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 #include <linux/dmi.h> 43 #include <linux/units.h> 44 #include <asm/unaligned.h> 45 46 #include <acpi/cppc_acpi.h> 47 48 struct cppc_pcc_data { 49 struct pcc_mbox_chan *pcc_channel; 50 void __iomem *pcc_comm_addr; 51 bool pcc_channel_acquired; 52 unsigned int deadline_us; 53 unsigned int pcc_mpar, pcc_mrtt, pcc_nominal; 54 55 bool pending_pcc_write_cmd; /* Any pending/batched PCC write cmds? */ 56 bool platform_owns_pcc; /* Ownership of PCC subspace */ 57 unsigned int pcc_write_cnt; /* Running count of PCC write commands */ 58 59 /* 60 * Lock to provide controlled access to the PCC channel. 61 * 62 * For performance critical usecases(currently cppc_set_perf) 63 * We need to take read_lock and check if channel belongs to OSPM 64 * before reading or writing to PCC subspace 65 * We need to take write_lock before transferring the channel 66 * ownership to the platform via a Doorbell 67 * This allows us to batch a number of CPPC requests if they happen 68 * to originate in about the same time 69 * 70 * For non-performance critical usecases(init) 71 * Take write_lock for all purposes which gives exclusive access 72 */ 73 struct rw_semaphore pcc_lock; 74 75 /* Wait queue for CPUs whose requests were batched */ 76 wait_queue_head_t pcc_write_wait_q; 77 ktime_t last_cmd_cmpl_time; 78 ktime_t last_mpar_reset; 79 int mpar_count; 80 int refcount; 81 }; 82 83 /* Array to represent the PCC channel per subspace ID */ 84 static struct cppc_pcc_data *pcc_data[MAX_PCC_SUBSPACES]; 85 /* The cpu_pcc_subspace_idx contains per CPU subspace ID */ 86 static DEFINE_PER_CPU(int, cpu_pcc_subspace_idx); 87 88 /* 89 * The cpc_desc structure contains the ACPI register details 90 * as described in the per CPU _CPC tables. The details 91 * include the type of register (e.g. PCC, System IO, FFH etc.) 92 * and destination addresses which lets us READ/WRITE CPU performance 93 * information using the appropriate I/O methods. 94 */ 95 static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); 96 97 /* pcc mapped address + header size + offset within PCC subspace */ 98 #define GET_PCC_VADDR(offs, pcc_ss_id) (pcc_data[pcc_ss_id]->pcc_comm_addr + \ 99 0x8 + (offs)) 100 101 /* Check if a CPC register is in PCC */ 102 #define CPC_IN_PCC(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ 103 (cpc)->cpc_entry.reg.space_id == \ 104 ACPI_ADR_SPACE_PLATFORM_COMM) 105 106 /* Check if a CPC register is in FFH */ 107 #define CPC_IN_FFH(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ 108 (cpc)->cpc_entry.reg.space_id == \ 109 ACPI_ADR_SPACE_FIXED_HARDWARE) 110 111 /* Check if a CPC register is in SystemMemory */ 112 #define CPC_IN_SYSTEM_MEMORY(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ 113 (cpc)->cpc_entry.reg.space_id == \ 114 ACPI_ADR_SPACE_SYSTEM_MEMORY) 115 116 /* Check if a CPC register is in SystemIo */ 117 #define CPC_IN_SYSTEM_IO(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ 118 (cpc)->cpc_entry.reg.space_id == \ 119 ACPI_ADR_SPACE_SYSTEM_IO) 120 121 /* Evaluates to True if reg is a NULL register descriptor */ 122 #define IS_NULL_REG(reg) ((reg)->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY && \ 123 (reg)->address == 0 && \ 124 (reg)->bit_width == 0 && \ 125 (reg)->bit_offset == 0 && \ 126 (reg)->access_width == 0) 127 128 /* Evaluates to True if an optional cpc field is supported */ 129 #define CPC_SUPPORTED(cpc) ((cpc)->type == ACPI_TYPE_INTEGER ? \ 130 !!(cpc)->cpc_entry.int_value : \ 131 !IS_NULL_REG(&(cpc)->cpc_entry.reg)) 132 /* 133 * Arbitrary Retries in case the remote processor is slow to respond 134 * to PCC commands. Keeping it high enough to cover emulators where 135 * the processors run painfully slow. 136 */ 137 #define NUM_RETRIES 500ULL 138 139 #define OVER_16BTS_MASK ~0xFFFFULL 140 141 #define define_one_cppc_ro(_name) \ 142 static struct kobj_attribute _name = \ 143 __ATTR(_name, 0444, show_##_name, NULL) 144 145 #define to_cpc_desc(a) container_of(a, struct cpc_desc, kobj) 146 147 #define show_cppc_data(access_fn, struct_name, member_name) \ 148 static ssize_t show_##member_name(struct kobject *kobj, \ 149 struct kobj_attribute *attr, char *buf) \ 150 { \ 151 struct cpc_desc *cpc_ptr = to_cpc_desc(kobj); \ 152 struct struct_name st_name = {0}; \ 153 int ret; \ 154 \ 155 ret = access_fn(cpc_ptr->cpu_id, &st_name); \ 156 if (ret) \ 157 return ret; \ 158 \ 159 return sysfs_emit(buf, "%llu\n", \ 160 (u64)st_name.member_name); \ 161 } \ 162 define_one_cppc_ro(member_name) 163 164 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, highest_perf); 165 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_perf); 166 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_perf); 167 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_nonlinear_perf); 168 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_freq); 169 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_freq); 170 171 show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf); 172 show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time); 173 174 /* Check for valid access_width, otherwise, fallback to using bit_width */ 175 #define GET_BIT_WIDTH(reg) ((reg)->access_width ? (8 << ((reg)->access_width - 1)) : (reg)->bit_width) 176 177 /* Shift and apply the mask for CPC reads/writes */ 178 #define MASK_VAL_READ(reg, val) (((val) >> (reg)->bit_offset) & \ 179 GENMASK(((reg)->bit_width) - 1, 0)) 180 #define MASK_VAL_WRITE(reg, prev_val, val) \ 181 ((((val) & GENMASK(((reg)->bit_width) - 1, 0)) << (reg)->bit_offset) | \ 182 ((prev_val) & ~(GENMASK(((reg)->bit_width) - 1, 0) << (reg)->bit_offset))) \ 183 184 static ssize_t show_feedback_ctrs(struct kobject *kobj, 185 struct kobj_attribute *attr, char *buf) 186 { 187 struct cpc_desc *cpc_ptr = to_cpc_desc(kobj); 188 struct cppc_perf_fb_ctrs fb_ctrs = {0}; 189 int ret; 190 191 ret = cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs); 192 if (ret) 193 return ret; 194 195 return sysfs_emit(buf, "ref:%llu del:%llu\n", 196 fb_ctrs.reference, fb_ctrs.delivered); 197 } 198 define_one_cppc_ro(feedback_ctrs); 199 200 static struct attribute *cppc_attrs[] = { 201 &feedback_ctrs.attr, 202 &reference_perf.attr, 203 &wraparound_time.attr, 204 &highest_perf.attr, 205 &lowest_perf.attr, 206 &lowest_nonlinear_perf.attr, 207 &nominal_perf.attr, 208 &nominal_freq.attr, 209 &lowest_freq.attr, 210 NULL 211 }; 212 ATTRIBUTE_GROUPS(cppc); 213 214 static const struct kobj_type cppc_ktype = { 215 .sysfs_ops = &kobj_sysfs_ops, 216 .default_groups = cppc_groups, 217 }; 218 219 static int check_pcc_chan(int pcc_ss_id, bool chk_err_bit) 220 { 221 int ret, status; 222 struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; 223 struct acpi_pcct_shared_memory __iomem *generic_comm_base = 224 pcc_ss_data->pcc_comm_addr; 225 226 if (!pcc_ss_data->platform_owns_pcc) 227 return 0; 228 229 /* 230 * Poll PCC status register every 3us(delay_us) for maximum of 231 * deadline_us(timeout_us) until PCC command complete bit is set(cond) 232 */ 233 ret = readw_relaxed_poll_timeout(&generic_comm_base->status, status, 234 status & PCC_CMD_COMPLETE_MASK, 3, 235 pcc_ss_data->deadline_us); 236 237 if (likely(!ret)) { 238 pcc_ss_data->platform_owns_pcc = false; 239 if (chk_err_bit && (status & PCC_ERROR_MASK)) 240 ret = -EIO; 241 } 242 243 if (unlikely(ret)) 244 pr_err("PCC check channel failed for ss: %d. ret=%d\n", 245 pcc_ss_id, ret); 246 247 return ret; 248 } 249 250 /* 251 * This function transfers the ownership of the PCC to the platform 252 * So it must be called while holding write_lock(pcc_lock) 253 */ 254 static int send_pcc_cmd(int pcc_ss_id, u16 cmd) 255 { 256 int ret = -EIO, i; 257 struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; 258 struct acpi_pcct_shared_memory __iomem *generic_comm_base = 259 pcc_ss_data->pcc_comm_addr; 260 unsigned int time_delta; 261 262 /* 263 * For CMD_WRITE we know for a fact the caller should have checked 264 * the channel before writing to PCC space 265 */ 266 if (cmd == CMD_READ) { 267 /* 268 * If there are pending cpc_writes, then we stole the channel 269 * before write completion, so first send a WRITE command to 270 * platform 271 */ 272 if (pcc_ss_data->pending_pcc_write_cmd) 273 send_pcc_cmd(pcc_ss_id, CMD_WRITE); 274 275 ret = check_pcc_chan(pcc_ss_id, false); 276 if (ret) 277 goto end; 278 } else /* CMD_WRITE */ 279 pcc_ss_data->pending_pcc_write_cmd = FALSE; 280 281 /* 282 * Handle the Minimum Request Turnaround Time(MRTT) 283 * "The minimum amount of time that OSPM must wait after the completion 284 * of a command before issuing the next command, in microseconds" 285 */ 286 if (pcc_ss_data->pcc_mrtt) { 287 time_delta = ktime_us_delta(ktime_get(), 288 pcc_ss_data->last_cmd_cmpl_time); 289 if (pcc_ss_data->pcc_mrtt > time_delta) 290 udelay(pcc_ss_data->pcc_mrtt - time_delta); 291 } 292 293 /* 294 * Handle the non-zero Maximum Periodic Access Rate(MPAR) 295 * "The maximum number of periodic requests that the subspace channel can 296 * support, reported in commands per minute. 0 indicates no limitation." 297 * 298 * This parameter should be ideally zero or large enough so that it can 299 * handle maximum number of requests that all the cores in the system can 300 * collectively generate. If it is not, we will follow the spec and just 301 * not send the request to the platform after hitting the MPAR limit in 302 * any 60s window 303 */ 304 if (pcc_ss_data->pcc_mpar) { 305 if (pcc_ss_data->mpar_count == 0) { 306 time_delta = ktime_ms_delta(ktime_get(), 307 pcc_ss_data->last_mpar_reset); 308 if ((time_delta < 60 * MSEC_PER_SEC) && pcc_ss_data->last_mpar_reset) { 309 pr_debug("PCC cmd for subspace %d not sent due to MPAR limit", 310 pcc_ss_id); 311 ret = -EIO; 312 goto end; 313 } 314 pcc_ss_data->last_mpar_reset = ktime_get(); 315 pcc_ss_data->mpar_count = pcc_ss_data->pcc_mpar; 316 } 317 pcc_ss_data->mpar_count--; 318 } 319 320 /* Write to the shared comm region. */ 321 writew_relaxed(cmd, &generic_comm_base->command); 322 323 /* Flip CMD COMPLETE bit */ 324 writew_relaxed(0, &generic_comm_base->status); 325 326 pcc_ss_data->platform_owns_pcc = true; 327 328 /* Ring doorbell */ 329 ret = mbox_send_message(pcc_ss_data->pcc_channel->mchan, &cmd); 330 if (ret < 0) { 331 pr_err("Err sending PCC mbox message. ss: %d cmd:%d, ret:%d\n", 332 pcc_ss_id, cmd, ret); 333 goto end; 334 } 335 336 /* wait for completion and check for PCC error bit */ 337 ret = check_pcc_chan(pcc_ss_id, true); 338 339 if (pcc_ss_data->pcc_mrtt) 340 pcc_ss_data->last_cmd_cmpl_time = ktime_get(); 341 342 if (pcc_ss_data->pcc_channel->mchan->mbox->txdone_irq) 343 mbox_chan_txdone(pcc_ss_data->pcc_channel->mchan, ret); 344 else 345 mbox_client_txdone(pcc_ss_data->pcc_channel->mchan, ret); 346 347 end: 348 if (cmd == CMD_WRITE) { 349 if (unlikely(ret)) { 350 for_each_possible_cpu(i) { 351 struct cpc_desc *desc = per_cpu(cpc_desc_ptr, i); 352 353 if (!desc) 354 continue; 355 356 if (desc->write_cmd_id == pcc_ss_data->pcc_write_cnt) 357 desc->write_cmd_status = ret; 358 } 359 } 360 pcc_ss_data->pcc_write_cnt++; 361 wake_up_all(&pcc_ss_data->pcc_write_wait_q); 362 } 363 364 return ret; 365 } 366 367 static void cppc_chan_tx_done(struct mbox_client *cl, void *msg, int ret) 368 { 369 if (ret < 0) 370 pr_debug("TX did not complete: CMD sent:%x, ret:%d\n", 371 *(u16 *)msg, ret); 372 else 373 pr_debug("TX completed. CMD sent:%x, ret:%d\n", 374 *(u16 *)msg, ret); 375 } 376 377 static struct mbox_client cppc_mbox_cl = { 378 .tx_done = cppc_chan_tx_done, 379 .knows_txdone = true, 380 }; 381 382 static int acpi_get_psd(struct cpc_desc *cpc_ptr, acpi_handle handle) 383 { 384 int result = -EFAULT; 385 acpi_status status = AE_OK; 386 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 387 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; 388 struct acpi_buffer state = {0, NULL}; 389 union acpi_object *psd = NULL; 390 struct acpi_psd_package *pdomain; 391 392 status = acpi_evaluate_object_typed(handle, "_PSD", NULL, 393 &buffer, ACPI_TYPE_PACKAGE); 394 if (status == AE_NOT_FOUND) /* _PSD is optional */ 395 return 0; 396 if (ACPI_FAILURE(status)) 397 return -ENODEV; 398 399 psd = buffer.pointer; 400 if (!psd || psd->package.count != 1) { 401 pr_debug("Invalid _PSD data\n"); 402 goto end; 403 } 404 405 pdomain = &(cpc_ptr->domain_info); 406 407 state.length = sizeof(struct acpi_psd_package); 408 state.pointer = pdomain; 409 410 status = acpi_extract_package(&(psd->package.elements[0]), 411 &format, &state); 412 if (ACPI_FAILURE(status)) { 413 pr_debug("Invalid _PSD data for CPU:%d\n", cpc_ptr->cpu_id); 414 goto end; 415 } 416 417 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { 418 pr_debug("Unknown _PSD:num_entries for CPU:%d\n", cpc_ptr->cpu_id); 419 goto end; 420 } 421 422 if (pdomain->revision != ACPI_PSD_REV0_REVISION) { 423 pr_debug("Unknown _PSD:revision for CPU: %d\n", cpc_ptr->cpu_id); 424 goto end; 425 } 426 427 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 428 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 429 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 430 pr_debug("Invalid _PSD:coord_type for CPU:%d\n", cpc_ptr->cpu_id); 431 goto end; 432 } 433 434 result = 0; 435 end: 436 kfree(buffer.pointer); 437 return result; 438 } 439 440 bool acpi_cpc_valid(void) 441 { 442 struct cpc_desc *cpc_ptr; 443 int cpu; 444 445 if (acpi_disabled) 446 return false; 447 448 for_each_present_cpu(cpu) { 449 cpc_ptr = per_cpu(cpc_desc_ptr, cpu); 450 if (!cpc_ptr) 451 return false; 452 } 453 454 return true; 455 } 456 EXPORT_SYMBOL_GPL(acpi_cpc_valid); 457 458 bool cppc_allow_fast_switch(void) 459 { 460 struct cpc_register_resource *desired_reg; 461 struct cpc_desc *cpc_ptr; 462 int cpu; 463 464 for_each_possible_cpu(cpu) { 465 cpc_ptr = per_cpu(cpc_desc_ptr, cpu); 466 desired_reg = &cpc_ptr->cpc_regs[DESIRED_PERF]; 467 if (!CPC_IN_SYSTEM_MEMORY(desired_reg) && 468 !CPC_IN_SYSTEM_IO(desired_reg)) 469 return false; 470 } 471 472 return true; 473 } 474 EXPORT_SYMBOL_GPL(cppc_allow_fast_switch); 475 476 /** 477 * acpi_get_psd_map - Map the CPUs in the freq domain of a given cpu 478 * @cpu: Find all CPUs that share a domain with cpu. 479 * @cpu_data: Pointer to CPU specific CPPC data including PSD info. 480 * 481 * Return: 0 for success or negative value for err. 482 */ 483 int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data) 484 { 485 struct cpc_desc *cpc_ptr, *match_cpc_ptr; 486 struct acpi_psd_package *match_pdomain; 487 struct acpi_psd_package *pdomain; 488 int count_target, i; 489 490 /* 491 * Now that we have _PSD data from all CPUs, let's setup P-state 492 * domain info. 493 */ 494 cpc_ptr = per_cpu(cpc_desc_ptr, cpu); 495 if (!cpc_ptr) 496 return -EFAULT; 497 498 pdomain = &(cpc_ptr->domain_info); 499 cpumask_set_cpu(cpu, cpu_data->shared_cpu_map); 500 if (pdomain->num_processors <= 1) 501 return 0; 502 503 /* Validate the Domain info */ 504 count_target = pdomain->num_processors; 505 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 506 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ALL; 507 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 508 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_HW; 509 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 510 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ANY; 511 512 for_each_possible_cpu(i) { 513 if (i == cpu) 514 continue; 515 516 match_cpc_ptr = per_cpu(cpc_desc_ptr, i); 517 if (!match_cpc_ptr) 518 goto err_fault; 519 520 match_pdomain = &(match_cpc_ptr->domain_info); 521 if (match_pdomain->domain != pdomain->domain) 522 continue; 523 524 /* Here i and cpu are in the same domain */ 525 if (match_pdomain->num_processors != count_target) 526 goto err_fault; 527 528 if (pdomain->coord_type != match_pdomain->coord_type) 529 goto err_fault; 530 531 cpumask_set_cpu(i, cpu_data->shared_cpu_map); 532 } 533 534 return 0; 535 536 err_fault: 537 /* Assume no coordination on any error parsing domain info */ 538 cpumask_clear(cpu_data->shared_cpu_map); 539 cpumask_set_cpu(cpu, cpu_data->shared_cpu_map); 540 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_NONE; 541 542 return -EFAULT; 543 } 544 EXPORT_SYMBOL_GPL(acpi_get_psd_map); 545 546 static int register_pcc_channel(int pcc_ss_idx) 547 { 548 struct pcc_mbox_chan *pcc_chan; 549 u64 usecs_lat; 550 551 if (pcc_ss_idx >= 0) { 552 pcc_chan = pcc_mbox_request_channel(&cppc_mbox_cl, pcc_ss_idx); 553 554 if (IS_ERR(pcc_chan)) { 555 pr_err("Failed to find PCC channel for subspace %d\n", 556 pcc_ss_idx); 557 return -ENODEV; 558 } 559 560 pcc_data[pcc_ss_idx]->pcc_channel = pcc_chan; 561 /* 562 * cppc_ss->latency is just a Nominal value. In reality 563 * the remote processor could be much slower to reply. 564 * So add an arbitrary amount of wait on top of Nominal. 565 */ 566 usecs_lat = NUM_RETRIES * pcc_chan->latency; 567 pcc_data[pcc_ss_idx]->deadline_us = usecs_lat; 568 pcc_data[pcc_ss_idx]->pcc_mrtt = pcc_chan->min_turnaround_time; 569 pcc_data[pcc_ss_idx]->pcc_mpar = pcc_chan->max_access_rate; 570 pcc_data[pcc_ss_idx]->pcc_nominal = pcc_chan->latency; 571 572 pcc_data[pcc_ss_idx]->pcc_comm_addr = 573 acpi_os_ioremap(pcc_chan->shmem_base_addr, 574 pcc_chan->shmem_size); 575 if (!pcc_data[pcc_ss_idx]->pcc_comm_addr) { 576 pr_err("Failed to ioremap PCC comm region mem for %d\n", 577 pcc_ss_idx); 578 return -ENOMEM; 579 } 580 581 /* Set flag so that we don't come here for each CPU. */ 582 pcc_data[pcc_ss_idx]->pcc_channel_acquired = true; 583 } 584 585 return 0; 586 } 587 588 /** 589 * cpc_ffh_supported() - check if FFH reading supported 590 * 591 * Check if the architecture has support for functional fixed hardware 592 * read/write capability. 593 * 594 * Return: true for supported, false for not supported 595 */ 596 bool __weak cpc_ffh_supported(void) 597 { 598 return false; 599 } 600 601 /** 602 * cpc_supported_by_cpu() - check if CPPC is supported by CPU 603 * 604 * Check if the architectural support for CPPC is present even 605 * if the _OSC hasn't prescribed it 606 * 607 * Return: true for supported, false for not supported 608 */ 609 bool __weak cpc_supported_by_cpu(void) 610 { 611 return false; 612 } 613 614 /** 615 * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace 616 * @pcc_ss_id: PCC Subspace index as in the PCC client ACPI package. 617 * 618 * Check and allocate the cppc_pcc_data memory. 619 * In some processor configurations it is possible that same subspace 620 * is shared between multiple CPUs. This is seen especially in CPUs 621 * with hardware multi-threading support. 622 * 623 * Return: 0 for success, errno for failure 624 */ 625 static int pcc_data_alloc(int pcc_ss_id) 626 { 627 if (pcc_ss_id < 0 || pcc_ss_id >= MAX_PCC_SUBSPACES) 628 return -EINVAL; 629 630 if (pcc_data[pcc_ss_id]) { 631 pcc_data[pcc_ss_id]->refcount++; 632 } else { 633 pcc_data[pcc_ss_id] = kzalloc(sizeof(struct cppc_pcc_data), 634 GFP_KERNEL); 635 if (!pcc_data[pcc_ss_id]) 636 return -ENOMEM; 637 pcc_data[pcc_ss_id]->refcount++; 638 } 639 640 return 0; 641 } 642 643 /* 644 * An example CPC table looks like the following. 645 * 646 * Name (_CPC, Package() { 647 * 17, // NumEntries 648 * 1, // Revision 649 * ResourceTemplate() {Register(PCC, 32, 0, 0x120, 2)}, // Highest Performance 650 * ResourceTemplate() {Register(PCC, 32, 0, 0x124, 2)}, // Nominal Performance 651 * ResourceTemplate() {Register(PCC, 32, 0, 0x128, 2)}, // Lowest Nonlinear Performance 652 * ResourceTemplate() {Register(PCC, 32, 0, 0x12C, 2)}, // Lowest Performance 653 * ResourceTemplate() {Register(PCC, 32, 0, 0x130, 2)}, // Guaranteed Performance Register 654 * ResourceTemplate() {Register(PCC, 32, 0, 0x110, 2)}, // Desired Performance Register 655 * ResourceTemplate() {Register(SystemMemory, 0, 0, 0, 0)}, 656 * ... 657 * ... 658 * ... 659 * } 660 * Each Register() encodes how to access that specific register. 661 * e.g. a sample PCC entry has the following encoding: 662 * 663 * Register ( 664 * PCC, // AddressSpaceKeyword 665 * 8, // RegisterBitWidth 666 * 8, // RegisterBitOffset 667 * 0x30, // RegisterAddress 668 * 9, // AccessSize (subspace ID) 669 * ) 670 */ 671 672 #ifndef arch_init_invariance_cppc 673 static inline void arch_init_invariance_cppc(void) { } 674 #endif 675 676 /** 677 * acpi_cppc_processor_probe - Search for per CPU _CPC objects. 678 * @pr: Ptr to acpi_processor containing this CPU's logical ID. 679 * 680 * Return: 0 for success or negative value for err. 681 */ 682 int acpi_cppc_processor_probe(struct acpi_processor *pr) 683 { 684 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL}; 685 union acpi_object *out_obj, *cpc_obj; 686 struct cpc_desc *cpc_ptr; 687 struct cpc_reg *gas_t; 688 struct device *cpu_dev; 689 acpi_handle handle = pr->handle; 690 unsigned int num_ent, i, cpc_rev; 691 int pcc_subspace_id = -1; 692 acpi_status status; 693 int ret = -ENODATA; 694 695 if (!osc_sb_cppc2_support_acked) { 696 pr_debug("CPPC v2 _OSC not acked\n"); 697 if (!cpc_supported_by_cpu()) 698 return -ENODEV; 699 } 700 701 /* Parse the ACPI _CPC table for this CPU. */ 702 status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output, 703 ACPI_TYPE_PACKAGE); 704 if (ACPI_FAILURE(status)) { 705 ret = -ENODEV; 706 goto out_buf_free; 707 } 708 709 out_obj = (union acpi_object *) output.pointer; 710 711 cpc_ptr = kzalloc(sizeof(struct cpc_desc), GFP_KERNEL); 712 if (!cpc_ptr) { 713 ret = -ENOMEM; 714 goto out_buf_free; 715 } 716 717 /* First entry is NumEntries. */ 718 cpc_obj = &out_obj->package.elements[0]; 719 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 720 num_ent = cpc_obj->integer.value; 721 if (num_ent <= 1) { 722 pr_debug("Unexpected _CPC NumEntries value (%d) for CPU:%d\n", 723 num_ent, pr->id); 724 goto out_free; 725 } 726 } else { 727 pr_debug("Unexpected _CPC NumEntries entry type (%d) for CPU:%d\n", 728 cpc_obj->type, pr->id); 729 goto out_free; 730 } 731 732 /* Second entry should be revision. */ 733 cpc_obj = &out_obj->package.elements[1]; 734 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 735 cpc_rev = cpc_obj->integer.value; 736 } else { 737 pr_debug("Unexpected _CPC Revision entry type (%d) for CPU:%d\n", 738 cpc_obj->type, pr->id); 739 goto out_free; 740 } 741 742 if (cpc_rev < CPPC_V2_REV) { 743 pr_debug("Unsupported _CPC Revision (%d) for CPU:%d\n", cpc_rev, 744 pr->id); 745 goto out_free; 746 } 747 748 /* 749 * Disregard _CPC if the number of entries in the return pachage is not 750 * as expected, but support future revisions being proper supersets of 751 * the v3 and only causing more entries to be returned by _CPC. 752 */ 753 if ((cpc_rev == CPPC_V2_REV && num_ent != CPPC_V2_NUM_ENT) || 754 (cpc_rev == CPPC_V3_REV && num_ent != CPPC_V3_NUM_ENT) || 755 (cpc_rev > CPPC_V3_REV && num_ent <= CPPC_V3_NUM_ENT)) { 756 pr_debug("Unexpected number of _CPC return package entries (%d) for CPU:%d\n", 757 num_ent, pr->id); 758 goto out_free; 759 } 760 if (cpc_rev > CPPC_V3_REV) { 761 num_ent = CPPC_V3_NUM_ENT; 762 cpc_rev = CPPC_V3_REV; 763 } 764 765 cpc_ptr->num_entries = num_ent; 766 cpc_ptr->version = cpc_rev; 767 768 /* Iterate through remaining entries in _CPC */ 769 for (i = 2; i < num_ent; i++) { 770 cpc_obj = &out_obj->package.elements[i]; 771 772 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 773 cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_INTEGER; 774 cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = cpc_obj->integer.value; 775 } else if (cpc_obj->type == ACPI_TYPE_BUFFER) { 776 gas_t = (struct cpc_reg *) 777 cpc_obj->buffer.pointer; 778 779 /* 780 * The PCC Subspace index is encoded inside 781 * the CPC table entries. The same PCC index 782 * will be used for all the PCC entries, 783 * so extract it only once. 784 */ 785 if (gas_t->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { 786 if (pcc_subspace_id < 0) { 787 pcc_subspace_id = gas_t->access_width; 788 if (pcc_data_alloc(pcc_subspace_id)) 789 goto out_free; 790 } else if (pcc_subspace_id != gas_t->access_width) { 791 pr_debug("Mismatched PCC ids in _CPC for CPU:%d\n", 792 pr->id); 793 goto out_free; 794 } 795 } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { 796 if (gas_t->address) { 797 void __iomem *addr; 798 size_t access_width; 799 800 if (!osc_cpc_flexible_adr_space_confirmed) { 801 pr_debug("Flexible address space capability not supported\n"); 802 if (!cpc_supported_by_cpu()) 803 goto out_free; 804 } 805 806 access_width = GET_BIT_WIDTH(gas_t) / 8; 807 addr = ioremap(gas_t->address, access_width); 808 if (!addr) 809 goto out_free; 810 cpc_ptr->cpc_regs[i-2].sys_mem_vaddr = addr; 811 } 812 } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { 813 if (gas_t->access_width < 1 || gas_t->access_width > 3) { 814 /* 815 * 1 = 8-bit, 2 = 16-bit, and 3 = 32-bit. 816 * SystemIO doesn't implement 64-bit 817 * registers. 818 */ 819 pr_debug("Invalid access width %d for SystemIO register in _CPC\n", 820 gas_t->access_width); 821 goto out_free; 822 } 823 if (gas_t->address & OVER_16BTS_MASK) { 824 /* SystemIO registers use 16-bit integer addresses */ 825 pr_debug("Invalid IO port %llu for SystemIO register in _CPC\n", 826 gas_t->address); 827 goto out_free; 828 } 829 if (!osc_cpc_flexible_adr_space_confirmed) { 830 pr_debug("Flexible address space capability not supported\n"); 831 if (!cpc_supported_by_cpu()) 832 goto out_free; 833 } 834 } else { 835 if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) { 836 /* Support only PCC, SystemMemory, SystemIO, and FFH type regs. */ 837 pr_debug("Unsupported register type (%d) in _CPC\n", 838 gas_t->space_id); 839 goto out_free; 840 } 841 } 842 843 cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_BUFFER; 844 memcpy(&cpc_ptr->cpc_regs[i-2].cpc_entry.reg, gas_t, sizeof(*gas_t)); 845 } else { 846 pr_debug("Invalid entry type (%d) in _CPC for CPU:%d\n", 847 i, pr->id); 848 goto out_free; 849 } 850 } 851 per_cpu(cpu_pcc_subspace_idx, pr->id) = pcc_subspace_id; 852 853 /* 854 * Initialize the remaining cpc_regs as unsupported. 855 * Example: In case FW exposes CPPC v2, the below loop will initialize 856 * LOWEST_FREQ and NOMINAL_FREQ regs as unsupported 857 */ 858 for (i = num_ent - 2; i < MAX_CPC_REG_ENT; i++) { 859 cpc_ptr->cpc_regs[i].type = ACPI_TYPE_INTEGER; 860 cpc_ptr->cpc_regs[i].cpc_entry.int_value = 0; 861 } 862 863 864 /* Store CPU Logical ID */ 865 cpc_ptr->cpu_id = pr->id; 866 raw_spin_lock_init(&cpc_ptr->rmw_lock); 867 868 /* Parse PSD data for this CPU */ 869 ret = acpi_get_psd(cpc_ptr, handle); 870 if (ret) 871 goto out_free; 872 873 /* Register PCC channel once for all PCC subspace ID. */ 874 if (pcc_subspace_id >= 0 && !pcc_data[pcc_subspace_id]->pcc_channel_acquired) { 875 ret = register_pcc_channel(pcc_subspace_id); 876 if (ret) 877 goto out_free; 878 879 init_rwsem(&pcc_data[pcc_subspace_id]->pcc_lock); 880 init_waitqueue_head(&pcc_data[pcc_subspace_id]->pcc_write_wait_q); 881 } 882 883 /* Everything looks okay */ 884 pr_debug("Parsed CPC struct for CPU: %d\n", pr->id); 885 886 /* Add per logical CPU nodes for reading its feedback counters. */ 887 cpu_dev = get_cpu_device(pr->id); 888 if (!cpu_dev) { 889 ret = -EINVAL; 890 goto out_free; 891 } 892 893 /* Plug PSD data into this CPU's CPC descriptor. */ 894 per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr; 895 896 ret = kobject_init_and_add(&cpc_ptr->kobj, &cppc_ktype, &cpu_dev->kobj, 897 "acpi_cppc"); 898 if (ret) { 899 per_cpu(cpc_desc_ptr, pr->id) = NULL; 900 kobject_put(&cpc_ptr->kobj); 901 goto out_free; 902 } 903 904 arch_init_invariance_cppc(); 905 906 kfree(output.pointer); 907 return 0; 908 909 out_free: 910 /* Free all the mapped sys mem areas for this CPU */ 911 for (i = 2; i < cpc_ptr->num_entries; i++) { 912 void __iomem *addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr; 913 914 if (addr) 915 iounmap(addr); 916 } 917 kfree(cpc_ptr); 918 919 out_buf_free: 920 kfree(output.pointer); 921 return ret; 922 } 923 EXPORT_SYMBOL_GPL(acpi_cppc_processor_probe); 924 925 /** 926 * acpi_cppc_processor_exit - Cleanup CPC structs. 927 * @pr: Ptr to acpi_processor containing this CPU's logical ID. 928 * 929 * Return: Void 930 */ 931 void acpi_cppc_processor_exit(struct acpi_processor *pr) 932 { 933 struct cpc_desc *cpc_ptr; 934 unsigned int i; 935 void __iomem *addr; 936 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, pr->id); 937 938 if (pcc_ss_id >= 0 && pcc_data[pcc_ss_id]) { 939 if (pcc_data[pcc_ss_id]->pcc_channel_acquired) { 940 pcc_data[pcc_ss_id]->refcount--; 941 if (!pcc_data[pcc_ss_id]->refcount) { 942 pcc_mbox_free_channel(pcc_data[pcc_ss_id]->pcc_channel); 943 kfree(pcc_data[pcc_ss_id]); 944 pcc_data[pcc_ss_id] = NULL; 945 } 946 } 947 } 948 949 cpc_ptr = per_cpu(cpc_desc_ptr, pr->id); 950 if (!cpc_ptr) 951 return; 952 953 /* Free all the mapped sys mem areas for this CPU */ 954 for (i = 2; i < cpc_ptr->num_entries; i++) { 955 addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr; 956 if (addr) 957 iounmap(addr); 958 } 959 960 kobject_put(&cpc_ptr->kobj); 961 kfree(cpc_ptr); 962 } 963 EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit); 964 965 /** 966 * cpc_read_ffh() - Read FFH register 967 * @cpunum: CPU number to read 968 * @reg: cppc register information 969 * @val: place holder for return value 970 * 971 * Read bit_width bits from a specified address and bit_offset 972 * 973 * Return: 0 for success and error code 974 */ 975 int __weak cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val) 976 { 977 return -ENOTSUPP; 978 } 979 980 /** 981 * cpc_write_ffh() - Write FFH register 982 * @cpunum: CPU number to write 983 * @reg: cppc register information 984 * @val: value to write 985 * 986 * Write value of bit_width bits to a specified address and bit_offset 987 * 988 * Return: 0 for success and error code 989 */ 990 int __weak cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) 991 { 992 return -ENOTSUPP; 993 } 994 995 /* 996 * Since cpc_read and cpc_write are called while holding pcc_lock, it should be 997 * as fast as possible. We have already mapped the PCC subspace during init, so 998 * we can directly write to it. 999 */ 1000 1001 static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val) 1002 { 1003 void __iomem *vaddr = NULL; 1004 int size; 1005 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1006 struct cpc_reg *reg = ®_res->cpc_entry.reg; 1007 1008 if (reg_res->type == ACPI_TYPE_INTEGER) { 1009 *val = reg_res->cpc_entry.int_value; 1010 return 0; 1011 } 1012 1013 *val = 0; 1014 size = GET_BIT_WIDTH(reg); 1015 1016 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { 1017 u32 val_u32; 1018 acpi_status status; 1019 1020 status = acpi_os_read_port((acpi_io_address)reg->address, 1021 &val_u32, size); 1022 if (ACPI_FAILURE(status)) { 1023 pr_debug("Error: Failed to read SystemIO port %llx\n", 1024 reg->address); 1025 return -EFAULT; 1026 } 1027 1028 *val = val_u32; 1029 return 0; 1030 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) { 1031 /* 1032 * For registers in PCC space, the register size is determined 1033 * by the bit width field; the access size is used to indicate 1034 * the PCC subspace id. 1035 */ 1036 size = reg->bit_width; 1037 vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); 1038 } 1039 else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1040 vaddr = reg_res->sys_mem_vaddr; 1041 else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) 1042 return cpc_read_ffh(cpu, reg, val); 1043 else 1044 return acpi_os_read_memory((acpi_physical_address)reg->address, 1045 val, size); 1046 1047 switch (size) { 1048 case 8: 1049 *val = readb_relaxed(vaddr); 1050 break; 1051 case 16: 1052 *val = readw_relaxed(vaddr); 1053 break; 1054 case 32: 1055 *val = readl_relaxed(vaddr); 1056 break; 1057 case 64: 1058 *val = readq_relaxed(vaddr); 1059 break; 1060 default: 1061 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { 1062 pr_debug("Error: Cannot read %u bit width from system memory: 0x%llx\n", 1063 size, reg->address); 1064 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { 1065 pr_debug("Error: Cannot read %u bit width from PCC for ss: %d\n", 1066 size, pcc_ss_id); 1067 } 1068 return -EFAULT; 1069 } 1070 1071 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1072 *val = MASK_VAL_READ(reg, *val); 1073 1074 return 0; 1075 } 1076 1077 static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) 1078 { 1079 int ret_val = 0; 1080 int size; 1081 u64 prev_val; 1082 void __iomem *vaddr = NULL; 1083 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1084 struct cpc_reg *reg = ®_res->cpc_entry.reg; 1085 struct cpc_desc *cpc_desc; 1086 unsigned long flags; 1087 1088 size = GET_BIT_WIDTH(reg); 1089 1090 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { 1091 acpi_status status; 1092 1093 status = acpi_os_write_port((acpi_io_address)reg->address, 1094 (u32)val, size); 1095 if (ACPI_FAILURE(status)) { 1096 pr_debug("Error: Failed to write SystemIO port %llx\n", 1097 reg->address); 1098 return -EFAULT; 1099 } 1100 1101 return 0; 1102 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) { 1103 /* 1104 * For registers in PCC space, the register size is determined 1105 * by the bit width field; the access size is used to indicate 1106 * the PCC subspace id. 1107 */ 1108 size = reg->bit_width; 1109 vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); 1110 } 1111 else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1112 vaddr = reg_res->sys_mem_vaddr; 1113 else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) 1114 return cpc_write_ffh(cpu, reg, val); 1115 else 1116 return acpi_os_write_memory((acpi_physical_address)reg->address, 1117 val, size); 1118 1119 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { 1120 cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1121 if (!cpc_desc) { 1122 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1123 return -ENODEV; 1124 } 1125 1126 raw_spin_lock_irqsave(&cpc_desc->rmw_lock, flags); 1127 switch (size) { 1128 case 8: 1129 prev_val = readb_relaxed(vaddr); 1130 break; 1131 case 16: 1132 prev_val = readw_relaxed(vaddr); 1133 break; 1134 case 32: 1135 prev_val = readl_relaxed(vaddr); 1136 break; 1137 case 64: 1138 prev_val = readq_relaxed(vaddr); 1139 break; 1140 default: 1141 raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags); 1142 return -EFAULT; 1143 } 1144 val = MASK_VAL_WRITE(reg, prev_val, val); 1145 val |= prev_val; 1146 } 1147 1148 switch (size) { 1149 case 8: 1150 writeb_relaxed(val, vaddr); 1151 break; 1152 case 16: 1153 writew_relaxed(val, vaddr); 1154 break; 1155 case 32: 1156 writel_relaxed(val, vaddr); 1157 break; 1158 case 64: 1159 writeq_relaxed(val, vaddr); 1160 break; 1161 default: 1162 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { 1163 pr_debug("Error: Cannot write %u bit width to system memory: 0x%llx\n", 1164 size, reg->address); 1165 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { 1166 pr_debug("Error: Cannot write %u bit width to PCC for ss: %d\n", 1167 size, pcc_ss_id); 1168 } 1169 ret_val = -EFAULT; 1170 break; 1171 } 1172 1173 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1174 raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags); 1175 1176 return ret_val; 1177 } 1178 1179 static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) 1180 { 1181 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1182 struct cpc_register_resource *reg; 1183 1184 if (!cpc_desc) { 1185 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1186 return -ENODEV; 1187 } 1188 1189 reg = &cpc_desc->cpc_regs[reg_idx]; 1190 1191 if (CPC_IN_PCC(reg)) { 1192 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1193 struct cppc_pcc_data *pcc_ss_data = NULL; 1194 int ret = 0; 1195 1196 if (pcc_ss_id < 0) 1197 return -EIO; 1198 1199 pcc_ss_data = pcc_data[pcc_ss_id]; 1200 1201 down_write(&pcc_ss_data->pcc_lock); 1202 1203 if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) 1204 cpc_read(cpunum, reg, perf); 1205 else 1206 ret = -EIO; 1207 1208 up_write(&pcc_ss_data->pcc_lock); 1209 1210 return ret; 1211 } 1212 1213 cpc_read(cpunum, reg, perf); 1214 1215 return 0; 1216 } 1217 1218 /** 1219 * cppc_get_desired_perf - Get the desired performance register value. 1220 * @cpunum: CPU from which to get desired performance. 1221 * @desired_perf: Return address. 1222 * 1223 * Return: 0 for success, -EIO otherwise. 1224 */ 1225 int cppc_get_desired_perf(int cpunum, u64 *desired_perf) 1226 { 1227 return cppc_get_perf(cpunum, DESIRED_PERF, desired_perf); 1228 } 1229 EXPORT_SYMBOL_GPL(cppc_get_desired_perf); 1230 1231 /** 1232 * cppc_get_nominal_perf - Get the nominal performance register value. 1233 * @cpunum: CPU from which to get nominal performance. 1234 * @nominal_perf: Return address. 1235 * 1236 * Return: 0 for success, -EIO otherwise. 1237 */ 1238 int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) 1239 { 1240 return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf); 1241 } 1242 1243 /** 1244 * cppc_get_highest_perf - Get the highest performance register value. 1245 * @cpunum: CPU from which to get highest performance. 1246 * @highest_perf: Return address. 1247 * 1248 * Return: 0 for success, -EIO otherwise. 1249 */ 1250 int cppc_get_highest_perf(int cpunum, u64 *highest_perf) 1251 { 1252 return cppc_get_perf(cpunum, HIGHEST_PERF, highest_perf); 1253 } 1254 EXPORT_SYMBOL_GPL(cppc_get_highest_perf); 1255 1256 /** 1257 * cppc_get_epp_perf - Get the epp register value. 1258 * @cpunum: CPU from which to get epp preference value. 1259 * @epp_perf: Return address. 1260 * 1261 * Return: 0 for success, -EIO otherwise. 1262 */ 1263 int cppc_get_epp_perf(int cpunum, u64 *epp_perf) 1264 { 1265 return cppc_get_perf(cpunum, ENERGY_PERF, epp_perf); 1266 } 1267 EXPORT_SYMBOL_GPL(cppc_get_epp_perf); 1268 1269 /** 1270 * cppc_get_perf_caps - Get a CPU's performance capabilities. 1271 * @cpunum: CPU from which to get capabilities info. 1272 * @perf_caps: ptr to cppc_perf_caps. See cppc_acpi.h 1273 * 1274 * Return: 0 for success with perf_caps populated else -ERRNO. 1275 */ 1276 int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) 1277 { 1278 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1279 struct cpc_register_resource *highest_reg, *lowest_reg, 1280 *lowest_non_linear_reg, *nominal_reg, *guaranteed_reg, 1281 *low_freq_reg = NULL, *nom_freq_reg = NULL; 1282 u64 high, low, guaranteed, nom, min_nonlinear, low_f = 0, nom_f = 0; 1283 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1284 struct cppc_pcc_data *pcc_ss_data = NULL; 1285 int ret = 0, regs_in_pcc = 0; 1286 1287 if (!cpc_desc) { 1288 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1289 return -ENODEV; 1290 } 1291 1292 highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF]; 1293 lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF]; 1294 lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF]; 1295 nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; 1296 low_freq_reg = &cpc_desc->cpc_regs[LOWEST_FREQ]; 1297 nom_freq_reg = &cpc_desc->cpc_regs[NOMINAL_FREQ]; 1298 guaranteed_reg = &cpc_desc->cpc_regs[GUARANTEED_PERF]; 1299 1300 /* Are any of the regs PCC ?*/ 1301 if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) || 1302 CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg) || 1303 CPC_IN_PCC(low_freq_reg) || CPC_IN_PCC(nom_freq_reg)) { 1304 if (pcc_ss_id < 0) { 1305 pr_debug("Invalid pcc_ss_id\n"); 1306 return -ENODEV; 1307 } 1308 pcc_ss_data = pcc_data[pcc_ss_id]; 1309 regs_in_pcc = 1; 1310 down_write(&pcc_ss_data->pcc_lock); 1311 /* Ring doorbell once to update PCC subspace */ 1312 if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) { 1313 ret = -EIO; 1314 goto out_err; 1315 } 1316 } 1317 1318 cpc_read(cpunum, highest_reg, &high); 1319 perf_caps->highest_perf = high; 1320 1321 cpc_read(cpunum, lowest_reg, &low); 1322 perf_caps->lowest_perf = low; 1323 1324 cpc_read(cpunum, nominal_reg, &nom); 1325 perf_caps->nominal_perf = nom; 1326 1327 if (guaranteed_reg->type != ACPI_TYPE_BUFFER || 1328 IS_NULL_REG(&guaranteed_reg->cpc_entry.reg)) { 1329 perf_caps->guaranteed_perf = 0; 1330 } else { 1331 cpc_read(cpunum, guaranteed_reg, &guaranteed); 1332 perf_caps->guaranteed_perf = guaranteed; 1333 } 1334 1335 cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear); 1336 perf_caps->lowest_nonlinear_perf = min_nonlinear; 1337 1338 if (!high || !low || !nom || !min_nonlinear) 1339 ret = -EFAULT; 1340 1341 /* Read optional lowest and nominal frequencies if present */ 1342 if (CPC_SUPPORTED(low_freq_reg)) 1343 cpc_read(cpunum, low_freq_reg, &low_f); 1344 1345 if (CPC_SUPPORTED(nom_freq_reg)) 1346 cpc_read(cpunum, nom_freq_reg, &nom_f); 1347 1348 perf_caps->lowest_freq = low_f; 1349 perf_caps->nominal_freq = nom_f; 1350 1351 1352 out_err: 1353 if (regs_in_pcc) 1354 up_write(&pcc_ss_data->pcc_lock); 1355 return ret; 1356 } 1357 EXPORT_SYMBOL_GPL(cppc_get_perf_caps); 1358 1359 /** 1360 * cppc_perf_ctrs_in_pcc - Check if any perf counters are in a PCC region. 1361 * 1362 * CPPC has flexibility about how CPU performance counters are accessed. 1363 * One of the choices is PCC regions, which can have a high access latency. This 1364 * routine allows callers of cppc_get_perf_ctrs() to know this ahead of time. 1365 * 1366 * Return: true if any of the counters are in PCC regions, false otherwise 1367 */ 1368 bool cppc_perf_ctrs_in_pcc(void) 1369 { 1370 int cpu; 1371 1372 for_each_present_cpu(cpu) { 1373 struct cpc_register_resource *ref_perf_reg; 1374 struct cpc_desc *cpc_desc; 1375 1376 cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1377 1378 if (CPC_IN_PCC(&cpc_desc->cpc_regs[DELIVERED_CTR]) || 1379 CPC_IN_PCC(&cpc_desc->cpc_regs[REFERENCE_CTR]) || 1380 CPC_IN_PCC(&cpc_desc->cpc_regs[CTR_WRAP_TIME])) 1381 return true; 1382 1383 1384 ref_perf_reg = &cpc_desc->cpc_regs[REFERENCE_PERF]; 1385 1386 /* 1387 * If reference perf register is not supported then we should 1388 * use the nominal perf value 1389 */ 1390 if (!CPC_SUPPORTED(ref_perf_reg)) 1391 ref_perf_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; 1392 1393 if (CPC_IN_PCC(ref_perf_reg)) 1394 return true; 1395 } 1396 1397 return false; 1398 } 1399 EXPORT_SYMBOL_GPL(cppc_perf_ctrs_in_pcc); 1400 1401 /** 1402 * cppc_get_perf_ctrs - Read a CPU's performance feedback counters. 1403 * @cpunum: CPU from which to read counters. 1404 * @perf_fb_ctrs: ptr to cppc_perf_fb_ctrs. See cppc_acpi.h 1405 * 1406 * Return: 0 for success with perf_fb_ctrs populated else -ERRNO. 1407 */ 1408 int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) 1409 { 1410 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1411 struct cpc_register_resource *delivered_reg, *reference_reg, 1412 *ref_perf_reg, *ctr_wrap_reg; 1413 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1414 struct cppc_pcc_data *pcc_ss_data = NULL; 1415 u64 delivered, reference, ref_perf, ctr_wrap_time; 1416 int ret = 0, regs_in_pcc = 0; 1417 1418 if (!cpc_desc) { 1419 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1420 return -ENODEV; 1421 } 1422 1423 delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR]; 1424 reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR]; 1425 ref_perf_reg = &cpc_desc->cpc_regs[REFERENCE_PERF]; 1426 ctr_wrap_reg = &cpc_desc->cpc_regs[CTR_WRAP_TIME]; 1427 1428 /* 1429 * If reference perf register is not supported then we should 1430 * use the nominal perf value 1431 */ 1432 if (!CPC_SUPPORTED(ref_perf_reg)) 1433 ref_perf_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; 1434 1435 /* Are any of the regs PCC ?*/ 1436 if (CPC_IN_PCC(delivered_reg) || CPC_IN_PCC(reference_reg) || 1437 CPC_IN_PCC(ctr_wrap_reg) || CPC_IN_PCC(ref_perf_reg)) { 1438 if (pcc_ss_id < 0) { 1439 pr_debug("Invalid pcc_ss_id\n"); 1440 return -ENODEV; 1441 } 1442 pcc_ss_data = pcc_data[pcc_ss_id]; 1443 down_write(&pcc_ss_data->pcc_lock); 1444 regs_in_pcc = 1; 1445 /* Ring doorbell once to update PCC subspace */ 1446 if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) { 1447 ret = -EIO; 1448 goto out_err; 1449 } 1450 } 1451 1452 cpc_read(cpunum, delivered_reg, &delivered); 1453 cpc_read(cpunum, reference_reg, &reference); 1454 cpc_read(cpunum, ref_perf_reg, &ref_perf); 1455 1456 /* 1457 * Per spec, if ctr_wrap_time optional register is unsupported, then the 1458 * performance counters are assumed to never wrap during the lifetime of 1459 * platform 1460 */ 1461 ctr_wrap_time = (u64)(~((u64)0)); 1462 if (CPC_SUPPORTED(ctr_wrap_reg)) 1463 cpc_read(cpunum, ctr_wrap_reg, &ctr_wrap_time); 1464 1465 if (!delivered || !reference || !ref_perf) { 1466 ret = -EFAULT; 1467 goto out_err; 1468 } 1469 1470 perf_fb_ctrs->delivered = delivered; 1471 perf_fb_ctrs->reference = reference; 1472 perf_fb_ctrs->reference_perf = ref_perf; 1473 perf_fb_ctrs->wraparound_time = ctr_wrap_time; 1474 out_err: 1475 if (regs_in_pcc) 1476 up_write(&pcc_ss_data->pcc_lock); 1477 return ret; 1478 } 1479 EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs); 1480 1481 /* 1482 * Set Energy Performance Preference Register value through 1483 * Performance Controls Interface 1484 */ 1485 int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable) 1486 { 1487 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1488 struct cpc_register_resource *epp_set_reg; 1489 struct cpc_register_resource *auto_sel_reg; 1490 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1491 struct cppc_pcc_data *pcc_ss_data = NULL; 1492 int ret; 1493 1494 if (!cpc_desc) { 1495 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1496 return -ENODEV; 1497 } 1498 1499 auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; 1500 epp_set_reg = &cpc_desc->cpc_regs[ENERGY_PERF]; 1501 1502 if (CPC_IN_PCC(epp_set_reg) || CPC_IN_PCC(auto_sel_reg)) { 1503 if (pcc_ss_id < 0) { 1504 pr_debug("Invalid pcc_ss_id for CPU:%d\n", cpu); 1505 return -ENODEV; 1506 } 1507 1508 if (CPC_SUPPORTED(auto_sel_reg)) { 1509 ret = cpc_write(cpu, auto_sel_reg, enable); 1510 if (ret) 1511 return ret; 1512 } 1513 1514 if (CPC_SUPPORTED(epp_set_reg)) { 1515 ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf); 1516 if (ret) 1517 return ret; 1518 } 1519 1520 pcc_ss_data = pcc_data[pcc_ss_id]; 1521 1522 down_write(&pcc_ss_data->pcc_lock); 1523 /* after writing CPC, transfer the ownership of PCC to platform */ 1524 ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1525 up_write(&pcc_ss_data->pcc_lock); 1526 } else if (osc_cpc_flexible_adr_space_confirmed && 1527 CPC_SUPPORTED(epp_set_reg) && CPC_IN_FFH(epp_set_reg)) { 1528 ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf); 1529 } else { 1530 ret = -ENOTSUPP; 1531 pr_debug("_CPC in PCC and _CPC in FFH are not supported\n"); 1532 } 1533 1534 return ret; 1535 } 1536 EXPORT_SYMBOL_GPL(cppc_set_epp_perf); 1537 1538 /** 1539 * cppc_get_auto_sel_caps - Read autonomous selection register. 1540 * @cpunum : CPU from which to read register. 1541 * @perf_caps : struct where autonomous selection register value is updated. 1542 */ 1543 int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf_caps) 1544 { 1545 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1546 struct cpc_register_resource *auto_sel_reg; 1547 u64 auto_sel; 1548 1549 if (!cpc_desc) { 1550 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1551 return -ENODEV; 1552 } 1553 1554 auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; 1555 1556 if (!CPC_SUPPORTED(auto_sel_reg)) 1557 pr_warn_once("Autonomous mode is not unsupported!\n"); 1558 1559 if (CPC_IN_PCC(auto_sel_reg)) { 1560 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1561 struct cppc_pcc_data *pcc_ss_data = NULL; 1562 int ret = 0; 1563 1564 if (pcc_ss_id < 0) 1565 return -ENODEV; 1566 1567 pcc_ss_data = pcc_data[pcc_ss_id]; 1568 1569 down_write(&pcc_ss_data->pcc_lock); 1570 1571 if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) { 1572 cpc_read(cpunum, auto_sel_reg, &auto_sel); 1573 perf_caps->auto_sel = (bool)auto_sel; 1574 } else { 1575 ret = -EIO; 1576 } 1577 1578 up_write(&pcc_ss_data->pcc_lock); 1579 1580 return ret; 1581 } 1582 1583 return 0; 1584 } 1585 EXPORT_SYMBOL_GPL(cppc_get_auto_sel_caps); 1586 1587 /** 1588 * cppc_set_auto_sel - Write autonomous selection register. 1589 * @cpu : CPU to which to write register. 1590 * @enable : the desired value of autonomous selection resiter to be updated. 1591 */ 1592 int cppc_set_auto_sel(int cpu, bool enable) 1593 { 1594 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1595 struct cpc_register_resource *auto_sel_reg; 1596 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1597 struct cppc_pcc_data *pcc_ss_data = NULL; 1598 int ret = -EINVAL; 1599 1600 if (!cpc_desc) { 1601 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1602 return -ENODEV; 1603 } 1604 1605 auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; 1606 1607 if (CPC_IN_PCC(auto_sel_reg)) { 1608 if (pcc_ss_id < 0) { 1609 pr_debug("Invalid pcc_ss_id\n"); 1610 return -ENODEV; 1611 } 1612 1613 if (CPC_SUPPORTED(auto_sel_reg)) { 1614 ret = cpc_write(cpu, auto_sel_reg, enable); 1615 if (ret) 1616 return ret; 1617 } 1618 1619 pcc_ss_data = pcc_data[pcc_ss_id]; 1620 1621 down_write(&pcc_ss_data->pcc_lock); 1622 /* after writing CPC, transfer the ownership of PCC to platform */ 1623 ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1624 up_write(&pcc_ss_data->pcc_lock); 1625 } else { 1626 ret = -ENOTSUPP; 1627 pr_debug("_CPC in PCC is not supported\n"); 1628 } 1629 1630 return ret; 1631 } 1632 EXPORT_SYMBOL_GPL(cppc_set_auto_sel); 1633 1634 /** 1635 * cppc_set_enable - Set to enable CPPC on the processor by writing the 1636 * Continuous Performance Control package EnableRegister field. 1637 * @cpu: CPU for which to enable CPPC register. 1638 * @enable: 0 - disable, 1 - enable CPPC feature on the processor. 1639 * 1640 * Return: 0 for success, -ERRNO or -EIO otherwise. 1641 */ 1642 int cppc_set_enable(int cpu, bool enable) 1643 { 1644 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1645 struct cpc_register_resource *enable_reg; 1646 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1647 struct cppc_pcc_data *pcc_ss_data = NULL; 1648 int ret = -EINVAL; 1649 1650 if (!cpc_desc) { 1651 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1652 return -EINVAL; 1653 } 1654 1655 enable_reg = &cpc_desc->cpc_regs[ENABLE]; 1656 1657 if (CPC_IN_PCC(enable_reg)) { 1658 1659 if (pcc_ss_id < 0) 1660 return -EIO; 1661 1662 ret = cpc_write(cpu, enable_reg, enable); 1663 if (ret) 1664 return ret; 1665 1666 pcc_ss_data = pcc_data[pcc_ss_id]; 1667 1668 down_write(&pcc_ss_data->pcc_lock); 1669 /* after writing CPC, transfer the ownership of PCC to platfrom */ 1670 ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1671 up_write(&pcc_ss_data->pcc_lock); 1672 return ret; 1673 } 1674 1675 return cpc_write(cpu, enable_reg, enable); 1676 } 1677 EXPORT_SYMBOL_GPL(cppc_set_enable); 1678 1679 /** 1680 * cppc_set_perf - Set a CPU's performance controls. 1681 * @cpu: CPU for which to set performance controls. 1682 * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h 1683 * 1684 * Return: 0 for success, -ERRNO otherwise. 1685 */ 1686 int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls) 1687 { 1688 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1689 struct cpc_register_resource *desired_reg, *min_perf_reg, *max_perf_reg; 1690 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1691 struct cppc_pcc_data *pcc_ss_data = NULL; 1692 int ret = 0; 1693 1694 if (!cpc_desc) { 1695 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1696 return -ENODEV; 1697 } 1698 1699 desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; 1700 min_perf_reg = &cpc_desc->cpc_regs[MIN_PERF]; 1701 max_perf_reg = &cpc_desc->cpc_regs[MAX_PERF]; 1702 1703 /* 1704 * This is Phase-I where we want to write to CPC registers 1705 * -> We want all CPUs to be able to execute this phase in parallel 1706 * 1707 * Since read_lock can be acquired by multiple CPUs simultaneously we 1708 * achieve that goal here 1709 */ 1710 if (CPC_IN_PCC(desired_reg) || CPC_IN_PCC(min_perf_reg) || CPC_IN_PCC(max_perf_reg)) { 1711 if (pcc_ss_id < 0) { 1712 pr_debug("Invalid pcc_ss_id\n"); 1713 return -ENODEV; 1714 } 1715 pcc_ss_data = pcc_data[pcc_ss_id]; 1716 down_read(&pcc_ss_data->pcc_lock); /* BEGIN Phase-I */ 1717 if (pcc_ss_data->platform_owns_pcc) { 1718 ret = check_pcc_chan(pcc_ss_id, false); 1719 if (ret) { 1720 up_read(&pcc_ss_data->pcc_lock); 1721 return ret; 1722 } 1723 } 1724 /* 1725 * Update the pending_write to make sure a PCC CMD_READ will not 1726 * arrive and steal the channel during the switch to write lock 1727 */ 1728 pcc_ss_data->pending_pcc_write_cmd = true; 1729 cpc_desc->write_cmd_id = pcc_ss_data->pcc_write_cnt; 1730 cpc_desc->write_cmd_status = 0; 1731 } 1732 1733 cpc_write(cpu, desired_reg, perf_ctrls->desired_perf); 1734 1735 /* 1736 * Only write if min_perf and max_perf not zero. Some drivers pass zero 1737 * value to min and max perf, but they don't mean to set the zero value, 1738 * they just don't want to write to those registers. 1739 */ 1740 if (perf_ctrls->min_perf) 1741 cpc_write(cpu, min_perf_reg, perf_ctrls->min_perf); 1742 if (perf_ctrls->max_perf) 1743 cpc_write(cpu, max_perf_reg, perf_ctrls->max_perf); 1744 1745 if (CPC_IN_PCC(desired_reg) || CPC_IN_PCC(min_perf_reg) || CPC_IN_PCC(max_perf_reg)) 1746 up_read(&pcc_ss_data->pcc_lock); /* END Phase-I */ 1747 /* 1748 * This is Phase-II where we transfer the ownership of PCC to Platform 1749 * 1750 * Short Summary: Basically if we think of a group of cppc_set_perf 1751 * requests that happened in short overlapping interval. The last CPU to 1752 * come out of Phase-I will enter Phase-II and ring the doorbell. 1753 * 1754 * We have the following requirements for Phase-II: 1755 * 1. We want to execute Phase-II only when there are no CPUs 1756 * currently executing in Phase-I 1757 * 2. Once we start Phase-II we want to avoid all other CPUs from 1758 * entering Phase-I. 1759 * 3. We want only one CPU among all those who went through Phase-I 1760 * to run phase-II 1761 * 1762 * If write_trylock fails to get the lock and doesn't transfer the 1763 * PCC ownership to the platform, then one of the following will be TRUE 1764 * 1. There is at-least one CPU in Phase-I which will later execute 1765 * write_trylock, so the CPUs in Phase-I will be responsible for 1766 * executing the Phase-II. 1767 * 2. Some other CPU has beaten this CPU to successfully execute the 1768 * write_trylock and has already acquired the write_lock. We know for a 1769 * fact it (other CPU acquiring the write_lock) couldn't have happened 1770 * before this CPU's Phase-I as we held the read_lock. 1771 * 3. Some other CPU executing pcc CMD_READ has stolen the 1772 * down_write, in which case, send_pcc_cmd will check for pending 1773 * CMD_WRITE commands by checking the pending_pcc_write_cmd. 1774 * So this CPU can be certain that its request will be delivered 1775 * So in all cases, this CPU knows that its request will be delivered 1776 * by another CPU and can return 1777 * 1778 * After getting the down_write we still need to check for 1779 * pending_pcc_write_cmd to take care of the following scenario 1780 * The thread running this code could be scheduled out between 1781 * Phase-I and Phase-II. Before it is scheduled back on, another CPU 1782 * could have delivered the request to Platform by triggering the 1783 * doorbell and transferred the ownership of PCC to platform. So this 1784 * avoids triggering an unnecessary doorbell and more importantly before 1785 * triggering the doorbell it makes sure that the PCC channel ownership 1786 * is still with OSPM. 1787 * pending_pcc_write_cmd can also be cleared by a different CPU, if 1788 * there was a pcc CMD_READ waiting on down_write and it steals the lock 1789 * before the pcc CMD_WRITE is completed. send_pcc_cmd checks for this 1790 * case during a CMD_READ and if there are pending writes it delivers 1791 * the write command before servicing the read command 1792 */ 1793 if (CPC_IN_PCC(desired_reg) || CPC_IN_PCC(min_perf_reg) || CPC_IN_PCC(max_perf_reg)) { 1794 if (down_write_trylock(&pcc_ss_data->pcc_lock)) {/* BEGIN Phase-II */ 1795 /* Update only if there are pending write commands */ 1796 if (pcc_ss_data->pending_pcc_write_cmd) 1797 send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1798 up_write(&pcc_ss_data->pcc_lock); /* END Phase-II */ 1799 } else 1800 /* Wait until pcc_write_cnt is updated by send_pcc_cmd */ 1801 wait_event(pcc_ss_data->pcc_write_wait_q, 1802 cpc_desc->write_cmd_id != pcc_ss_data->pcc_write_cnt); 1803 1804 /* send_pcc_cmd updates the status in case of failure */ 1805 ret = cpc_desc->write_cmd_status; 1806 } 1807 return ret; 1808 } 1809 EXPORT_SYMBOL_GPL(cppc_set_perf); 1810 1811 /** 1812 * cppc_get_transition_latency - returns frequency transition latency in ns 1813 * @cpu_num: CPU number for per_cpu(). 1814 * 1815 * ACPI CPPC does not explicitly specify how a platform can specify the 1816 * transition latency for performance change requests. The closest we have 1817 * is the timing information from the PCCT tables which provides the info 1818 * on the number and frequency of PCC commands the platform can handle. 1819 * 1820 * If desired_reg is in the SystemMemory or SystemIo ACPI address space, 1821 * then assume there is no latency. 1822 */ 1823 unsigned int cppc_get_transition_latency(int cpu_num) 1824 { 1825 /* 1826 * Expected transition latency is based on the PCCT timing values 1827 * Below are definition from ACPI spec: 1828 * pcc_nominal- Expected latency to process a command, in microseconds 1829 * pcc_mpar - The maximum number of periodic requests that the subspace 1830 * channel can support, reported in commands per minute. 0 1831 * indicates no limitation. 1832 * pcc_mrtt - The minimum amount of time that OSPM must wait after the 1833 * completion of a command before issuing the next command, 1834 * in microseconds. 1835 */ 1836 unsigned int latency_ns = 0; 1837 struct cpc_desc *cpc_desc; 1838 struct cpc_register_resource *desired_reg; 1839 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu_num); 1840 struct cppc_pcc_data *pcc_ss_data; 1841 1842 cpc_desc = per_cpu(cpc_desc_ptr, cpu_num); 1843 if (!cpc_desc) 1844 return CPUFREQ_ETERNAL; 1845 1846 desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; 1847 if (CPC_IN_SYSTEM_MEMORY(desired_reg) || CPC_IN_SYSTEM_IO(desired_reg)) 1848 return 0; 1849 else if (!CPC_IN_PCC(desired_reg)) 1850 return CPUFREQ_ETERNAL; 1851 1852 if (pcc_ss_id < 0) 1853 return CPUFREQ_ETERNAL; 1854 1855 pcc_ss_data = pcc_data[pcc_ss_id]; 1856 if (pcc_ss_data->pcc_mpar) 1857 latency_ns = 60 * (1000 * 1000 * 1000 / pcc_ss_data->pcc_mpar); 1858 1859 latency_ns = max(latency_ns, pcc_ss_data->pcc_nominal * 1000); 1860 latency_ns = max(latency_ns, pcc_ss_data->pcc_mrtt * 1000); 1861 1862 return latency_ns; 1863 } 1864 EXPORT_SYMBOL_GPL(cppc_get_transition_latency); 1865 1866 /* Minimum struct length needed for the DMI processor entry we want */ 1867 #define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48 1868 1869 /* Offset in the DMI processor structure for the max frequency */ 1870 #define DMI_PROCESSOR_MAX_SPEED 0x14 1871 1872 /* Callback function used to retrieve the max frequency from DMI */ 1873 static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private) 1874 { 1875 const u8 *dmi_data = (const u8 *)dm; 1876 u16 *mhz = (u16 *)private; 1877 1878 if (dm->type == DMI_ENTRY_PROCESSOR && 1879 dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) { 1880 u16 val = (u16)get_unaligned((const u16 *) 1881 (dmi_data + DMI_PROCESSOR_MAX_SPEED)); 1882 *mhz = val > *mhz ? val : *mhz; 1883 } 1884 } 1885 1886 /* Look up the max frequency in DMI */ 1887 static u64 cppc_get_dmi_max_khz(void) 1888 { 1889 u16 mhz = 0; 1890 1891 dmi_walk(cppc_find_dmi_mhz, &mhz); 1892 1893 /* 1894 * Real stupid fallback value, just in case there is no 1895 * actual value set. 1896 */ 1897 mhz = mhz ? mhz : 1; 1898 1899 return KHZ_PER_MHZ * mhz; 1900 } 1901 1902 /* 1903 * If CPPC lowest_freq and nominal_freq registers are exposed then we can 1904 * use them to convert perf to freq and vice versa. The conversion is 1905 * extrapolated as an affine function passing by the 2 points: 1906 * - (Low perf, Low freq) 1907 * - (Nominal perf, Nominal freq) 1908 */ 1909 unsigned int cppc_perf_to_khz(struct cppc_perf_caps *caps, unsigned int perf) 1910 { 1911 s64 retval, offset = 0; 1912 static u64 max_khz; 1913 u64 mul, div; 1914 1915 if (caps->lowest_freq && caps->nominal_freq) { 1916 /* Avoid special case when nominal_freq is equal to lowest_freq */ 1917 if (caps->lowest_freq == caps->nominal_freq) { 1918 mul = caps->nominal_freq; 1919 div = caps->nominal_perf; 1920 } else { 1921 mul = caps->nominal_freq - caps->lowest_freq; 1922 div = caps->nominal_perf - caps->lowest_perf; 1923 } 1924 mul *= KHZ_PER_MHZ; 1925 offset = caps->nominal_freq * KHZ_PER_MHZ - 1926 div64_u64(caps->nominal_perf * mul, div); 1927 } else { 1928 if (!max_khz) 1929 max_khz = cppc_get_dmi_max_khz(); 1930 mul = max_khz; 1931 div = caps->highest_perf; 1932 } 1933 1934 retval = offset + div64_u64(perf * mul, div); 1935 if (retval >= 0) 1936 return retval; 1937 return 0; 1938 } 1939 EXPORT_SYMBOL_GPL(cppc_perf_to_khz); 1940 1941 unsigned int cppc_khz_to_perf(struct cppc_perf_caps *caps, unsigned int freq) 1942 { 1943 s64 retval, offset = 0; 1944 static u64 max_khz; 1945 u64 mul, div; 1946 1947 if (caps->lowest_freq && caps->nominal_freq) { 1948 /* Avoid special case when nominal_freq is equal to lowest_freq */ 1949 if (caps->lowest_freq == caps->nominal_freq) { 1950 mul = caps->nominal_perf; 1951 div = caps->nominal_freq; 1952 } else { 1953 mul = caps->nominal_perf - caps->lowest_perf; 1954 div = caps->nominal_freq - caps->lowest_freq; 1955 } 1956 /* 1957 * We don't need to convert to kHz for computing offset and can 1958 * directly use nominal_freq and lowest_freq as the div64_u64 1959 * will remove the frequency unit. 1960 */ 1961 offset = caps->nominal_perf - 1962 div64_u64(caps->nominal_freq * mul, div); 1963 /* But we need it for computing the perf level. */ 1964 div *= KHZ_PER_MHZ; 1965 } else { 1966 if (!max_khz) 1967 max_khz = cppc_get_dmi_max_khz(); 1968 mul = caps->highest_perf; 1969 div = max_khz; 1970 } 1971 1972 retval = offset + div64_u64(freq * mul, div); 1973 if (retval >= 0) 1974 return retval; 1975 return 0; 1976 } 1977 EXPORT_SYMBOL_GPL(cppc_khz_to_perf); 1978