer *xfer) 1317 { 1318 struct scmi_info *info = handle_to_scmi_info(cinfo->handle); 1319 struct device *dev = info->dev; 1320 1321 trace_scmi_xfer_response_wait(xfer->transfer_id, xfer->hdr.id, 1322 xfer->hdr.protocol_id, xfer->hdr.seq, 1323 info->desc->max_rx_timeout_ms, 1324 xfer->hdr.poll_completion); 1325 1326 return scmi_wait_for_reply(dev, info->desc, cinfo, xfer, 1327 info->desc->max_rx_timeout_ms); 1328 } 1329 1330 /** 1331 * scmi_xfer_raw_wait_for_message_response - An helper to wait for a message 1332 * reply to an xfer raw request on a specific channel for the required timeout. 1333 * 1334 * @cinfo: SCMI channel info 1335 * @xfer: Reference to the transfer being waited for. 1336 * @timeout_ms: The maximum timeout in milliseconds 1337 * 1338 * Return: 0 on Success, error otherwise. 1339 */ 1340 int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo, 1341 struct scmi_xfer *xfer, 1342 unsigned int timeout_ms) 1343 { 1344 int ret; 1345 struct scmi_info *info = handle_to_scmi_info(cinfo->handle); 1346 struct device *dev = info->dev; 1347 1348 ret = scmi_wait_for_reply(dev, info->desc, cinfo, xfer, timeout_ms); 1349 if (ret) 1350 dev_dbg(dev, "timed out in RAW response - HDR:%08X\n", 1351 pack_scmi_header(&xfer->hdr)); 1352 1353 return ret; 1354 } 1355 1356 /** 1357 * do_xfer() - Do one transfer 1358 * 1359 * @ph: Pointer to SCMI protocol handle 1360 * @xfer: Transfer to initiate and wait for response 1361 * 1362 * Return: -ETIMEDOUT in case of no response, if transmit error, 1363 * return corresponding error, else if all goes well, 1364 * return 0. 1365 */ 1366 static int do_xfer(const struct scmi_protocol_handle *ph, 1367 struct scmi_xfer *xfer) 1368 { 1369 int ret; 1370 const struct scmi_protocol_instance *pi = ph_to_pi(ph); 1371 struct scmi_info *info = handle_to_scmi_info(pi->handle); 1372 struct device *dev = info->dev; 1373 struct scmi_chan_info *cinfo; 1374 1375 /* Check for polling request on custom command xfers at first */ 1376 if (xfer->hdr.poll_completion && 1377 !is_transport_polling_capable(info->desc)) { 1378 dev_warn_once(dev, 1379 "Polling mode is not supported by transport.\n"); 1380 scmi_inc_count(info->dbg->counters, SENT_FAIL_POLLING_UNSUPPORTED); 1381 return -EINVAL; 1382 } 1383 1384 cinfo = idr_find(&info->tx_idr, pi->proto->id); 1385 if (unlikely(!cinfo)) { 1386 scmi_inc_count(info->dbg->counters, SENT_FAIL_CHANNEL_NOT_FOUND); 1387 return -EINVAL; 1388 } 1389 /* True ONLY if also supported by transport. */ 1390 if (is_polling_enabled(cinfo, info->desc)) 1391 xfer->hdr.poll_completion = true; 1392 1393 /* 1394 * Initialise protocol id now from protocol handle to avoid it being 1395 * overridden by mistake (or malice) by the protocol code mangling with 1396 * the scmi_xfer structure prior to this. 1397 */ 1398 xfer->hdr.protocol_id = pi->proto->id; 1399 reinit_completion(&xfer->done); 1400 1401 trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id, 1402 xfer->hdr.protocol_id, xfer->hdr.seq, 1403 xfer->hdr.poll_completion); 1404 1405 /* Clear any stale status */ 1406 xfer->hdr.status = SCMI_SUCCESS; 1407 xfer->state = SCMI_XFER_SENT_OK; 1408 /* 1409 * Even though spinlocking is not needed here since no race is possible 1410 * on xfer->state due to the monotonically increasing tokens allocation, 1411 * we must anyway ensure xfer->state initialization is not re-ordered 1412 * after the .send_message() to be sure that on the RX path an early 1413 * ISR calling scmi_rx_callback() cannot see an old stale xfer->state. 1414 */ 1415 smp_mb(); 1416 1417 ret = info->desc->ops->send_message(cinfo, xfer); 1418 if (ret < 0) { 1419 dev_dbg(dev, "Failed to send message %d\n", ret); 1420 scmi_inc_count(info->dbg->counters, SENT_FAIL); 1421 return ret; 1422 } 1423 1424 trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id, 1425 xfer->hdr.id, "CMND", xfer->hdr.seq, 1426 xfer->hdr.status, xfer->tx.buf, xfer->tx.len); 1427 scmi_inc_count(info->dbg->counters, SENT_OK); 1428 1429 ret = scmi_wait_for_message_response(cinfo, xfer); 1430 if (!ret && xfer->hdr.status) { 1431 ret = scmi_to_linux_errno(xfer->hdr.status); 1432 scmi_inc_count(info->dbg->counters, ERR_PROTOCOL); 1433 } 1434 1435 if (info->desc->ops->mark_txdone) 1436 info->desc->ops->mark_txdone(cinfo, ret, xfer); 1437 1438 trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id, 1439 xfer->hdr.protocol_id, xfer->hdr.seq, ret); 1440 1441 return ret; 1442 } 1443 1444 static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph, 1445 struct scmi_xfer *xfer) 1446 { 1447 const struct scmi_protocol_instance *pi = ph_to_pi(ph); 1448 struct scmi_info *info = handle_to_scmi_info(pi->handle); 1449 1450 xfer->rx.len = info->desc->max_msg_size; 1451 } 1452 1453 /** 1454 * do_xfer_with_response() - Do one transfer and wait until the delayed 1455 * response is received 1456 * 1457 * @ph: Pointer to SCMI protocol handle 1458 * @xfer: Transfer to initiate and wait for response 1459 * 1460 * Using asynchronous commands in atomic/polling mode should be avoided since 1461 * it could cause long busy-waiting here, so ignore polling for the delayed 1462 * response and WARN if it was requested for this command transaction since 1463 * upper layers should refrain from issuing such kind of requests. 1464 * 1465 * The only other option would have been to refrain from using any asynchronous 1466 * command even if made available, when an atomic transport is detected, and 1467 * instead forcibly use the synchronous version (thing that can be easily 1468 * attained at the protocol layer), but this would also have led to longer 1469 * stalls of the channel for synchronous commands and possibly timeouts. 1470 * (in other words there is usually a good reason if a platform provides an 1471 * asynchronous version of a command and we should prefer to use it...just not 1472 * when using atomic/polling mode) 1473 * 1474 * Return: -ETIMEDOUT in case of no delayed response, if transmit error, 1475 * return corresponding error, else if all goes well, return 0. 1476 */ 1477 static int do_xfer_with_response(const struct scmi_protocol_handle *ph, 1478 struct scmi_xfer *xfer) 1479 { 1480 int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT); 1481 DECLARE_COMPLETION_ONSTACK(async_response); 1482 1483 xfer->async_done = &async_response; 1484 1485 /* 1486 * Delayed responses should not be polled, so an async command should 1487 * not have been used when requiring an atomic/poll context; WARN and 1488 * perform instead a sleeping wait. 1489 * (Note Async + IgnoreDelayedResponses are sent via do_xfer) 1490 */ 1491 WARN_ON_ONCE(xfer->hdr.poll_completion); 1492 1493 ret = do_xfer(ph, xfer); 1494 if (!ret) { 1495 if (!wait_for_completion_timeout(xfer->async_done, timeout)) { 1496 dev_err(ph->dev, 1497 "timed out in delayed resp(caller: %pS)\n", 1498 (void *)_RET_IP_); 1499 ret = -ETIMEDOUT; 1500 } else if (xfer->hdr.status) { 1501 ret = scmi_to_linux_errno(xfer->hdr.status); 1502 } 1503 } 1504 1505 xfer->async_done = NULL; 1506 return ret; 1507 } 1508 1509 /** 1510 * xfer_get_init() - Allocate and initialise one message for transmit 1511 * 1512 * @ph: Pointer to SCMI protocol handle 1513 * @msg_id: Message identifier 1514 * @tx_size: transmit message size 1515 * @rx_size: receive message size 1516 * @p: pointer to the allocated and initialised message 1517 * 1518 * This function allocates the message using @scmi_xfer_get and 1519 * initialise the header. 1520 * 1521 * Return: 0 if all went fine with @p pointing to message, else 1522 * corresponding error. 1523 */ 1524 static int xfer_get_init(const struct scmi_protocol_handle *ph, 1525 u8 msg_id, size_t tx_size, size_t rx_size, 1526 struct scmi_xfer **p) 1527 { 1528 int ret; 1529 struct scmi_xfer *xfer; 1530 const struct scmi_protocol_instance *pi = ph_to_pi(ph); 1531 struct scmi_info *info = handle_to_scmi_info(pi->handle); 1532 struct scmi_xfers_info *minfo = &info->tx_minfo; 1533 struct device *dev = info->dev; 1534 1535 /* Ensure we have sane transfer sizes */ 1536 if (rx_size > info->desc->max_msg_size || 1537 tx_size > info->desc->max_msg_size) 1538 return -ERANGE; 1539 1540 xfer = scmi_xfer_get(pi->handle, minfo); 1541 if (IS_ERR(xfer)) { 1542 ret = PTR_ERR(xfer); 1543 dev_err(dev, "failed to get free message slot(%d)\n", ret); 1544 return ret; 1545 } 1546 1547 /* Pick a sequence number and register this xfer as in-flight */ 1548 ret = scmi_xfer_pending_set(xfer, minfo); 1549 if (ret) { 1550 dev_err(pi->handle->dev, 1551 "Failed to get monotonic token %d\n", ret); 1552 __scmi_xfer_put(minfo, xfer); 1553 return ret; 1554 } 1555 1556 xfer->tx.len = tx_size; 1557 xfer->rx.len = rx_size ? : info->desc->max_msg_size; 1558 xfer->hdr.type = MSG_TYPE_COMMAND; 1559 xfer->hdr.id = msg_id; 1560 xfer->hdr.poll_completion = false; 1561 1562 *p = xfer; 1563 1564 return 0; 1565 } 1566 1567 /** 1568 * version_get() - command to get the revision of the SCMI entity 1569 * 1570 * @ph: Pointer to SCMI protocol handle 1571 * @version: Holds returned version of protocol. 1572 * 1573 * Updates the SCMI information in the internal data structure. 1574 * 1575 * Return: 0 if all went fine, else return appropriate error. 1576 */ 1577 static int version_get(const struct scmi_protocol_handle *ph, u32 *version) 1578 { 1579 int ret; 1580 __le32 *rev_info; 1581 struct scmi_xfer *t; 1582 1583 ret = xfer_get_init(ph, PROTOCOL_VERSION, 0, sizeof(*version), &t); 1584 if (ret) 1585 return ret; 1586 1587 ret = do_xfer(ph, t); 1588 if (!ret) { 1589 rev_info = t->rx.buf; 1590 *version = le32_to_cpu(*rev_info); 1591 } 1592 1593 xfer_put(ph, t); 1594 return ret; 1595 } 1596 1597 /** 1598 * scmi_set_protocol_priv - Set protocol specific data at init time 1599 * 1600 * @ph: A reference to the protocol handle. 1601 * @priv: The private data to set. 1602 * @version: The detected protocol version for the core to register. 1603 * 1604 * Return: 0 on Success 1605 */ 1606 static int scmi_set_protocol_priv(const struct scmi_protocol_handle *ph, 1607 void *priv, u32 version) 1608 { 1609 struct scmi_protocol_instance *pi = ph_to_pi(ph); 1610 1611 pi->priv = priv; 1612 pi->version = version; 1613 1614 return 0; 1615 } 1616 1617 /** 1618 * scmi_get_protocol_priv - Set protocol specific data at init time 1619 * 1620 * @ph: A reference to the protocol handle. 1621 * 1622 * Return: Protocol private data if any was set. 1623 */ 1624 static void *scmi_get_protocol_priv(const struct scmi_protocol_handle *ph) 1625 { 1626 const struct scmi_protocol_instance *pi = ph_to_pi(ph); 1627 1628 return pi->priv; 1629 } 1630 1631 static const struct scmi_xfer_ops xfer_ops = { 1632 .version_get = version_get, 1633 .xfer_get_init = xfer_get_init, 1634 .reset_rx_to_maxsz = reset_rx_to_maxsz, 1635 .do_xfer = do_xfer, 1636 .do_xfer_with_response = do_xfer_with_response, 1637 .xfer_put = xfer_put, 1638 }; 1639 1640 struct scmi_msg_resp_domain_name_get { 1641 __le32 flags; 1642 u8 name[SCMI_MAX_STR_SIZE]; 1643 }; 1644 1645 /** 1646 * scmi_common_extended_name_get - Common helper to get extended resources name 1647 * @ph: A protocol handle reference. 1648 * @cmd_id: The specific command ID to use. 1649 * @res_id: The specific resource ID to use. 1650 * @flags: A pointer to specific flags to use, if any. 1651 * @name: A pointer to the preallocated area where the retrieved name will be 1652 * stored as a NULL terminated string. 1653 * @len: The len in bytes of the @name char array. 1654 * 1655 * Return: 0 on Succcess 1656 */ 1657 static int scmi_common_extended_name_get(const struct scmi_protocol_handle *ph, 1658 u8 cmd_id, u32 res_id, u32 *flags, 1659 char *name, size_t len) 1660 { 1661 int ret; 1662 size_t txlen; 1663 struct scmi_xfer *t; 1664 struct scmi_msg_resp_domain_name_get *resp; 1665 1666 txlen = !flags ? sizeof(res_id) : sizeof(res_id) + sizeof(*flags); 1667 ret = ph->xops->xfer_get_init(ph, cmd_id, txlen, sizeof(*resp), &t); 1668 if (ret) 1669 goto out; 1670 1671 put_unaligned_le32(res_id, t->tx.buf); 1672 if (flags) 1673 put_unaligned_le32(*flags, t->tx.buf + sizeof(res_id)); 1674 resp = t->rx.buf; 1675 1676 ret = ph->xops->do_xfer(ph, t); 1677 if (!ret) 1678 strscpy(name, resp->name, len); 1679 1680 ph->xops->xfer_put(ph, t); 1681 out: 1682 if (ret) 1683 dev_warn(ph->dev, 1684 "Failed to get extended name - id:%u (ret:%d). Using %s\n", 1685 res_id, ret, name); 1686 return ret; 1687 } 1688 1689 /** 1690 * scmi_common_get_max_msg_size - Get maximum message size 1691 * @ph: A protocol handle reference. 1692 * 1693 * Return: Maximum message size for the current protocol. 1694 */ 1695 static int scmi_common_get_max_msg_size(const struct scmi_protocol_handle *ph) 1696 { 1697 const struct scmi_protocol_instance *pi = ph_to_pi(ph); 1698 struct scmi_info *info = handle_to_scmi_info(pi->handle); 1699 1700 return info->desc->max_msg_size; 1701 } 1702 1703 /** 1704 * struct scmi_iterator - Iterator descriptor 1705 * @msg: A reference to the message TX buffer; filled by @prepare_message with 1706 * a proper custom command payload for each multi-part command request. 1707 * @resp: A reference to the response RX buffer; used by @update_state and 1708 * @process_response to parse the multi-part replies. 1709 * @t: A reference to the underlying xfer initialized and used transparently by 1710 * the iterator internal routines. 1711 * @ph: A reference to the associated protocol handle to be used. 1712 * @ops: A reference to the custom provided iterator operations. 1713 * @state: The current iterator state; used and updated in turn by the iterators 1714 * internal routines and by the caller-provided @scmi_iterator_ops. 1715 * @priv: A reference to optional private data as provided by the caller and 1716 * passed back to the @@scmi_iterator_ops. 1717 */ 1718 struct scmi_iterator { 1719 void *msg; 1720 void *resp; 1721 struct scmi_xfer *t; 1722 const struct scmi_protocol_handle *ph; 1723 struct scmi_iterator_ops *ops; 1724 struct scmi_iterator_state state; 1725 void *priv; 1726 }; 1727 1728 static void *scmi_iterator_init(const struct scmi_protocol_handle *ph, 1729 struct scmi_iterator_ops *ops, 1730 unsigned int max_resources, u8 msg_id, 1731 size_t tx_size, void *priv) 1732 { 1733 int ret; 1734 struct scmi_iterator *i; 1735 1736 i = devm_kzalloc(ph->dev, sizeof(*i), GFP_KERNEL); 1737 if (!i) 1738 return ERR_PTR(-ENOMEM); 1739 1740 i->ph = ph; 1741 i->ops = ops; 1742 i->priv = priv; 1743 1744 ret = ph->xops->xfer_get_init(ph, msg_id, tx_size, 0, &i->t); 1745 if (ret) { 1746 devm_kfree(ph->dev, i); 1747 return ERR_PTR(ret); 1748 } 1749 1750 i->state.max_resources = max_resources; 1751 i->msg = i->t->tx.buf; 1752 i->resp = i->t->rx.buf; 1753 1754 return i; 1755 } 1756 1757 static int scmi_iterator_run(void *iter) 1758 { 1759 int ret = -EINVAL; 1760 struct scmi_iterator_ops *iops; 1761 const struct scmi_protocol_handle *ph; 1762 struct scmi_iterator_state *st; 1763 struct scmi_iterator *i = iter; 1764 1765 if (!i || !i->ops || !i->ph) 1766 return ret; 1767 1768 iops = i->ops; 1769 ph = i->ph; 1770 st = &i->state; 1771 1772 do { 1773 iops->prepare_message(i->msg, st->desc_index, i->priv); 1774 ret = ph->xops->do_xfer(ph, i->t); 1775 if (ret) 1776 break; 1777 1778 st->rx_len = i->t->rx.len; 1779 ret = iops->update_state(st, i->resp, i->priv); 1780 if (ret) 1781 break; 1782 1783 if (st->num_returned > st->max_resources - st->desc_index) { 1784 dev_err(ph->dev, 1785 "No. of resources can't exceed %d\n", 1786 st->max_resources); 1787 ret = -EINVAL; 1788 break; 1789 } 1790 1791 for (st->loop_idx = 0; st->loop_idx < st->num_returned; 1792 st->loop_idx++) { 1793 ret = iops->process_response(ph, i->resp, st, i->priv); 1794 if (ret) 1795 goto out; 1796 } 1797 1798 st->desc_index += st->num_returned; 1799 ph->xops->reset_rx_to_maxsz(ph, i->t); 1800 /* 1801 * check for both returned and remaining to avoid infinite 1802 * loop due to buggy firmware 1803 */ 1804 } while (st->num_returned && st->num_remaining); 1805 1806 out: 1807 /* Finalize and destroy iterator */ 1808 ph->xops->xfer_put(ph, i->t); 1809 devm_kfree(ph->dev, i); 1810 1811 return ret; 1812 } 1813 1814 struct scmi_msg_get_fc_info { 1815 __le32 domain; 1816 __le32 message_id; 1817 }; 1818 1819 struct scmi_msg_resp_desc_fc { 1820 __le32 attr; 1821 #define SUPPORTS_DOORBELL(x) ((x) & BIT(0)) 1822 #define DOORBELL_REG_WIDTH(x) FIELD_GET(GENMASK(2, 1), (x)) 1823 __le32 rate_limit; 1824 __le32 chan_addr_low; 1825 __le32 chan_addr_high; 1826 __le32 chan_size; 1827 __le32 db_addr_low; 1828 __le32 db_addr_high; 1829 __le32 db_set_lmask; 1830 __le32 db_set_hmask; 1831 __le32 db_preserve_lmask; 1832 __le32 db_preserve_hmask; 1833 }; 1834 1835 static void 1836 scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, 1837 u8 describe_id, u32 message_id, u32 valid_size, 1838 u32 domain, void __iomem **p_addr, 1839 struct scmi_fc_db_info **p_db, u32 *rate_limit) 1840 { 1841 int ret; 1842 u32 flags; 1843 u64 phys_addr; 1844 u8 size; 1845 void __iomem *addr; 1846 struct scmi_xfer *t; 1847 struct scmi_fc_db_info *db = NULL; 1848 struct scmi_msg_get_fc_info *info; 1849 struct scmi_msg_resp_desc_fc *resp; 1850 const struct scmi_protocol_instance *pi = ph_to_pi(ph); 1851 1852 if (!p_addr) { 1853 ret = -EINVAL; 1854 goto err_out; 1855 } 1856 1857 ret = ph->xops->xfer_get_init(ph, describe_id, 1858 sizeof(*info), sizeof(*resp), &t); 1859 if (ret) 1860 goto err_out; 1861 1862 info = t->tx.buf; 1863 info->domain = cpu_to_le32(domain); 1864 info->message_id = cpu_to_le32(message_id); 1865 1866 /* 1867 * Bail out on error leaving fc_info addresses zeroed; this includes 1868 * the case in which the requested domain/message_id does NOT support 1869 * fastchannels at all. 1870 */ 1871 ret = ph->xops->do_xfer(ph, t); 1872 if (ret) 1873 goto err_xfer; 1874 1875 resp = t->rx.buf; 1876 flags = le32_to_cpu(resp->attr); 1877 size = le32_to_cpu(resp->chan_size); 1878 if (size != valid_size) { 1879 ret = -EINVAL; 1880 goto err_xfer; 1881 } 1882 1883 if (rate_limit) 1884 *rate_limit = le32_to_cpu(resp->rate_limit) & GENMASK(19, 0); 1885 1886 phys_addr = le32_to_cpu(resp->chan_addr_low); 1887 phys_addr |= (u64)le32_to_cpu(resp->chan_addr_high) << 32; 1888 addr = devm_ioremap(ph->dev, phys_addr, size); 1889 if (!addr) { 1890 ret = -EADDRNOTAVAIL; 1891 goto err_xfer; 1892 } 1893 1894 *p_addr = addr; 1895 1896 if (p_db && SUPPORTS_DOORBELL(flags)) { 1897 db = devm_kzalloc(ph->dev, sizeof(*db), GFP_KERNEL); 1898 if (!db) { 1899 ret = -ENOMEM; 1900 goto err_db; 1901 } 1902 1903 size = 1 << DOORBELL_REG_WIDTH(flags); 1904 phys_addr = le32_to_cpu(resp->db_addr_low); 1905 phys_addr |= (u64)le32_to_cpu(resp->db_addr_high) << 32; 1906 addr = devm_ioremap(ph->dev, phys_addr, size); 1907 if (!addr) { 1908 ret = -EADDRNOTAVAIL; 1909 goto err_db_mem; 1910 } 1911 1912 db->addr = addr; 1913 db->width = size; 1914 db->set = le32_to_cpu(resp->db_set_lmask); 1915 db->set |= (u64)le32_to_cpu(resp->db_set_hmask) << 32; 1916 db->mask = le32_to_cpu(resp->db_preserve_lmask); 1917 db->mask |= (u64)le32_to_cpu(resp->db_preserve_hmask) << 32; 1918 1919 *p_db = db; 1920 } 1921 1922 ph->xops->xfer_put(ph, t); 1923 1924 dev_dbg(ph->dev, 1925 "Using valid FC for protocol %X [MSG_ID:%u / RES_ID:%u]\n", 1926 pi->proto->id, message_id, domain); 1927 1928 return; 1929 1930 err_db_mem: 1931 devm_kfree(ph->dev, db); 1932 1933 err_db: 1934 *p_addr = NULL; 1935 1936 err_xfer: 1937 ph->xops->xfer_put(ph, t); 1938 1939 err_out: 1940 dev_warn(ph->dev, 1941 "Failed to get FC for protocol %X [MSG_ID:%u / RES_ID:%u] - ret:%d. Using regular messaging.\n", 1942 pi->proto->id, message_id, domain, ret); 1943 } 1944 1945 #define SCMI_PROTO_FC_RING_DB(w) \ 1946 do { \ 1947 u##w val = 0; \ 1948 \ 1949 if (db->mask) \ 1950 val = ioread##w(db->addr) & db->mask; \ 1951 iowrite##w((u##w)db->set | val, db->addr); \ 1952 } while (0) 1953 1954 static void scmi_common_fastchannel_db_ring(struct scmi_fc_db_info *db) 1955 { 1956 if (!db || !db->addr) 1957 return; 1958 1959 if (db->width == 1) 1960 SCMI_PROTO_FC_RING_DB(8); 1961 else if (db->width == 2) 1962 SCMI_PROTO_FC_RING_DB(16); 1963 else if (db->width == 4) 1964 SCMI_PROTO_FC_RING_DB(32); 1965 else /* db->width == 8 */ 1966 #ifdef CONFIG_64BIT 1967 SCMI_PROTO_FC_RING_DB(64); 1968 #else 1969 { 1970 u64 val = 0; 1971 1972 if (db->mask) 1973 val = ioread64_hi_lo(db->addr) & db->mask; 1974 iowrite64_hi_lo(db->set | val, db->addr); 1975 } 1976 #endif 1977 } 1978 1979 /** 1980 * scmi_protocol_msg_check - Check protocol message attributes 1981 * 1982 * @ph: A reference to the protocol handle. 1983 * @message_id: The ID of the message to check. 1984 * @attributes: A parameter to optionally return the retrieved message 1985 * attributes, in case of Success. 1986 * 1987 * An helper to check protocol message attributes for a specific protocol 1988 * and message pair. 1989 * 1990 * Return: 0 on SUCCESS 1991 */ 1992 static int scmi_protocol_msg_check(const struct scmi_protocol_handle *ph, 1993 u32 message_id, u32 *attributes) 1994 { 1995 int ret; 1996 struct scmi_xfer *t; 1997 1998 ret = xfer_get_init(ph, PROTOCOL_MESSAGE_ATTRIBUTES, 1999 sizeof(__le32), 0, &t); 2000 if (ret) 2001 return ret; 2002 2003 put_unaligned_le32(message_id, t->tx.buf); 2004 ret = do_xfer(ph, t); 2005 if (!ret && attributes) 2006 *attributes = get_unaligned_le32(t->rx.buf); 2007 xfer_put(ph, t); 2008 2009 return ret; 2010 } 2011 2012 static const struct scmi_proto_helpers_ops helpers_ops = { 2013 .extended_name_get = scmi_common_extended_name_get, 2014 .get_max_msg_size = scmi_common_get_max_msg_size, 2015 .iter_response_init = scmi_iterator_init, 2016 .iter_response_run = scmi_iterator_run, 2017 .protocol_msg_check = scmi_protocol_msg_check, 2018 .fastchannel_init = scmi_common_fastchannel_init, 2019 .fastchannel_db_ring = scmi_common_fastchannel_db_ring, 2020 }; 2021 2022 /** 2023 * scmi_revision_area_get - Retrieve version memory area. 2024 * 2025 * @ph: A reference to the protocol handle. 2026 * 2027 * A helper to grab the version memory area reference during SCMI Base protocol 2028 * initialization. 2029 * 2030 * Return: A reference to the version memory area associated to the SCMI 2031 * instance underlying this protocol handle. 2032 */ 2033 struct scmi_revision_info * 2034 scmi_revision_area_get(const struct scmi_protocol_handle *ph) 2035 { 2036 const struct scmi_protocol_instance *pi = ph_to_pi(ph); 2037 2038 return pi->handle->version; 2039 } 2040 2041 /** 2042 * scmi_protocol_version_negotiate - Negotiate protocol version 2043 * 2044 * @ph: A reference to the protocol handle. 2045 * 2046 * An helper to negotiate a protocol version different from the latest 2047 * advertised as supported from the platform: on Success backward 2048 * compatibility is assured by the platform. 2049 * 2050 * Return: 0 on Success 2051 */ 2052 static int scmi_protocol_version_negotiate(struct scmi_protocol_handle *ph) 2053 { 2054 int ret; 2055 struct scmi_xfer *t; 2056 struct scmi_protocol_instance *pi = ph_to_pi(ph); 2057 2058 /* At first check if NEGOTIATE_PROTOCOL_VERSION is supported ... */ 2059 ret = scmi_protocol_msg_check(ph, NEGOTIATE_PROTOCOL_VERSION, NULL); 2060 if (ret) 2061 return ret; 2062 2063 /* ... then attempt protocol version negotiation */ 2064 ret = xfer_get_init(ph, NEGOTIATE_PROTOCOL_VERSION, 2065 sizeof(__le32), 0, &t); 2066 if (ret) 2067 return ret; 2068 2069 put_unaligned_le32(pi->proto->supported_version, t->tx.buf); 2070 ret = do_xfer(ph, t); 2071 if (!ret) 2072 pi->negotiated_version = pi->proto->supported_version; 2073 2074 xfer_put(ph, t); 2075 2076 return ret; 2077 } 2078 2079 /** 2080 * scmi_alloc_init_protocol_instance - Allocate and initialize a protocol 2081 * instance descriptor. 2082 * @info: The reference to the related SCMI instance. 2083 * @proto: The protocol descriptor. 2084 * 2085 * Allocate a new protocol instance descriptor, using the provided @proto 2086 * description, against the specified SCMI instance @info, and initialize it; 2087 * all resources management is handled via a dedicated per-protocol devres 2088 * group. 2089 * 2090 * Context: Assumes to be called with @protocols_mtx already acquired. 2091 * Return: A reference to a freshly allocated and initialized protocol instance 2092 * or ERR_PTR on failure. On failure the @proto reference is at first 2093 * put using @scmi_protocol_put() before releasing all the devres group. 2094 */ 2095 static struct scmi_protocol_instance * 2096 scmi_alloc_init_protocol_instance(struct scmi_info *info, 2097 const struct scmi_protocol *proto) 2098 { 2099 int ret = -ENOMEM; 2100 void *gid; 2101 struct scmi_protocol_instance *pi; 2102 const struct scmi_handle *handle = &info->handle; 2103 2104 /* Protocol specific devres group */ 2105 gid = devres_open_group(handle->dev, NULL, GFP_KERNEL); 2106 if (!gid) { 2107 scmi_protocol_put(proto); 2108 goto out; 2109 } 2110 2111 pi = devm_kzalloc(handle->dev, sizeof(*pi), GFP_KERNEL); 2112 if (!pi) 2113 goto clean; 2114 2115 pi->gid = gid; 2116 pi->proto = proto; 2117 pi->handle = handle; 2118 pi->ph.dev = handle->dev; 2119 pi->ph.xops = &xfer_ops; 2120 pi->ph.hops = &helpers_ops; 2121 pi->ph.set_priv = scmi_set_protocol_priv; 2122 pi->ph.get_priv = scmi_get_protocol_priv; 2123 refcount_set(&pi->users, 1); 2124 /* proto->init is assured NON NULL by scmi_protocol_register */ 2125 ret = pi->proto->instance_init(&pi->ph); 2126 if (ret) 2127 goto clean; 2128 2129 ret = idr_alloc(&info->protocols, pi, proto->id, proto->id + 1, 2130 GFP_KERNEL); 2131 if (ret != proto->id) 2132 goto clean; 2133 2134 /* 2135 * Warn but ignore events registration errors since we do not want 2136 * to skip whole protocols if their notifications are messed up. 2137 */ 2138 if (pi->proto->events) { 2139 ret = scmi_register_protocol_events(handle, pi->proto->id, 2140 &pi->ph, 2141 pi->proto->events); 2142 if (ret) 2143 dev_warn(handle->dev, 2144 "Protocol:%X - Events Registration Failed - err:%d\n", 2145 pi->proto->id, ret); 2146 } 2147 2148 devres_close_group(handle->dev, pi->gid); 2149 dev_dbg(handle->dev, "Initialized protocol: 0x%X\n", pi->proto->id); 2150 2151 if (pi->version > proto->supported_version) { 2152 ret = scmi_protocol_version_negotiate(&pi->ph); 2153 if (!ret) { 2154 dev_info(handle->dev, 2155 "Protocol 0x%X successfully negotiated version 0x%X\n", 2156 proto->id, pi->negotiated_version); 2157 } else { 2158 dev_warn(handle->dev, 2159 "Detected UNSUPPORTED higher version 0x%X for protocol 0x%X.\n", 2160 pi->version, pi->proto->id); 2161 dev_warn(handle->dev, 2162 "Trying version 0x%X. Backward compatibility is NOT assured.\n", 2163 pi->proto->supported_version); 2164 } 2165 } 2166 2167 return pi; 2168 2169 clean: 2170 /* Take care to put the protocol module's owner before releasing all */ 2171 scmi_protocol_put(proto); 2172 devres_release_group(handle->dev, gid); 2173 out: 2174 return ERR_PTR(ret); 2175 } 2176 2177 /** 2178 * scmi_get_protocol_instance - Protocol initialization helper. 2179 * @handle: A reference to the SCMI platform instance. 2180 * @protocol_id: The protocol being requested. 2181 * 2182 * In case the required protocol has never been requested before for this 2183 * instance, allocate and initialize all the needed structures while handling 2184 * resource allocation with a dedicated per-protocol devres subgroup. 2185 * 2186 * Return: A reference to an initialized protocol instance or error on failure: 2187 * in particular returns -EPROBE_DEFER when the desired protocol could 2188 * NOT be found. 2189 */ 2190 static struct scmi_protocol_instance * __must_check 2191 scmi_get_protocol_instance(const struct scmi_handle *handle, u8 protocol_id) 2192 { 2193 struct scmi_protocol_instance *pi; 2194 struct scmi_info *info = handle_to_scmi_info(handle); 2195 2196 mutex_lock(&info->protocols_mtx); 2197 pi = idr_find(&info->protocols, protocol_id); 2198 2199 if (pi) { 2200 refcount_inc(&pi->users); 2201 } else { 2202 const struct scmi_protocol *proto; 2203 2204 /* Fails if protocol not registered on bus */ 2205 proto = scmi_protocol_get(protocol_id, &info->version); 2206 if (proto) 2207 pi = scmi_alloc_init_protocol_instance(info, proto); 2208 else 2209 pi = ERR_PTR(-EPROBE_DEFER); 2210 } 2211 mutex_unlock(&info->protocols_mtx); 2212 2213 return pi; 2214 } 2215 2216 /** 2217 * scmi_protocol_acquire - Protocol acquire 2218 * @handle: A reference to the SCMI platform instance. 2219 * @protocol_id: The protocol being requested. 2220 * 2221 * Register a new user for the requested protocol on the specified SCMI 2222 * platform instance, possibly triggering its initialization on first user. 2223 * 2224 * Return: 0 if protocol was acquired successfully. 2225 */ 2226 int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id) 2227 { 2228 return PTR_ERR_OR_ZERO(scmi_get_protocol_instance(handle, protocol_id)); 2229 } 2230 2231 /** 2232 * scmi_protocol_release - Protocol de-initialization helper. 2233 * @handle: A reference to the SCMI platform instance. 2234 * @protocol_id: The protocol being requested. 2235 * 2236 * Remove one user for the specified protocol and triggers de-initialization 2237 * and resources de-allocation once the last user has gone. 2238 */ 2239 void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id) 2240 { 2241 struct scmi_info *info = handle_to_scmi_info(handle); 2242 struct scmi_protocol_instance *pi; 2243 2244 mutex_lock(&info->protocols_mtx); 2245 pi = idr_find(&info->protocols, protocol_id); 2246 if (WARN_ON(!pi)) 2247 goto out; 2248 2249 if (refcount_dec_and_test(&pi->users)) { 2250 void *gid = pi->gid; 2251 2252 if (pi->proto->events) 2253 scmi_deregister_protocol_events(handle, protocol_id); 2254 2255 if (pi->proto->instance_deinit) 2256 pi->proto->instance_deinit(&pi->ph); 2257 2258 idr_remove(&info->protocols, protocol_id); 2259 2260 scmi_protocol_put(pi->proto); 2261 2262 devres_release_group(handle->dev, gid); 2263 dev_dbg(handle->dev, "De-Initialized protocol: 0x%X\n", 2264 protocol_id); 2265 } 2266 2267 out: 2268 mutex_unlock(&info->protocols_mtx); 2269 } 2270 2271 void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, 2272 u8 *prot_imp) 2273 { 2274 const struct scmi_protocol_instance *pi = ph_to_pi(ph); 2275 struct scmi_info *info = handle_to_scmi_info(pi->handle); 2276 2277 info->protocols_imp = prot_imp; 2278 } 2279 2280 static bool 2281 scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id) 2282 { 2283 int i; 2284 struct scmi_info *info = handle_to_scmi_info(handle); 2285 struct scmi_revision_info *rev = handle->version; 2286 2287 if (!info->protocols_imp) 2288 return false; 2289 2290 for (i = 0; i < rev->num_protocols; i++) 2291 if (info->protocols_imp[i] == prot_id) 2292 return true; 2293 return false; 2294 } 2295 2296 struct scmi_protocol_devres { 2297 const struct scmi_handle *handle; 2298 u8 protocol_id; 2299 }; 2300 2301 static void scmi_devm_release_protocol(struct device *dev, void *res) 2302 { 2303 struct scmi_protocol_devres *dres = res; 2304 2305 scmi_protocol_release(dres->handle, dres->protocol_id); 2306 } 2307 2308 static struct scmi_protocol_instance __must_check * 2309 scmi_devres_protocol_instance_get(struct scmi_device *sdev, u8 protocol_id) 2310 { 2311 struct scmi_protocol_instance *pi; 2312 struct scmi_protocol_devres *dres; 2313 2314 dres = devres_alloc(scmi_devm_release_protocol, 2315 sizeof(*dres), GFP_KERNEL); 2316 if (!dres) 2317 return ERR_PTR(-ENOMEM); 2318 2319 pi = scmi_get_protocol_instance(sdev->handle, protocol_id); 2320 if (IS_ERR(pi)) { 2321 devres_free(dres); 2322 return pi; 2323 } 2324 2325 dres->handle = sdev->handle; 2326 dres->protocol_id = protocol_id; 2327 devres_add(&sdev->dev, dres); 2328 2329 return pi; 2330 } 2331 2332 /** 2333 * scmi_devm_protocol_get - Devres managed get protocol operations and handle 2334 * @sdev: A reference to an scmi_device whose embedded struct device is to 2335 * be used for devres accounting. 2336 * @protocol_id: The protocol being requested. 2337 * @ph: A pointer reference used to pass back the associated protocol handle. 2338 * 2339 * Get hold of a protocol accounting for its usage, eventually triggering its 2340 * initialization, and returning the protocol specific operations and related 2341 * protocol handle which will be used as first argument in most of the 2342 * protocols operations methods. 2343 * Being a devres based managed method, protocol hold will be automatically 2344 * released, and possibly de-initialized on last user, once the SCMI driver 2345 * owning the scmi_device is unbound from it. 2346 * 2347 * Return: A reference to the requested protocol operations or error. 2348 * Must be checked for errors by caller. 2349 */ 2350 static const void __must_check * 2351 scmi_devm_protocol_get(struct scmi_device *sdev, u8 protocol_id, 2352 struct scmi_protocol_handle **ph) 2353 { 2354 struct scmi_protocol_instance *pi; 2355 2356 if (!ph) 2357 return ERR_PTR(-EINVAL); 2358 2359 pi = scmi_devres_protocol_instance_get(sdev, protocol_id); 2360 if (IS_ERR(pi)) 2361 return pi; 2362 2363 *ph = &pi->ph; 2364 2365 return pi->proto->ops; 2366 } 2367 2368 /** 2369 * scmi_devm_protocol_acquire - Devres managed helper to get hold of a protocol 2370 * @sdev: A reference to an scmi_device whose embedded struct device is to 2371 * be used for devres accounting. 2372 * @protocol_id: The protocol being requested. 2373 * 2374 * Get hold of a protocol accounting for its usage, possibly triggering its 2375 * initialization but without getting access to its protocol specific operations 2376 * and handle. 2377 * 2378 * Being a devres based managed method, protocol hold will be automatically 2379 * released, and possibly de-initialized on last user, once the SCMI driver 2380 * owning the scmi_device is unbound from it. 2381 * 2382 * Return: 0 on SUCCESS 2383 */ 2384 static int __must_check scmi_devm_protocol_acquire(struct scmi_device *sdev, 2385 u8 protocol_id) 2386 { 2387 struct scmi_protocol_instance *pi; 2388 2389 pi = scmi_devres_protocol_instance_get(sdev, protocol_id); 2390 if (IS_ERR(pi)) 2391 return PTR_ERR(pi); 2392 2393 return 0; 2394 } 2395 2396 static int scmi_devm_protocol_match(struct device *dev, void *res, void *data) 2397 { 2398 struct scmi_protocol_devres *dres = res; 2399 2400 if (WARN_ON(!dres || !data)) 2401 return 0; 2402 2403 return dres->protocol_id == *((u8 *)data); 2404 } 2405 2406 /** 2407 * scmi_devm_protocol_put - Devres managed put protocol operations and handle 2408 * @sdev: A reference to an scmi_device whose embedded struct device is to 2409 * be used for devres accounting. 2410 * @protocol_id: The protocol being requested. 2411 * 2412 * Explicitly release a protocol hold previously obtained calling the above 2413 * @scmi_devm_protocol_get. 2414 */ 2415 static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id) 2416 { 2417 int ret; 2418 2419 ret = devres_release(&sdev->dev, scmi_devm_release_protocol, 2420 scmi_devm_protocol_match, &protocol_id); 2421 WARN_ON(ret); 2422 } 2423 2424 /** 2425 * scmi_is_transport_atomic - Method to check if underlying transport for an 2426 * SCMI instance is configured as atomic. 2427 * 2428 * @handle: A reference to the SCMI platform instance. 2429 * @atomic_threshold: An optional return value for the system wide currently 2430 * configured threshold for atomic operations. 2431 * 2432 * Return: True if transport is configured as atomic 2433 */ 2434 static bool scmi_is_transport_atomic(const struct scmi_handle *handle, 2435 unsigned int *atomic_threshold) 2436 { 2437 bool ret; 2438 struct scmi_info *info = handle_to_scmi_info(handle); 2439 2440 ret = info->desc->atomic_enabled && 2441 is_transport_polling_capable(info->desc); 2442 if (ret && atomic_threshold) 2443 *atomic_threshold = info->atomic_threshold; 2444 2445 return ret; 2446 } 2447 2448 /** 2449 * scmi_handle_get() - Get the SCMI handle for a device 2450 * 2451 * @dev: pointer to device for which we want SCMI handle 2452 * 2453 * NOTE: The function does not track individual clients of the framework 2454 * and is expected to be maintained by caller of SCMI protocol library. 2455 * scmi_handle_put must be balanced with successful scmi_handle_get 2456 * 2457 * Return: pointer to handle if successful, NULL on error 2458 */ 2459 static struct scmi_handle *scmi_handle_get(struct device *dev) 2460 { 2461 struct list_head *p; 2462 struct scmi_info *info; 2463 struct scmi_handle *handle = NULL; 2464 2465 mutex_lock(&scmi_list_mutex); 2466 list_for_each(p, &scmi_list) { 2467 info = list_entry(p, struct scmi_info, node); 2468 if (dev->parent == info->dev) { 2469 info->users++; 2470 handle = &info->handle; 2471 break; 2472 } 2473 } 2474 mutex_unlock(&scmi_list_mutex); 2475 2476 return handle; 2477 } 2478 2479 /** 2480 * scmi_handle_put() - Release the handle acquired by scmi_handle_get 2481 * 2482 * @handle: handle acquired by scmi_handle_get 2483 * 2484 * NOTE: The function does not track individual clients of the framework 2485 * and is expected to be maintained by caller of SCMI protocol library. 2486 * scmi_handle_put must be balanced with successful scmi_handle_get 2487 * 2488 * Return: 0 is successfully released 2489 * if null was passed, it returns -EINVAL; 2490 */ 2491 static int scmi_handle_put(const struct scmi_handle *handle) 2492 { 2493 struct scmi_info *info; 2494 2495 if (!handle) 2496 return -EINVAL; 2497 2498 info = handle_to_scmi_info(handle); 2499 mutex_lock(&scmi_list_mutex); 2500 if (!WARN_ON(!info->users)) 2501 info->users--; 2502 mutex_unlock(&scmi_list_mutex); 2503 2504 return 0; 2505 } 2506 2507 static void scmi_device_link_add(struct device *consumer, 2508 struct device *supplier) 2509 { 2510 struct device_link *link; 2511 2512 link = device_link_add(consumer, supplier, DL_FLAG_AUTOREMOVE_CONSUMER); 2513 2514 WARN_ON(!link); 2515 } 2516 2517 static void scmi_set_handle(struct scmi_device *scmi_dev) 2518 { 2519 scmi_dev->handle = scmi_handle_get(&scmi_dev->dev); 2520 if (scmi_dev->handle) 2521 scmi_device_link_add(&scmi_dev->dev, scmi_dev->handle->dev); 2522 } 2523 2524 static int __scmi_xfer_info_init(struct scmi_info *sinfo, 2525 struct scmi_xfers_info *info) 2526 { 2527 int i; 2528 struct scmi_xfer *xfer; 2529 struct device *dev = sinfo->dev; 2530 const struct scmi_desc *desc = sinfo->desc; 2531 2532 /* Pre-allocated messages, no more than what hdr.seq can support */ 2533 if (WARN_ON(!info->max_msg || info->max_msg > MSG_TOKEN_MAX)) { 2534 dev_err(dev, 2535 "Invalid maximum messages %d, not in range [1 - %lu]\n", 2536 info->max_msg, MSG_TOKEN_MAX); 2537 return -EINVAL; 2538 } 2539 2540 hash_init(info->pending_xfers); 2541 2542 /* Allocate a bitmask sized to hold MSG_TOKEN_MAX tokens */ 2543 info->xfer_alloc_table = devm_bitmap_zalloc(dev, MSG_TOKEN_MAX, 2544 GFP_KERNEL); 2545 if (!info->xfer_alloc_table) 2546 return -ENOMEM; 2547 2548 /* 2549 * Preallocate a number of xfers equal to max inflight messages, 2550 * pre-initialize the buffer pointer to pre-allocated buffers and 2551 * attach all of them to the free list 2552 */ 2553 INIT_HLIST_HEAD(&info->free_xfers); 2554 for (i = 0; i < info->max_msg; i++) { 2555 xfer = devm_kzalloc(dev, sizeof(*xfer), GFP_KERNEL); 2556 if (!xfer) 2557 return -ENOMEM; 2558 2559 xfer->rx.buf = devm_kcalloc(dev, sizeof(u8), desc->max_msg_size, 2560 GFP_KERNEL); 2561 if (!xfer->rx.buf) 2562 return -ENOMEM; 2563 2564 xfer->tx.buf = xfer->rx.buf; 2565 init_completion(&xfer->done); 2566 spin_lock_init(&xfer->lock); 2567 2568 /* Add initialized xfer to the free list */ 2569 hlist_add_head(&xfer->node, &info->free_xfers); 2570 } 2571 2572 spin_lock_init(&info->xfer_lock); 2573 2574 return 0; 2575 } 2576 2577 static int scmi_channels_max_msg_configure(struct scmi_info *sinfo) 2578 { 2579 const struct scmi_desc *desc = sinfo->desc; 2580 2581 if (!desc->ops->get_max_msg) { 2582 sinfo->tx_minfo.max_msg = desc->max_msg; 2583 sinfo->rx_minfo.max_msg = desc->max_msg; 2584 } else { 2585 struct scmi_chan_info *base_cinfo; 2586 2587 base_cinfo = idr_find(&sinfo->tx_idr, SCMI_PROTOCOL_BASE); 2588 if (!base_cinfo) 2589 return -EINVAL; 2590 sinfo->tx_minfo.max_msg = desc->ops->get_max_msg(base_cinfo); 2591 2592 /* RX channel is optional so can be skipped */ 2593 base_cinfo = idr_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE); 2594 if (base_cinfo) 2595 sinfo->rx_minfo.max_msg = 2596 desc->ops->get_max_msg(base_cinfo); 2597 } 2598 2599 return 0; 2600 } 2601 2602 static int scmi_xfer_info_init(struct scmi_info *sinfo) 2603 { 2604 int ret; 2605 2606 ret = scmi_channels_max_msg_configure(sinfo); 2607 if (ret) 2608 return ret; 2609 2610 ret = __scmi_xfer_info_init(sinfo, &sinfo->tx_minfo); 2611 if (!ret && !idr_is_empty(&sinfo->rx_idr)) 2612 ret = __scmi_xfer_info_init(sinfo, &sinfo->rx_minfo); 2613 2614 return ret; 2615 } 2616 2617 static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node, 2618 int prot_id, bool tx) 2619 { 2620 int ret, idx; 2621 char name[32]; 2622 struct scmi_chan_info *cinfo; 2623 struct idr *idr; 2624 struct scmi_device *tdev = NULL; 2625 2626 /* Transmit channel is first entry i.e. index 0 */ 2627 idx = tx ? 0 : 1; 2628 idr = tx ? &info->tx_idr : &info->rx_idr; 2629 2630 if (!info->desc->ops->chan_available(of_node, idx)) { 2631 cinfo = idr_find(idr, SCMI_PROTOCOL_BASE); 2632 if (unlikely(!cinfo)) /* Possible only if platform has no Rx */ 2633 return -EINVAL; 2634 goto idr_alloc; 2635 } 2636 2637 cinfo = devm_kzalloc(info->dev, sizeof(*cinfo), GFP_KERNEL); 2638 if (!cinfo) 2639 return -ENOMEM; 2640 2641 cinfo->rx_timeout_ms = info->desc->max_rx_timeout_ms; 2642 2643 /* Create a unique name for this transport device */ 2644 snprintf(name, 32, "__scmi_transport_device_%s_%02X", 2645 idx ? "rx" : "tx", prot_id); 2646 /* Create a uniquely named, dedicated transport device for this chan */ 2647 tdev = scmi_device_create(of_node, info->dev, prot_id, name); 2648 if (!tdev) { 2649 dev_err(info->dev, 2650 "failed to create transport device (%s)\n", name); 2651 devm_kfree(info->dev, cinfo); 2652 return -EINVAL; 2653 } 2654 of_node_get(of_node); 2655 2656 cinfo->id = prot_id; 2657 cinfo->dev = &tdev->dev; 2658 ret = info->desc->ops->chan_setup(cinfo, info->dev, tx); 2659 if (ret) { 2660 of_node_put(of_node); 2661 scmi_device_destroy(info->dev, prot_id, name); 2662 devm_kfree(info->dev, cinfo); 2663 return ret; 2664 } 2665 2666 if (tx && is_polling_required(cinfo, info->desc)) { 2667 if (is_transport_polling_capable(info->desc)) 2668 dev_info(&tdev->dev, 2669 "Enabled polling mode TX channel - prot_id:%d\n", 2670 prot_id); 2671 else 2672 dev_warn(&tdev->dev, 2673 "Polling mode NOT supported by transport.\n"); 2674 } 2675 2676 idr_alloc: 2677 ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL); 2678 if (ret != prot_id) { 2679 dev_err(info->dev, 2680 "unable to allocate SCMI idr slot err %d\n", ret); 2681 /* Destroy channel and device only if created by this call. */ 2682 if (tdev) { 2683 of_node_put(of_node); 2684 scmi_device_destroy(info->dev, prot_id, name); 2685 devm_kfree(info->dev, cinfo); 2686 } 2687 return ret; 2688 } 2689 2690 cinfo->handle = &info->handle; 2691 return 0; 2692 } 2693 2694 static inline int 2695 scmi_txrx_setup(struct scmi_info *info, struct device_node *of_node, 2696 int prot_id) 2697 { 2698 int ret = scmi_chan_setup(info, of_node, prot_id, true); 2699 2700 if (!ret) { 2701 /* Rx is optional, report only memory errors */ 2702 ret = scmi_chan_setup(info, of_node, prot_id, false); 2703 if (ret && ret != -ENOMEM) 2704 ret = 0; 2705 } 2706 2707 if (ret) 2708 dev_err(info->dev, 2709 "failed to setup channel for protocol:0x%X\n", prot_id); 2710 2711 return ret; 2712 } 2713 2714 /** 2715 * scmi_channels_setup - Helper to initialize all required channels 2716 * 2717 * @info: The SCMI instance descriptor. 2718 * 2719 * Initialize all the channels found described in the DT against the underlying 2720 * configured transport using custom defined dedicated devices instead of 2721 * borrowing devices from the SCMI drivers; this way channels are initialized 2722 * upfront during core SCMI stack probing and are no more coupled with SCMI 2723 * devices used by SCMI drivers. 2724 * 2725 * Note that, even though a pair of TX/RX channels is associated to each 2726 * protocol defined in the DT, a distinct freshly initialized channel is 2727 * created only if the DT node for the protocol at hand describes a dedicated 2728 * channel: in all the other cases the common BASE protocol channel is reused. 2729 * 2730 * Return: 0 on Success 2731 */ 2732 static int scmi_channels_setup(struct scmi_info *info) 2733 { 2734 int ret; 2735 struct device_node *top_np = info->dev->of_node; 2736 2737 /* Initialize a common generic channel at first */ 2738 ret = scmi_txrx_setup(info, top_np, SCMI_PROTOCOL_BASE); 2739 if (ret) 2740 return ret; 2741 2742 for_each_available_child_of_node_scoped(top_np, child) { 2743 u32 prot_id; 2744 2745 if (of_property_read_u32(child, "reg", &prot_id)) 2746 continue; 2747 2748 if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id)) 2749 dev_err(info->dev, 2750 "Out of range protocol %d\n", prot_id); 2751 2752 ret = scmi_txrx_setup(info, child, prot_id); 2753 if (ret) 2754 return ret; 2755 } 2756 2757 return 0; 2758 } 2759 2760 static int scmi_chan_destroy(int id, void *p, void *idr) 2761 { 2762 struct scmi_chan_info *cinfo = p; 2763 2764 if (cinfo->dev) { 2765 struct scmi_info *info = handle_to_scmi_info(cinfo->handle); 2766 struct scmi_device *sdev = to_scmi_dev(cinfo->dev); 2767 2768 of_node_put(cinfo->dev->of_node); 2769 scmi_device_destroy(info->dev, id, sdev->name); 2770 cinfo->dev = NULL; 2771 } 2772 2773 idr_remove(idr, id); 2774 2775 return 0; 2776 } 2777 2778 static void scmi_cleanup_channels(struct scmi_info *info, struct idr *idr) 2779 { 2780 /* At first free all channels at the transport layer ... */ 2781 idr_for_each(idr, info->desc->ops->chan_free, idr); 2782 2783 /* ...then destroy all underlying devices */ 2784 idr_for_each(idr, scmi_chan_destroy, idr); 2785 2786 idr_destroy(idr); 2787 } 2788 2789 static void scmi_cleanup_txrx_channels(struct scmi_info *info) 2790 { 2791 scmi_cleanup_channels(info, &info->tx_idr); 2792 2793 scmi_cleanup_channels(info, &info->rx_idr); 2794 } 2795 2796 static int scmi_bus_notifier(struct notifier_block *nb, 2797 unsigned long action, void *data) 2798 { 2799 struct scmi_info *info = bus_nb_to_scmi_info(nb); 2800 struct scmi_device *sdev = to_scmi_dev(data); 2801 2802 /* Skip transport devices and devices of different SCMI instances */ 2803 if (!strncmp(sdev->name, "__scmi_transport_device", 23) || 2804 sdev->dev.parent != info->dev) 2805 return NOTIFY_DONE; 2806 2807 switch (action) { 2808 case BUS_NOTIFY_BIND_DRIVER: 2809 /* setup handle now as the transport is ready */ 2810 scmi_set_handle(sdev); 2811 break; 2812 case BUS_NOTIFY_UNBOUND_DRIVER: 2813 scmi_handle_put(sdev->handle); 2814 sdev->handle = NULL; 2815 break; 2816 default: 2817 return NOTIFY_DONE; 2818 } 2819 2820 dev_dbg(info->dev, "Device %s (%s) is now %s\n", dev_name(&sdev->dev), 2821 sdev->name, action == BUS_NOTIFY_BIND_DRIVER ? 2822 "about to be BOUND." : "UNBOUND."); 2823 2824 return NOTIFY_OK; 2825 } 2826 2827 static int scmi_device_request_notifier(struct notifier_block *nb, 2828 unsigned long action, void *data) 2829 { 2830 struct device_node *np; 2831 struct scmi_device_id *id_table = data; 2832 struct scmi_info *info = req_nb_to_scmi_info(nb); 2833 2834 np = idr_find(&info->active_protocols, id_table->protocol_id); 2835 if (!np) 2836 return NOTIFY_DONE; 2837 2838 dev_dbg(info->dev, "%sRequested device (%s) for protocol 0x%x\n", 2839 action == SCMI_BUS_NOTIFY_DEVICE_REQUEST ? "" : "UN-", 2840 id_table->name, id_table->protocol_id); 2841 2842 switch (action) { 2843 case SCMI_BUS_NOTIFY_DEVICE_REQUEST: 2844 scmi_create_protocol_devices(np, info, id_table->protocol_id, 2845 id_table->name); 2846 break; 2847 case SCMI_BUS_NOTIFY_DEVICE_UNREQUEST: 2848 scmi_destroy_protocol_devices(info, id_table->protocol_id, 2849 id_table->name); 2850 break; 2851 default: 2852 return NOTIFY_DONE; 2853 } 2854 2855 return NOTIFY_OK; 2856 } 2857 2858 static const char * const dbg_counter_strs[] = { 2859 "sent_ok", 2860 "sent_fail", 2861 "sent_fail_polling_unsupported", 2862 "sent_fail_channel_not_found", 2863 "response_ok", 2864 "notification_ok", 2865 "delayed_response_ok", 2866 "xfers_response_timeout", 2867 "xfers_response_polled_timeout", 2868 "response_polled_ok", 2869 "err_msg_unexpected", 2870 "err_msg_invalid", 2871 "err_msg_nomem", 2872 "err_protocol", 2873 }; 2874 2875 static ssize_t reset_all_on_write(struct file *filp, const char __user *buf, 2876 size_t count, loff_t *ppos) 2877 { 2878 struct scmi_debug_info *dbg = filp->private_data; 2879 2880 for (int i = 0; i < SCMI_DEBUG_COUNTERS_LAST; i++) 2881 atomic_set(&dbg->counters[i], 0); 2882 2883 return count; 2884 } 2885 2886 static const struct file_operations fops_reset_counts = { 2887 .owner = THIS_MODULE, 2888 .open = simple_open, 2889 .write = reset_all_on_write, 2890 }; 2891 2892 static void scmi_debugfs_counters_setup(struct scmi_debug_info *dbg, 2893 struct dentry *trans) 2894 { 2895 struct dentry *counters; 2896 int idx; 2897 2898 counters = debugfs_create_dir("counters", trans); 2899 2900 for (idx = 0; idx < SCMI_DEBUG_COUNTERS_LAST; idx++) 2901 debugfs_create_atomic_t(dbg_counter_strs[idx], 0600, counters, 2902 &dbg->counters[idx]); 2903 2904 debugfs_create_file("reset", 0200, counters, dbg, &fops_reset_counts); 2905 } 2906 2907 static void scmi_debugfs_common_cleanup(void *d) 2908 { 2909 struct scmi_debug_info *dbg = d; 2910 2911 if (!dbg) 2912 return; 2913 2914 debugfs_remove_recursive(dbg->top_dentry); 2915 kfree(dbg->name); 2916 kfree(dbg->type); 2917 } 2918 2919 static struct scmi_debug_info *scmi_debugfs_common_setup(struct scmi_info *info) 2920 { 2921 char top_dir[16]; 2922 struct dentry *trans, *top_dentry; 2923 struct scmi_debug_info *dbg; 2924 const char *c_ptr = NULL; 2925 2926 dbg = devm_kzalloc(info->dev, sizeof(*dbg), GFP_KERNEL); 2927 if (!dbg) 2928 return NULL; 2929 2930 dbg->name = kstrdup(of_node_full_name(info->dev->of_node), GFP_KERNEL); 2931 if (!dbg->name) { 2932 devm_kfree(info->dev, dbg); 2933 return NULL; 2934 } 2935 2936 of_property_read_string(info->dev->of_node, "compatible", &c_ptr); 2937 dbg->type = kstrdup(c_ptr, GFP_KERNEL); 2938 if (!dbg->type) { 2939 kfree(dbg->name); 2940 devm_kfree(info->dev, dbg); 2941 return NULL; 2942 } 2943 2944 snprintf(top_dir, 16, "%d", info->id); 2945 top_dentry = debugfs_create_dir(top_dir, scmi_top_dentry); 2946 trans = debugfs_create_dir("transport", top_dentry); 2947 2948 dbg->is_atomic = info->desc->atomic_enabled && 2949 is_transport_polling_capable(info->desc); 2950 2951 debugfs_create_str("instance_name", 0400, top_dentry, 2952 (char **)&dbg->name); 2953 2954 debugfs_create_u32("atomic_threshold_us", 0400, top_dentry, 2955 &info->atomic_threshold); 2956 2957 debugfs_create_str("type", 0400, trans, (char **)&dbg->type); 2958 2959 debugfs_create_bool("is_atomic", 0400, trans, &dbg->is_atomic); 2960 2961 debugfs_create_u32("max_rx_timeout_ms", 0400, trans, 2962 (u32 *)&info->desc->max_rx_timeout_ms); 2963 2964 debugfs_create_u32("max_msg_size", 0400, trans, 2965 (u32 *)&info->desc->max_msg_size); 2966 2967 debugfs_create_u32("tx_max_msg", 0400, trans, 2968 (u32 *)&info->tx_minfo.max_msg); 2969 2970 debugfs_create_u32("rx_max_msg", 0400, trans, 2971 (u32 *)&info->rx_minfo.max_msg); 2972 2973 if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) 2974 scmi_debugfs_counters_setup(dbg, trans); 2975 2976 dbg->top_dentry = top_dentry; 2977 2978 if (devm_add_action_or_reset(info->dev, 2979 scmi_debugfs_common_cleanup, dbg)) { 2980 scmi_debugfs_common_cleanup(dbg); 2981 return NULL; 2982 } 2983 2984 return dbg; 2985 } 2986 2987 static int scmi_debugfs_raw_mode_setup(struct scmi_info *info) 2988 { 2989 int id, num_chans = 0, ret = 0; 2990 struct scmi_chan_info *cinfo; 2991 u8 channels[SCMI_MAX_CHANNELS] = {}; 2992 DECLARE_BITMAP(protos, SCMI_MAX_CHANNELS) = {}; 2993 2994 if (!info->dbg) 2995 return -EINVAL; 2996 2997 /* Enumerate all channels to collect their ids */ 2998 idr_for_each_entry(&info->tx_idr, cinfo, id) { 2999 /* 3000 * Cannot happen, but be defensive. 3001 * Zero as num_chans is ok, warn and carry on. 3002 */ 3003 if (num_chans >= SCMI_MAX_CHANNELS || !cinfo) { 3004 dev_warn(info->dev, 3005 "SCMI RAW - Error enumerating channels\n"); 3006 break; 3007 } 3008 3009 if (!test_bit(cinfo->id, protos)) { 3010 channels[num_chans++] = cinfo->id; 3011 set_bit(cinfo->id, protos); 3012 } 3013 } 3014 3015 info->raw = scmi_raw_mode_init(&info->handle, info->dbg->top_dentry, 3016 info->id, channels, num_chans, 3017 info->desc, info->tx_minfo.max_msg); 3018 if (IS_ERR(info->raw)) { 3019 dev_err(info->dev, "Failed to initialize SCMI RAW Mode !\n"); 3020 ret = PTR_ERR(info->raw); 3021 info->raw = NULL; 3022 } 3023 3024 return ret; 3025 } 3026 3027 static const struct scmi_desc *scmi_transport_setup(struct device *dev) 3028 { 3029 struct scmi_transport *trans; 3030 int ret; 3031 3032 trans = dev_get_platdata(dev); 3033 if (!trans || !trans->desc || !trans->supplier || !trans->core_ops) 3034 return NULL; 3035 3036 if (!device_link_add(dev, trans->supplier, DL_FLAG_AUTOREMOVE_CONSUMER)) { 3037 dev_err(dev, 3038 "Adding link to supplier transport device failed\n"); 3039 return NULL; 3040 } 3041 3042 /* Provide core transport ops */ 3043 *trans->core_ops = &scmi_trans_core_ops; 3044 3045 dev_info(dev, "Using %s\n", dev_driver_string(trans->supplier)); 3046 3047 ret = of_property_read_u32(dev->of_node, "max-rx-timeout-ms", 3048 &trans->desc->max_rx_timeout_ms); 3049 if (ret && ret != -EINVAL) 3050 dev_err(dev, "Malformed max-rx-timeout-ms DT property.\n"); 3051 3052 dev_info(dev, "SCMI max-rx-timeout: %dms\n", 3053 trans->desc->max_rx_timeout_ms); 3054 3055 return trans->desc; 3056 } 3057 3058 static int scmi_probe(struct platform_device *pdev) 3059 { 3060 int ret; 3061 char *err_str = "probe failure\n"; 3062 struct scmi_handle *handle; 3063 const struct scmi_desc *desc; 3064 struct scmi_info *info; 3065 bool coex = IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX); 3066 struct device *dev = &pdev->dev; 3067 struct device_node *child, *np = dev->of_node; 3068 3069 desc = scmi_transport_setup(dev); 3070 if (!desc) { 3071 err_str = "transport invalid\n"; 3072 ret = -EINVAL; 3073 goto out_err; 3074 } 3075 3076 info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); 3077 if (!info) 3078 return -ENOMEM; 3079 3080 info->id = ida_alloc_min(&scmi_id, 0, GFP_KERNEL); 3081 if (info->id < 0) 3082 return info->id; 3083 3084 info->dev = dev; 3085 info->desc = desc; 3086 info->bus_nb.notifier_call = scmi_bus_notifier; 3087 info->dev_req_nb.notifier_call = scmi_device_request_notifier; 3088 INIT_LIST_HEAD(&info->node); 3089 idr_init(&info->protocols); 3090 mutex_init(&info->protocols_mtx); 3091 idr_init(&info->active_protocols); 3092 mutex_init(&info->devreq_mtx); 3093 3094 platform_set_drvdata(pdev, info); 3095 idr_init(&info->tx_idr); 3096 idr_init(&info->rx_idr); 3097 3098 handle = &info->handle; 3099 handle->dev = info->dev; 3100 handle->version = &info->version; 3101 handle->devm_protocol_acquire = scmi_devm_protocol_acquire; 3102 handle->devm_protocol_get = scmi_devm_protocol_get; 3103 handle->devm_protocol_put = scmi_devm_protocol_put; 3104 3105 /* System wide atomic threshold for atomic ops .. if any */ 3106 if (!of_property_read_u32(np, "atomic-threshold-us", 3107 &info->atomic_threshold)) 3108 dev_info(dev, 3109 "SCMI System wide atomic threshold set to %d us\n", 3110 info->atomic_threshold); 3111 handle->is_transport_atomic = scmi_is_transport_atomic; 3112 3113 /* Setup all channels described in the DT at first */ 3114 ret = scmi_channels_setup(info); 3115 if (ret) { 3116 err_str = "failed to setup channels\n"; 3117 goto clear_ida; 3118 } 3119 3120 ret = bus_register_notifier(&scmi_bus_type, &info->bus_nb); 3121 if (ret) { 3122 err_str = "failed to register bus notifier\n"; 3123 goto clear_txrx_setup; 3124 } 3125 3126 ret = blocking_notifier_chain_register(&scmi_requested_devices_nh, 3127 &info->dev_req_nb); 3128 if (ret) { 3129 err_str = "failed to register device notifier\n"; 3130 goto clear_bus_notifier; 3131 } 3132 3133 ret = scmi_xfer_info_init(info); 3134 if (ret) { 3135 err_str = "failed to init xfers pool\n"; 3136 goto clear_dev_req_notifier; 3137 } 3138 3139 if (scmi_top_dentry) { 3140 info->dbg = scmi_debugfs_common_setup(info); 3141 if (!info->dbg) 3142 dev_warn(dev, "Failed to setup SCMI debugfs.\n"); 3143 3144 if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { 3145 ret = scmi_debugfs_raw_mode_setup(info); 3146 if (!coex) { 3147 if (ret) 3148 goto clear_dev_req_notifier; 3149 3150 /* Bail out anyway when coex disabled. */ 3151 return 0; 3152 } 3153 3154 /* Coex enabled, carry on in any case. */ 3155 dev_info(dev, "SCMI RAW Mode COEX enabled !\n"); 3156 } 3157 } 3158 3159 if (scmi_notification_init(handle)) 3160 dev_err(dev, "SCMI Notifications NOT available.\n"); 3161 3162 if (info->desc->atomic_enabled && 3163 !is_transport_polling_capable(info->desc)) 3164 dev_err(dev, 3165 "Transport is not polling capable. Atomic mode not supported.\n"); 3166 3167 /* 3168 * Trigger SCMI Base protocol initialization. 3169 * It's mandatory and won't be ever released/deinit until the 3170 * SCMI stack is shutdown/unloaded as a whole. 3171 */ 3172 ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE); 3173 if (ret) { 3174 err_str = "unable to communicate with SCMI\n"; 3175 if (coex) { 3176 dev_err(dev, "%s", err_str); 3177 return 0; 3178 } 3179 goto notification_exit; 3180 } 3181 3182 mutex_lock(&scmi_list_mutex); 3183 list_add_tail(&info->node, &scmi_list); 3184 mutex_unlock(&scmi_list_mutex); 3185 3186 for_each_available_child_of_node(np, child) { 3187 u32 prot_id; 3188 3189 if (of_property_read_u32(child, "reg", &prot_id)) 3190 continue; 3191 3192 if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id)) 3193 dev_err(dev, "Out of range protocol %d\n", prot_id); 3194 3195 if (!scmi_is_protocol_implemented(handle, prot_id)) { 3196 dev_err(dev, "SCMI protocol %d not implemented\n", 3197 prot_id); 3198 continue; 3199 } 3200 3201 /* 3202 * Save this valid DT protocol descriptor amongst 3203 * @active_protocols for this SCMI instance/ 3204 */ 3205 ret = idr_alloc(&info->active_protocols, child, 3206 prot_id, prot_id + 1, GFP_KERNEL); 3207 if (ret != prot_id) { 3208 dev_err(dev, "SCMI protocol %d already activated. Skip\n", 3209 prot_id); 3210 continue; 3211 } 3212 3213 of_node_get(child); 3214 scmi_create_protocol_devices(child, info, prot_id, NULL); 3215 } 3216 3217 return 0; 3218 3219 notification_exit: 3220 if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) 3221 scmi_raw_mode_cleanup(info->raw); 3222 scmi_notification_exit(&info->handle); 3223 clear_dev_req_notifier: 3224 blocking_notifier_chain_unregister(&scmi_requested_devices_nh, 3225 &info->dev_req_nb); 3226 clear_bus_notifier: 3227 bus_unregister_notifier(&scmi_bus_type, &info->bus_nb); 3228 clear_txrx_setup: 3229 scmi_cleanup_txrx_channels(info); 3230 clear_ida: 3231 ida_free(&scmi_id, info->id); 3232 3233 out_err: 3234 return dev_err_probe(dev, ret, "%s", err_str); 3235 } 3236 3237 static void scmi_remove(struct platform_device *pdev) 3238 { 3239 int id; 3240 struct scmi_info *info = platform_get_drvdata(pdev); 3241 struct device_node *child; 3242 3243 if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) 3244 scmi_raw_mode_cleanup(info->raw); 3245 3246 mutex_lock(&scmi_list_mutex); 3247 if (info->users) 3248 dev_warn(&pdev->dev, 3249 "Still active SCMI users will be forcibly unbound.\n"); 3250 list_del(&info->node); 3251 mutex_unlock(&scmi_list_mutex); 3252 3253 scmi_notification_exit(&info->handle); 3254 3255 mutex_lock(&info->protocols_mtx); 3256 idr_destroy(&info->protocols); 3257 mutex_unlock(&info->protocols_mtx); 3258 3259 idr_for_each_entry(&info->active_protocols, child, id) 3260 of_node_put(child); 3261 idr_destroy(&info->active_protocols); 3262 3263 blocking_notifier_chain_unregister(&scmi_requested_devices_nh, 3264 &info->dev_req_nb); 3265 bus_unregister_notifier(&scmi_bus_type, &info->bus_nb); 3266 3267 /* Safe to free channels since no more users */ 3268 scmi_cleanup_txrx_channels(info); 3269 3270 ida_free(&scmi_id, info->id); 3271 } 3272 3273 static ssize_t protocol_version_show(struct device *dev, 3274 struct device_attribute *attr, char *buf) 3275 { 3276 struct scmi_info *info = dev_get_drvdata(dev); 3277 3278 return sprintf(buf, "%u.%u\n", info->version.major_ver, 3279 info->version.minor_ver); 3280 } 3281 static DEVICE_ATTR_RO(protocol_version); 3282 3283 static ssize_t firmware_version_show(struct device *dev, 3284 struct device_attribute *attr, char *buf) 3285 { 3286 struct scmi_info *info = dev_get_drvdata(dev); 3287 3288 return sprintf(buf, "0x%x\n", info->version.impl_ver); 3289 } 3290 static DEVICE_ATTR_RO(firmware_version); 3291 3292 static ssize_t vendor_id_show(struct device *dev, 3293 struct device_attribute *attr, char *buf) 3294 { 3295 struct scmi_info *info = dev_get_drvdata(dev); 3296 3297 return sprintf(buf, "%s\n", info->version.vendor_id); 3298 } 3299 static DEVICE_ATTR_RO(vendor_id); 3300 3301 static ssize_t sub_vendor_id_show(struct device *dev, 3302 struct device_attribute *attr, char *buf) 3303 { 3304 struct scmi_info *info = dev_get_drvdata(dev); 3305 3306 return sprintf(buf, "%s\n", info->version.sub_vendor_id); 3307 } 3308 static DEVICE_ATTR_RO(sub_vendor_id); 3309 3310 static struct attribute *versions_attrs[] = { 3311 &dev_attr_firmware_version.attr, 3312 &dev_attr_protocol_version.attr, 3313 &dev_attr_vendor_id.attr, 3314 &dev_attr_sub_vendor_id.attr, 3315 NULL, 3316 }; 3317 ATTRIBUTE_GROUPS(versions); 3318 3319 static struct platform_driver scmi_driver = { 3320 .driver = { 3321 .name = "arm-scmi", 3322 .suppress_bind_attrs = true, 3323 .dev_groups = versions_groups, 3324 }, 3325 .probe = scmi_probe, 3326 .remove_new = scmi_remove, 3327 }; 3328 3329 static struct dentry *scmi_debugfs_init(void) 3330 { 3331 struct dentry *d; 3332 3333 d = debugfs_create_dir("scmi", NULL); 3334 if (IS_ERR(d)) { 3335 pr_err("Could NOT create SCMI top dentry.\n"); 3336 return NULL; 3337 } 3338 3339 return d; 3340 } 3341 3342 static int __init scmi_driver_init(void) 3343 { 3344 /* Bail out if no SCMI transport was configured */ 3345 if (WARN_ON(!IS_ENABLED(CONFIG_ARM_SCMI_HAVE_TRANSPORT))) 3346 return -EINVAL; 3347 3348 if (IS_ENABLED(CONFIG_ARM_SCMI_HAVE_SHMEM)) 3349 scmi_trans_core_ops.shmem = scmi_shared_mem_operations_get(); 3350 3351 if (IS_ENABLED(CONFIG_ARM_SCMI_HAVE_MSG)) 3352 scmi_trans_core_ops.msg = scmi_message_operations_get(); 3353 3354 if (IS_ENABLED(CONFIG_ARM_SCMI_NEED_DEBUGFS)) 3355 scmi_top_dentry = scmi_debugfs_init(); 3356 3357 scmi_base_register(); 3358 3359 scmi_clock_register(); 3360 scmi_perf_register(); 3361 scmi_power_register(); 3362 scmi_reset_register(); 3363 scmi_sensors_register(); 3364 scmi_voltage_register(); 3365 scmi_system_register(); 3366 scmi_powercap_register(); 3367 scmi_pinctrl_register(); 3368 3369 return platform_driver_register(&scmi_driver); 3370 } 3371 module_init(scmi_driver_init); 3372 3373 static void __exit scmi_driver_exit(void) 3374 { 3375 scmi_base_unregister(); 3376 3377 scmi_clock_unregister(); 3378 scmi_perf_unregister(); 3379 scmi_power_unregister(); 3380 scmi_reset_unregister(); 3381 scmi_sensors_unregister(); 3382 scmi_voltage_unregister(); 3383 scmi_system_unregister(); 3384 scmi_powercap_unregister(); 3385 scmi_pinctrl_unregister(); 3386 3387 platform_driver_unregister(&scmi_driver); 3388 3389 debugfs_remove_recursive(scmi_top_dentry); 3390 } 3391 module_exit(scmi_driver_exit); 3392 3393 MODULE_ALIAS("platform:arm-scmi"); 3394 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); 3395 MODULE_DESCRIPTION("ARM SCMI protocol driver"); 3396 MODULE_LICENSE("GPL v2"); 3397