1 /* 2 * CPPC (Collaborative Processor Performance Control) methods used by CPUfreq drivers. 3 * 4 * (C) Copyright 2014, 2015 Linaro Ltd. 5 * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; version 2 10 * of the License. 11 * 12 * CPPC describes a few methods for controlling CPU performance using 13 * information from a per CPU table called CPC. This table is described in 14 * the ACPI v5.0+ specification. The table consists of a list of 15 * registers which may be memory mapped or hardware registers and also may 16 * include some static integer values. 17 * 18 * CPU performance is on an abstract continuous scale as against a discretized 19 * P-state scale which is tied to CPU frequency only. In brief, the basic 20 * operation involves: 21 * 22 * - OS makes a CPU performance request. (Can provide min and max bounds) 23 * 24 * - Platform (such as BMC) is free to optimize request within requested bounds 25 * depending on power/thermal budgets etc. 26 * 27 * - Platform conveys its decision back to OS 28 * 29 * The communication between OS and platform occurs through another medium 30 * called (PCC) Platform Communication Channel. This is a generic mailbox like 31 * mechanism which includes doorbell semantics to indicate register updates. 32 * See drivers/mailbox/pcc.c for details on PCC. 33 * 34 * Finer details about the PCC and CPPC spec are available in the ACPI v5.1 and 35 * above specifications. 36 */ 37 38 #define pr_fmt(fmt) "ACPI CPPC: " fmt 39 40 #include <linux/cpufreq.h> 41 #include <linux/delay.h> 42 43 #include <acpi/cppc_acpi.h> 44 /* 45 * Lock to provide mutually exclusive access to the PCC 46 * channel. e.g. When the remote updates the shared region 47 * with new data, the reader needs to be protected from 48 * other CPUs activity on the same channel. 49 */ 50 static DEFINE_SPINLOCK(pcc_lock); 51 52 /* 53 * The cpc_desc structure contains the ACPI register details 54 * as described in the per CPU _CPC tables. The details 55 * include the type of register (e.g. PCC, System IO, FFH etc.) 56 * and destination addresses which lets us READ/WRITE CPU performance 57 * information using the appropriate I/O methods. 58 */ 59 static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); 60 61 /* This layer handles all the PCC specifics for CPPC. */ 62 static struct mbox_chan *pcc_channel; 63 static void __iomem *pcc_comm_addr; 64 static u64 comm_base_addr; 65 static int pcc_subspace_idx = -1; 66 static u16 pcc_cmd_delay; 67 static bool pcc_channel_acquired; 68 69 /* 70 * Arbitrary Retries in case the remote processor is slow to respond 71 * to PCC commands. 72 */ 73 #define NUM_RETRIES 500 74 75 static int send_pcc_cmd(u16 cmd) 76 { 77 int retries, result = -EIO; 78 struct acpi_pcct_hw_reduced *pcct_ss = pcc_channel->con_priv; 79 struct acpi_pcct_shared_memory *generic_comm_base = 80 (struct acpi_pcct_shared_memory *) pcc_comm_addr; 81 u32 cmd_latency = pcct_ss->latency; 82 83 /* Min time OS should wait before sending next command. */ 84 udelay(pcc_cmd_delay); 85 86 /* Write to the shared comm region. */ 87 writew(cmd, &generic_comm_base->command); 88 89 /* Flip CMD COMPLETE bit */ 90 writew(0, &generic_comm_base->status); 91 92 /* Ring doorbell */ 93 result = mbox_send_message(pcc_channel, &cmd); 94 if (result < 0) { 95 pr_err("Err sending PCC mbox message. cmd:%d, ret:%d\n", 96 cmd, result); 97 return result; 98 } 99 100 /* Wait for a nominal time to let platform process command. */ 101 udelay(cmd_latency); 102 103 /* Retry in case the remote processor was too slow to catch up. */ 104 for (retries = NUM_RETRIES; retries > 0; retries--) { 105 if (readw_relaxed(&generic_comm_base->status) & PCC_CMD_COMPLETE) { 106 result = 0; 107 break; 108 } 109 } 110 111 mbox_client_txdone(pcc_channel, result); 112 return result; 113 } 114 115 static void cppc_chan_tx_done(struct mbox_client *cl, void *msg, int ret) 116 { 117 if (ret) 118 pr_debug("TX did not complete: CMD sent:%x, ret:%d\n", 119 *(u16 *)msg, ret); 120 else 121 pr_debug("TX completed. CMD sent:%x, ret:%d\n", 122 *(u16 *)msg, ret); 123 } 124 125 struct mbox_client cppc_mbox_cl = { 126 .tx_done = cppc_chan_tx_done, 127 .knows_txdone = true, 128 }; 129 130 static int acpi_get_psd(struct cpc_desc *cpc_ptr, acpi_handle handle) 131 { 132 int result = -EFAULT; 133 acpi_status status = AE_OK; 134 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 135 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; 136 struct acpi_buffer state = {0, NULL}; 137 union acpi_object *psd = NULL; 138 struct acpi_psd_package *pdomain; 139 140 status = acpi_evaluate_object_typed(handle, "_PSD", NULL, &buffer, 141 ACPI_TYPE_PACKAGE); 142 if (ACPI_FAILURE(status)) 143 return -ENODEV; 144 145 psd = buffer.pointer; 146 if (!psd || psd->package.count != 1) { 147 pr_debug("Invalid _PSD data\n"); 148 goto end; 149 } 150 151 pdomain = &(cpc_ptr->domain_info); 152 153 state.length = sizeof(struct acpi_psd_package); 154 state.pointer = pdomain; 155 156 status = acpi_extract_package(&(psd->package.elements[0]), 157 &format, &state); 158 if (ACPI_FAILURE(status)) { 159 pr_debug("Invalid _PSD data for CPU:%d\n", cpc_ptr->cpu_id); 160 goto end; 161 } 162 163 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { 164 pr_debug("Unknown _PSD:num_entries for CPU:%d\n", cpc_ptr->cpu_id); 165 goto end; 166 } 167 168 if (pdomain->revision != ACPI_PSD_REV0_REVISION) { 169 pr_debug("Unknown _PSD:revision for CPU: %d\n", cpc_ptr->cpu_id); 170 goto end; 171 } 172 173 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 174 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 175 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 176 pr_debug("Invalid _PSD:coord_type for CPU:%d\n", cpc_ptr->cpu_id); 177 goto end; 178 } 179 180 result = 0; 181 end: 182 kfree(buffer.pointer); 183 return result; 184 } 185 186 /** 187 * acpi_get_psd_map - Map the CPUs in a common freq domain. 188 * @all_cpu_data: Ptrs to CPU specific CPPC data including PSD info. 189 * 190 * Return: 0 for success or negative value for err. 191 */ 192 int acpi_get_psd_map(struct cpudata **all_cpu_data) 193 { 194 int count_target; 195 int retval = 0; 196 unsigned int i, j; 197 cpumask_var_t covered_cpus; 198 struct cpudata *pr, *match_pr; 199 struct acpi_psd_package *pdomain; 200 struct acpi_psd_package *match_pdomain; 201 struct cpc_desc *cpc_ptr, *match_cpc_ptr; 202 203 if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL)) 204 return -ENOMEM; 205 206 /* 207 * Now that we have _PSD data from all CPUs, lets setup P-state 208 * domain info. 209 */ 210 for_each_possible_cpu(i) { 211 pr = all_cpu_data[i]; 212 if (!pr) 213 continue; 214 215 if (cpumask_test_cpu(i, covered_cpus)) 216 continue; 217 218 cpc_ptr = per_cpu(cpc_desc_ptr, i); 219 if (!cpc_ptr) 220 continue; 221 222 pdomain = &(cpc_ptr->domain_info); 223 cpumask_set_cpu(i, pr->shared_cpu_map); 224 cpumask_set_cpu(i, covered_cpus); 225 if (pdomain->num_processors <= 1) 226 continue; 227 228 /* Validate the Domain info */ 229 count_target = pdomain->num_processors; 230 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 231 pr->shared_type = CPUFREQ_SHARED_TYPE_ALL; 232 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 233 pr->shared_type = CPUFREQ_SHARED_TYPE_HW; 234 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 235 pr->shared_type = CPUFREQ_SHARED_TYPE_ANY; 236 237 for_each_possible_cpu(j) { 238 if (i == j) 239 continue; 240 241 match_cpc_ptr = per_cpu(cpc_desc_ptr, j); 242 if (!match_cpc_ptr) 243 continue; 244 245 match_pdomain = &(match_cpc_ptr->domain_info); 246 if (match_pdomain->domain != pdomain->domain) 247 continue; 248 249 /* Here i and j are in the same domain */ 250 if (match_pdomain->num_processors != count_target) { 251 retval = -EFAULT; 252 goto err_ret; 253 } 254 255 if (pdomain->coord_type != match_pdomain->coord_type) { 256 retval = -EFAULT; 257 goto err_ret; 258 } 259 260 cpumask_set_cpu(j, covered_cpus); 261 cpumask_set_cpu(j, pr->shared_cpu_map); 262 } 263 264 for_each_possible_cpu(j) { 265 if (i == j) 266 continue; 267 268 match_pr = all_cpu_data[j]; 269 if (!match_pr) 270 continue; 271 272 match_cpc_ptr = per_cpu(cpc_desc_ptr, j); 273 if (!match_cpc_ptr) 274 continue; 275 276 match_pdomain = &(match_cpc_ptr->domain_info); 277 if (match_pdomain->domain != pdomain->domain) 278 continue; 279 280 match_pr->shared_type = pr->shared_type; 281 cpumask_copy(match_pr->shared_cpu_map, 282 pr->shared_cpu_map); 283 } 284 } 285 286 err_ret: 287 for_each_possible_cpu(i) { 288 pr = all_cpu_data[i]; 289 if (!pr) 290 continue; 291 292 /* Assume no coordination on any error parsing domain info */ 293 if (retval) { 294 cpumask_clear(pr->shared_cpu_map); 295 cpumask_set_cpu(i, pr->shared_cpu_map); 296 pr->shared_type = CPUFREQ_SHARED_TYPE_ALL; 297 } 298 } 299 300 free_cpumask_var(covered_cpus); 301 return retval; 302 } 303 EXPORT_SYMBOL_GPL(acpi_get_psd_map); 304 305 static int register_pcc_channel(int pcc_subspace_idx) 306 { 307 struct acpi_pcct_hw_reduced *cppc_ss; 308 unsigned int len; 309 310 if (pcc_subspace_idx >= 0) { 311 pcc_channel = pcc_mbox_request_channel(&cppc_mbox_cl, 312 pcc_subspace_idx); 313 314 if (IS_ERR(pcc_channel)) { 315 pr_err("Failed to find PCC communication channel\n"); 316 return -ENODEV; 317 } 318 319 /* 320 * The PCC mailbox controller driver should 321 * have parsed the PCCT (global table of all 322 * PCC channels) and stored pointers to the 323 * subspace communication region in con_priv. 324 */ 325 cppc_ss = pcc_channel->con_priv; 326 327 if (!cppc_ss) { 328 pr_err("No PCC subspace found for CPPC\n"); 329 return -ENODEV; 330 } 331 332 /* 333 * This is the shared communication region 334 * for the OS and Platform to communicate over. 335 */ 336 comm_base_addr = cppc_ss->base_address; 337 len = cppc_ss->length; 338 pcc_cmd_delay = cppc_ss->min_turnaround_time; 339 340 pcc_comm_addr = acpi_os_ioremap(comm_base_addr, len); 341 if (!pcc_comm_addr) { 342 pr_err("Failed to ioremap PCC comm region mem\n"); 343 return -ENOMEM; 344 } 345 346 /* Set flag so that we dont come here for each CPU. */ 347 pcc_channel_acquired = true; 348 } 349 350 return 0; 351 } 352 353 /* 354 * An example CPC table looks like the following. 355 * 356 * Name(_CPC, Package() 357 * { 358 * 17, 359 * NumEntries 360 * 1, 361 * // Revision 362 * ResourceTemplate(){Register(PCC, 32, 0, 0x120, 2)}, 363 * // Highest Performance 364 * ResourceTemplate(){Register(PCC, 32, 0, 0x124, 2)}, 365 * // Nominal Performance 366 * ResourceTemplate(){Register(PCC, 32, 0, 0x128, 2)}, 367 * // Lowest Nonlinear Performance 368 * ResourceTemplate(){Register(PCC, 32, 0, 0x12C, 2)}, 369 * // Lowest Performance 370 * ResourceTemplate(){Register(PCC, 32, 0, 0x130, 2)}, 371 * // Guaranteed Performance Register 372 * ResourceTemplate(){Register(PCC, 32, 0, 0x110, 2)}, 373 * // Desired Performance Register 374 * ResourceTemplate(){Register(SystemMemory, 0, 0, 0, 0)}, 375 * .. 376 * .. 377 * .. 378 * 379 * } 380 * Each Register() encodes how to access that specific register. 381 * e.g. a sample PCC entry has the following encoding: 382 * 383 * Register ( 384 * PCC, 385 * AddressSpaceKeyword 386 * 8, 387 * //RegisterBitWidth 388 * 8, 389 * //RegisterBitOffset 390 * 0x30, 391 * //RegisterAddress 392 * 9 393 * //AccessSize (subspace ID) 394 * 0 395 * ) 396 * } 397 */ 398 399 /** 400 * acpi_cppc_processor_probe - Search for per CPU _CPC objects. 401 * @pr: Ptr to acpi_processor containing this CPUs logical Id. 402 * 403 * Return: 0 for success or negative value for err. 404 */ 405 int acpi_cppc_processor_probe(struct acpi_processor *pr) 406 { 407 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL}; 408 union acpi_object *out_obj, *cpc_obj; 409 struct cpc_desc *cpc_ptr; 410 struct cpc_reg *gas_t; 411 acpi_handle handle = pr->handle; 412 unsigned int num_ent, i, cpc_rev; 413 acpi_status status; 414 int ret = -EFAULT; 415 416 /* Parse the ACPI _CPC table for this cpu. */ 417 status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output, 418 ACPI_TYPE_PACKAGE); 419 if (ACPI_FAILURE(status)) { 420 ret = -ENODEV; 421 goto out_buf_free; 422 } 423 424 out_obj = (union acpi_object *) output.pointer; 425 426 cpc_ptr = kzalloc(sizeof(struct cpc_desc), GFP_KERNEL); 427 if (!cpc_ptr) { 428 ret = -ENOMEM; 429 goto out_buf_free; 430 } 431 432 /* First entry is NumEntries. */ 433 cpc_obj = &out_obj->package.elements[0]; 434 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 435 num_ent = cpc_obj->integer.value; 436 } else { 437 pr_debug("Unexpected entry type(%d) for NumEntries\n", 438 cpc_obj->type); 439 goto out_free; 440 } 441 442 /* Only support CPPCv2. Bail otherwise. */ 443 if (num_ent != CPPC_NUM_ENT) { 444 pr_debug("Firmware exports %d entries. Expected: %d\n", 445 num_ent, CPPC_NUM_ENT); 446 goto out_free; 447 } 448 449 /* Second entry should be revision. */ 450 cpc_obj = &out_obj->package.elements[1]; 451 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 452 cpc_rev = cpc_obj->integer.value; 453 } else { 454 pr_debug("Unexpected entry type(%d) for Revision\n", 455 cpc_obj->type); 456 goto out_free; 457 } 458 459 if (cpc_rev != CPPC_REV) { 460 pr_debug("Firmware exports revision:%d. Expected:%d\n", 461 cpc_rev, CPPC_REV); 462 goto out_free; 463 } 464 465 /* Iterate through remaining entries in _CPC */ 466 for (i = 2; i < num_ent; i++) { 467 cpc_obj = &out_obj->package.elements[i]; 468 469 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 470 cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_INTEGER; 471 cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = cpc_obj->integer.value; 472 } else if (cpc_obj->type == ACPI_TYPE_BUFFER) { 473 gas_t = (struct cpc_reg *) 474 cpc_obj->buffer.pointer; 475 476 /* 477 * The PCC Subspace index is encoded inside 478 * the CPC table entries. The same PCC index 479 * will be used for all the PCC entries, 480 * so extract it only once. 481 */ 482 if (gas_t->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { 483 if (pcc_subspace_idx < 0) 484 pcc_subspace_idx = gas_t->access_width; 485 else if (pcc_subspace_idx != gas_t->access_width) { 486 pr_debug("Mismatched PCC ids.\n"); 487 goto out_free; 488 } 489 } else if (gas_t->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) { 490 /* Support only PCC and SYS MEM type regs */ 491 pr_debug("Unsupported register type: %d\n", gas_t->space_id); 492 goto out_free; 493 } 494 495 cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_BUFFER; 496 memcpy(&cpc_ptr->cpc_regs[i-2].cpc_entry.reg, gas_t, sizeof(*gas_t)); 497 } else { 498 pr_debug("Err in entry:%d in CPC table of CPU:%d \n", i, pr->id); 499 goto out_free; 500 } 501 } 502 /* Store CPU Logical ID */ 503 cpc_ptr->cpu_id = pr->id; 504 505 /* Plug it into this CPUs CPC descriptor. */ 506 per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr; 507 508 /* Parse PSD data for this CPU */ 509 ret = acpi_get_psd(cpc_ptr, handle); 510 if (ret) 511 goto out_free; 512 513 /* Register PCC channel once for all CPUs. */ 514 if (!pcc_channel_acquired) { 515 ret = register_pcc_channel(pcc_subspace_idx); 516 if (ret) 517 goto out_free; 518 } 519 520 /* Everything looks okay */ 521 pr_debug("Parsed CPC struct for CPU: %d\n", pr->id); 522 523 kfree(output.pointer); 524 return 0; 525 526 out_free: 527 kfree(cpc_ptr); 528 529 out_buf_free: 530 kfree(output.pointer); 531 return ret; 532 } 533 EXPORT_SYMBOL_GPL(acpi_cppc_processor_probe); 534 535 /** 536 * acpi_cppc_processor_exit - Cleanup CPC structs. 537 * @pr: Ptr to acpi_processor containing this CPUs logical Id. 538 * 539 * Return: Void 540 */ 541 void acpi_cppc_processor_exit(struct acpi_processor *pr) 542 { 543 struct cpc_desc *cpc_ptr; 544 cpc_ptr = per_cpu(cpc_desc_ptr, pr->id); 545 kfree(cpc_ptr); 546 } 547 EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit); 548 549 static u64 get_phys_addr(struct cpc_reg *reg) 550 { 551 /* PCC communication addr space begins at byte offset 0x8. */ 552 if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) 553 return (u64)comm_base_addr + 0x8 + reg->address; 554 else 555 return reg->address; 556 } 557 558 static void cpc_read(struct cpc_reg *reg, u64 *val) 559 { 560 u64 addr = get_phys_addr(reg); 561 562 acpi_os_read_memory((acpi_physical_address)addr, 563 val, reg->bit_width); 564 } 565 566 static void cpc_write(struct cpc_reg *reg, u64 val) 567 { 568 u64 addr = get_phys_addr(reg); 569 570 acpi_os_write_memory((acpi_physical_address)addr, 571 val, reg->bit_width); 572 } 573 574 /** 575 * cppc_get_perf_caps - Get a CPUs performance capabilities. 576 * @cpunum: CPU from which to get capabilities info. 577 * @perf_caps: ptr to cppc_perf_caps. See cppc_acpi.h 578 * 579 * Return: 0 for success with perf_caps populated else -ERRNO. 580 */ 581 int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) 582 { 583 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 584 struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf, 585 *nom_perf; 586 u64 high, low, ref, nom; 587 int ret = 0; 588 589 if (!cpc_desc) { 590 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 591 return -ENODEV; 592 } 593 594 highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF]; 595 lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF]; 596 ref_perf = &cpc_desc->cpc_regs[REFERENCE_PERF]; 597 nom_perf = &cpc_desc->cpc_regs[NOMINAL_PERF]; 598 599 spin_lock(&pcc_lock); 600 601 /* Are any of the regs PCC ?*/ 602 if ((highest_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) || 603 (lowest_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) || 604 (ref_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) || 605 (nom_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)) { 606 /* Ring doorbell once to update PCC subspace */ 607 if (send_pcc_cmd(CMD_READ)) { 608 ret = -EIO; 609 goto out_err; 610 } 611 } 612 613 cpc_read(&highest_reg->cpc_entry.reg, &high); 614 perf_caps->highest_perf = high; 615 616 cpc_read(&lowest_reg->cpc_entry.reg, &low); 617 perf_caps->lowest_perf = low; 618 619 cpc_read(&ref_perf->cpc_entry.reg, &ref); 620 perf_caps->reference_perf = ref; 621 622 cpc_read(&nom_perf->cpc_entry.reg, &nom); 623 perf_caps->nominal_perf = nom; 624 625 if (!ref) 626 perf_caps->reference_perf = perf_caps->nominal_perf; 627 628 if (!high || !low || !nom) 629 ret = -EFAULT; 630 631 out_err: 632 spin_unlock(&pcc_lock); 633 return ret; 634 } 635 EXPORT_SYMBOL_GPL(cppc_get_perf_caps); 636 637 /** 638 * cppc_get_perf_ctrs - Read a CPUs performance feedback counters. 639 * @cpunum: CPU from which to read counters. 640 * @perf_fb_ctrs: ptr to cppc_perf_fb_ctrs. See cppc_acpi.h 641 * 642 * Return: 0 for success with perf_fb_ctrs populated else -ERRNO. 643 */ 644 int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) 645 { 646 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 647 struct cpc_register_resource *delivered_reg, *reference_reg; 648 u64 delivered, reference; 649 int ret = 0; 650 651 if (!cpc_desc) { 652 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 653 return -ENODEV; 654 } 655 656 delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR]; 657 reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR]; 658 659 spin_lock(&pcc_lock); 660 661 /* Are any of the regs PCC ?*/ 662 if ((delivered_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) || 663 (reference_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)) { 664 /* Ring doorbell once to update PCC subspace */ 665 if (send_pcc_cmd(CMD_READ)) { 666 ret = -EIO; 667 goto out_err; 668 } 669 } 670 671 cpc_read(&delivered_reg->cpc_entry.reg, &delivered); 672 cpc_read(&reference_reg->cpc_entry.reg, &reference); 673 674 if (!delivered || !reference) { 675 ret = -EFAULT; 676 goto out_err; 677 } 678 679 perf_fb_ctrs->delivered = delivered; 680 perf_fb_ctrs->reference = reference; 681 682 perf_fb_ctrs->delivered -= perf_fb_ctrs->prev_delivered; 683 perf_fb_ctrs->reference -= perf_fb_ctrs->prev_reference; 684 685 perf_fb_ctrs->prev_delivered = delivered; 686 perf_fb_ctrs->prev_reference = reference; 687 688 out_err: 689 spin_unlock(&pcc_lock); 690 return ret; 691 } 692 EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs); 693 694 /** 695 * cppc_set_perf - Set a CPUs performance controls. 696 * @cpu: CPU for which to set performance controls. 697 * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h 698 * 699 * Return: 0 for success, -ERRNO otherwise. 700 */ 701 int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls) 702 { 703 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 704 struct cpc_register_resource *desired_reg; 705 int ret = 0; 706 707 if (!cpc_desc) { 708 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 709 return -ENODEV; 710 } 711 712 desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; 713 714 spin_lock(&pcc_lock); 715 716 /* 717 * Skip writing MIN/MAX until Linux knows how to come up with 718 * useful values. 719 */ 720 cpc_write(&desired_reg->cpc_entry.reg, perf_ctrls->desired_perf); 721 722 /* Is this a PCC reg ?*/ 723 if (desired_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { 724 /* Ring doorbell so Remote can get our perf request. */ 725 if (send_pcc_cmd(CMD_WRITE)) 726 ret = -EIO; 727 } 728 729 spin_unlock(&pcc_lock); 730 731 return ret; 732 } 733 EXPORT_SYMBOL_GPL(cppc_set_perf); 734