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 <linux/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, guaranteed_perf); 169 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_freq); 170 show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_freq); 171 172 show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf); 173 show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time); 174 175 /* Check for valid access_width, otherwise, fallback to using bit_width */ 176 #define GET_BIT_WIDTH(reg) ((reg)->access_width ? (8 << ((reg)->access_width - 1)) : (reg)->bit_width) 177 178 /* Shift and apply the mask for CPC reads/writes */ 179 #define MASK_VAL_READ(reg, val) (((val) >> (reg)->bit_offset) & \ 180 GENMASK(((reg)->bit_width) - 1, 0)) 181 #define MASK_VAL_WRITE(reg, prev_val, val) \ 182 ((((val) & GENMASK(((reg)->bit_width) - 1, 0)) << (reg)->bit_offset) | \ 183 ((prev_val) & ~(GENMASK(((reg)->bit_width) - 1, 0) << (reg)->bit_offset))) \ 184 185 static ssize_t show_feedback_ctrs(struct kobject *kobj, 186 struct kobj_attribute *attr, char *buf) 187 { 188 struct cpc_desc *cpc_ptr = to_cpc_desc(kobj); 189 struct cppc_perf_fb_ctrs fb_ctrs = {0}; 190 int ret; 191 192 ret = cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs); 193 if (ret) 194 return ret; 195 196 return sysfs_emit(buf, "ref:%llu del:%llu\n", 197 fb_ctrs.reference, fb_ctrs.delivered); 198 } 199 define_one_cppc_ro(feedback_ctrs); 200 201 static struct attribute *cppc_attrs[] = { 202 &feedback_ctrs.attr, 203 &reference_perf.attr, 204 &wraparound_time.attr, 205 &highest_perf.attr, 206 &lowest_perf.attr, 207 &lowest_nonlinear_perf.attr, 208 &guaranteed_perf.attr, 209 &nominal_perf.attr, 210 &nominal_freq.attr, 211 &lowest_freq.attr, 212 NULL 213 }; 214 ATTRIBUTE_GROUPS(cppc); 215 216 static const struct kobj_type cppc_ktype = { 217 .sysfs_ops = &kobj_sysfs_ops, 218 .default_groups = cppc_groups, 219 }; 220 221 static int check_pcc_chan(int pcc_ss_id, bool chk_err_bit) 222 { 223 int ret, status; 224 struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; 225 struct acpi_pcct_shared_memory __iomem *generic_comm_base = 226 pcc_ss_data->pcc_comm_addr; 227 228 if (!pcc_ss_data->platform_owns_pcc) 229 return 0; 230 231 /* 232 * Poll PCC status register every 3us(delay_us) for maximum of 233 * deadline_us(timeout_us) until PCC command complete bit is set(cond) 234 */ 235 ret = readw_relaxed_poll_timeout(&generic_comm_base->status, status, 236 status & PCC_CMD_COMPLETE_MASK, 3, 237 pcc_ss_data->deadline_us); 238 239 if (likely(!ret)) { 240 pcc_ss_data->platform_owns_pcc = false; 241 if (chk_err_bit && (status & PCC_ERROR_MASK)) 242 ret = -EIO; 243 } 244 245 if (unlikely(ret)) 246 pr_err("PCC check channel failed for ss: %d. ret=%d\n", 247 pcc_ss_id, ret); 248 249 return ret; 250 } 251 252 /* 253 * This function transfers the ownership of the PCC to the platform 254 * So it must be called while holding write_lock(pcc_lock) 255 */ 256 static int send_pcc_cmd(int pcc_ss_id, u16 cmd) 257 { 258 int ret = -EIO, i; 259 struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; 260 struct acpi_pcct_shared_memory __iomem *generic_comm_base = 261 pcc_ss_data->pcc_comm_addr; 262 unsigned int time_delta; 263 264 /* 265 * For CMD_WRITE we know for a fact the caller should have checked 266 * the channel before writing to PCC space 267 */ 268 if (cmd == CMD_READ) { 269 /* 270 * If there are pending cpc_writes, then we stole the channel 271 * before write completion, so first send a WRITE command to 272 * platform 273 */ 274 if (pcc_ss_data->pending_pcc_write_cmd) 275 send_pcc_cmd(pcc_ss_id, CMD_WRITE); 276 277 ret = check_pcc_chan(pcc_ss_id, false); 278 if (ret) 279 goto end; 280 } else /* CMD_WRITE */ 281 pcc_ss_data->pending_pcc_write_cmd = FALSE; 282 283 /* 284 * Handle the Minimum Request Turnaround Time(MRTT) 285 * "The minimum amount of time that OSPM must wait after the completion 286 * of a command before issuing the next command, in microseconds" 287 */ 288 if (pcc_ss_data->pcc_mrtt) { 289 time_delta = ktime_us_delta(ktime_get(), 290 pcc_ss_data->last_cmd_cmpl_time); 291 if (pcc_ss_data->pcc_mrtt > time_delta) 292 udelay(pcc_ss_data->pcc_mrtt - time_delta); 293 } 294 295 /* 296 * Handle the non-zero Maximum Periodic Access Rate(MPAR) 297 * "The maximum number of periodic requests that the subspace channel can 298 * support, reported in commands per minute. 0 indicates no limitation." 299 * 300 * This parameter should be ideally zero or large enough so that it can 301 * handle maximum number of requests that all the cores in the system can 302 * collectively generate. If it is not, we will follow the spec and just 303 * not send the request to the platform after hitting the MPAR limit in 304 * any 60s window 305 */ 306 if (pcc_ss_data->pcc_mpar) { 307 if (pcc_ss_data->mpar_count == 0) { 308 time_delta = ktime_ms_delta(ktime_get(), 309 pcc_ss_data->last_mpar_reset); 310 if ((time_delta < 60 * MSEC_PER_SEC) && pcc_ss_data->last_mpar_reset) { 311 pr_debug("PCC cmd for subspace %d not sent due to MPAR limit", 312 pcc_ss_id); 313 ret = -EIO; 314 goto end; 315 } 316 pcc_ss_data->last_mpar_reset = ktime_get(); 317 pcc_ss_data->mpar_count = pcc_ss_data->pcc_mpar; 318 } 319 pcc_ss_data->mpar_count--; 320 } 321 322 /* Write to the shared comm region. */ 323 writew_relaxed(cmd, &generic_comm_base->command); 324 325 /* Flip CMD COMPLETE bit */ 326 writew_relaxed(0, &generic_comm_base->status); 327 328 pcc_ss_data->platform_owns_pcc = true; 329 330 /* Ring doorbell */ 331 ret = mbox_send_message(pcc_ss_data->pcc_channel->mchan, &cmd); 332 if (ret < 0) { 333 pr_err("Err sending PCC mbox message. ss: %d cmd:%d, ret:%d\n", 334 pcc_ss_id, cmd, ret); 335 goto end; 336 } 337 338 /* wait for completion and check for PCC error bit */ 339 ret = check_pcc_chan(pcc_ss_id, true); 340 341 if (pcc_ss_data->pcc_mrtt) 342 pcc_ss_data->last_cmd_cmpl_time = ktime_get(); 343 344 if (pcc_ss_data->pcc_channel->mchan->mbox->txdone_irq) 345 mbox_chan_txdone(pcc_ss_data->pcc_channel->mchan, ret); 346 else 347 mbox_client_txdone(pcc_ss_data->pcc_channel->mchan, ret); 348 349 end: 350 if (cmd == CMD_WRITE) { 351 if (unlikely(ret)) { 352 for_each_possible_cpu(i) { 353 struct cpc_desc *desc = per_cpu(cpc_desc_ptr, i); 354 355 if (!desc) 356 continue; 357 358 if (desc->write_cmd_id == pcc_ss_data->pcc_write_cnt) 359 desc->write_cmd_status = ret; 360 } 361 } 362 pcc_ss_data->pcc_write_cnt++; 363 wake_up_all(&pcc_ss_data->pcc_write_wait_q); 364 } 365 366 return ret; 367 } 368 369 static void cppc_chan_tx_done(struct mbox_client *cl, void *msg, int ret) 370 { 371 if (ret < 0) 372 pr_debug("TX did not complete: CMD sent:%x, ret:%d\n", 373 *(u16 *)msg, ret); 374 else 375 pr_debug("TX completed. CMD sent:%x, ret:%d\n", 376 *(u16 *)msg, ret); 377 } 378 379 static struct mbox_client cppc_mbox_cl = { 380 .tx_done = cppc_chan_tx_done, 381 .knows_txdone = true, 382 }; 383 384 static int acpi_get_psd(struct cpc_desc *cpc_ptr, acpi_handle handle) 385 { 386 int result = -EFAULT; 387 acpi_status status = AE_OK; 388 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 389 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; 390 struct acpi_buffer state = {0, NULL}; 391 union acpi_object *psd = NULL; 392 struct acpi_psd_package *pdomain; 393 394 status = acpi_evaluate_object_typed(handle, "_PSD", NULL, 395 &buffer, ACPI_TYPE_PACKAGE); 396 if (status == AE_NOT_FOUND) /* _PSD is optional */ 397 return 0; 398 if (ACPI_FAILURE(status)) 399 return -ENODEV; 400 401 psd = buffer.pointer; 402 if (!psd || psd->package.count != 1) { 403 pr_debug("Invalid _PSD data\n"); 404 goto end; 405 } 406 407 pdomain = &(cpc_ptr->domain_info); 408 409 state.length = sizeof(struct acpi_psd_package); 410 state.pointer = pdomain; 411 412 status = acpi_extract_package(&(psd->package.elements[0]), 413 &format, &state); 414 if (ACPI_FAILURE(status)) { 415 pr_debug("Invalid _PSD data for CPU:%d\n", cpc_ptr->cpu_id); 416 goto end; 417 } 418 419 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { 420 pr_debug("Unknown _PSD:num_entries for CPU:%d\n", cpc_ptr->cpu_id); 421 goto end; 422 } 423 424 if (pdomain->revision != ACPI_PSD_REV0_REVISION) { 425 pr_debug("Unknown _PSD:revision for CPU: %d\n", cpc_ptr->cpu_id); 426 goto end; 427 } 428 429 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 430 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 431 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 432 pr_debug("Invalid _PSD:coord_type for CPU:%d\n", cpc_ptr->cpu_id); 433 goto end; 434 } 435 436 result = 0; 437 end: 438 kfree(buffer.pointer); 439 return result; 440 } 441 442 bool acpi_cpc_valid(void) 443 { 444 struct cpc_desc *cpc_ptr; 445 int cpu; 446 447 if (acpi_disabled) 448 return false; 449 450 for_each_present_cpu(cpu) { 451 cpc_ptr = per_cpu(cpc_desc_ptr, cpu); 452 if (!cpc_ptr) 453 return false; 454 } 455 456 return true; 457 } 458 EXPORT_SYMBOL_GPL(acpi_cpc_valid); 459 460 bool cppc_allow_fast_switch(void) 461 { 462 struct cpc_register_resource *desired_reg; 463 struct cpc_desc *cpc_ptr; 464 int cpu; 465 466 for_each_possible_cpu(cpu) { 467 cpc_ptr = per_cpu(cpc_desc_ptr, cpu); 468 desired_reg = &cpc_ptr->cpc_regs[DESIRED_PERF]; 469 if (!CPC_IN_SYSTEM_MEMORY(desired_reg) && 470 !CPC_IN_SYSTEM_IO(desired_reg)) 471 return false; 472 } 473 474 return true; 475 } 476 EXPORT_SYMBOL_GPL(cppc_allow_fast_switch); 477 478 /** 479 * acpi_get_psd_map - Map the CPUs in the freq domain of a given cpu 480 * @cpu: Find all CPUs that share a domain with cpu. 481 * @cpu_data: Pointer to CPU specific CPPC data including PSD info. 482 * 483 * Return: 0 for success or negative value for err. 484 */ 485 int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data) 486 { 487 struct cpc_desc *cpc_ptr, *match_cpc_ptr; 488 struct acpi_psd_package *match_pdomain; 489 struct acpi_psd_package *pdomain; 490 int count_target, i; 491 492 /* 493 * Now that we have _PSD data from all CPUs, let's setup P-state 494 * domain info. 495 */ 496 cpc_ptr = per_cpu(cpc_desc_ptr, cpu); 497 if (!cpc_ptr) 498 return -EFAULT; 499 500 pdomain = &(cpc_ptr->domain_info); 501 cpumask_set_cpu(cpu, cpu_data->shared_cpu_map); 502 if (pdomain->num_processors <= 1) 503 return 0; 504 505 /* Validate the Domain info */ 506 count_target = pdomain->num_processors; 507 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 508 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ALL; 509 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 510 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_HW; 511 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 512 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ANY; 513 514 for_each_possible_cpu(i) { 515 if (i == cpu) 516 continue; 517 518 match_cpc_ptr = per_cpu(cpc_desc_ptr, i); 519 if (!match_cpc_ptr) 520 goto err_fault; 521 522 match_pdomain = &(match_cpc_ptr->domain_info); 523 if (match_pdomain->domain != pdomain->domain) 524 continue; 525 526 /* Here i and cpu are in the same domain */ 527 if (match_pdomain->num_processors != count_target) 528 goto err_fault; 529 530 if (pdomain->coord_type != match_pdomain->coord_type) 531 goto err_fault; 532 533 cpumask_set_cpu(i, cpu_data->shared_cpu_map); 534 } 535 536 return 0; 537 538 err_fault: 539 /* Assume no coordination on any error parsing domain info */ 540 cpumask_clear(cpu_data->shared_cpu_map); 541 cpumask_set_cpu(cpu, cpu_data->shared_cpu_map); 542 cpu_data->shared_type = CPUFREQ_SHARED_TYPE_NONE; 543 544 return -EFAULT; 545 } 546 EXPORT_SYMBOL_GPL(acpi_get_psd_map); 547 548 static int register_pcc_channel(int pcc_ss_idx) 549 { 550 struct pcc_mbox_chan *pcc_chan; 551 u64 usecs_lat; 552 553 if (pcc_ss_idx >= 0) { 554 pcc_chan = pcc_mbox_request_channel(&cppc_mbox_cl, pcc_ss_idx); 555 556 if (IS_ERR(pcc_chan)) { 557 pr_err("Failed to find PCC channel for subspace %d\n", 558 pcc_ss_idx); 559 return -ENODEV; 560 } 561 562 pcc_data[pcc_ss_idx]->pcc_channel = pcc_chan; 563 /* 564 * cppc_ss->latency is just a Nominal value. In reality 565 * the remote processor could be much slower to reply. 566 * So add an arbitrary amount of wait on top of Nominal. 567 */ 568 usecs_lat = NUM_RETRIES * pcc_chan->latency; 569 pcc_data[pcc_ss_idx]->deadline_us = usecs_lat; 570 pcc_data[pcc_ss_idx]->pcc_mrtt = pcc_chan->min_turnaround_time; 571 pcc_data[pcc_ss_idx]->pcc_mpar = pcc_chan->max_access_rate; 572 pcc_data[pcc_ss_idx]->pcc_nominal = pcc_chan->latency; 573 574 pcc_data[pcc_ss_idx]->pcc_comm_addr = 575 acpi_os_ioremap(pcc_chan->shmem_base_addr, 576 pcc_chan->shmem_size); 577 if (!pcc_data[pcc_ss_idx]->pcc_comm_addr) { 578 pr_err("Failed to ioremap PCC comm region mem for %d\n", 579 pcc_ss_idx); 580 return -ENOMEM; 581 } 582 583 /* Set flag so that we don't come here for each CPU. */ 584 pcc_data[pcc_ss_idx]->pcc_channel_acquired = true; 585 } 586 587 return 0; 588 } 589 590 /** 591 * cpc_ffh_supported() - check if FFH reading supported 592 * 593 * Check if the architecture has support for functional fixed hardware 594 * read/write capability. 595 * 596 * Return: true for supported, false for not supported 597 */ 598 bool __weak cpc_ffh_supported(void) 599 { 600 return false; 601 } 602 603 /** 604 * cpc_supported_by_cpu() - check if CPPC is supported by CPU 605 * 606 * Check if the architectural support for CPPC is present even 607 * if the _OSC hasn't prescribed it 608 * 609 * Return: true for supported, false for not supported 610 */ 611 bool __weak cpc_supported_by_cpu(void) 612 { 613 return false; 614 } 615 616 /** 617 * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace 618 * @pcc_ss_id: PCC Subspace index as in the PCC client ACPI package. 619 * 620 * Check and allocate the cppc_pcc_data memory. 621 * In some processor configurations it is possible that same subspace 622 * is shared between multiple CPUs. This is seen especially in CPUs 623 * with hardware multi-threading support. 624 * 625 * Return: 0 for success, errno for failure 626 */ 627 static int pcc_data_alloc(int pcc_ss_id) 628 { 629 if (pcc_ss_id < 0 || pcc_ss_id >= MAX_PCC_SUBSPACES) 630 return -EINVAL; 631 632 if (pcc_data[pcc_ss_id]) { 633 pcc_data[pcc_ss_id]->refcount++; 634 } else { 635 pcc_data[pcc_ss_id] = kzalloc(sizeof(struct cppc_pcc_data), 636 GFP_KERNEL); 637 if (!pcc_data[pcc_ss_id]) 638 return -ENOMEM; 639 pcc_data[pcc_ss_id]->refcount++; 640 } 641 642 return 0; 643 } 644 645 /* 646 * An example CPC table looks like the following. 647 * 648 * Name (_CPC, Package() { 649 * 17, // NumEntries 650 * 1, // Revision 651 * ResourceTemplate() {Register(PCC, 32, 0, 0x120, 2)}, // Highest Performance 652 * ResourceTemplate() {Register(PCC, 32, 0, 0x124, 2)}, // Nominal Performance 653 * ResourceTemplate() {Register(PCC, 32, 0, 0x128, 2)}, // Lowest Nonlinear Performance 654 * ResourceTemplate() {Register(PCC, 32, 0, 0x12C, 2)}, // Lowest Performance 655 * ResourceTemplate() {Register(PCC, 32, 0, 0x130, 2)}, // Guaranteed Performance Register 656 * ResourceTemplate() {Register(PCC, 32, 0, 0x110, 2)}, // Desired Performance Register 657 * ResourceTemplate() {Register(SystemMemory, 0, 0, 0, 0)}, 658 * ... 659 * ... 660 * ... 661 * } 662 * Each Register() encodes how to access that specific register. 663 * e.g. a sample PCC entry has the following encoding: 664 * 665 * Register ( 666 * PCC, // AddressSpaceKeyword 667 * 8, // RegisterBitWidth 668 * 8, // RegisterBitOffset 669 * 0x30, // RegisterAddress 670 * 9, // AccessSize (subspace ID) 671 * ) 672 */ 673 674 #ifndef arch_init_invariance_cppc 675 static inline void arch_init_invariance_cppc(void) { } 676 #endif 677 678 /** 679 * acpi_cppc_processor_probe - Search for per CPU _CPC objects. 680 * @pr: Ptr to acpi_processor containing this CPU's logical ID. 681 * 682 * Return: 0 for success or negative value for err. 683 */ 684 int acpi_cppc_processor_probe(struct acpi_processor *pr) 685 { 686 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL}; 687 union acpi_object *out_obj, *cpc_obj; 688 struct cpc_desc *cpc_ptr; 689 struct cpc_reg *gas_t; 690 struct device *cpu_dev; 691 acpi_handle handle = pr->handle; 692 unsigned int num_ent, i, cpc_rev; 693 int pcc_subspace_id = -1; 694 acpi_status status; 695 int ret = -ENODATA; 696 697 if (!osc_sb_cppc2_support_acked) { 698 pr_debug("CPPC v2 _OSC not acked\n"); 699 if (!cpc_supported_by_cpu()) { 700 pr_debug("CPPC is not supported by the CPU\n"); 701 return -ENODEV; 702 } 703 } 704 705 /* Parse the ACPI _CPC table for this CPU. */ 706 status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output, 707 ACPI_TYPE_PACKAGE); 708 if (ACPI_FAILURE(status)) { 709 ret = -ENODEV; 710 goto out_buf_free; 711 } 712 713 out_obj = (union acpi_object *) output.pointer; 714 715 cpc_ptr = kzalloc(sizeof(struct cpc_desc), GFP_KERNEL); 716 if (!cpc_ptr) { 717 ret = -ENOMEM; 718 goto out_buf_free; 719 } 720 721 /* First entry is NumEntries. */ 722 cpc_obj = &out_obj->package.elements[0]; 723 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 724 num_ent = cpc_obj->integer.value; 725 if (num_ent <= 1) { 726 pr_debug("Unexpected _CPC NumEntries value (%d) for CPU:%d\n", 727 num_ent, pr->id); 728 goto out_free; 729 } 730 } else { 731 pr_debug("Unexpected _CPC NumEntries entry type (%d) for CPU:%d\n", 732 cpc_obj->type, pr->id); 733 goto out_free; 734 } 735 736 /* Second entry should be revision. */ 737 cpc_obj = &out_obj->package.elements[1]; 738 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 739 cpc_rev = cpc_obj->integer.value; 740 } else { 741 pr_debug("Unexpected _CPC Revision entry type (%d) for CPU:%d\n", 742 cpc_obj->type, pr->id); 743 goto out_free; 744 } 745 746 if (cpc_rev < CPPC_V2_REV) { 747 pr_debug("Unsupported _CPC Revision (%d) for CPU:%d\n", cpc_rev, 748 pr->id); 749 goto out_free; 750 } 751 752 /* 753 * Disregard _CPC if the number of entries in the return pachage is not 754 * as expected, but support future revisions being proper supersets of 755 * the v3 and only causing more entries to be returned by _CPC. 756 */ 757 if ((cpc_rev == CPPC_V2_REV && num_ent != CPPC_V2_NUM_ENT) || 758 (cpc_rev == CPPC_V3_REV && num_ent != CPPC_V3_NUM_ENT) || 759 (cpc_rev > CPPC_V3_REV && num_ent <= CPPC_V3_NUM_ENT)) { 760 pr_debug("Unexpected number of _CPC return package entries (%d) for CPU:%d\n", 761 num_ent, pr->id); 762 goto out_free; 763 } 764 if (cpc_rev > CPPC_V3_REV) { 765 num_ent = CPPC_V3_NUM_ENT; 766 cpc_rev = CPPC_V3_REV; 767 } 768 769 cpc_ptr->num_entries = num_ent; 770 cpc_ptr->version = cpc_rev; 771 772 /* Iterate through remaining entries in _CPC */ 773 for (i = 2; i < num_ent; i++) { 774 cpc_obj = &out_obj->package.elements[i]; 775 776 if (cpc_obj->type == ACPI_TYPE_INTEGER) { 777 cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_INTEGER; 778 cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = cpc_obj->integer.value; 779 } else if (cpc_obj->type == ACPI_TYPE_BUFFER) { 780 gas_t = (struct cpc_reg *) 781 cpc_obj->buffer.pointer; 782 783 /* 784 * The PCC Subspace index is encoded inside 785 * the CPC table entries. The same PCC index 786 * will be used for all the PCC entries, 787 * so extract it only once. 788 */ 789 if (gas_t->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { 790 if (pcc_subspace_id < 0) { 791 pcc_subspace_id = gas_t->access_width; 792 if (pcc_data_alloc(pcc_subspace_id)) 793 goto out_free; 794 } else if (pcc_subspace_id != gas_t->access_width) { 795 pr_debug("Mismatched PCC ids in _CPC for CPU:%d\n", 796 pr->id); 797 goto out_free; 798 } 799 } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { 800 if (gas_t->address) { 801 void __iomem *addr; 802 size_t access_width; 803 804 if (!osc_cpc_flexible_adr_space_confirmed) { 805 pr_debug("Flexible address space capability not supported\n"); 806 if (!cpc_supported_by_cpu()) 807 goto out_free; 808 } 809 810 access_width = GET_BIT_WIDTH(gas_t) / 8; 811 addr = ioremap(gas_t->address, access_width); 812 if (!addr) 813 goto out_free; 814 cpc_ptr->cpc_regs[i-2].sys_mem_vaddr = addr; 815 } 816 } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { 817 if (gas_t->access_width < 1 || gas_t->access_width > 3) { 818 /* 819 * 1 = 8-bit, 2 = 16-bit, and 3 = 32-bit. 820 * SystemIO doesn't implement 64-bit 821 * registers. 822 */ 823 pr_debug("Invalid access width %d for SystemIO register in _CPC\n", 824 gas_t->access_width); 825 goto out_free; 826 } 827 if (gas_t->address & OVER_16BTS_MASK) { 828 /* SystemIO registers use 16-bit integer addresses */ 829 pr_debug("Invalid IO port %llu for SystemIO register in _CPC\n", 830 gas_t->address); 831 goto out_free; 832 } 833 if (!osc_cpc_flexible_adr_space_confirmed) { 834 pr_debug("Flexible address space capability not supported\n"); 835 if (!cpc_supported_by_cpu()) 836 goto out_free; 837 } 838 } else { 839 if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) { 840 /* Support only PCC, SystemMemory, SystemIO, and FFH type regs. */ 841 pr_debug("Unsupported register type (%d) in _CPC\n", 842 gas_t->space_id); 843 goto out_free; 844 } 845 } 846 847 cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_BUFFER; 848 memcpy(&cpc_ptr->cpc_regs[i-2].cpc_entry.reg, gas_t, sizeof(*gas_t)); 849 } else { 850 pr_debug("Invalid entry type (%d) in _CPC for CPU:%d\n", 851 i, pr->id); 852 goto out_free; 853 } 854 } 855 per_cpu(cpu_pcc_subspace_idx, pr->id) = pcc_subspace_id; 856 857 /* 858 * Initialize the remaining cpc_regs as unsupported. 859 * Example: In case FW exposes CPPC v2, the below loop will initialize 860 * LOWEST_FREQ and NOMINAL_FREQ regs as unsupported 861 */ 862 for (i = num_ent - 2; i < MAX_CPC_REG_ENT; i++) { 863 cpc_ptr->cpc_regs[i].type = ACPI_TYPE_INTEGER; 864 cpc_ptr->cpc_regs[i].cpc_entry.int_value = 0; 865 } 866 867 868 /* Store CPU Logical ID */ 869 cpc_ptr->cpu_id = pr->id; 870 raw_spin_lock_init(&cpc_ptr->rmw_lock); 871 872 /* Parse PSD data for this CPU */ 873 ret = acpi_get_psd(cpc_ptr, handle); 874 if (ret) 875 goto out_free; 876 877 /* Register PCC channel once for all PCC subspace ID. */ 878 if (pcc_subspace_id >= 0 && !pcc_data[pcc_subspace_id]->pcc_channel_acquired) { 879 ret = register_pcc_channel(pcc_subspace_id); 880 if (ret) 881 goto out_free; 882 883 init_rwsem(&pcc_data[pcc_subspace_id]->pcc_lock); 884 init_waitqueue_head(&pcc_data[pcc_subspace_id]->pcc_write_wait_q); 885 } 886 887 /* Everything looks okay */ 888 pr_debug("Parsed CPC struct for CPU: %d\n", pr->id); 889 890 /* Add per logical CPU nodes for reading its feedback counters. */ 891 cpu_dev = get_cpu_device(pr->id); 892 if (!cpu_dev) { 893 ret = -EINVAL; 894 goto out_free; 895 } 896 897 /* Plug PSD data into this CPU's CPC descriptor. */ 898 per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr; 899 900 ret = kobject_init_and_add(&cpc_ptr->kobj, &cppc_ktype, &cpu_dev->kobj, 901 "acpi_cppc"); 902 if (ret) { 903 per_cpu(cpc_desc_ptr, pr->id) = NULL; 904 kobject_put(&cpc_ptr->kobj); 905 goto out_free; 906 } 907 908 arch_init_invariance_cppc(); 909 910 kfree(output.pointer); 911 return 0; 912 913 out_free: 914 /* Free all the mapped sys mem areas for this CPU */ 915 for (i = 2; i < cpc_ptr->num_entries; i++) { 916 void __iomem *addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr; 917 918 if (addr) 919 iounmap(addr); 920 } 921 kfree(cpc_ptr); 922 923 out_buf_free: 924 kfree(output.pointer); 925 return ret; 926 } 927 EXPORT_SYMBOL_GPL(acpi_cppc_processor_probe); 928 929 /** 930 * acpi_cppc_processor_exit - Cleanup CPC structs. 931 * @pr: Ptr to acpi_processor containing this CPU's logical ID. 932 * 933 * Return: Void 934 */ 935 void acpi_cppc_processor_exit(struct acpi_processor *pr) 936 { 937 struct cpc_desc *cpc_ptr; 938 unsigned int i; 939 void __iomem *addr; 940 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, pr->id); 941 942 if (pcc_ss_id >= 0 && pcc_data[pcc_ss_id]) { 943 if (pcc_data[pcc_ss_id]->pcc_channel_acquired) { 944 pcc_data[pcc_ss_id]->refcount--; 945 if (!pcc_data[pcc_ss_id]->refcount) { 946 pcc_mbox_free_channel(pcc_data[pcc_ss_id]->pcc_channel); 947 kfree(pcc_data[pcc_ss_id]); 948 pcc_data[pcc_ss_id] = NULL; 949 } 950 } 951 } 952 953 cpc_ptr = per_cpu(cpc_desc_ptr, pr->id); 954 if (!cpc_ptr) 955 return; 956 957 /* Free all the mapped sys mem areas for this CPU */ 958 for (i = 2; i < cpc_ptr->num_entries; i++) { 959 addr = cpc_ptr->cpc_regs[i-2].sys_mem_vaddr; 960 if (addr) 961 iounmap(addr); 962 } 963 964 kobject_put(&cpc_ptr->kobj); 965 kfree(cpc_ptr); 966 } 967 EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit); 968 969 /** 970 * cpc_read_ffh() - Read FFH register 971 * @cpunum: CPU number to read 972 * @reg: cppc register information 973 * @val: place holder for return value 974 * 975 * Read bit_width bits from a specified address and bit_offset 976 * 977 * Return: 0 for success and error code 978 */ 979 int __weak cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val) 980 { 981 return -ENOTSUPP; 982 } 983 984 /** 985 * cpc_write_ffh() - Write FFH register 986 * @cpunum: CPU number to write 987 * @reg: cppc register information 988 * @val: value to write 989 * 990 * Write value of bit_width bits to a specified address and bit_offset 991 * 992 * Return: 0 for success and error code 993 */ 994 int __weak cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) 995 { 996 return -ENOTSUPP; 997 } 998 999 /* 1000 * Since cpc_read and cpc_write are called while holding pcc_lock, it should be 1001 * as fast as possible. We have already mapped the PCC subspace during init, so 1002 * we can directly write to it. 1003 */ 1004 1005 static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val) 1006 { 1007 void __iomem *vaddr = NULL; 1008 int size; 1009 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1010 struct cpc_reg *reg = ®_res->cpc_entry.reg; 1011 1012 if (reg_res->type == ACPI_TYPE_INTEGER) { 1013 *val = reg_res->cpc_entry.int_value; 1014 return 0; 1015 } 1016 1017 *val = 0; 1018 size = GET_BIT_WIDTH(reg); 1019 1020 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { 1021 u32 val_u32; 1022 acpi_status status; 1023 1024 status = acpi_os_read_port((acpi_io_address)reg->address, 1025 &val_u32, size); 1026 if (ACPI_FAILURE(status)) { 1027 pr_debug("Error: Failed to read SystemIO port %llx\n", 1028 reg->address); 1029 return -EFAULT; 1030 } 1031 1032 *val = val_u32; 1033 return 0; 1034 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) { 1035 /* 1036 * For registers in PCC space, the register size is determined 1037 * by the bit width field; the access size is used to indicate 1038 * the PCC subspace id. 1039 */ 1040 size = reg->bit_width; 1041 vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); 1042 } 1043 else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1044 vaddr = reg_res->sys_mem_vaddr; 1045 else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) 1046 return cpc_read_ffh(cpu, reg, val); 1047 else 1048 return acpi_os_read_memory((acpi_physical_address)reg->address, 1049 val, size); 1050 1051 switch (size) { 1052 case 8: 1053 *val = readb_relaxed(vaddr); 1054 break; 1055 case 16: 1056 *val = readw_relaxed(vaddr); 1057 break; 1058 case 32: 1059 *val = readl_relaxed(vaddr); 1060 break; 1061 case 64: 1062 *val = readq_relaxed(vaddr); 1063 break; 1064 default: 1065 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { 1066 pr_debug("Error: Cannot read %u bit width from system memory: 0x%llx\n", 1067 size, reg->address); 1068 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { 1069 pr_debug("Error: Cannot read %u bit width from PCC for ss: %d\n", 1070 size, pcc_ss_id); 1071 } 1072 return -EFAULT; 1073 } 1074 1075 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1076 *val = MASK_VAL_READ(reg, *val); 1077 1078 return 0; 1079 } 1080 1081 static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) 1082 { 1083 int ret_val = 0; 1084 int size; 1085 u64 prev_val; 1086 void __iomem *vaddr = NULL; 1087 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1088 struct cpc_reg *reg = ®_res->cpc_entry.reg; 1089 struct cpc_desc *cpc_desc; 1090 unsigned long flags; 1091 1092 size = GET_BIT_WIDTH(reg); 1093 1094 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { 1095 acpi_status status; 1096 1097 status = acpi_os_write_port((acpi_io_address)reg->address, 1098 (u32)val, size); 1099 if (ACPI_FAILURE(status)) { 1100 pr_debug("Error: Failed to write SystemIO port %llx\n", 1101 reg->address); 1102 return -EFAULT; 1103 } 1104 1105 return 0; 1106 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) { 1107 /* 1108 * For registers in PCC space, the register size is determined 1109 * by the bit width field; the access size is used to indicate 1110 * the PCC subspace id. 1111 */ 1112 size = reg->bit_width; 1113 vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); 1114 } 1115 else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1116 vaddr = reg_res->sys_mem_vaddr; 1117 else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) 1118 return cpc_write_ffh(cpu, reg, val); 1119 else 1120 return acpi_os_write_memory((acpi_physical_address)reg->address, 1121 val, size); 1122 1123 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { 1124 cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1125 if (!cpc_desc) { 1126 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1127 return -ENODEV; 1128 } 1129 1130 raw_spin_lock_irqsave(&cpc_desc->rmw_lock, flags); 1131 switch (size) { 1132 case 8: 1133 prev_val = readb_relaxed(vaddr); 1134 break; 1135 case 16: 1136 prev_val = readw_relaxed(vaddr); 1137 break; 1138 case 32: 1139 prev_val = readl_relaxed(vaddr); 1140 break; 1141 case 64: 1142 prev_val = readq_relaxed(vaddr); 1143 break; 1144 default: 1145 raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags); 1146 return -EFAULT; 1147 } 1148 val = MASK_VAL_WRITE(reg, prev_val, val); 1149 val |= prev_val; 1150 } 1151 1152 switch (size) { 1153 case 8: 1154 writeb_relaxed(val, vaddr); 1155 break; 1156 case 16: 1157 writew_relaxed(val, vaddr); 1158 break; 1159 case 32: 1160 writel_relaxed(val, vaddr); 1161 break; 1162 case 64: 1163 writeq_relaxed(val, vaddr); 1164 break; 1165 default: 1166 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { 1167 pr_debug("Error: Cannot write %u bit width to system memory: 0x%llx\n", 1168 size, reg->address); 1169 } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { 1170 pr_debug("Error: Cannot write %u bit width to PCC for ss: %d\n", 1171 size, pcc_ss_id); 1172 } 1173 ret_val = -EFAULT; 1174 break; 1175 } 1176 1177 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) 1178 raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags); 1179 1180 return ret_val; 1181 } 1182 1183 static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) 1184 { 1185 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1186 struct cpc_register_resource *reg; 1187 1188 if (!cpc_desc) { 1189 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1190 return -ENODEV; 1191 } 1192 1193 reg = &cpc_desc->cpc_regs[reg_idx]; 1194 1195 if (CPC_IN_PCC(reg)) { 1196 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1197 struct cppc_pcc_data *pcc_ss_data = NULL; 1198 int ret = 0; 1199 1200 if (pcc_ss_id < 0) 1201 return -EIO; 1202 1203 pcc_ss_data = pcc_data[pcc_ss_id]; 1204 1205 down_write(&pcc_ss_data->pcc_lock); 1206 1207 if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) 1208 cpc_read(cpunum, reg, perf); 1209 else 1210 ret = -EIO; 1211 1212 up_write(&pcc_ss_data->pcc_lock); 1213 1214 return ret; 1215 } 1216 1217 cpc_read(cpunum, reg, perf); 1218 1219 return 0; 1220 } 1221 1222 /** 1223 * cppc_get_desired_perf - Get the desired performance register value. 1224 * @cpunum: CPU from which to get desired performance. 1225 * @desired_perf: Return address. 1226 * 1227 * Return: 0 for success, -EIO otherwise. 1228 */ 1229 int cppc_get_desired_perf(int cpunum, u64 *desired_perf) 1230 { 1231 return cppc_get_perf(cpunum, DESIRED_PERF, desired_perf); 1232 } 1233 EXPORT_SYMBOL_GPL(cppc_get_desired_perf); 1234 1235 /** 1236 * cppc_get_nominal_perf - Get the nominal performance register value. 1237 * @cpunum: CPU from which to get nominal performance. 1238 * @nominal_perf: Return address. 1239 * 1240 * Return: 0 for success, -EIO otherwise. 1241 */ 1242 int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) 1243 { 1244 return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf); 1245 } 1246 1247 /** 1248 * cppc_get_highest_perf - Get the highest performance register value. 1249 * @cpunum: CPU from which to get highest performance. 1250 * @highest_perf: Return address. 1251 * 1252 * Return: 0 for success, -EIO otherwise. 1253 */ 1254 int cppc_get_highest_perf(int cpunum, u64 *highest_perf) 1255 { 1256 return cppc_get_perf(cpunum, HIGHEST_PERF, highest_perf); 1257 } 1258 EXPORT_SYMBOL_GPL(cppc_get_highest_perf); 1259 1260 /** 1261 * cppc_get_epp_perf - Get the epp register value. 1262 * @cpunum: CPU from which to get epp preference value. 1263 * @epp_perf: Return address. 1264 * 1265 * Return: 0 for success, -EIO otherwise. 1266 */ 1267 int cppc_get_epp_perf(int cpunum, u64 *epp_perf) 1268 { 1269 return cppc_get_perf(cpunum, ENERGY_PERF, epp_perf); 1270 } 1271 EXPORT_SYMBOL_GPL(cppc_get_epp_perf); 1272 1273 /** 1274 * cppc_get_perf_caps - Get a CPU's performance capabilities. 1275 * @cpunum: CPU from which to get capabilities info. 1276 * @perf_caps: ptr to cppc_perf_caps. See cppc_acpi.h 1277 * 1278 * Return: 0 for success with perf_caps populated else -ERRNO. 1279 */ 1280 int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) 1281 { 1282 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1283 struct cpc_register_resource *highest_reg, *lowest_reg, 1284 *lowest_non_linear_reg, *nominal_reg, *guaranteed_reg, 1285 *low_freq_reg = NULL, *nom_freq_reg = NULL; 1286 u64 high, low, guaranteed, nom, min_nonlinear, low_f = 0, nom_f = 0; 1287 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1288 struct cppc_pcc_data *pcc_ss_data = NULL; 1289 int ret = 0, regs_in_pcc = 0; 1290 1291 if (!cpc_desc) { 1292 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1293 return -ENODEV; 1294 } 1295 1296 highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF]; 1297 lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF]; 1298 lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF]; 1299 nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; 1300 low_freq_reg = &cpc_desc->cpc_regs[LOWEST_FREQ]; 1301 nom_freq_reg = &cpc_desc->cpc_regs[NOMINAL_FREQ]; 1302 guaranteed_reg = &cpc_desc->cpc_regs[GUARANTEED_PERF]; 1303 1304 /* Are any of the regs PCC ?*/ 1305 if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) || 1306 CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg) || 1307 CPC_IN_PCC(low_freq_reg) || CPC_IN_PCC(nom_freq_reg)) { 1308 if (pcc_ss_id < 0) { 1309 pr_debug("Invalid pcc_ss_id\n"); 1310 return -ENODEV; 1311 } 1312 pcc_ss_data = pcc_data[pcc_ss_id]; 1313 regs_in_pcc = 1; 1314 down_write(&pcc_ss_data->pcc_lock); 1315 /* Ring doorbell once to update PCC subspace */ 1316 if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) { 1317 ret = -EIO; 1318 goto out_err; 1319 } 1320 } 1321 1322 cpc_read(cpunum, highest_reg, &high); 1323 perf_caps->highest_perf = high; 1324 1325 cpc_read(cpunum, lowest_reg, &low); 1326 perf_caps->lowest_perf = low; 1327 1328 cpc_read(cpunum, nominal_reg, &nom); 1329 perf_caps->nominal_perf = nom; 1330 1331 if (guaranteed_reg->type != ACPI_TYPE_BUFFER || 1332 IS_NULL_REG(&guaranteed_reg->cpc_entry.reg)) { 1333 perf_caps->guaranteed_perf = 0; 1334 } else { 1335 cpc_read(cpunum, guaranteed_reg, &guaranteed); 1336 perf_caps->guaranteed_perf = guaranteed; 1337 } 1338 1339 cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear); 1340 perf_caps->lowest_nonlinear_perf = min_nonlinear; 1341 1342 if (!high || !low || !nom || !min_nonlinear) 1343 ret = -EFAULT; 1344 1345 /* Read optional lowest and nominal frequencies if present */ 1346 if (CPC_SUPPORTED(low_freq_reg)) 1347 cpc_read(cpunum, low_freq_reg, &low_f); 1348 1349 if (CPC_SUPPORTED(nom_freq_reg)) 1350 cpc_read(cpunum, nom_freq_reg, &nom_f); 1351 1352 perf_caps->lowest_freq = low_f; 1353 perf_caps->nominal_freq = nom_f; 1354 1355 1356 out_err: 1357 if (regs_in_pcc) 1358 up_write(&pcc_ss_data->pcc_lock); 1359 return ret; 1360 } 1361 EXPORT_SYMBOL_GPL(cppc_get_perf_caps); 1362 1363 /** 1364 * cppc_perf_ctrs_in_pcc - Check if any perf counters are in a PCC region. 1365 * 1366 * CPPC has flexibility about how CPU performance counters are accessed. 1367 * One of the choices is PCC regions, which can have a high access latency. This 1368 * routine allows callers of cppc_get_perf_ctrs() to know this ahead of time. 1369 * 1370 * Return: true if any of the counters are in PCC regions, false otherwise 1371 */ 1372 bool cppc_perf_ctrs_in_pcc(void) 1373 { 1374 int cpu; 1375 1376 for_each_present_cpu(cpu) { 1377 struct cpc_register_resource *ref_perf_reg; 1378 struct cpc_desc *cpc_desc; 1379 1380 cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1381 1382 if (CPC_IN_PCC(&cpc_desc->cpc_regs[DELIVERED_CTR]) || 1383 CPC_IN_PCC(&cpc_desc->cpc_regs[REFERENCE_CTR]) || 1384 CPC_IN_PCC(&cpc_desc->cpc_regs[CTR_WRAP_TIME])) 1385 return true; 1386 1387 1388 ref_perf_reg = &cpc_desc->cpc_regs[REFERENCE_PERF]; 1389 1390 /* 1391 * If reference perf register is not supported then we should 1392 * use the nominal perf value 1393 */ 1394 if (!CPC_SUPPORTED(ref_perf_reg)) 1395 ref_perf_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; 1396 1397 if (CPC_IN_PCC(ref_perf_reg)) 1398 return true; 1399 } 1400 1401 return false; 1402 } 1403 EXPORT_SYMBOL_GPL(cppc_perf_ctrs_in_pcc); 1404 1405 /** 1406 * cppc_get_perf_ctrs - Read a CPU's performance feedback counters. 1407 * @cpunum: CPU from which to read counters. 1408 * @perf_fb_ctrs: ptr to cppc_perf_fb_ctrs. See cppc_acpi.h 1409 * 1410 * Return: 0 for success with perf_fb_ctrs populated else -ERRNO. 1411 */ 1412 int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) 1413 { 1414 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1415 struct cpc_register_resource *delivered_reg, *reference_reg, 1416 *ref_perf_reg, *ctr_wrap_reg; 1417 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1418 struct cppc_pcc_data *pcc_ss_data = NULL; 1419 u64 delivered, reference, ref_perf, ctr_wrap_time; 1420 int ret = 0, regs_in_pcc = 0; 1421 1422 if (!cpc_desc) { 1423 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1424 return -ENODEV; 1425 } 1426 1427 delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR]; 1428 reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR]; 1429 ref_perf_reg = &cpc_desc->cpc_regs[REFERENCE_PERF]; 1430 ctr_wrap_reg = &cpc_desc->cpc_regs[CTR_WRAP_TIME]; 1431 1432 /* 1433 * If reference perf register is not supported then we should 1434 * use the nominal perf value 1435 */ 1436 if (!CPC_SUPPORTED(ref_perf_reg)) 1437 ref_perf_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; 1438 1439 /* Are any of the regs PCC ?*/ 1440 if (CPC_IN_PCC(delivered_reg) || CPC_IN_PCC(reference_reg) || 1441 CPC_IN_PCC(ctr_wrap_reg) || CPC_IN_PCC(ref_perf_reg)) { 1442 if (pcc_ss_id < 0) { 1443 pr_debug("Invalid pcc_ss_id\n"); 1444 return -ENODEV; 1445 } 1446 pcc_ss_data = pcc_data[pcc_ss_id]; 1447 down_write(&pcc_ss_data->pcc_lock); 1448 regs_in_pcc = 1; 1449 /* Ring doorbell once to update PCC subspace */ 1450 if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) { 1451 ret = -EIO; 1452 goto out_err; 1453 } 1454 } 1455 1456 cpc_read(cpunum, delivered_reg, &delivered); 1457 cpc_read(cpunum, reference_reg, &reference); 1458 cpc_read(cpunum, ref_perf_reg, &ref_perf); 1459 1460 /* 1461 * Per spec, if ctr_wrap_time optional register is unsupported, then the 1462 * performance counters are assumed to never wrap during the lifetime of 1463 * platform 1464 */ 1465 ctr_wrap_time = (u64)(~((u64)0)); 1466 if (CPC_SUPPORTED(ctr_wrap_reg)) 1467 cpc_read(cpunum, ctr_wrap_reg, &ctr_wrap_time); 1468 1469 if (!delivered || !reference || !ref_perf) { 1470 ret = -EFAULT; 1471 goto out_err; 1472 } 1473 1474 perf_fb_ctrs->delivered = delivered; 1475 perf_fb_ctrs->reference = reference; 1476 perf_fb_ctrs->reference_perf = ref_perf; 1477 perf_fb_ctrs->wraparound_time = ctr_wrap_time; 1478 out_err: 1479 if (regs_in_pcc) 1480 up_write(&pcc_ss_data->pcc_lock); 1481 return ret; 1482 } 1483 EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs); 1484 1485 /* 1486 * Set Energy Performance Preference Register value through 1487 * Performance Controls Interface 1488 */ 1489 int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable) 1490 { 1491 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1492 struct cpc_register_resource *epp_set_reg; 1493 struct cpc_register_resource *auto_sel_reg; 1494 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1495 struct cppc_pcc_data *pcc_ss_data = NULL; 1496 int ret; 1497 1498 if (!cpc_desc) { 1499 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1500 return -ENODEV; 1501 } 1502 1503 auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; 1504 epp_set_reg = &cpc_desc->cpc_regs[ENERGY_PERF]; 1505 1506 if (CPC_IN_PCC(epp_set_reg) || CPC_IN_PCC(auto_sel_reg)) { 1507 if (pcc_ss_id < 0) { 1508 pr_debug("Invalid pcc_ss_id for CPU:%d\n", cpu); 1509 return -ENODEV; 1510 } 1511 1512 if (CPC_SUPPORTED(auto_sel_reg)) { 1513 ret = cpc_write(cpu, auto_sel_reg, enable); 1514 if (ret) 1515 return ret; 1516 } 1517 1518 if (CPC_SUPPORTED(epp_set_reg)) { 1519 ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf); 1520 if (ret) 1521 return ret; 1522 } 1523 1524 pcc_ss_data = pcc_data[pcc_ss_id]; 1525 1526 down_write(&pcc_ss_data->pcc_lock); 1527 /* after writing CPC, transfer the ownership of PCC to platform */ 1528 ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1529 up_write(&pcc_ss_data->pcc_lock); 1530 } else if (osc_cpc_flexible_adr_space_confirmed && 1531 CPC_SUPPORTED(epp_set_reg) && CPC_IN_FFH(epp_set_reg)) { 1532 ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf); 1533 } else { 1534 ret = -ENOTSUPP; 1535 pr_debug("_CPC in PCC and _CPC in FFH are not supported\n"); 1536 } 1537 1538 return ret; 1539 } 1540 EXPORT_SYMBOL_GPL(cppc_set_epp_perf); 1541 1542 /** 1543 * cppc_get_auto_sel_caps - Read autonomous selection register. 1544 * @cpunum : CPU from which to read register. 1545 * @perf_caps : struct where autonomous selection register value is updated. 1546 */ 1547 int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf_caps) 1548 { 1549 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); 1550 struct cpc_register_resource *auto_sel_reg; 1551 u64 auto_sel; 1552 1553 if (!cpc_desc) { 1554 pr_debug("No CPC descriptor for CPU:%d\n", cpunum); 1555 return -ENODEV; 1556 } 1557 1558 auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; 1559 1560 if (!CPC_SUPPORTED(auto_sel_reg)) 1561 pr_warn_once("Autonomous mode is not unsupported!\n"); 1562 1563 if (CPC_IN_PCC(auto_sel_reg)) { 1564 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); 1565 struct cppc_pcc_data *pcc_ss_data = NULL; 1566 int ret = 0; 1567 1568 if (pcc_ss_id < 0) 1569 return -ENODEV; 1570 1571 pcc_ss_data = pcc_data[pcc_ss_id]; 1572 1573 down_write(&pcc_ss_data->pcc_lock); 1574 1575 if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0) { 1576 cpc_read(cpunum, auto_sel_reg, &auto_sel); 1577 perf_caps->auto_sel = (bool)auto_sel; 1578 } else { 1579 ret = -EIO; 1580 } 1581 1582 up_write(&pcc_ss_data->pcc_lock); 1583 1584 return ret; 1585 } 1586 1587 return 0; 1588 } 1589 EXPORT_SYMBOL_GPL(cppc_get_auto_sel_caps); 1590 1591 /** 1592 * cppc_set_auto_sel - Write autonomous selection register. 1593 * @cpu : CPU to which to write register. 1594 * @enable : the desired value of autonomous selection resiter to be updated. 1595 */ 1596 int cppc_set_auto_sel(int cpu, bool enable) 1597 { 1598 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1599 struct cpc_register_resource *auto_sel_reg; 1600 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1601 struct cppc_pcc_data *pcc_ss_data = NULL; 1602 int ret = -EINVAL; 1603 1604 if (!cpc_desc) { 1605 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1606 return -ENODEV; 1607 } 1608 1609 auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE]; 1610 1611 if (CPC_IN_PCC(auto_sel_reg)) { 1612 if (pcc_ss_id < 0) { 1613 pr_debug("Invalid pcc_ss_id\n"); 1614 return -ENODEV; 1615 } 1616 1617 if (CPC_SUPPORTED(auto_sel_reg)) { 1618 ret = cpc_write(cpu, auto_sel_reg, enable); 1619 if (ret) 1620 return ret; 1621 } 1622 1623 pcc_ss_data = pcc_data[pcc_ss_id]; 1624 1625 down_write(&pcc_ss_data->pcc_lock); 1626 /* after writing CPC, transfer the ownership of PCC to platform */ 1627 ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1628 up_write(&pcc_ss_data->pcc_lock); 1629 } else { 1630 ret = -ENOTSUPP; 1631 pr_debug("_CPC in PCC is not supported\n"); 1632 } 1633 1634 return ret; 1635 } 1636 EXPORT_SYMBOL_GPL(cppc_set_auto_sel); 1637 1638 /** 1639 * cppc_set_enable - Set to enable CPPC on the processor by writing the 1640 * Continuous Performance Control package EnableRegister field. 1641 * @cpu: CPU for which to enable CPPC register. 1642 * @enable: 0 - disable, 1 - enable CPPC feature on the processor. 1643 * 1644 * Return: 0 for success, -ERRNO or -EIO otherwise. 1645 */ 1646 int cppc_set_enable(int cpu, bool enable) 1647 { 1648 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1649 struct cpc_register_resource *enable_reg; 1650 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1651 struct cppc_pcc_data *pcc_ss_data = NULL; 1652 int ret = -EINVAL; 1653 1654 if (!cpc_desc) { 1655 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1656 return -EINVAL; 1657 } 1658 1659 enable_reg = &cpc_desc->cpc_regs[ENABLE]; 1660 1661 if (CPC_IN_PCC(enable_reg)) { 1662 1663 if (pcc_ss_id < 0) 1664 return -EIO; 1665 1666 ret = cpc_write(cpu, enable_reg, enable); 1667 if (ret) 1668 return ret; 1669 1670 pcc_ss_data = pcc_data[pcc_ss_id]; 1671 1672 down_write(&pcc_ss_data->pcc_lock); 1673 /* after writing CPC, transfer the ownership of PCC to platfrom */ 1674 ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1675 up_write(&pcc_ss_data->pcc_lock); 1676 return ret; 1677 } 1678 1679 return cpc_write(cpu, enable_reg, enable); 1680 } 1681 EXPORT_SYMBOL_GPL(cppc_set_enable); 1682 1683 /** 1684 * cppc_set_perf - Set a CPU's performance controls. 1685 * @cpu: CPU for which to set performance controls. 1686 * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h 1687 * 1688 * Return: 0 for success, -ERRNO otherwise. 1689 */ 1690 int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls) 1691 { 1692 struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu); 1693 struct cpc_register_resource *desired_reg, *min_perf_reg, *max_perf_reg; 1694 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); 1695 struct cppc_pcc_data *pcc_ss_data = NULL; 1696 int ret = 0; 1697 1698 if (!cpc_desc) { 1699 pr_debug("No CPC descriptor for CPU:%d\n", cpu); 1700 return -ENODEV; 1701 } 1702 1703 desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; 1704 min_perf_reg = &cpc_desc->cpc_regs[MIN_PERF]; 1705 max_perf_reg = &cpc_desc->cpc_regs[MAX_PERF]; 1706 1707 /* 1708 * This is Phase-I where we want to write to CPC registers 1709 * -> We want all CPUs to be able to execute this phase in parallel 1710 * 1711 * Since read_lock can be acquired by multiple CPUs simultaneously we 1712 * achieve that goal here 1713 */ 1714 if (CPC_IN_PCC(desired_reg) || CPC_IN_PCC(min_perf_reg) || CPC_IN_PCC(max_perf_reg)) { 1715 if (pcc_ss_id < 0) { 1716 pr_debug("Invalid pcc_ss_id\n"); 1717 return -ENODEV; 1718 } 1719 pcc_ss_data = pcc_data[pcc_ss_id]; 1720 down_read(&pcc_ss_data->pcc_lock); /* BEGIN Phase-I */ 1721 if (pcc_ss_data->platform_owns_pcc) { 1722 ret = check_pcc_chan(pcc_ss_id, false); 1723 if (ret) { 1724 up_read(&pcc_ss_data->pcc_lock); 1725 return ret; 1726 } 1727 } 1728 /* 1729 * Update the pending_write to make sure a PCC CMD_READ will not 1730 * arrive and steal the channel during the switch to write lock 1731 */ 1732 pcc_ss_data->pending_pcc_write_cmd = true; 1733 cpc_desc->write_cmd_id = pcc_ss_data->pcc_write_cnt; 1734 cpc_desc->write_cmd_status = 0; 1735 } 1736 1737 cpc_write(cpu, desired_reg, perf_ctrls->desired_perf); 1738 1739 /* 1740 * Only write if min_perf and max_perf not zero. Some drivers pass zero 1741 * value to min and max perf, but they don't mean to set the zero value, 1742 * they just don't want to write to those registers. 1743 */ 1744 if (perf_ctrls->min_perf) 1745 cpc_write(cpu, min_perf_reg, perf_ctrls->min_perf); 1746 if (perf_ctrls->max_perf) 1747 cpc_write(cpu, max_perf_reg, perf_ctrls->max_perf); 1748 1749 if (CPC_IN_PCC(desired_reg) || CPC_IN_PCC(min_perf_reg) || CPC_IN_PCC(max_perf_reg)) 1750 up_read(&pcc_ss_data->pcc_lock); /* END Phase-I */ 1751 /* 1752 * This is Phase-II where we transfer the ownership of PCC to Platform 1753 * 1754 * Short Summary: Basically if we think of a group of cppc_set_perf 1755 * requests that happened in short overlapping interval. The last CPU to 1756 * come out of Phase-I will enter Phase-II and ring the doorbell. 1757 * 1758 * We have the following requirements for Phase-II: 1759 * 1. We want to execute Phase-II only when there are no CPUs 1760 * currently executing in Phase-I 1761 * 2. Once we start Phase-II we want to avoid all other CPUs from 1762 * entering Phase-I. 1763 * 3. We want only one CPU among all those who went through Phase-I 1764 * to run phase-II 1765 * 1766 * If write_trylock fails to get the lock and doesn't transfer the 1767 * PCC ownership to the platform, then one of the following will be TRUE 1768 * 1. There is at-least one CPU in Phase-I which will later execute 1769 * write_trylock, so the CPUs in Phase-I will be responsible for 1770 * executing the Phase-II. 1771 * 2. Some other CPU has beaten this CPU to successfully execute the 1772 * write_trylock and has already acquired the write_lock. We know for a 1773 * fact it (other CPU acquiring the write_lock) couldn't have happened 1774 * before this CPU's Phase-I as we held the read_lock. 1775 * 3. Some other CPU executing pcc CMD_READ has stolen the 1776 * down_write, in which case, send_pcc_cmd will check for pending 1777 * CMD_WRITE commands by checking the pending_pcc_write_cmd. 1778 * So this CPU can be certain that its request will be delivered 1779 * So in all cases, this CPU knows that its request will be delivered 1780 * by another CPU and can return 1781 * 1782 * After getting the down_write we still need to check for 1783 * pending_pcc_write_cmd to take care of the following scenario 1784 * The thread running this code could be scheduled out between 1785 * Phase-I and Phase-II. Before it is scheduled back on, another CPU 1786 * could have delivered the request to Platform by triggering the 1787 * doorbell and transferred the ownership of PCC to platform. So this 1788 * avoids triggering an unnecessary doorbell and more importantly before 1789 * triggering the doorbell it makes sure that the PCC channel ownership 1790 * is still with OSPM. 1791 * pending_pcc_write_cmd can also be cleared by a different CPU, if 1792 * there was a pcc CMD_READ waiting on down_write and it steals the lock 1793 * before the pcc CMD_WRITE is completed. send_pcc_cmd checks for this 1794 * case during a CMD_READ and if there are pending writes it delivers 1795 * the write command before servicing the read command 1796 */ 1797 if (CPC_IN_PCC(desired_reg) || CPC_IN_PCC(min_perf_reg) || CPC_IN_PCC(max_perf_reg)) { 1798 if (down_write_trylock(&pcc_ss_data->pcc_lock)) {/* BEGIN Phase-II */ 1799 /* Update only if there are pending write commands */ 1800 if (pcc_ss_data->pending_pcc_write_cmd) 1801 send_pcc_cmd(pcc_ss_id, CMD_WRITE); 1802 up_write(&pcc_ss_data->pcc_lock); /* END Phase-II */ 1803 } else 1804 /* Wait until pcc_write_cnt is updated by send_pcc_cmd */ 1805 wait_event(pcc_ss_data->pcc_write_wait_q, 1806 cpc_desc->write_cmd_id != pcc_ss_data->pcc_write_cnt); 1807 1808 /* send_pcc_cmd updates the status in case of failure */ 1809 ret = cpc_desc->write_cmd_status; 1810 } 1811 return ret; 1812 } 1813 EXPORT_SYMBOL_GPL(cppc_set_perf); 1814 1815 /** 1816 * cppc_get_transition_latency - returns frequency transition latency in ns 1817 * @cpu_num: CPU number for per_cpu(). 1818 * 1819 * ACPI CPPC does not explicitly specify how a platform can specify the 1820 * transition latency for performance change requests. The closest we have 1821 * is the timing information from the PCCT tables which provides the info 1822 * on the number and frequency of PCC commands the platform can handle. 1823 * 1824 * If desired_reg is in the SystemMemory or SystemIo ACPI address space, 1825 * then assume there is no latency. 1826 */ 1827 unsigned int cppc_get_transition_latency(int cpu_num) 1828 { 1829 /* 1830 * Expected transition latency is based on the PCCT timing values 1831 * Below are definition from ACPI spec: 1832 * pcc_nominal- Expected latency to process a command, in microseconds 1833 * pcc_mpar - The maximum number of periodic requests that the subspace 1834 * channel can support, reported in commands per minute. 0 1835 * indicates no limitation. 1836 * pcc_mrtt - The minimum amount of time that OSPM must wait after the 1837 * completion of a command before issuing the next command, 1838 * in microseconds. 1839 */ 1840 unsigned int latency_ns = 0; 1841 struct cpc_desc *cpc_desc; 1842 struct cpc_register_resource *desired_reg; 1843 int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu_num); 1844 struct cppc_pcc_data *pcc_ss_data; 1845 1846 cpc_desc = per_cpu(cpc_desc_ptr, cpu_num); 1847 if (!cpc_desc) 1848 return CPUFREQ_ETERNAL; 1849 1850 desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; 1851 if (CPC_IN_SYSTEM_MEMORY(desired_reg) || CPC_IN_SYSTEM_IO(desired_reg)) 1852 return 0; 1853 else if (!CPC_IN_PCC(desired_reg)) 1854 return CPUFREQ_ETERNAL; 1855 1856 if (pcc_ss_id < 0) 1857 return CPUFREQ_ETERNAL; 1858 1859 pcc_ss_data = pcc_data[pcc_ss_id]; 1860 if (pcc_ss_data->pcc_mpar) 1861 latency_ns = 60 * (1000 * 1000 * 1000 / pcc_ss_data->pcc_mpar); 1862 1863 latency_ns = max(latency_ns, pcc_ss_data->pcc_nominal * 1000); 1864 latency_ns = max(latency_ns, pcc_ss_data->pcc_mrtt * 1000); 1865 1866 return latency_ns; 1867 } 1868 EXPORT_SYMBOL_GPL(cppc_get_transition_latency); 1869 1870 /* Minimum struct length needed for the DMI processor entry we want */ 1871 #define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48 1872 1873 /* Offset in the DMI processor structure for the max frequency */ 1874 #define DMI_PROCESSOR_MAX_SPEED 0x14 1875 1876 /* Callback function used to retrieve the max frequency from DMI */ 1877 static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private) 1878 { 1879 const u8 *dmi_data = (const u8 *)dm; 1880 u16 *mhz = (u16 *)private; 1881 1882 if (dm->type == DMI_ENTRY_PROCESSOR && 1883 dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) { 1884 u16 val = (u16)get_unaligned((const u16 *) 1885 (dmi_data + DMI_PROCESSOR_MAX_SPEED)); 1886 *mhz = umax(val, *mhz); 1887 } 1888 } 1889 1890 /* Look up the max frequency in DMI */ 1891 static u64 cppc_get_dmi_max_khz(void) 1892 { 1893 u16 mhz = 0; 1894 1895 dmi_walk(cppc_find_dmi_mhz, &mhz); 1896 1897 /* 1898 * Real stupid fallback value, just in case there is no 1899 * actual value set. 1900 */ 1901 mhz = mhz ? mhz : 1; 1902 1903 return KHZ_PER_MHZ * mhz; 1904 } 1905 1906 /* 1907 * If CPPC lowest_freq and nominal_freq registers are exposed then we can 1908 * use them to convert perf to freq and vice versa. The conversion is 1909 * extrapolated as an affine function passing by the 2 points: 1910 * - (Low perf, Low freq) 1911 * - (Nominal perf, Nominal freq) 1912 */ 1913 unsigned int cppc_perf_to_khz(struct cppc_perf_caps *caps, unsigned int perf) 1914 { 1915 s64 retval, offset = 0; 1916 static u64 max_khz; 1917 u64 mul, div; 1918 1919 if (caps->lowest_freq && caps->nominal_freq) { 1920 /* Avoid special case when nominal_freq is equal to lowest_freq */ 1921 if (caps->lowest_freq == caps->nominal_freq) { 1922 mul = caps->nominal_freq; 1923 div = caps->nominal_perf; 1924 } else { 1925 mul = caps->nominal_freq - caps->lowest_freq; 1926 div = caps->nominal_perf - caps->lowest_perf; 1927 } 1928 mul *= KHZ_PER_MHZ; 1929 offset = caps->nominal_freq * KHZ_PER_MHZ - 1930 div64_u64(caps->nominal_perf * mul, div); 1931 } else { 1932 if (!max_khz) 1933 max_khz = cppc_get_dmi_max_khz(); 1934 mul = max_khz; 1935 div = caps->highest_perf; 1936 } 1937 1938 retval = offset + div64_u64(perf * mul, div); 1939 if (retval >= 0) 1940 return retval; 1941 return 0; 1942 } 1943 EXPORT_SYMBOL_GPL(cppc_perf_to_khz); 1944 1945 unsigned int cppc_khz_to_perf(struct cppc_perf_caps *caps, unsigned int freq) 1946 { 1947 s64 retval, offset = 0; 1948 static u64 max_khz; 1949 u64 mul, div; 1950 1951 if (caps->lowest_freq && caps->nominal_freq) { 1952 /* Avoid special case when nominal_freq is equal to lowest_freq */ 1953 if (caps->lowest_freq == caps->nominal_freq) { 1954 mul = caps->nominal_perf; 1955 div = caps->nominal_freq; 1956 } else { 1957 mul = caps->nominal_perf - caps->lowest_perf; 1958 div = caps->nominal_freq - caps->lowest_freq; 1959 } 1960 /* 1961 * We don't need to convert to kHz for computing offset and can 1962 * directly use nominal_freq and lowest_freq as the div64_u64 1963 * will remove the frequency unit. 1964 */ 1965 offset = caps->nominal_perf - 1966 div64_u64(caps->nominal_freq * mul, div); 1967 /* But we need it for computing the perf level. */ 1968 div *= KHZ_PER_MHZ; 1969 } else { 1970 if (!max_khz) 1971 max_khz = cppc_get_dmi_max_khz(); 1972 mul = caps->highest_perf; 1973 div = max_khz; 1974 } 1975 1976 retval = offset + div64_u64(freq * mul, div); 1977 if (retval >= 0) 1978 return retval; 1979 return 0; 1980 } 1981 EXPORT_SYMBOL_GPL(cppc_khz_to_perf); 1982