1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2012 by Oracle Inc 4 * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 5 * 6 * This code borrows ideas from https://lkml.org/lkml/2011/11/30/249 7 * so many thanks go to Kevin Tian <kevin.tian@intel.com> 8 * and Yu Ke <ke.yu@intel.com>. 9 */ 10 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 12 13 #include <linux/cpumask.h> 14 #include <linux/cpufreq.h> 15 #include <linux/freezer.h> 16 #include <linux/kernel.h> 17 #include <linux/kthread.h> 18 #include <linux/init.h> 19 #include <linux/module.h> 20 #include <linux/types.h> 21 #include <linux/syscore_ops.h> 22 #include <linux/acpi.h> 23 #include <acpi/processor.h> 24 #include <xen/xen.h> 25 #include <xen/interface/platform.h> 26 #include <asm/xen/hypercall.h> 27 28 static int no_hypercall; 29 MODULE_PARM_DESC(off, "Inhibit the hypercall."); 30 module_param_named(off, no_hypercall, int, 0400); 31 32 /* 33 * Note: Do not convert the acpi_id* below to cpumask_var_t or use cpumask_bit 34 * - as those shrink to nr_cpu_bits (which is dependent on possible_cpu), which 35 * can be less than what we want to put in. Instead use the 'nr_acpi_bits' 36 * which is dynamically computed based on the MADT or x2APIC table. 37 */ 38 static unsigned int nr_acpi_bits; 39 /* Mutex to protect the acpi_ids_done - for CPU hotplug use. */ 40 static DEFINE_MUTEX(acpi_ids_mutex); 41 /* Which ACPI ID we have processed from 'struct acpi_processor'. */ 42 static unsigned long *acpi_ids_done; 43 /* Which ACPI ID exist in the SSDT/DSDT processor definitions. */ 44 static unsigned long *acpi_id_present; 45 /* And if there is an _CST definition (or a PBLK) for the ACPI IDs */ 46 static unsigned long *acpi_id_cst_present; 47 /* Which ACPI P-State dependencies for a enumerated processor */ 48 static struct acpi_psd_package *acpi_psd; 49 50 static int push_cxx_to_hypervisor(struct acpi_processor *_pr) 51 { 52 struct xen_platform_op op = { 53 .cmd = XENPF_set_processor_pminfo, 54 .interface_version = XENPF_INTERFACE_VERSION, 55 .u.set_pminfo.id = _pr->acpi_id, 56 .u.set_pminfo.type = XEN_PM_CX, 57 }; 58 struct xen_processor_cx *dst_cx, *dst_cx_states = NULL; 59 struct acpi_processor_cx *cx; 60 unsigned int i, ok; 61 int ret = 0; 62 63 dst_cx_states = kcalloc(_pr->power.count, 64 sizeof(struct xen_processor_cx), GFP_KERNEL); 65 if (!dst_cx_states) 66 return -ENOMEM; 67 68 for (ok = 0, i = 1; i <= _pr->power.count; i++) { 69 cx = &_pr->power.states[i]; 70 if (!cx->valid) 71 continue; 72 73 dst_cx = &(dst_cx_states[ok++]); 74 75 dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO; 76 if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 77 dst_cx->reg.bit_width = 8; 78 dst_cx->reg.bit_offset = 0; 79 dst_cx->reg.access_size = 1; 80 } else { 81 dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE; 82 if (cx->entry_method == ACPI_CSTATE_FFH) { 83 /* NATIVE_CSTATE_BEYOND_HALT */ 84 dst_cx->reg.bit_offset = 2; 85 dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */ 86 } 87 dst_cx->reg.access_size = 0; 88 } 89 dst_cx->reg.address = cx->address; 90 91 dst_cx->type = cx->type; 92 dst_cx->latency = cx->latency; 93 94 dst_cx->dpcnt = 0; 95 set_xen_guest_handle(dst_cx->dp, NULL); 96 } 97 if (!ok) { 98 pr_debug("No _Cx for ACPI CPU %u\n", _pr->acpi_id); 99 kfree(dst_cx_states); 100 return -EINVAL; 101 } 102 op.u.set_pminfo.power.count = ok; 103 op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control; 104 op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check; 105 op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst; 106 op.u.set_pminfo.power.flags.power_setup_done = 107 _pr->flags.power_setup_done; 108 109 set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states); 110 111 if (!no_hypercall) 112 ret = HYPERVISOR_platform_op(&op); 113 114 if (!ret) { 115 pr_debug("ACPI CPU%u - C-states uploaded.\n", _pr->acpi_id); 116 for (i = 1; i <= _pr->power.count; i++) { 117 cx = &_pr->power.states[i]; 118 if (!cx->valid) 119 continue; 120 pr_debug(" C%d: %s %d uS\n", 121 cx->type, cx->desc, (u32)cx->latency); 122 } 123 } else if ((ret != -EINVAL) && (ret != -ENOSYS)) 124 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI 125 * table is referencing a non-existing CPU - which can happen 126 * with broken ACPI tables. */ 127 pr_err("(CX): Hypervisor error (%d) for ACPI CPU%u\n", 128 ret, _pr->acpi_id); 129 130 kfree(dst_cx_states); 131 132 return ret; 133 } 134 static struct xen_processor_px * 135 xen_copy_pss_data(struct acpi_processor *_pr, 136 struct xen_processor_performance *dst_perf) 137 { 138 struct xen_processor_px *dst_states = NULL; 139 unsigned int i; 140 141 BUILD_BUG_ON(sizeof(struct xen_processor_px) != 142 sizeof(struct acpi_processor_px)); 143 144 dst_states = kcalloc(_pr->performance->state_count, 145 sizeof(struct xen_processor_px), GFP_KERNEL); 146 if (!dst_states) 147 return ERR_PTR(-ENOMEM); 148 149 dst_perf->state_count = _pr->performance->state_count; 150 for (i = 0; i < _pr->performance->state_count; i++) { 151 /* Fortunatly for us, they are both the same size */ 152 memcpy(&(dst_states[i]), &(_pr->performance->states[i]), 153 sizeof(struct acpi_processor_px)); 154 } 155 return dst_states; 156 } 157 static int xen_copy_psd_data(struct acpi_processor *_pr, 158 struct xen_processor_performance *dst) 159 { 160 struct acpi_psd_package *pdomain; 161 162 BUILD_BUG_ON(sizeof(struct xen_psd_package) != 163 sizeof(struct acpi_psd_package)); 164 165 /* This information is enumerated only if acpi_processor_preregister_performance 166 * has been called. 167 */ 168 dst->shared_type = _pr->performance->shared_type; 169 170 pdomain = &(_pr->performance->domain_info); 171 172 /* 'acpi_processor_preregister_performance' does not parse if the 173 * num_processors <= 1, but Xen still requires it. Do it manually here. 174 */ 175 if (pdomain->num_processors <= 1) { 176 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 177 dst->shared_type = CPUFREQ_SHARED_TYPE_ALL; 178 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 179 dst->shared_type = CPUFREQ_SHARED_TYPE_HW; 180 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 181 dst->shared_type = CPUFREQ_SHARED_TYPE_ANY; 182 183 } 184 memcpy(&(dst->domain_info), pdomain, sizeof(struct acpi_psd_package)); 185 return 0; 186 } 187 static int xen_copy_pct_data(struct acpi_pct_register *pct, 188 struct xen_pct_register *dst_pct) 189 { 190 /* It would be nice if you could just do 'memcpy(pct, dst_pct') but 191 * sadly the Xen structure did not have the proper padding so the 192 * descriptor field takes two (dst_pct) bytes instead of one (pct). 193 */ 194 dst_pct->descriptor = pct->descriptor; 195 dst_pct->length = pct->length; 196 dst_pct->space_id = pct->space_id; 197 dst_pct->bit_width = pct->bit_width; 198 dst_pct->bit_offset = pct->bit_offset; 199 dst_pct->reserved = pct->reserved; 200 dst_pct->address = pct->address; 201 return 0; 202 } 203 static int push_pxx_to_hypervisor(struct acpi_processor *_pr) 204 { 205 int ret = 0; 206 struct xen_platform_op op = { 207 .cmd = XENPF_set_processor_pminfo, 208 .interface_version = XENPF_INTERFACE_VERSION, 209 .u.set_pminfo.id = _pr->acpi_id, 210 .u.set_pminfo.type = XEN_PM_PX, 211 }; 212 struct xen_processor_performance *dst_perf; 213 struct xen_processor_px *dst_states = NULL; 214 215 dst_perf = &op.u.set_pminfo.perf; 216 217 dst_perf->platform_limit = _pr->performance_platform_limit; 218 dst_perf->flags |= XEN_PX_PPC; 219 xen_copy_pct_data(&(_pr->performance->control_register), 220 &dst_perf->control_register); 221 xen_copy_pct_data(&(_pr->performance->status_register), 222 &dst_perf->status_register); 223 dst_perf->flags |= XEN_PX_PCT; 224 dst_states = xen_copy_pss_data(_pr, dst_perf); 225 if (!IS_ERR_OR_NULL(dst_states)) { 226 set_xen_guest_handle(dst_perf->states, dst_states); 227 dst_perf->flags |= XEN_PX_PSS; 228 } 229 if (!xen_copy_psd_data(_pr, dst_perf)) 230 dst_perf->flags |= XEN_PX_PSD; 231 232 if (dst_perf->flags != (XEN_PX_PSD | XEN_PX_PSS | XEN_PX_PCT | XEN_PX_PPC)) { 233 pr_warn("ACPI CPU%u missing some P-state data (%x), skipping\n", 234 _pr->acpi_id, dst_perf->flags); 235 ret = -ENODEV; 236 goto err_free; 237 } 238 239 if (!no_hypercall) 240 ret = HYPERVISOR_platform_op(&op); 241 242 if (!ret) { 243 struct acpi_processor_performance *perf; 244 unsigned int i; 245 246 perf = _pr->performance; 247 pr_debug("ACPI CPU%u - P-states uploaded.\n", _pr->acpi_id); 248 for (i = 0; i < perf->state_count; i++) { 249 pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n", 250 (i == perf->state ? '*' : ' '), i, 251 (u32) perf->states[i].core_frequency, 252 (u32) perf->states[i].power, 253 (u32) perf->states[i].transition_latency); 254 } 255 } else if ((ret != -EINVAL) && (ret != -ENOSYS)) 256 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI 257 * table is referencing a non-existing CPU - which can happen 258 * with broken ACPI tables. */ 259 pr_warn("(_PXX): Hypervisor error (%d) for ACPI CPU%u\n", 260 ret, _pr->acpi_id); 261 err_free: 262 if (!IS_ERR_OR_NULL(dst_states)) 263 kfree(dst_states); 264 265 return ret; 266 } 267 static int upload_pm_data(struct acpi_processor *_pr) 268 { 269 int err = 0; 270 271 mutex_lock(&acpi_ids_mutex); 272 if (__test_and_set_bit(_pr->acpi_id, acpi_ids_done)) { 273 mutex_unlock(&acpi_ids_mutex); 274 return -EBUSY; 275 } 276 if (_pr->flags.power) 277 err = push_cxx_to_hypervisor(_pr); 278 279 if (_pr->performance && _pr->performance->states) 280 err |= push_pxx_to_hypervisor(_pr); 281 282 mutex_unlock(&acpi_ids_mutex); 283 return err; 284 } 285 static unsigned int __init get_max_acpi_id(void) 286 { 287 struct xenpf_pcpuinfo *info; 288 struct xen_platform_op op = { 289 .cmd = XENPF_get_cpuinfo, 290 .interface_version = XENPF_INTERFACE_VERSION, 291 }; 292 int ret = 0; 293 unsigned int i, last_cpu, max_acpi_id = 0; 294 295 info = &op.u.pcpu_info; 296 info->xen_cpuid = 0; 297 298 ret = HYPERVISOR_platform_op(&op); 299 if (ret) 300 return NR_CPUS; 301 302 /* The max_present is the same irregardless of the xen_cpuid */ 303 last_cpu = op.u.pcpu_info.max_present; 304 for (i = 0; i <= last_cpu; i++) { 305 info->xen_cpuid = i; 306 ret = HYPERVISOR_platform_op(&op); 307 if (ret) 308 continue; 309 max_acpi_id = max(info->acpi_id, max_acpi_id); 310 } 311 max_acpi_id *= 2; /* Slack for CPU hotplug support. */ 312 pr_debug("Max ACPI ID: %u\n", max_acpi_id); 313 return max_acpi_id; 314 } 315 /* 316 * The read_acpi_id and check_acpi_ids are there to support the Xen 317 * oddity of virtual CPUs != physical CPUs in the initial domain. 318 * The user can supply 'xen_max_vcpus=X' on the Xen hypervisor line 319 * which will band the amount of CPUs the initial domain can see. 320 * In general that is OK, except it plays havoc with any of the 321 * for_each_[present|online]_cpu macros which are banded to the virtual 322 * CPU amount. 323 */ 324 static acpi_status 325 read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv) 326 { 327 u32 acpi_id; 328 acpi_status status; 329 acpi_object_type acpi_type; 330 unsigned long long tmp; 331 union acpi_object object = { 0 }; 332 struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; 333 acpi_io_address pblk = 0; 334 335 status = acpi_get_type(handle, &acpi_type); 336 if (ACPI_FAILURE(status)) 337 return AE_OK; 338 339 switch (acpi_type) { 340 case ACPI_TYPE_PROCESSOR: 341 status = acpi_evaluate_object(handle, NULL, NULL, &buffer); 342 if (ACPI_FAILURE(status)) 343 return AE_OK; 344 acpi_id = object.processor.proc_id; 345 pblk = object.processor.pblk_address; 346 break; 347 case ACPI_TYPE_DEVICE: 348 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp); 349 if (ACPI_FAILURE(status)) 350 return AE_OK; 351 acpi_id = tmp; 352 break; 353 default: 354 return AE_OK; 355 } 356 if (invalid_phys_cpuid(acpi_get_phys_id(handle, 357 acpi_type == ACPI_TYPE_DEVICE, 358 acpi_id))) { 359 pr_debug("CPU with ACPI ID %u is unavailable\n", acpi_id); 360 return AE_OK; 361 } 362 /* There are more ACPI Processor objects than in x2APIC or MADT. 363 * This can happen with incorrect ACPI SSDT declerations. */ 364 if (acpi_id >= nr_acpi_bits) { 365 pr_debug("max acpi id %u, trying to set %u\n", 366 nr_acpi_bits - 1, acpi_id); 367 return AE_OK; 368 } 369 /* OK, There is a ACPI Processor object */ 370 __set_bit(acpi_id, acpi_id_present); 371 372 pr_debug("ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, (unsigned long)pblk); 373 374 /* It has P-state dependencies */ 375 if (!acpi_processor_get_psd(handle, &acpi_psd[acpi_id])) { 376 pr_debug("ACPI CPU%u w/ PST:coord_type = %llu domain = %llu\n", 377 acpi_id, acpi_psd[acpi_id].coord_type, 378 acpi_psd[acpi_id].domain); 379 } 380 381 status = acpi_evaluate_object(handle, "_CST", NULL, &buffer); 382 if (ACPI_FAILURE(status)) { 383 if (!pblk) 384 return AE_OK; 385 } 386 /* .. and it has a C-state */ 387 __set_bit(acpi_id, acpi_id_cst_present); 388 389 return AE_OK; 390 } 391 static int check_acpi_ids(struct acpi_processor *pr_backup) 392 { 393 394 if (!pr_backup) 395 return -ENODEV; 396 397 if (acpi_id_present && acpi_id_cst_present) 398 /* OK, done this once .. skip to uploading */ 399 goto upload; 400 401 /* All online CPUs have been processed at this stage. Now verify 402 * whether in fact "online CPUs" == physical CPUs. 403 */ 404 acpi_id_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL); 405 if (!acpi_id_present) 406 return -ENOMEM; 407 408 acpi_id_cst_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL); 409 if (!acpi_id_cst_present) { 410 bitmap_free(acpi_id_present); 411 return -ENOMEM; 412 } 413 414 acpi_psd = kcalloc(nr_acpi_bits, sizeof(struct acpi_psd_package), 415 GFP_KERNEL); 416 if (!acpi_psd) { 417 bitmap_free(acpi_id_present); 418 bitmap_free(acpi_id_cst_present); 419 return -ENOMEM; 420 } 421 422 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, 423 ACPI_UINT32_MAX, 424 read_acpi_id, NULL, NULL, NULL); 425 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, read_acpi_id, NULL, NULL); 426 427 upload: 428 if (!bitmap_equal(acpi_id_present, acpi_ids_done, nr_acpi_bits)) { 429 unsigned int i; 430 for_each_set_bit(i, acpi_id_present, nr_acpi_bits) { 431 pr_backup->acpi_id = i; 432 /* Mask out C-states if there are no _CST or PBLK */ 433 pr_backup->flags.power = test_bit(i, acpi_id_cst_present); 434 /* num_entries is non-zero if we evaluated _PSD */ 435 if (acpi_psd[i].num_entries) { 436 memcpy(&pr_backup->performance->domain_info, 437 &acpi_psd[i], 438 sizeof(struct acpi_psd_package)); 439 } 440 (void)upload_pm_data(pr_backup); 441 } 442 } 443 444 return 0; 445 } 446 447 /* acpi_perf_data is a pointer to percpu data. */ 448 static struct acpi_processor_performance __percpu *acpi_perf_data; 449 450 static void free_acpi_perf_data(void) 451 { 452 unsigned int i; 453 454 /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */ 455 for_each_possible_cpu(i) 456 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i) 457 ->shared_cpu_map); 458 free_percpu(acpi_perf_data); 459 } 460 461 static int xen_upload_processor_pm_data(void) 462 { 463 struct acpi_processor *pr_backup = NULL; 464 unsigned int i; 465 int rc = 0; 466 467 pr_info("Uploading Xen processor PM info\n"); 468 469 for_each_possible_cpu(i) { 470 struct acpi_processor *_pr; 471 _pr = per_cpu(processors, i /* APIC ID */); 472 if (!_pr) 473 continue; 474 475 if (!pr_backup) { 476 pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL); 477 if (pr_backup) 478 memcpy(pr_backup, _pr, sizeof(struct acpi_processor)); 479 } 480 (void)upload_pm_data(_pr); 481 } 482 483 rc = check_acpi_ids(pr_backup); 484 kfree(pr_backup); 485 486 return rc; 487 } 488 489 static void xen_acpi_processor_resume_worker(struct work_struct *dummy) 490 { 491 int rc; 492 493 bitmap_zero(acpi_ids_done, nr_acpi_bits); 494 495 rc = xen_upload_processor_pm_data(); 496 if (rc != 0) 497 pr_info("ACPI data upload failed, error = %d\n", rc); 498 } 499 500 static void xen_acpi_processor_resume(void) 501 { 502 static DECLARE_WORK(wq, xen_acpi_processor_resume_worker); 503 504 /* 505 * xen_upload_processor_pm_data() calls non-atomic code. 506 * However, the context for xen_acpi_processor_resume is syscore 507 * with only the boot CPU online and in an atomic context. 508 * 509 * So defer the upload for some point safer. 510 */ 511 schedule_work(&wq); 512 } 513 514 static struct syscore_ops xap_syscore_ops = { 515 .resume = xen_acpi_processor_resume, 516 }; 517 518 static int __init xen_acpi_processor_init(void) 519 { 520 unsigned int i; 521 int rc; 522 523 if (!xen_initial_domain()) 524 return -ENODEV; 525 526 nr_acpi_bits = get_max_acpi_id() + 1; 527 acpi_ids_done = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL); 528 if (!acpi_ids_done) 529 return -ENOMEM; 530 531 acpi_perf_data = alloc_percpu(struct acpi_processor_performance); 532 if (!acpi_perf_data) { 533 pr_debug("Memory allocation error for acpi_perf_data\n"); 534 bitmap_free(acpi_ids_done); 535 return -ENOMEM; 536 } 537 for_each_possible_cpu(i) { 538 if (!zalloc_cpumask_var_node( 539 &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map, 540 GFP_KERNEL, cpu_to_node(i))) { 541 rc = -ENOMEM; 542 goto err_out; 543 } 544 } 545 546 /* Do initialization in ACPI core. It is OK to fail here. */ 547 (void)acpi_processor_preregister_performance(acpi_perf_data); 548 549 for_each_possible_cpu(i) { 550 struct acpi_processor *pr; 551 struct acpi_processor_performance *perf; 552 553 pr = per_cpu(processors, i); 554 perf = per_cpu_ptr(acpi_perf_data, i); 555 if (!pr) 556 continue; 557 558 pr->performance = perf; 559 rc = acpi_processor_get_performance_info(pr); 560 if (rc) 561 goto err_out; 562 } 563 564 rc = xen_upload_processor_pm_data(); 565 if (rc) 566 goto err_unregister; 567 568 register_syscore_ops(&xap_syscore_ops); 569 570 return 0; 571 err_unregister: 572 for_each_possible_cpu(i) 573 acpi_processor_unregister_performance(i); 574 575 err_out: 576 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */ 577 free_acpi_perf_data(); 578 bitmap_free(acpi_ids_done); 579 return rc; 580 } 581 static void __exit xen_acpi_processor_exit(void) 582 { 583 int i; 584 585 unregister_syscore_ops(&xap_syscore_ops); 586 bitmap_free(acpi_ids_done); 587 bitmap_free(acpi_id_present); 588 bitmap_free(acpi_id_cst_present); 589 kfree(acpi_psd); 590 for_each_possible_cpu(i) 591 acpi_processor_unregister_performance(i); 592 593 free_acpi_perf_data(); 594 } 595 596 MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>"); 597 MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor"); 598 MODULE_LICENSE("GPL"); 599 600 /* We want to be loaded before the CPU freq scaling drivers are loaded. 601 * They are loaded in late_initcall. */ 602 device_initcall(xen_acpi_processor_init); 603 module_exit(xen_acpi_processor_exit); 604