1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * CPPC (Collaborative Processor Performance Control) methods used by CPUfreq drivers. 4 * 5 * (C) Copyright 2014, 2015 Linaro Ltd. 6 * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org> 7 * 8 * CPPC describes a few methods for controlling CPU performance using 9 * information from a per CPU table called CPC. This table is described in 10 * the ACPI v5.0+ specification. The table consists of a list of 11 * registers which may be memory mapped or hardware registers and also may 12 * include some static integer values. 13 * 14 * CPU performance is on an abstract continuous scale as against a discretized 15 * P-state scale which is tied to CPU frequency only. In brief, the basic 16 * operation involves: 17 * 18 * - OS makes a CPU performance request. (Can provide min and max bounds) 19 * 20 * - Platform (such as BMC) is free to optimize request within requested bounds 21 * depending on power/thermal budgets etc. 22 * 23 * - Platform conveys its decision back to OS 24 * 25 * The communication between OS and platform occurs through another medium 26 * called (PCC) Platform Communication Channel. This is a generic mailbox like 27 * mechanism which includes doorbell semantics to indicate register updates. 28 * See drivers/mailbox/pcc.c for details on PCC. 29 * 30 * Finer details about the PCC and CPPC spec are available in the ACPI v5.1 and 31 * above specifications. 32 */ 33 34 #define pr_fmt(fmt) "ACPI CPPC: " fmt 35 36 #include <linux/delay.h> 37 #include <linux/iopoll.h> 38 #include <linux/ktime.h> 39 #include <linux/rwsem.h> 40 #include <linux/wait.h> 41 #include <linux/topology.h> 42 43 #include <acpi/cppc_acpi.h> 44 45 struct cppc_pcc_data { 46 struct pcc_mbox_chan *pcc_channel; 47 void __iomem *pcc_comm_addr; 48 bool pcc_channel_acquired; 49 unsigned int deadline_us; 50 unsigned int pcc_mpar, pcc_mrtt, pcc_nominal; 51 52 bool pending_pcc_write_cmd; /* Any pending/batched PCC write cmds? */ 53 bool platform_owns_pcc; /* Ownership of PCC subspace */ 54 unsigned int pcc_write_cnt; /* Running count of PCC write commands */ 55 56 /* 57 * Lock to provide controlled access to the PCC channel. 58 * 59 * For performance critical usecases(currently cppc_set_perf) 60 * We need to take read_lock and check if channel belongs to OSPM 61 * before reading or writing to PCC subspace 62 * We need to take write_lock before transferring the channel 63 * ownership to the platform via a Doorbell 64 * This allows us to batch a number of CPPC requests if they happen 65 * to originate in about the same time 66 * 67 * For non-performance critical usecases(init) 68 * Take write_lock for all purposes which gives exclusive access 69 */ 70 struct rw_semaphore pcc_lock; 71 72 /* Wait queue for CPUs whose requests were batched */ 73 wait_queue_head_t pcc_write_wait_q; 74 ktime_t last_cmd_cmpl_time; 75 ktime_t last_mpar_reset; 76 int mpar_count; 77 int refcount; 78 }; 79 80 /* Array to represent the PCC channel per subspace ID */ 81 static struct cppc_pcc_data *pcc_data[MAX_PCC_SUBSPACES]; 82 /* The cpu_pcc_subspace_idx contains per CPU subspace ID */ 83 static DEFINE_PER_CPU(int, cpu_pcc_subspace_idx); 84 85 /* 86 * The cpc_desc structure contains the ACPI register details 87 * as described in the per CPU _CPC tables. The details 88 * include the type of register (e.g. PCC, System IO, FFH etc.) 89 * and destination addresses which lets us READ/WRITE CPU performance 90 * information using the appropriate I/O methods. 91 */ 92 static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); 93 94 /* pcc mapped address + header size + offset within PCC subspace */ 95 #define GET_PCC_VADDR(offs, pcc_ss_id) (pcc_data[pcc_ss_id]->pcc_comm_addr + \ 96 0x8 + (offs)) 97 98 /* Check if a CPC register is in PCC */ 99 #define CPC_IN_PCC(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ 100 (cpc)->cpc_entry.reg.space_id == \ 101 ACPI_ADR_SPACE_PLATFORM_COMM) 102 103 /* Check if a CPC register is in SystemMemory */ 104 #define CPC_IN_SYSTEM_MEMORY(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ 105 (cpc)->cpc_entry.reg.space_id == \ 106 ACPI_ADR_SPACE_SYSTEM_MEMORY) 107 108 /* Check if a CPC register is in SystemIo */ 109 #define CPC_IN_SYSTEM_IO(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ 110 (cpc)->cpc_entry.reg.space_id == \ 111 ACPI_ADR_SPACE_SYSTEM_IO) 112 113 /* Evaluates to True if reg is a NULL register descriptor */ 114 #define IS_NULL_REG(reg) ((reg)->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY && \ 115 (reg)->address == 0 && \ 116 (reg)->bit_width == 0 && \ 117 (reg)->bit_offset == 0 && \ 118 (reg)->access_width == 0) 119 120 /* Evaluates to True if an optional cpc field is supported */ 121 #define CPC_SUPPORTED(cpc) ((cpc)->type == ACPI_TYPE_INTEGER ? \ 122 !!(cpc)->cpc_entry.int_value : \ 123 !IS_NULL_REG(&(cpc)->cpc_entry.reg)) 124 /* 125 * Arbitrary Retries in case the remote processor is slow to respond 126 * to PCC commands. Keeping it high enough to cover emulators where 127 * the processors run painfully slow. 128 */ 129 #define NUM_RETRIES 500ULL 130 131 #define OVER_16BTS_MASK ~0xFFFFULL 132 133 #define define_one_cppc_ro(_name) \ 134 static struct kobj_attribute _name = \ 135 __ATTR(_name, 0444, show_##_name, NULL) 136 137 #define to_cpc_desc(a) container_of(a, struct cpc_desc, kobj) 138 139 #define show_cppc_data(access_fn, struct_name, member_name) \ 140 static ssize_t show_##member_name(struct kobject *kobj, \ 141 struct kobj_attribute *attr, char *buf) \ 142 { \ 143 struct cpc_desc *cpc_ptr = to_cpc_desc(kobj); \ 144 struct struct_name st_name = {0}; \ 145 int ret; \ 146 \ 147 ret = access_fn(cpc_ptr->cpu_id, &st_name); \ 148 if (ret) \ 149 return ret; \ 150 \ 151 return scnprintf(buf, PAGE_SIZE, "%llu\n", \ 152 (u64)st_name.member_name); \ 153 } \ 154 define_one_cppc_ro(member_name) 155 156 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, highest_perf); 157 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_perf); 158 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_perf); 159 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_nonlinear_perf); 160 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_freq); 161 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_freq); 162 163 show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf); 164 show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time); 165 166 static ssize_t show_feedback_ctrs(struct kobject *kobj, 167 struct kobj_attribute *attr, char *buf) 168 { 169 struct cpc_desc *cpc_ptr = to_cpc_desc(kobj); 170 struct cppc_perf_fb_ctrs fb_ctrs = {0}; 171 int ret; 172 173 ret = cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs); 174 if (ret) 175 return ret; 176 177 return scnprintf(buf, PAGE_SIZE, "ref:%llu del:%llu\n", 178 fb_ctrs.reference, fb_ctrs.delivered); 179 } 180 define_one_cppc_ro(feedback_ctrs); 181 182 static struct attribute *cppc_attrs[] = { 183 &feedback_ctrs.attr, 184 &reference_perf.attr, 185 &wraparound_time.attr, 186 &highest_perf.attr, 187 &lowest_perf.attr, 188 &lowest_nonlinear_perf.attr, 189 &nominal_perf.attr, 190 &nominal_freq.attr, 191 &lowest_freq.attr, 192 NULL 193 }; 194 ATTRIBUTE_GROUPS(cppc); 195 196 static struct kobj_type cppc_ktype = { 197 .sysfs_ops = &kobj_sysfs_ops, 198 .default_groups = cppc_groups, 199 }; 200 201 static int check_pcc_chan(int pcc_ss_id, bool chk_err_bit) 202 { 203 int ret, status; 204 struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; 205 struct acpi_pcct_shared_memory __iomem *generic_comm_base = 206 pcc_ss_data->pcc_comm_addr; 207 208 if (!pcc_ss_data->platform_owns_pcc) 209 return 0; 210 211 /* 212 * Poll PCC status register every 3us(delay_us) for maximum of 213 * deadline_us(timeout_us) until PCC command complete bit is set(cond) 214 */ 215 ret = readw_relaxed_poll_timeout(&generic_comm_base->status, status, 216 status & PCC_CMD_COMPLETE_MASK, 3, 217 pcc_ss_data->deadline_us); 218 219 if (likely(!ret)) { 220 pcc_ss_data->platform_owns_pcc = false; 221 if (chk_err_bit && (status & PCC_ERROR_MASK)) 222 ret = -EIO; 223 } 224 225 if (unlikely(ret)) 226 pr_err("PCC check channel failed for ss: %d. ret=%d\n", 227 pcc_ss_id, ret); 228 229 return ret; 230 } 231 232 /* 233 * This function transfers the ownership of the PCC to the platform 234 * So it must be called while holding write_lock(pcc_lock) 235 */ 236 static int send_pcc_cmd(int pcc_ss_id, u16 cmd) 237 { 238 int ret = -EIO, i; 239 struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; 240 struct acpi_pcct_shared_memory __iomem *generic_comm_base = 241 pcc_ss_data->pcc_comm_addr; 242 unsigned int time_delta; 243 244 /* 245 * For CMD_WRITE we know for a fact the caller should have checked 246 * the channel before writing to PCC space 247 */ 248 if (cmd == CMD_READ) { 249 /* 250 * If there are pending cpc_writes, then we stole the channel 251 * before write completion, so first send a WRITE command to 252 * platform 253 */ 254 if (pcc_ss_data->pending_pcc_write_cmd) 255 send_pcc_cmd(pcc_ss_id, CMD_WRITE); 256 257 ret = check_pcc_chan(pcc_ss_id, false); 258 if (ret) 259 goto end; 260 } else /* CMD_WRITE */ 261 pcc_ss_data->pending_pcc_write_cmd = FALSE; 262 263 /* 264 * Handle the Minimum Request Turnaround Time(MRTT) 265 * "The minimum amount of time that OSPM must wait after the completion 266 * of a command before issuing the next command, in microseconds" 267 */ 268 if (pcc_ss_data->pcc_mrtt) { 269 time_delta = ktime_us_delta(ktime_get(), 270 pcc_ss_data->last_cmd_cmpl_time); 271 if (pcc_ss_data->pcc_mrtt > time_delta) 272 udelay(pcc_ss_data->pcc_mrtt - time_delta); 273 } 274 275 /* 276 * Handle the non-zero Maximum Periodic Access Rate(MPAR) 277 * "The maximum number of periodic requests that the subspace channel can 278 * support, reported in commands per minute. 0 indicates no limitation." 279 * 280 * This parameter should be ideally zero or large enough so that it can 281 * handle maximum number of requests that all the cores in the system can 282 * collectively generate. If it is not, we will follow the spec and just 283 * not send the request to the platform after hitting the MPAR limit in 284 * any 60s window 285 */ 286 if (pcc_ss_data->pcc_mpar) { 287 if (pcc_ss_data->mpar_count == 0) { 288 time_delta = ktime_ms_delta(ktime_get(), 289 pcc_ss_data->last_mpar_reset); 290 if ((time_delta < 60 * MSEC_PER_SEC) && pcc_ss_data->last_mpar_reset) { 291 pr_debug("PCC cmd for subspace %d not sent due to MPAR limit", 292 pcc_ss_id); 293 ret = -EIO; 294 goto end; 295 } 296 pcc_ss_data->last_mpar_reset = ktime_get(); 297 pcc_ss_data->mpar_count = pcc_ss_data->pcc_mpar; 298 } 299 pcc_ss_data->mpar_count--; 300 } 301 302 /* Write to the shared comm region. */ 303 writew_relaxed(cmd, &generic_comm_base->command); 304 305 /* Flip CMD COMPLETE bit */ 306 writew_relaxed(0, &generic_comm_base->status); 307 308 pcc_ss_data->platform_owns_pcc = true; 309 310 /* Ring doorbell */ 311 ret = mbox_send_message(pcc_ss_data->pcc_channel->mchan, &cmd); 312 if (ret < 0) { 313 pr_err("Err sending PCC mbox message. ss: %d cmd:%d, ret:%d\n", 314 pcc_ss_id, cmd, ret); 315 goto end; 316 } 317 318 /* wait for completion and check for PCC error bit */ 319 ret = check_pcc_chan(pcc_ss_id, true); 320 321 if (pcc_ss_data->pcc_mrtt) 322 pcc_ss_data->last_cmd_cmpl_time = ktime_get(); 323 324 if (pcc_ss_data->pcc_channel->mchan->mbox->txdone_irq) 325 mbox_chan_txdone(pcc_ss_data->pcc_channel->mchan, ret); 326 else 327 mbox_client_txdone(pcc_ss_data->pcc_channel->mchan, ret); 328 329 end: 330 if (cmd == CMD_WRITE) { 331 if (unlikely(ret)) { 332 for_each_possible_cpu(i) { 333 struct cpc_desc *desc = per_cpu(cpc_desc_ptr, i); 334 335 if (!desc) 336 continue; 337 338 if (desc->write_cmd_id == pcc_ss_data->pcc_write_cnt) 339 desc->write_cmd_status = ret; 340 } 341 } 342 pcc_ss_data->pcc_write_cnt++; 343 wake_up_all(&pcc_ss_data->pcc_write_wait_q); 344 } 345 346 return ret; 347 } 348 349 static void cppc_chan_tx_done(struct mbox_client *cl, void *msg, int ret) 350 { 351 if (ret < 0) 352 pr_debug("TX did not complete: CMD sent:%x, ret:%d\n", 353 *(u16 *)msg, ret); 354 else 355 pr_debug("TX completed. CMD sent:%x, ret:%d\n", 356 *(u16 *)msg, ret); 357 } 358 359 static struct mbox_client cppc_mbox_cl = { 360 .tx_done = cppc_chan_tx_done, 361 .knows_txdone = true, 362 }; 363 364 static int acpi_get_psd(struct cpc_desc *cpc_ptr, acpi_handle handle) 365 { 366 int result = -EFAULT; 367 acpi_status status = AE_OK; 368 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 369 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; 370 struct acpi_buffer state = {0, NULL}; 371 union acpi_object *psd = NULL; 372 struct acpi_psd_package *pdomain; 373 374 status = acpi_evaluate_object_typed(handle, "_PSD", NULL, 375 &buffer, ACPI_TYPE_PACKAGE); 376 if (status == AE_NOT_FOUND) /* _PSD is optional */ 377 return 0; 378 if (ACPI_FAILURE(status)) 379 return -ENODEV; 380 381 psd = buffer.pointer; 382 if (!psd || psd->package.count != 1) { 383 pr_debug("Invalid _PSD data\n"); 384 goto end; 385 } 386 387 pdomain = &(cpc_ptr->domain_info); 388 389 state.length = sizeof(struct acpi_psd_package); 390 state.pointer = pdomain; 391 392 status = acpi_extract_package(&(psd->package.elements[0]), 393 &format, &state); 394 if (ACPI_FAILURE(status)) { 395 pr_debug("Invalid _PSD data for CPU:%d\n", cpc_ptr->cpu_id); 396 goto end; 397 } 398 399 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { 400 pr_debug("Unknown _PSD:num_entries for CPU:%d\n", cpc_ptr->cpu_id); 401 goto end; 402 } 403 404 if (pdomain->revision != ACPI_PSD_REV0_REVISION) { 405 pr_debug("Unknown _PSD:revision for CPU: %d\n", cpc_ptr->cpu_id); 406 goto end; 407 } 408 409 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 410 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 411 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 412 pr_debug("Invalid _PSD:coord_type for CPU:%d\n", cpc_ptr->cpu_id); 413 goto end; 414 } 415 416 result = 0; 417 end: 418 kfree(buffer.pointer); 419 return result; 420 } 421 422 bool acpi_cpc_valid(void) 423 { 424 struct cpc_desc *cpc_ptr; 425 int cpu; 426 427 for_each_present_cpu(cpu) { 428 cpc_ptr = per_cpu(cpc_desc_ptr, cpu); 429 if (!cpc_ptr) 430 return false; 431 } 432 433 return true; 434 } 435 EXPORT_SYMBOL_GPL(acpi_cpc_valid); 436 437 bool cppc_allow_fast_switch(void) 438 { 439 struct cpc_register_resource *desired_reg; 440 struct cpc_desc *cpc_ptr; 441 int cpu; 442 443 for_each_possible_cpu(cpu) { 444 cpc_ptr = per_cpu(cpc_desc_ptr, cpu); 445 desired_reg = &cpc_ptr->cpc_regs[DESIRED_PERF]; 446 if (!CPC_IN_SYSTEM_MEMORY(desired_reg) && 447 !CPC_IN_SYSTEM_IO(desired_reg)) 448 return false; 449 } 450 451 return true; 452 } 453 EXPORT_SYMBOL_GPL(cppc_allow_fast_switch); 454 455 /** 456 * acpi_get_psd_map - Map the CPUs in the freq domain of a given cpu 457 * @cpu: Find all CPUs that share a domain with cpu. 458 * @cpu_data: Pointer to CPU specific CPPC data including PSD info. 459 * 460 * Return: 0 for success or negative value for err. 461 */ 462 int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data) 463 { 464 struct cpc_desc *cpc_ptr, *match_cpc_ptr; 465 struct acpi_psd_package *match_pdomain; 466 struct acpi_psd_package *pdomain; 467 int count_target, i; 468 469 /* 470 * Now that we have _PSD data from all CPUs, let's setup P-state 471 * domain info. 472 */ 473 cpc_ptr = per_cpu(cpc_desc_ptr, cpu); 474 if (!cpc_ptr) 475 return -EFAULT; 476 477 pdomain = &(cpc_ptr->domain_info); 478 cpumask_set_cpu(cpu, cpu_data->shared_cpu_map); 479 if (pdomain->num_processors <= 1) 480 return 0; 481 482 /* Validate the Domain info */ 483 count_target = pdomain->num_processors; 484 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 485 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ALL; 486 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 487 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_HW; 488 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 489 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ANY; 490 491 for_each_possible_cpu(i) { 492 if (i == cpu) 493 continue; 494 495 match_cpc_ptr = per_cpu(cpc_desc_ptr, i); 496 if (!match_cpc_ptr) 497 goto err_fault; 498 499 match_pdomain = &(match_cpc_ptr->domain_info); 500 if (match_pdomain->domain != pdomain->domain) 501 continue; 502 503 /* Here i and cpu are in the same domain */ 504 if (match_pdomain->num_processors != count_target) 505 goto err_fault; 506 507 if (pdomain->coord_type != match_pdomain->coord_type) 508 goto err_fault; 509 510 cpumask_set_cpu(i, cpu_data->shared_cpu_map); 511 } 512 513 return 0; 514 515 err_fault: 516 /* Assume no coordination on any error parsing domain info */ 517 cpumask_clear(cpu_data->shared_cpu_map); 518 cpumask_set_cpu(cpu, cpu_data->shared_cpu_map); 519 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_NONE; 520 521 return -EFAULT; 522 } 523 EXPORT_SYMBOL_GPL(acpi_get_psd_map); 524 525 static int register_pcc_channel(int pcc_ss_idx) 526 { 527 struct pcc_mbox_chan *pcc_chan; 528 u64 usecs_lat; 529 530 if (pcc_ss_idx >= 0) { 531 pcc_chan = pcc_mbox_request_channel(&cppc_mbox_cl, pcc_ss_idx); 532 533 if (IS_ERR(pcc_chan)) { 534 pr_err("Failed to find PCC channel for subspace %d\n", 535 pcc_ss_idx); 536 return -ENODEV; 537 } 538 539 pcc_data[pcc_ss_idx]->pcc_channel = pcc_chan; 540 /* 541 * cppc_ss->latency is just a Nominal value. In reality 542 * the remote processor could be much slower to reply. 543 * So add an arbitrary amount of wait on top of Nominal. 544 */ 545 usecs_lat = NUM_RETRIES * pcc_chan->latency; 546 pcc_data[pcc_ss_idx]->deadline_us = usecs_lat; 547 pcc_data[pcc_ss_idx]->pcc_mrtt = pcc_chan->min_turnaround_time; 548 pcc_data[pcc_ss_idx]->pcc_mpar = pcc_chan->max_access_rate; 549 pcc_data[pcc_ss_idx]->pcc_nominal = pcc_chan->latency; 550 551 pcc_data[pcc_ss_idx]->pcc_comm_addr = 552 acpi_os_ioremap(pcc_chan->shmem_base_addr, 553 pcc_chan->shmem_size); 554 if (!pcc_data[pcc_ss_idx]->pcc_comm_addr) { 555 pr_err("Failed to ioremap PCC comm region mem for %d\n", 556 pcc_ss_idx); 557 return -ENOMEM; 558 } 559 560 /* Set flag so that we don't come here for each CPU. */ 561 pcc_data[pcc_ss_idx]->pcc_channel_acquired = true; 562 } 563 564 return 0; 565 } 566 567 /** 568 * cpc_ffh_supported() - check if FFH reading supported 569 * 570 * Check if the architecture has support for functional fixed hardware 571 * read/write capability. 572 * 573 * Return: true for supported, false for not supported 574 */ 575 bool __weak cpc_ffh_supported(void) 576 { 577 return false; 578 } 579 580 /** 581 * cpc_supported_by_cpu() - check if CPPC is supported by CPU 582 * 583 * Check if the architectural support for CPPC is present even 584 * if the _OSC hasn't prescribed it 585 * 586 * Return: true for supported, false for not supported 587 */ 588 bool __weak cpc_supported_by_cpu(void) 589 { 590 return false; 591 } 592 593 /** 594 * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace 595 * 596 * Check and allocate the cppc_pcc_data memory. 597 * In some processor configurations it is possible that same subspace 598 * is shared between multiple CPUs. This is seen especially in CPUs 599 * with hardware multi-threading support. 600 * 601 * Return: 0 for success, errno for failure 602 */ 603 static int pcc_data_alloc(int pcc_ss_id) 604 { 605 if (pcc_ss_id < 0 || pcc_ss_id >= MAX_PCC_SUBSPACES) 606 return -EINVAL; 607 608 if (pcc_data[pcc_ss_id]) { 609 pcc_data[pcc_ss_id]->refcount++; 610 } else { 611 pcc_data[pcc_ss_id] = kzalloc(sizeof(struct cppc_pcc_data), 612 GFP_KERNEL); 613 if (!pcc_data[pcc_ss_id]) 614 return -ENOMEM; 615 pcc_data[pcc_ss_id]->refcount++; 616 } 617 618 return 0; 619 } 620 621 /* Check if CPPC revision + num_ent combination is supported */ 622 static bool is_cppc_supported(int revision, int num_ent) 623 { 624 int expected_num_ent; 625 626 switch (revision) { 627 case CPPC_V2_REV: 628 expected_num_ent = CPPC_V2_NUM_ENT; 629 break; 630 case CPPC_V3_REV: 631 expected_num_ent = CPPC_V3_NUM_ENT; 632 break; 633 default: 634 pr_debug("Firmware exports unsupported CPPC revision: %d\n", 635 revision); 636 return false; 637 } 638 639 if (expected_num_ent != num_ent) { 640 pr_debug("Firmware exports %d entries. Expected: %d for CPPC rev:%d\n", 641 num_ent, expected_num_ent, revision); 642 return false; 643 } 644 645 return true; 646 } 647 648 /* 649 * An example CPC table looks like the following. 650 * 651 * Name (_CPC, Package() { 652 * 17, // NumEntries 653 * 1, // Revision 654 * ResourceTemplate() {Register(PCC, 32, 0, 0x120, 2)}, // Highest Performance 655 * ResourceTemplate() {Register(PCC, 32, 0, 0x124, 2)}, // Nominal Performance 656 * ResourceTemplate() {Register(PCC, 32, 0, 0x128, 2)}, // Lowest Nonlinear Performance 657 * ResourceTemplate() {Register(PCC, 32, 0, 0x12C, 2)}, // Lowest Performance 658 * ResourceTemplate() {Register(PCC, 32, 0, 0x130, 2)}, // Guaranteed Performance Register 659 * ResourceTemplate() {Register(PCC, 32, 0, 0x110, 2)}, // Desired Performance Register 660 * ResourceTemplate() {Register(SystemMemory, 0, 0, 0, 0)}, 661 * ... 662 * ... 663 * ... 664 * } 665 * Each Register() encodes how to access that specific register. 666 * e.g. a sample PCC entry has the following encoding: 667 * 668 * Register ( 669 * PCC, // AddressSpaceKeyword 670 * 8, // RegisterBitWidth 671 * 8, // RegisterBitOffset 672 * 0x30, // RegisterAddress 673 * 9, // AccessSize (subspace ID) 674 * ) 675 */ 676 677 #ifndef arch_init_invariance_cppc 678 static inline void arch_init_invariance_cppc(void) { } 679 #endif 680 681 /** 682 * acpi_cppc_processor_probe - Search for per CPU _CPC objects. 683 * @pr: Ptr to acpi_processor containing this CPU's logical ID. 684 * 685 * Return: 0 for success or negative value for err. 686 */ 687 int acpi_cppc_processor_probe(struct acpi_processor *pr) 688 { 689 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL}; 690 union acpi_object *out_obj, *cpc_obj; 691 struct cpc_desc *cpc_ptr; 692 struct cpc_reg *gas_t; 693 struct device *cpu_dev; 694 acpi_handle handle = pr->handle; 695 unsigned int num_ent, i, cpc_rev; 696 int pcc_subspace_id = -1; 697 acpi_status status; 698 int ret = -ENODATA; 699 700 if (!osc_sb_cppc2_support_acked) { 701 pr_debug("CPPC v2 _OSC not acked\n"); 702 if (!cpc_supported_by_cpu()) 703 return -ENODEV; 704 } 705 706 /* Parse the ACPI _CPC table for this CPU. */ 707 status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output, 708 ACPI_TYPE_PACKAGE); 709 if (ACPI_FAILURE(status)) { 710 ret = -ENODEV; 711 goto out_buf_free; 712 } 713 714 out_obj = (union acpi_object *) output.pointer; 715 716 cpc_ptr = kzalloc(sizeof(struct cpc_desc), GFP_KERNEL); 717 if (!cpc_ptr) { 718 ret = -ENOMEM; 719 goto out_buf_free; 720 } 721 722 /* First entry is NumEntries. */ 723 cpc_obj = &out_obj->package.elements[0]; 724 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 725 num_ent = cpc_obj->integer.value; 726 if (num_ent <= 1) { 727 pr_debug("Unexpected _CPC NumEntries value (%d) for CPU:%d\n", 728 num_ent, pr->id); 729 goto out_free; 730 } 731 } else { 732 pr_debug("Unexpected _CPC NumEntries entry type (%d) for CPU:%d\n", 733 cpc_obj->type, pr->id); 734 goto out_free; 735 } 736 cpc_ptr->num_entries = num_ent; 737 738 /* Second entry should be revision. */ 739 cpc_obj = &out_obj->package.elements[1]; 740 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 741 cpc_rev = cpc_obj->integer.value; 742 } else { 743 pr_debug("Unexpected _CPC Revision entry type (%d) for CPU:%d\n", 744 cpc_obj->type, pr->id); 745 goto out_free; 746 } 747 cpc_ptr->version = cpc_rev; 748 749 if (!is_cppc_supported(cpc_rev, num_ent)) 750 goto out_free; 751 752 /* Iterate through remaining entries in _CPC */ 753 for (i = 2; i < num_ent; i++) { 754 cpc_obj = &out_obj->package.elements[i]; 755 756 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 757 cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_INTEGER; 758 cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = cpc_obj->integer.value; 759 } else if (cpc_obj->type == ACPI_TYPE_BUFFER) { 760 gas_t = (struct cpc_reg *) 761 cpc_obj->buffer.pointer; 762 763 /* 764 * The PCC Subspace index is encoded inside 765 * the CPC table entries. The same PCC index 766 * will be used for all the PCC entries, 767 * so extract it only once. 768 */ 769 if (gas_t->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { 770 if (pcc_subspace_id < 0) { 771 pcc_subspace_id = gas_t->access_width; 772 if (pcc_data_alloc(pcc_subspace_id)) 773 goto out_free; 774 } else if (pcc_subspace_id != gas_t->access_width) { 775 pr_debug("Mismatched PCC ids in _CPC for CPU:%d\n", 776 pr->id); 777 goto out_free; 778 } 779 } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { 780 if (gas_t->address) { 781 void __iomem *addr; 782 783 if (!osc_cpc_flexible_adr_space_confirmed) { 784 pr_debug("Flexible address space capability not supported\n"); 785 goto out_free; 786 } 787 788 addr = ioremap(gas_t->address, gas_t->bit_width/8); 789 if (!addr) 790 goto out_free; 791 cpc_ptr->cpc_regs[i-2].sys_mem_vaddr = addr; 792 } 793 } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { 794 if (gas_t->access_width < 1 || gas_t->access_width > 3) { 795 /* 796 * 1 = 8-bit, 2 = 16-bit, and 3 = 32-bit. 797 * SystemIO doesn't implement 64-bit 798 * registers. 799 */ 800 pr_debug("Invalid access width %d for SystemIO register in _CPC\n", 801 gas_t->access_width); 802 goto out_free; 803 } 804 if (gas_t->address & OVER_16BTS_MASK) { 805 /* SystemIO registers use 16-bit integer addresses */ 806 pr_debug("Invalid IO port %llu for SystemIO register in _CPC\n", 807 gas_t->address); 808 goto out_free; 809 } 810 if (!osc_cpc_flexible_adr_space_confirmed) { 811 pr_debug("Flexible address space capability not supported\n"); 812 goto out_free; 813 } 814 } else { 815 if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) { 816 /* Support only PCC, SystemMemory, SystemIO, and FFH type regs. */ 817 pr_debug("Unsupported register type (%d) in _CPC\n", 818 gas_t->space_id); 819 goto out_free; 820 } 821 } 822 823 cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_BUFFER; 824 memcpy(&cpc_ptr->cpc_regs[i-2].cpc_entry.reg, gas_t, sizeof(*gas_t)); 825 } else { 826 pr_debug("Invalid entry type (%d) in _CPC for CPU:%d\n", 827 i, pr->id); 828 goto out_free; 829 } 830 } 831 per_cpu(cpu_pcc_subspace_idx, pr->id) = pcc_subspace_id; 832 833 /* 834 * Initialize the remaining cpc_regs as unsupported. 835 * Example: In case FW exposes CPPC v2, the below loop will initialize 836 * LOWEST_FREQ and NOMINAL_FREQ regs as unsupported 837 */ 838 for (i = num_ent - 2; i < MAX_CPC_REG_ENT; i++) { 839 cpc_ptr->cpc_regs[i].type = ACPI_TYPE_INTEGER; 840 cpc_ptr->cpc_regs[i].cpc_entry.int_value = 0; 841 } 842 843 844 /* Store CPU Logical ID */ 845 cpc_ptr->cpu_id = pr->id; 846 847 /* Parse PSD data for this CPU */ 848 ret = acpi_get_psd(cpc_ptr, handle); 849 if (ret) 850 goto out_free; 851 852 /* Register PCC channel once for all PCC subspace ID. */ 853 if (pcc_subspace_id >= 0 && !pcc_data[pcc_subspace_id]->pcc_channel_acquired) { 854 ret = register_pcc_channel(pcc_subspace_id); 855 if (ret) 856 goto out_free; 857 858 init_rwsem(&pcc_data[pcc_subspace_id]->pcc_lock); 859 init_waitqueue_head(&pcc_data[pcc_subspace_id]->pcc_write_wait_q); 860 } 861 862 /* Everything looks okay */ 863 pr_debug("Parsed CPC struct for CPU: %d\n", pr->id); 864 865 /* Add per logical CPU nodes for reading its feedback counters. */ 866 cpu_dev = get_cpu_device(pr->id); 867 if (!cpu_dev) { 868 ret = -EINVAL; 869 goto out_free; 870 } 871 872 /* Plug PSD data into this CPU's CPC descriptor. */ 873 per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr; 874 875 ret = kobject_init_and_add(&cpc_ptr->kobj, &cppc_ktype, &cpu_dev->kobj, 876 "acpi_cppc"); 877 if (ret) { 878 per_cpu(cpc_desc_ptr, pr->id) = NULL; 879 kobject_put(&cpc_ptr->kobj); 880 goto out_free; 881 } 882 883 arch_init_invariance_cppc(); 884 885 kfree(output.pointer); 886 return 0; 887 888 out_free: 889 /* Free all the mapped sys mem areas for this CPU */ 890 for (i = 2; i < cpc_ptr->num_entries; i++) { 891 void __iomem *addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr; 892 893 if (addr) 894 iounmap(addr); 895 } 896 kfree(cpc_ptr); 897 898 out_buf_free: 899 kfree(output.pointer); 900 return ret; 901 } 902 EXPORT_SYMBOL_GPL(acpi_cppc_processor_probe); 903 904 /** 905 * acpi_cppc_processor_exit - Cleanup CPC structs. 906 * @pr: Ptr to acpi_processor containing this CPU's logical ID. 907 * 908 * Return: Void 909 */ 910 void acpi_cppc_processor_exit(struct acpi_processor *pr) 911 { 912 struct cpc_desc *cpc_ptr; 913 unsigned int i; 914 void __iomem *addr; 915 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, pr->id); 916 917 if (pcc_ss_id >= 0 && pcc_data[pcc_ss_id]) { 918 if (pcc_data[pcc_ss_id]->pcc_channel_acquired) { 919 pcc_data[pcc_ss_id]->refcount--; 920 if (!pcc_data[pcc_ss_id]->refcount) { 921 pcc_mbox_free_channel(pcc_data[pcc_ss_id]->pcc_channel); 922 kfree(pcc_data[pcc_ss_id]); 923 pcc_data[pcc_ss_id] = NULL; 924 } 925 } 926 } 927 928 cpc_ptr = per_cpu(cpc_desc_ptr, pr->id); 929 if (!cpc_ptr) 930 return; 931 932 /* Free all the mapped sys mem areas for this CPU */ 933 for (i = 2; i < cpc_ptr->num_entries; i++) { 934 addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr; 935 if (addr) 936 iounmap(addr); 937 } 938 939 kobject_put(&cpc_ptr->kobj); 940 kfree(cpc_ptr); 941 } 942 EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit); 943 944 /** 945 * cpc_read_ffh() - Read FFH register 946 * @cpunum: CPU number to read 947 * @reg: cppc register information 948 * @val: place holder for return value 949 * 950 * Read bit_width bits from a specified address and bit_offset 951 * 952 * Return: 0 for success and error code 953 */ 954 int __weak cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val) 955 { 956 return -ENOTSUPP; 957 } 958 959 /** 960 * cpc_write_ffh() - Write FFH register 961 * @cpunum: CPU number to write 962 * @reg: cppc register information 963 * @val: value to write 964 * 965 * Write value of bit_width bits to a specified address and bit_offset 966 * 967 * Return: 0 for success and error code 968 */ 969 int __weak cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) 970 { 971 return -ENOTSUPP; 972 } 973 974 /* 975 * Since cpc_read and cpc_write are called while holding pcc_lock, it should be 976 * as fast as possible. We have already mapped the PCC subspace during init, so 977 * we can directly write to it. 978 */ 979 980 static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val) 981 { 982 void __iomem *vaddr = NULL; 983 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 984 struct cpc_reg *reg = ®_res->cpc_entry.reg; 985 986 if (reg_res->type == ACPI_TYPE_INTEGER) { 987 *val = reg_res->cpc_entry.int_value; 988 return 0; 989 } 990 991 *val = 0; 992 993 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { 994 u32 width = 8 << (reg->access_width - 1); 995 u32 val_u32; 996 acpi_status status; 997 998 status = acpi_os_read_port((acpi_io_address)reg->address, 999 &val_u32, width); 1000 if (ACPI_FAILURE(status)) { 1001 pr_debug("Error: Failed to read SystemIO port %llx\n", 1002 reg->address); 1003 return -EFAULT; 1004 } 1005 1006 *val = val_u32; 1007 return 0; 1008 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) 1009 vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); 1010 else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1011 vaddr = reg_res->sys_mem_vaddr; 1012 else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) 1013 return cpc_read_ffh(cpu, reg, val); 1014 else 1015 return acpi_os_read_memory((acpi_physical_address)reg->address, 1016 val, reg->bit_width); 1017 1018 switch (reg->bit_width) { 1019 case 8: 1020 *val = readb_relaxed(vaddr); 1021 break; 1022 case 16: 1023 *val = readw_relaxed(vaddr); 1024 break; 1025 case 32: 1026 *val = readl_relaxed(vaddr); 1027 break; 1028 case 64: 1029 *val = readq_relaxed(vaddr); 1030 break; 1031 default: 1032 pr_debug("Error: Cannot read %u bit width from PCC for ss: %d\n", 1033 reg->bit_width, pcc_ss_id); 1034 return -EFAULT; 1035 } 1036 1037 return 0; 1038 } 1039 1040 static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) 1041 { 1042 int ret_val = 0; 1043 void __iomem *vaddr = NULL; 1044 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1045 struct cpc_reg *reg = ®_res->cpc_entry.reg; 1046 1047 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { 1048 u32 width = 8 << (reg->access_width - 1); 1049 acpi_status status; 1050 1051 status = acpi_os_write_port((acpi_io_address)reg->address, 1052 (u32)val, width); 1053 if (ACPI_FAILURE(status)) { 1054 pr_debug("Error: Failed to write SystemIO port %llx\n", 1055 reg->address); 1056 return -EFAULT; 1057 } 1058 1059 return 0; 1060 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) 1061 vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); 1062 else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1063 vaddr = reg_res->sys_mem_vaddr; 1064 else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) 1065 return cpc_write_ffh(cpu, reg, val); 1066 else 1067 return acpi_os_write_memory((acpi_physical_address)reg->address, 1068 val, reg->bit_width); 1069 1070 switch (reg->bit_width) { 1071 case 8: 1072 writeb_relaxed(val, vaddr); 1073 break; 1074 case 16: 1075 writew_relaxed(val, vaddr); 1076 break; 1077 case 32: 1078 writel_relaxed(val, vaddr); 1079 break; 1080 case 64: 1081 writeq_relaxed(val, vaddr); 1082 break; 1083 default: 1084 pr_debug("Error: Cannot write %u bit width to PCC for ss: %d\n", 1085 reg->bit_width, pcc_ss_id); 1086 ret_val = -EFAULT; 1087 break; 1088 } 1089 1090 return ret_val; 1091 } 1092 1093 static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) 1094 { 1095 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1096 struct cpc_register_resource *reg; 1097 1098 if (!cpc_desc) { 1099 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1100 return -ENODEV; 1101 } 1102 1103 reg = &cpc_desc->cpc_regs[reg_idx]; 1104 1105 if (CPC_IN_PCC(reg)) { 1106 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1107 struct cppc_pcc_data *pcc_ss_data = NULL; 1108 int ret = 0; 1109 1110 if (pcc_ss_id < 0) 1111 return -EIO; 1112 1113 pcc_ss_data = pcc_data[pcc_ss_id]; 1114 1115 down_write(&pcc_ss_data->pcc_lock); 1116 1117 if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) 1118 cpc_read(cpunum, reg, perf); 1119 else 1120 ret = -EIO; 1121 1122 up_write(&pcc_ss_data->pcc_lock); 1123 1124 return ret; 1125 } 1126 1127 cpc_read(cpunum, reg, perf); 1128 1129 return 0; 1130 } 1131 1132 /** 1133 * cppc_get_desired_perf - Get the desired performance register value. 1134 * @cpunum: CPU from which to get desired performance. 1135 * @desired_perf: Return address. 1136 * 1137 * Return: 0 for success, -EIO otherwise. 1138 */ 1139 int cppc_get_desired_perf(int cpunum, u64 *desired_perf) 1140 { 1141 return cppc_get_perf(cpunum, DESIRED_PERF, desired_perf); 1142 } 1143 EXPORT_SYMBOL_GPL(cppc_get_desired_perf); 1144 1145 /** 1146 * cppc_get_nominal_perf - Get the nominal performance register value. 1147 * @cpunum: CPU from which to get nominal performance. 1148 * @nominal_perf: Return address. 1149 * 1150 * Return: 0 for success, -EIO otherwise. 1151 */ 1152 int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) 1153 { 1154 return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf); 1155 } 1156 1157 /** 1158 * cppc_get_perf_caps - Get a CPU's performance capabilities. 1159 * @cpunum: CPU from which to get capabilities info. 1160 * @perf_caps: ptr to cppc_perf_caps. See cppc_acpi.h 1161 * 1162 * Return: 0 for success with perf_caps populated else -ERRNO. 1163 */ 1164 int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) 1165 { 1166 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1167 struct cpc_register_resource *highest_reg, *lowest_reg, 1168 *lowest_non_linear_reg, *nominal_reg, *guaranteed_reg, 1169 *low_freq_reg = NULL, *nom_freq_reg = NULL; 1170 u64 high, low, guaranteed, nom, min_nonlinear, low_f = 0, nom_f = 0; 1171 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1172 struct cppc_pcc_data *pcc_ss_data = NULL; 1173 int ret = 0, regs_in_pcc = 0; 1174 1175 if (!cpc_desc) { 1176 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1177 return -ENODEV; 1178 } 1179 1180 highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF]; 1181 lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF]; 1182 lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF]; 1183 nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; 1184 low_freq_reg = &cpc_desc->cpc_regs[LOWEST_FREQ]; 1185 nom_freq_reg = &cpc_desc->cpc_regs[NOMINAL_FREQ]; 1186 guaranteed_reg = &cpc_desc->cpc_regs[GUARANTEED_PERF]; 1187 1188 /* Are any of the regs PCC ?*/ 1189 if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) || 1190 CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg) || 1191 CPC_IN_PCC(low_freq_reg) || CPC_IN_PCC(nom_freq_reg)) { 1192 if (pcc_ss_id < 0) { 1193 pr_debug("Invalid pcc_ss_id\n"); 1194 return -ENODEV; 1195 } 1196 pcc_ss_data = pcc_data[pcc_ss_id]; 1197 regs_in_pcc = 1; 1198 down_write(&pcc_ss_data->pcc_lock); 1199 /* Ring doorbell once to update PCC subspace */ 1200 if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) { 1201 ret = -EIO; 1202 goto out_err; 1203 } 1204 } 1205 1206 cpc_read(cpunum, highest_reg, &high); 1207 perf_caps->highest_perf = high; 1208 1209 cpc_read(cpunum, lowest_reg, &low); 1210 perf_caps->lowest_perf = low; 1211 1212 cpc_read(cpunum, nominal_reg, &nom); 1213 perf_caps->nominal_perf = nom; 1214 1215 if (guaranteed_reg->type != ACPI_TYPE_BUFFER || 1216 IS_NULL_REG(&guaranteed_reg->cpc_entry.reg)) { 1217 perf_caps->guaranteed_perf = 0; 1218 } else { 1219 cpc_read(cpunum, guaranteed_reg, &guaranteed); 1220 perf_caps->guaranteed_perf = guaranteed; 1221 } 1222 1223 cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear); 1224 perf_caps->lowest_nonlinear_perf = min_nonlinear; 1225 1226 if (!high || !low || !nom || !min_nonlinear) 1227 ret = -EFAULT; 1228 1229 /* Read optional lowest and nominal frequencies if present */ 1230 if (CPC_SUPPORTED(low_freq_reg)) 1231 cpc_read(cpunum, low_freq_reg, &low_f); 1232 1233 if (CPC_SUPPORTED(nom_freq_reg)) 1234 cpc_read(cpunum, nom_freq_reg, &nom_f); 1235 1236 perf_caps->lowest_freq = low_f; 1237 perf_caps->nominal_freq = nom_f; 1238 1239 1240 out_err: 1241 if (regs_in_pcc) 1242 up_write(&pcc_ss_data->pcc_lock); 1243 return ret; 1244 } 1245 EXPORT_SYMBOL_GPL(cppc_get_perf_caps); 1246 1247 /** 1248 * cppc_get_perf_ctrs - Read a CPU's performance feedback counters. 1249 * @cpunum: CPU from which to read counters. 1250 * @perf_fb_ctrs: ptr to cppc_perf_fb_ctrs. See cppc_acpi.h 1251 * 1252 * Return: 0 for success with perf_fb_ctrs populated else -ERRNO. 1253 */ 1254 int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) 1255 { 1256 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1257 struct cpc_register_resource *delivered_reg, *reference_reg, 1258 *ref_perf_reg, *ctr_wrap_reg; 1259 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1260 struct cppc_pcc_data *pcc_ss_data = NULL; 1261 u64 delivered, reference, ref_perf, ctr_wrap_time; 1262 int ret = 0, regs_in_pcc = 0; 1263 1264 if (!cpc_desc) { 1265 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1266 return -ENODEV; 1267 } 1268 1269 delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR]; 1270 reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR]; 1271 ref_perf_reg = &cpc_desc->cpc_regs[REFERENCE_PERF]; 1272 ctr_wrap_reg = &cpc_desc->cpc_regs[CTR_WRAP_TIME]; 1273 1274 /* 1275 * If reference perf register is not supported then we should 1276 * use the nominal perf value 1277 */ 1278 if (!CPC_SUPPORTED(ref_perf_reg)) 1279 ref_perf_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; 1280 1281 /* Are any of the regs PCC ?*/ 1282 if (CPC_IN_PCC(delivered_reg) || CPC_IN_PCC(reference_reg) || 1283 CPC_IN_PCC(ctr_wrap_reg) || CPC_IN_PCC(ref_perf_reg)) { 1284 if (pcc_ss_id < 0) { 1285 pr_debug("Invalid pcc_ss_id\n"); 1286 return -ENODEV; 1287 } 1288 pcc_ss_data = pcc_data[pcc_ss_id]; 1289 down_write(&pcc_ss_data->pcc_lock); 1290 regs_in_pcc = 1; 1291 /* Ring doorbell once to update PCC subspace */ 1292 if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) { 1293 ret = -EIO; 1294 goto out_err; 1295 } 1296 } 1297 1298 cpc_read(cpunum, delivered_reg, &delivered); 1299 cpc_read(cpunum, reference_reg, &reference); 1300 cpc_read(cpunum, ref_perf_reg, &ref_perf); 1301 1302 /* 1303 * Per spec, if ctr_wrap_time optional register is unsupported, then the 1304 * performance counters are assumed to never wrap during the lifetime of 1305 * platform 1306 */ 1307 ctr_wrap_time = (u64)(~((u64)0)); 1308 if (CPC_SUPPORTED(ctr_wrap_reg)) 1309 cpc_read(cpunum, ctr_wrap_reg, &ctr_wrap_time); 1310 1311 if (!delivered || !reference || !ref_perf) { 1312 ret = -EFAULT; 1313 goto out_err; 1314 } 1315 1316 perf_fb_ctrs->delivered = delivered; 1317 perf_fb_ctrs->reference = reference; 1318 perf_fb_ctrs->reference_perf = ref_perf; 1319 perf_fb_ctrs->wraparound_time = ctr_wrap_time; 1320 out_err: 1321 if (regs_in_pcc) 1322 up_write(&pcc_ss_data->pcc_lock); 1323 return ret; 1324 } 1325 EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs); 1326 1327 /** 1328 * cppc_set_enable - Set to enable CPPC on the processor by writing the 1329 * Continuous Performance Control package EnableRegister field. 1330 * @cpu: CPU for which to enable CPPC register. 1331 * @enable: 0 - disable, 1 - enable CPPC feature on the processor. 1332 * 1333 * Return: 0 for success, -ERRNO or -EIO otherwise. 1334 */ 1335 int cppc_set_enable(int cpu, bool enable) 1336 { 1337 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1338 struct cpc_register_resource *enable_reg; 1339 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1340 struct cppc_pcc_data *pcc_ss_data = NULL; 1341 int ret = -EINVAL; 1342 1343 if (!cpc_desc) { 1344 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1345 return -EINVAL; 1346 } 1347 1348 enable_reg = &cpc_desc->cpc_regs[ENABLE]; 1349 1350 if (CPC_IN_PCC(enable_reg)) { 1351 1352 if (pcc_ss_id < 0) 1353 return -EIO; 1354 1355 ret = cpc_write(cpu, enable_reg, enable); 1356 if (ret) 1357 return ret; 1358 1359 pcc_ss_data = pcc_data[pcc_ss_id]; 1360 1361 down_write(&pcc_ss_data->pcc_lock); 1362 /* after writing CPC, transfer the ownership of PCC to platfrom */ 1363 ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1364 up_write(&pcc_ss_data->pcc_lock); 1365 return ret; 1366 } 1367 1368 return cpc_write(cpu, enable_reg, enable); 1369 } 1370 EXPORT_SYMBOL_GPL(cppc_set_enable); 1371 1372 /** 1373 * cppc_set_perf - Set a CPU's performance controls. 1374 * @cpu: CPU for which to set performance controls. 1375 * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h 1376 * 1377 * Return: 0 for success, -ERRNO otherwise. 1378 */ 1379 int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls) 1380 { 1381 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1382 struct cpc_register_resource *desired_reg; 1383 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1384 struct cppc_pcc_data *pcc_ss_data = NULL; 1385 int ret = 0; 1386 1387 if (!cpc_desc) { 1388 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1389 return -ENODEV; 1390 } 1391 1392 desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; 1393 1394 /* 1395 * This is Phase-I where we want to write to CPC registers 1396 * -> We want all CPUs to be able to execute this phase in parallel 1397 * 1398 * Since read_lock can be acquired by multiple CPUs simultaneously we 1399 * achieve that goal here 1400 */ 1401 if (CPC_IN_PCC(desired_reg)) { 1402 if (pcc_ss_id < 0) { 1403 pr_debug("Invalid pcc_ss_id\n"); 1404 return -ENODEV; 1405 } 1406 pcc_ss_data = pcc_data[pcc_ss_id]; 1407 down_read(&pcc_ss_data->pcc_lock); /* BEGIN Phase-I */ 1408 if (pcc_ss_data->platform_owns_pcc) { 1409 ret = check_pcc_chan(pcc_ss_id, false); 1410 if (ret) { 1411 up_read(&pcc_ss_data->pcc_lock); 1412 return ret; 1413 } 1414 } 1415 /* 1416 * Update the pending_write to make sure a PCC CMD_READ will not 1417 * arrive and steal the channel during the switch to write lock 1418 */ 1419 pcc_ss_data->pending_pcc_write_cmd = true; 1420 cpc_desc->write_cmd_id = pcc_ss_data->pcc_write_cnt; 1421 cpc_desc->write_cmd_status = 0; 1422 } 1423 1424 /* 1425 * Skip writing MIN/MAX until Linux knows how to come up with 1426 * useful values. 1427 */ 1428 cpc_write(cpu, desired_reg, perf_ctrls->desired_perf); 1429 1430 if (CPC_IN_PCC(desired_reg)) 1431 up_read(&pcc_ss_data->pcc_lock); /* END Phase-I */ 1432 /* 1433 * This is Phase-II where we transfer the ownership of PCC to Platform 1434 * 1435 * Short Summary: Basically if we think of a group of cppc_set_perf 1436 * requests that happened in short overlapping interval. The last CPU to 1437 * come out of Phase-I will enter Phase-II and ring the doorbell. 1438 * 1439 * We have the following requirements for Phase-II: 1440 * 1. We want to execute Phase-II only when there are no CPUs 1441 * currently executing in Phase-I 1442 * 2. Once we start Phase-II we want to avoid all other CPUs from 1443 * entering Phase-I. 1444 * 3. We want only one CPU among all those who went through Phase-I 1445 * to run phase-II 1446 * 1447 * If write_trylock fails to get the lock and doesn't transfer the 1448 * PCC ownership to the platform, then one of the following will be TRUE 1449 * 1. There is at-least one CPU in Phase-I which will later execute 1450 * write_trylock, so the CPUs in Phase-I will be responsible for 1451 * executing the Phase-II. 1452 * 2. Some other CPU has beaten this CPU to successfully execute the 1453 * write_trylock and has already acquired the write_lock. We know for a 1454 * fact it (other CPU acquiring the write_lock) couldn't have happened 1455 * before this CPU's Phase-I as we held the read_lock. 1456 * 3. Some other CPU executing pcc CMD_READ has stolen the 1457 * down_write, in which case, send_pcc_cmd will check for pending 1458 * CMD_WRITE commands by checking the pending_pcc_write_cmd. 1459 * So this CPU can be certain that its request will be delivered 1460 * So in all cases, this CPU knows that its request will be delivered 1461 * by another CPU and can return 1462 * 1463 * After getting the down_write we still need to check for 1464 * pending_pcc_write_cmd to take care of the following scenario 1465 * The thread running this code could be scheduled out between 1466 * Phase-I and Phase-II. Before it is scheduled back on, another CPU 1467 * could have delivered the request to Platform by triggering the 1468 * doorbell and transferred the ownership of PCC to platform. So this 1469 * avoids triggering an unnecessary doorbell and more importantly before 1470 * triggering the doorbell it makes sure that the PCC channel ownership 1471 * is still with OSPM. 1472 * pending_pcc_write_cmd can also be cleared by a different CPU, if 1473 * there was a pcc CMD_READ waiting on down_write and it steals the lock 1474 * before the pcc CMD_WRITE is completed. send_pcc_cmd checks for this 1475 * case during a CMD_READ and if there are pending writes it delivers 1476 * the write command before servicing the read command 1477 */ 1478 if (CPC_IN_PCC(desired_reg)) { 1479 if (down_write_trylock(&pcc_ss_data->pcc_lock)) {/* BEGIN Phase-II */ 1480 /* Update only if there are pending write commands */ 1481 if (pcc_ss_data->pending_pcc_write_cmd) 1482 send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1483 up_write(&pcc_ss_data->pcc_lock); /* END Phase-II */ 1484 } else 1485 /* Wait until pcc_write_cnt is updated by send_pcc_cmd */ 1486 wait_event(pcc_ss_data->pcc_write_wait_q, 1487 cpc_desc->write_cmd_id != pcc_ss_data->pcc_write_cnt); 1488 1489 /* send_pcc_cmd updates the status in case of failure */ 1490 ret = cpc_desc->write_cmd_status; 1491 } 1492 return ret; 1493 } 1494 EXPORT_SYMBOL_GPL(cppc_set_perf); 1495 1496 /** 1497 * cppc_get_transition_latency - returns frequency transition latency in ns 1498 * 1499 * ACPI CPPC does not explicitly specify how a platform can specify the 1500 * transition latency for performance change requests. The closest we have 1501 * is the timing information from the PCCT tables which provides the info 1502 * on the number and frequency of PCC commands the platform can handle. 1503 * 1504 * If desired_reg is in the SystemMemory or SystemIo ACPI address space, 1505 * then assume there is no latency. 1506 */ 1507 unsigned int cppc_get_transition_latency(int cpu_num) 1508 { 1509 /* 1510 * Expected transition latency is based on the PCCT timing values 1511 * Below are definition from ACPI spec: 1512 * pcc_nominal- Expected latency to process a command, in microseconds 1513 * pcc_mpar - The maximum number of periodic requests that the subspace 1514 * channel can support, reported in commands per minute. 0 1515 * indicates no limitation. 1516 * pcc_mrtt - The minimum amount of time that OSPM must wait after the 1517 * completion of a command before issuing the next command, 1518 * in microseconds. 1519 */ 1520 unsigned int latency_ns = 0; 1521 struct cpc_desc *cpc_desc; 1522 struct cpc_register_resource *desired_reg; 1523 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu_num); 1524 struct cppc_pcc_data *pcc_ss_data; 1525 1526 cpc_desc = per_cpu(cpc_desc_ptr, cpu_num); 1527 if (!cpc_desc) 1528 return CPUFREQ_ETERNAL; 1529 1530 desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; 1531 if (CPC_IN_SYSTEM_MEMORY(desired_reg) || CPC_IN_SYSTEM_IO(desired_reg)) 1532 return 0; 1533 else if (!CPC_IN_PCC(desired_reg)) 1534 return CPUFREQ_ETERNAL; 1535 1536 if (pcc_ss_id < 0) 1537 return CPUFREQ_ETERNAL; 1538 1539 pcc_ss_data = pcc_data[pcc_ss_id]; 1540 if (pcc_ss_data->pcc_mpar) 1541 latency_ns = 60 * (1000 * 1000 * 1000 / pcc_ss_data->pcc_mpar); 1542 1543 latency_ns = max(latency_ns, pcc_ss_data->pcc_nominal * 1000); 1544 latency_ns = max(latency_ns, pcc_ss_data->pcc_mrtt * 1000); 1545 1546 return latency_ns; 1547 } 1548 EXPORT_SYMBOL_GPL(cppc_get_transition_latency); 1549