| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved. |
| 4 | */ |
| 5 | |
| 6 | #include <linux/atomic.h> |
| 7 | #include <linux/bug.h> |
| 8 | #include <linux/interrupt.h> |
| 9 | #include <linux/jiffies.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/list.h> |
| 12 | #include <linux/lockdep.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/of.h> |
| 15 | #include <linux/platform_device.h> |
| 16 | #include <linux/slab.h> |
| 17 | #include <linux/spinlock.h> |
| 18 | #include <linux/types.h> |
| 19 | #include <linux/wait.h> |
| 20 | |
| 21 | #include <soc/qcom/rpmh.h> |
| 22 | |
| 23 | #include "rpmh-internal.h" |
| 24 | |
| 25 | #define RPMH_TIMEOUT_MS msecs_to_jiffies(10000) |
| 26 | |
| 27 | #define DEFINE_RPMH_MSG_ONSTACK(device, s, q, name) \ |
| 28 | struct rpmh_request name = { \ |
| 29 | .msg = { \ |
| 30 | .state = s, \ |
| 31 | .cmds = name.cmd, \ |
| 32 | .num_cmds = 0, \ |
| 33 | .wait_for_compl = true, \ |
| 34 | }, \ |
| 35 | .cmd = { { 0 } }, \ |
| 36 | .completion = q, \ |
| 37 | .dev = device, \ |
| 38 | .needs_free = false, \ |
| 39 | } |
| 40 | |
| 41 | #define ctrlr_to_drv(ctrlr) container_of(ctrlr, struct rsc_drv, client) |
| 42 | |
| 43 | /** |
| 44 | * struct cache_req: the request object for caching |
| 45 | * |
| 46 | * @addr: the address of the resource |
| 47 | * @sleep_val: the sleep vote |
| 48 | * @wake_val: the wake vote |
| 49 | * @list: linked list obj |
| 50 | */ |
| 51 | struct cache_req { |
| 52 | u32 addr; |
| 53 | u32 sleep_val; |
| 54 | u32 wake_val; |
| 55 | struct list_head list; |
| 56 | }; |
| 57 | |
| 58 | /** |
| 59 | * struct batch_cache_req - An entry in our batch catch |
| 60 | * |
| 61 | * @list: linked list obj |
| 62 | * @count: number of messages |
| 63 | * @rpm_msgs: the messages |
| 64 | */ |
| 65 | |
| 66 | struct batch_cache_req { |
| 67 | struct list_head list; |
| 68 | int count; |
| 69 | struct rpmh_request rpm_msgs[]; |
| 70 | }; |
| 71 | |
| 72 | static struct rpmh_ctrlr *get_rpmh_ctrlr(const struct device *dev) |
| 73 | { |
| 74 | struct rsc_drv *drv = dev_get_drvdata(dev->parent); |
| 75 | |
| 76 | return &drv->client; |
| 77 | } |
| 78 | |
| 79 | void rpmh_tx_done(const struct tcs_request *msg) |
| 80 | { |
| 81 | struct rpmh_request *rpm_msg = container_of(msg, struct rpmh_request, |
| 82 | msg); |
| 83 | struct completion *compl = rpm_msg->completion; |
| 84 | bool free = rpm_msg->needs_free; |
| 85 | |
| 86 | if (!compl) |
| 87 | goto exit; |
| 88 | |
| 89 | /* Signal the blocking thread we are done */ |
| 90 | complete(compl); |
| 91 | |
| 92 | exit: |
| 93 | if (free) |
| 94 | kfree(rpm_msg); |
| 95 | } |
| 96 | |
| 97 | static struct cache_req *__find_req(struct rpmh_ctrlr *ctrlr, u32 addr) |
| 98 | { |
| 99 | struct cache_req *p, *req = NULL; |
| 100 | |
| 101 | list_for_each_entry(p, &ctrlr->cache, list) { |
| 102 | if (p->addr == addr) { |
| 103 | req = p; |
| 104 | break; |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | return req; |
| 109 | } |
| 110 | |
| 111 | static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr, |
| 112 | enum rpmh_state state, |
| 113 | struct tcs_cmd *cmd) |
| 114 | { |
| 115 | struct cache_req *req; |
| 116 | unsigned long flags; |
| 117 | u32 old_sleep_val, old_wake_val; |
| 118 | |
| 119 | spin_lock_irqsave(&ctrlr->cache_lock, flags); |
| 120 | req = __find_req(ctrlr, cmd->addr); |
| 121 | if (req) |
| 122 | goto existing; |
| 123 | |
| 124 | req = kzalloc(sizeof(*req), GFP_ATOMIC); |
| 125 | if (!req) { |
| 126 | req = ERR_PTR(-ENOMEM); |
| 127 | goto unlock; |
| 128 | } |
| 129 | |
| 130 | req->addr = cmd->addr; |
| 131 | req->sleep_val = req->wake_val = UINT_MAX; |
| 132 | list_add_tail(&req->list, &ctrlr->cache); |
| 133 | |
| 134 | existing: |
| 135 | old_sleep_val = req->sleep_val; |
| 136 | old_wake_val = req->wake_val; |
| 137 | |
| 138 | switch (state) { |
| 139 | case RPMH_ACTIVE_ONLY_STATE: |
| 140 | case RPMH_WAKE_ONLY_STATE: |
| 141 | req->wake_val = cmd->data; |
| 142 | break; |
| 143 | case RPMH_SLEEP_STATE: |
| 144 | req->sleep_val = cmd->data; |
| 145 | break; |
| 146 | } |
| 147 | |
| 148 | ctrlr->dirty |= (req->sleep_val != old_sleep_val || |
| 149 | req->wake_val != old_wake_val) && |
| 150 | req->sleep_val != UINT_MAX && |
| 151 | req->wake_val != UINT_MAX; |
| 152 | |
| 153 | unlock: |
| 154 | spin_unlock_irqrestore(&ctrlr->cache_lock, flags); |
| 155 | |
| 156 | return req; |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * __rpmh_write: Cache and send the RPMH request |
| 161 | * |
| 162 | * @dev: The device making the request |
| 163 | * @state: Active/Sleep request type |
| 164 | * @rpm_msg: The data that needs to be sent (cmds). |
| 165 | * |
| 166 | * Cache the RPMH request and send if the state is ACTIVE_ONLY. |
| 167 | * SLEEP/WAKE_ONLY requests are not sent to the controller at |
| 168 | * this time. Use rpmh_flush() to send them to the controller. |
| 169 | */ |
| 170 | static int __rpmh_write(const struct device *dev, enum rpmh_state state, |
| 171 | struct rpmh_request *rpm_msg) |
| 172 | { |
| 173 | struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev); |
| 174 | int ret = -EINVAL; |
| 175 | struct cache_req *req; |
| 176 | int i; |
| 177 | |
| 178 | /* Cache the request in our store and link the payload */ |
| 179 | for (i = 0; i < rpm_msg->msg.num_cmds; i++) { |
| 180 | req = cache_rpm_request(ctrlr, state, &rpm_msg->msg.cmds[i]); |
| 181 | if (IS_ERR(req)) |
| 182 | return PTR_ERR(req); |
| 183 | } |
| 184 | |
| 185 | if (state == RPMH_ACTIVE_ONLY_STATE) { |
| 186 | ret = rpmh_rsc_send_data(ctrlr_to_drv(ctrlr), &rpm_msg->msg); |
| 187 | } else { |
| 188 | /* Clean up our call by spoofing tx_done */ |
| 189 | ret = 0; |
| 190 | rpmh_tx_done(&rpm_msg->msg); |
| 191 | } |
| 192 | |
| 193 | return ret; |
| 194 | } |
| 195 | |
| 196 | static int __fill_rpmh_msg(struct rpmh_request *req, enum rpmh_state state, |
| 197 | const struct tcs_cmd *cmd, u32 n) |
| 198 | { |
| 199 | if (!cmd || !n || n > MAX_RPMH_PAYLOAD) |
| 200 | return -EINVAL; |
| 201 | |
| 202 | memcpy(req->cmd, cmd, n * sizeof(*cmd)); |
| 203 | |
| 204 | req->msg.state = state; |
| 205 | req->msg.cmds = req->cmd; |
| 206 | req->msg.num_cmds = n; |
| 207 | |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | /** |
| 212 | * rpmh_write_async: Write a set of RPMH commands |
| 213 | * |
| 214 | * @dev: The device making the request |
| 215 | * @state: Active/sleep set |
| 216 | * @cmd: The payload data |
| 217 | * @n: The number of elements in payload |
| 218 | * |
| 219 | * Write a set of RPMH commands, the order of commands is maintained |
| 220 | * and will be sent as a single shot. |
| 221 | */ |
| 222 | int rpmh_write_async(const struct device *dev, enum rpmh_state state, |
| 223 | const struct tcs_cmd *cmd, u32 n) |
| 224 | { |
| 225 | struct rpmh_request *rpm_msg; |
| 226 | int ret; |
| 227 | |
| 228 | rpm_msg = kzalloc(sizeof(*rpm_msg), GFP_ATOMIC); |
| 229 | if (!rpm_msg) |
| 230 | return -ENOMEM; |
| 231 | rpm_msg->needs_free = true; |
| 232 | |
| 233 | ret = __fill_rpmh_msg(rpm_msg, state, cmd, n); |
| 234 | if (ret) { |
| 235 | kfree(rpm_msg); |
| 236 | return ret; |
| 237 | } |
| 238 | |
| 239 | return __rpmh_write(dev, state, rpm_msg); |
| 240 | } |
| 241 | EXPORT_SYMBOL_GPL(rpmh_write_async); |
| 242 | |
| 243 | /** |
| 244 | * rpmh_write: Write a set of RPMH commands and block until response |
| 245 | * |
| 246 | * @dev: The device making the request |
| 247 | * @state: Active/sleep set |
| 248 | * @cmd: The payload data |
| 249 | * @n: The number of elements in @cmd |
| 250 | * |
| 251 | * May sleep. Do not call from atomic contexts. |
| 252 | */ |
| 253 | int rpmh_write(const struct device *dev, enum rpmh_state state, |
| 254 | const struct tcs_cmd *cmd, u32 n) |
| 255 | { |
| 256 | DECLARE_COMPLETION_ONSTACK(compl); |
| 257 | DEFINE_RPMH_MSG_ONSTACK(dev, state, &compl, rpm_msg); |
| 258 | int ret; |
| 259 | |
| 260 | ret = __fill_rpmh_msg(&rpm_msg, state, cmd, n); |
| 261 | if (ret) |
| 262 | return ret; |
| 263 | |
| 264 | ret = __rpmh_write(dev, state, &rpm_msg); |
| 265 | if (ret) |
| 266 | return ret; |
| 267 | |
| 268 | ret = wait_for_completion_timeout(&compl, RPMH_TIMEOUT_MS); |
| 269 | WARN_ON(!ret); |
| 270 | return (ret > 0) ? 0 : -ETIMEDOUT; |
| 271 | } |
| 272 | EXPORT_SYMBOL_GPL(rpmh_write); |
| 273 | |
| 274 | static void cache_batch(struct rpmh_ctrlr *ctrlr, struct batch_cache_req *req) |
| 275 | { |
| 276 | unsigned long flags; |
| 277 | |
| 278 | spin_lock_irqsave(&ctrlr->cache_lock, flags); |
| 279 | list_add_tail(&req->list, &ctrlr->batch_cache); |
| 280 | ctrlr->dirty = true; |
| 281 | spin_unlock_irqrestore(&ctrlr->cache_lock, flags); |
| 282 | } |
| 283 | |
| 284 | static int flush_batch(struct rpmh_ctrlr *ctrlr) |
| 285 | { |
| 286 | struct batch_cache_req *req; |
| 287 | const struct rpmh_request *rpm_msg; |
| 288 | int ret = 0; |
| 289 | int i; |
| 290 | |
| 291 | /* Send Sleep/Wake requests to the controller, expect no response */ |
| 292 | list_for_each_entry(req, &ctrlr->batch_cache, list) { |
| 293 | for (i = 0; i < req->count; i++) { |
| 294 | rpm_msg = req->rpm_msgs + i; |
| 295 | ret = rpmh_rsc_write_ctrl_data(ctrlr_to_drv(ctrlr), |
| 296 | &rpm_msg->msg); |
| 297 | if (ret) |
| 298 | break; |
| 299 | } |
| 300 | } |
| 301 | |
| 302 | return ret; |
| 303 | } |
| 304 | |
| 305 | /** |
| 306 | * rpmh_write_batch: Write multiple sets of RPMH commands and wait for the |
| 307 | * batch to finish. |
| 308 | * |
| 309 | * @dev: the device making the request |
| 310 | * @state: Active/sleep set |
| 311 | * @cmd: The payload data |
| 312 | * @n: The array of count of elements in each batch, 0 terminated. |
| 313 | * |
| 314 | * Write a request to the RSC controller without caching. If the request |
| 315 | * state is ACTIVE, then the requests are treated as completion request |
| 316 | * and sent to the controller immediately. The function waits until all the |
| 317 | * commands are complete. If the request was to SLEEP or WAKE_ONLY, then the |
| 318 | * request is sent as fire-n-forget and no ack is expected. |
| 319 | * |
| 320 | * May sleep. Do not call from atomic contexts for ACTIVE_ONLY requests. |
| 321 | */ |
| 322 | int rpmh_write_batch(const struct device *dev, enum rpmh_state state, |
| 323 | const struct tcs_cmd *cmd, u32 *n) |
| 324 | { |
| 325 | struct batch_cache_req *req; |
| 326 | struct rpmh_request *rpm_msgs; |
| 327 | struct completion *compls; |
| 328 | struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev); |
| 329 | unsigned long time_left; |
| 330 | int count = 0; |
| 331 | int ret, i; |
| 332 | void *ptr; |
| 333 | |
| 334 | if (!cmd || !n) |
| 335 | return -EINVAL; |
| 336 | |
| 337 | while (n[count] > 0) |
| 338 | count++; |
| 339 | if (!count) |
| 340 | return -EINVAL; |
| 341 | |
| 342 | ptr = kzalloc(sizeof(*req) + |
| 343 | count * (sizeof(req->rpm_msgs[0]) + sizeof(*compls)), |
| 344 | GFP_ATOMIC); |
| 345 | if (!ptr) |
| 346 | return -ENOMEM; |
| 347 | |
| 348 | req = ptr; |
| 349 | compls = ptr + sizeof(*req) + count * sizeof(*rpm_msgs); |
| 350 | |
| 351 | req->count = count; |
| 352 | rpm_msgs = req->rpm_msgs; |
| 353 | |
| 354 | for (i = 0; i < count; i++) { |
| 355 | __fill_rpmh_msg(rpm_msgs + i, state, cmd, n[i]); |
| 356 | cmd += n[i]; |
| 357 | } |
| 358 | |
| 359 | if (state != RPMH_ACTIVE_ONLY_STATE) { |
| 360 | cache_batch(ctrlr, req); |
| 361 | return 0; |
| 362 | } |
| 363 | |
| 364 | for (i = 0; i < count; i++) { |
| 365 | struct completion *compl = &compls[i]; |
| 366 | |
| 367 | init_completion(compl); |
| 368 | rpm_msgs[i].completion = compl; |
| 369 | ret = rpmh_rsc_send_data(ctrlr_to_drv(ctrlr), &rpm_msgs[i].msg); |
| 370 | if (ret) { |
| 371 | pr_err("Error(%d) sending RPMH message addr=%#x\n", |
| 372 | ret, rpm_msgs[i].msg.cmds[0].addr); |
| 373 | break; |
| 374 | } |
| 375 | } |
| 376 | |
| 377 | time_left = RPMH_TIMEOUT_MS; |
| 378 | while (i--) { |
| 379 | time_left = wait_for_completion_timeout(&compls[i], time_left); |
| 380 | if (!time_left) { |
| 381 | /* |
| 382 | * Better hope they never finish because they'll signal |
| 383 | * the completion that we're going to free once |
| 384 | * we've returned from this function. |
| 385 | */ |
| 386 | WARN_ON(1); |
| 387 | ret = -ETIMEDOUT; |
| 388 | goto exit; |
| 389 | } |
| 390 | } |
| 391 | |
| 392 | exit: |
| 393 | kfree(ptr); |
| 394 | |
| 395 | return ret; |
| 396 | } |
| 397 | EXPORT_SYMBOL_GPL(rpmh_write_batch); |
| 398 | |
| 399 | static int is_req_valid(struct cache_req *req) |
| 400 | { |
| 401 | return (req->sleep_val != UINT_MAX && |
| 402 | req->wake_val != UINT_MAX && |
| 403 | req->sleep_val != req->wake_val); |
| 404 | } |
| 405 | |
| 406 | static int send_single(struct rpmh_ctrlr *ctrlr, enum rpmh_state state, |
| 407 | u32 addr, u32 data) |
| 408 | { |
| 409 | DEFINE_RPMH_MSG_ONSTACK(NULL, state, NULL, rpm_msg); |
| 410 | |
| 411 | /* Wake sets are always complete and sleep sets are not */ |
| 412 | rpm_msg.msg.wait_for_compl = (state == RPMH_WAKE_ONLY_STATE); |
| 413 | rpm_msg.cmd[0].addr = addr; |
| 414 | rpm_msg.cmd[0].data = data; |
| 415 | rpm_msg.msg.num_cmds = 1; |
| 416 | |
| 417 | return rpmh_rsc_write_ctrl_data(ctrlr_to_drv(ctrlr), &rpm_msg.msg); |
| 418 | } |
| 419 | |
| 420 | /** |
| 421 | * rpmh_flush() - Flushes the buffered sleep and wake sets to TCSes |
| 422 | * |
| 423 | * @ctrlr: Controller making request to flush cached data |
| 424 | * |
| 425 | * Return: |
| 426 | * * 0 - Success |
| 427 | * * Error code - Otherwise |
| 428 | */ |
| 429 | int rpmh_flush(struct rpmh_ctrlr *ctrlr) |
| 430 | { |
| 431 | struct cache_req *p; |
| 432 | int ret = 0; |
| 433 | |
| 434 | lockdep_assert_irqs_disabled(); |
| 435 | |
| 436 | /* |
| 437 | * Currently rpmh_flush() is only called when we think we're running |
| 438 | * on the last processor. If the lock is busy it means another |
| 439 | * processor is up and it's better to abort than spin. |
| 440 | */ |
| 441 | if (!spin_trylock(&ctrlr->cache_lock)) |
| 442 | return -EBUSY; |
| 443 | |
| 444 | if (!ctrlr->dirty) { |
| 445 | pr_debug("Skipping flush, TCS has latest data.\n"); |
| 446 | goto write_next_wakeup; |
| 447 | } |
| 448 | |
| 449 | /* Invalidate the TCSes first to avoid stale data */ |
| 450 | rpmh_rsc_invalidate(ctrlr_to_drv(ctrlr)); |
| 451 | |
| 452 | /* First flush the cached batch requests */ |
| 453 | ret = flush_batch(ctrlr); |
| 454 | if (ret) |
| 455 | goto exit; |
| 456 | |
| 457 | list_for_each_entry(p, &ctrlr->cache, list) { |
| 458 | if (!is_req_valid(p)) { |
| 459 | pr_debug("%s: skipping RPMH req: a:%#x s:%#x w:%#x", |
| 460 | __func__, p->addr, p->sleep_val, p->wake_val); |
| 461 | continue; |
| 462 | } |
| 463 | ret = send_single(ctrlr, RPMH_SLEEP_STATE, p->addr, |
| 464 | p->sleep_val); |
| 465 | if (ret) |
| 466 | goto exit; |
| 467 | ret = send_single(ctrlr, RPMH_WAKE_ONLY_STATE, p->addr, |
| 468 | p->wake_val); |
| 469 | if (ret) |
| 470 | goto exit; |
| 471 | } |
| 472 | |
| 473 | ctrlr->dirty = false; |
| 474 | |
| 475 | write_next_wakeup: |
| 476 | rpmh_rsc_write_next_wakeup(ctrlr_to_drv(ctrlr)); |
| 477 | exit: |
| 478 | spin_unlock(&ctrlr->cache_lock); |
| 479 | return ret; |
| 480 | } |
| 481 | |
| 482 | /** |
| 483 | * rpmh_invalidate: Invalidate sleep and wake sets in batch_cache |
| 484 | * |
| 485 | * @dev: The device making the request |
| 486 | * |
| 487 | * Invalidate the sleep and wake values in batch_cache. |
| 488 | */ |
| 489 | void rpmh_invalidate(const struct device *dev) |
| 490 | { |
| 491 | struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev); |
| 492 | struct batch_cache_req *req, *tmp; |
| 493 | unsigned long flags; |
| 494 | |
| 495 | spin_lock_irqsave(&ctrlr->cache_lock, flags); |
| 496 | list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list) |
| 497 | kfree(req); |
| 498 | INIT_LIST_HEAD(&ctrlr->batch_cache); |
| 499 | ctrlr->dirty = true; |
| 500 | spin_unlock_irqrestore(&ctrlr->cache_lock, flags); |
| 501 | } |
| 502 | EXPORT_SYMBOL_GPL(rpmh_invalidate); |