1 /* 2 * Copyright 2012 by Oracle Inc 3 * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 4 * 5 * This code borrows ideas from https://lkml.org/lkml/2011/11/30/249 6 * so many thanks go to Kevin Tian <kevin.tian@intel.com> 7 * and Yu Ke <ke.yu@intel.com>. 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms and conditions of the GNU General Public License, 11 * version 2, as published by the Free Software Foundation. 12 * 13 * This program is distributed in the hope it will be useful, but WITHOUT 14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 16 * more details. 17 * 18 */ 19 20 #include <linux/cpumask.h> 21 #include <linux/cpufreq.h> 22 #include <linux/freezer.h> 23 #include <linux/kernel.h> 24 #include <linux/kthread.h> 25 #include <linux/init.h> 26 #include <linux/module.h> 27 #include <linux/types.h> 28 #include <linux/syscore_ops.h> 29 #include <acpi/acpi_bus.h> 30 #include <acpi/acpi_drivers.h> 31 #include <acpi/processor.h> 32 33 #include <xen/xen.h> 34 #include <xen/interface/platform.h> 35 #include <asm/xen/hypercall.h> 36 37 #define DRV_NAME "xen-acpi-processor: " 38 39 static int no_hypercall; 40 MODULE_PARM_DESC(off, "Inhibit the hypercall."); 41 module_param_named(off, no_hypercall, int, 0400); 42 43 /* 44 * Note: Do not convert the acpi_id* below to cpumask_var_t or use cpumask_bit 45 * - as those shrink to nr_cpu_bits (which is dependent on possible_cpu), which 46 * can be less than what we want to put in. Instead use the 'nr_acpi_bits' 47 * which is dynamically computed based on the MADT or x2APIC table. 48 */ 49 static unsigned int nr_acpi_bits; 50 /* Mutex to protect the acpi_ids_done - for CPU hotplug use. */ 51 static DEFINE_MUTEX(acpi_ids_mutex); 52 /* Which ACPI ID we have processed from 'struct acpi_processor'. */ 53 static unsigned long *acpi_ids_done; 54 /* Which ACPI ID exist in the SSDT/DSDT processor definitions. */ 55 static unsigned long *acpi_id_present; 56 /* And if there is an _CST definition (or a PBLK) for the ACPI IDs */ 57 static unsigned long *acpi_id_cst_present; 58 59 static int push_cxx_to_hypervisor(struct acpi_processor *_pr) 60 { 61 struct xen_platform_op op = { 62 .cmd = XENPF_set_processor_pminfo, 63 .interface_version = XENPF_INTERFACE_VERSION, 64 .u.set_pminfo.id = _pr->acpi_id, 65 .u.set_pminfo.type = XEN_PM_CX, 66 }; 67 struct xen_processor_cx *dst_cx, *dst_cx_states = NULL; 68 struct acpi_processor_cx *cx; 69 unsigned int i, ok; 70 int ret = 0; 71 72 dst_cx_states = kcalloc(_pr->power.count, 73 sizeof(struct xen_processor_cx), GFP_KERNEL); 74 if (!dst_cx_states) 75 return -ENOMEM; 76 77 for (ok = 0, i = 1; i <= _pr->power.count; i++) { 78 cx = &_pr->power.states[i]; 79 if (!cx->valid) 80 continue; 81 82 dst_cx = &(dst_cx_states[ok++]); 83 84 dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO; 85 if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 86 dst_cx->reg.bit_width = 8; 87 dst_cx->reg.bit_offset = 0; 88 dst_cx->reg.access_size = 1; 89 } else { 90 dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE; 91 if (cx->entry_method == ACPI_CSTATE_FFH) { 92 /* NATIVE_CSTATE_BEYOND_HALT */ 93 dst_cx->reg.bit_offset = 2; 94 dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */ 95 } 96 dst_cx->reg.access_size = 0; 97 } 98 dst_cx->reg.address = cx->address; 99 100 dst_cx->type = cx->type; 101 dst_cx->latency = cx->latency; 102 103 dst_cx->dpcnt = 0; 104 set_xen_guest_handle(dst_cx->dp, NULL); 105 } 106 if (!ok) { 107 pr_debug(DRV_NAME "No _Cx for ACPI CPU %u\n", _pr->acpi_id); 108 kfree(dst_cx_states); 109 return -EINVAL; 110 } 111 op.u.set_pminfo.power.count = ok; 112 op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control; 113 op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check; 114 op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst; 115 op.u.set_pminfo.power.flags.power_setup_done = 116 _pr->flags.power_setup_done; 117 118 set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states); 119 120 if (!no_hypercall) 121 ret = HYPERVISOR_dom0_op(&op); 122 123 if (!ret) { 124 pr_debug("ACPI CPU%u - C-states uploaded.\n", _pr->acpi_id); 125 for (i = 1; i <= _pr->power.count; i++) { 126 cx = &_pr->power.states[i]; 127 if (!cx->valid) 128 continue; 129 pr_debug(" C%d: %s %d uS\n", 130 cx->type, cx->desc, (u32)cx->latency); 131 } 132 } else if (ret != -EINVAL) 133 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI 134 * table is referencing a non-existing CPU - which can happen 135 * with broken ACPI tables. */ 136 pr_err(DRV_NAME "(CX): Hypervisor error (%d) for ACPI CPU%u\n", 137 ret, _pr->acpi_id); 138 139 kfree(dst_cx_states); 140 141 return ret; 142 } 143 static struct xen_processor_px * 144 xen_copy_pss_data(struct acpi_processor *_pr, 145 struct xen_processor_performance *dst_perf) 146 { 147 struct xen_processor_px *dst_states = NULL; 148 unsigned int i; 149 150 BUILD_BUG_ON(sizeof(struct xen_processor_px) != 151 sizeof(struct acpi_processor_px)); 152 153 dst_states = kcalloc(_pr->performance->state_count, 154 sizeof(struct xen_processor_px), GFP_KERNEL); 155 if (!dst_states) 156 return ERR_PTR(-ENOMEM); 157 158 dst_perf->state_count = _pr->performance->state_count; 159 for (i = 0; i < _pr->performance->state_count; i++) { 160 /* Fortunatly for us, they are both the same size */ 161 memcpy(&(dst_states[i]), &(_pr->performance->states[i]), 162 sizeof(struct acpi_processor_px)); 163 } 164 return dst_states; 165 } 166 static int xen_copy_psd_data(struct acpi_processor *_pr, 167 struct xen_processor_performance *dst) 168 { 169 struct acpi_psd_package *pdomain; 170 171 BUILD_BUG_ON(sizeof(struct xen_psd_package) != 172 sizeof(struct acpi_psd_package)); 173 174 /* This information is enumerated only if acpi_processor_preregister_performance 175 * has been called. 176 */ 177 dst->shared_type = _pr->performance->shared_type; 178 179 pdomain = &(_pr->performance->domain_info); 180 181 /* 'acpi_processor_preregister_performance' does not parse if the 182 * num_processors <= 1, but Xen still requires it. Do it manually here. 183 */ 184 if (pdomain->num_processors <= 1) { 185 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 186 dst->shared_type = CPUFREQ_SHARED_TYPE_ALL; 187 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 188 dst->shared_type = CPUFREQ_SHARED_TYPE_HW; 189 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 190 dst->shared_type = CPUFREQ_SHARED_TYPE_ANY; 191 192 } 193 memcpy(&(dst->domain_info), pdomain, sizeof(struct acpi_psd_package)); 194 return 0; 195 } 196 static int xen_copy_pct_data(struct acpi_pct_register *pct, 197 struct xen_pct_register *dst_pct) 198 { 199 /* It would be nice if you could just do 'memcpy(pct, dst_pct') but 200 * sadly the Xen structure did not have the proper padding so the 201 * descriptor field takes two (dst_pct) bytes instead of one (pct). 202 */ 203 dst_pct->descriptor = pct->descriptor; 204 dst_pct->length = pct->length; 205 dst_pct->space_id = pct->space_id; 206 dst_pct->bit_width = pct->bit_width; 207 dst_pct->bit_offset = pct->bit_offset; 208 dst_pct->reserved = pct->reserved; 209 dst_pct->address = pct->address; 210 return 0; 211 } 212 static int push_pxx_to_hypervisor(struct acpi_processor *_pr) 213 { 214 int ret = 0; 215 struct xen_platform_op op = { 216 .cmd = XENPF_set_processor_pminfo, 217 .interface_version = XENPF_INTERFACE_VERSION, 218 .u.set_pminfo.id = _pr->acpi_id, 219 .u.set_pminfo.type = XEN_PM_PX, 220 }; 221 struct xen_processor_performance *dst_perf; 222 struct xen_processor_px *dst_states = NULL; 223 224 dst_perf = &op.u.set_pminfo.perf; 225 226 dst_perf->platform_limit = _pr->performance_platform_limit; 227 dst_perf->flags |= XEN_PX_PPC; 228 xen_copy_pct_data(&(_pr->performance->control_register), 229 &dst_perf->control_register); 230 xen_copy_pct_data(&(_pr->performance->status_register), 231 &dst_perf->status_register); 232 dst_perf->flags |= XEN_PX_PCT; 233 dst_states = xen_copy_pss_data(_pr, dst_perf); 234 if (!IS_ERR_OR_NULL(dst_states)) { 235 set_xen_guest_handle(dst_perf->states, dst_states); 236 dst_perf->flags |= XEN_PX_PSS; 237 } 238 if (!xen_copy_psd_data(_pr, dst_perf)) 239 dst_perf->flags |= XEN_PX_PSD; 240 241 if (dst_perf->flags != (XEN_PX_PSD | XEN_PX_PSS | XEN_PX_PCT | XEN_PX_PPC)) { 242 pr_warn(DRV_NAME "ACPI CPU%u missing some P-state data (%x), skipping.\n", 243 _pr->acpi_id, dst_perf->flags); 244 ret = -ENODEV; 245 goto err_free; 246 } 247 248 if (!no_hypercall) 249 ret = HYPERVISOR_dom0_op(&op); 250 251 if (!ret) { 252 struct acpi_processor_performance *perf; 253 unsigned int i; 254 255 perf = _pr->performance; 256 pr_debug("ACPI CPU%u - P-states uploaded.\n", _pr->acpi_id); 257 for (i = 0; i < perf->state_count; i++) { 258 pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n", 259 (i == perf->state ? '*' : ' '), i, 260 (u32) perf->states[i].core_frequency, 261 (u32) perf->states[i].power, 262 (u32) perf->states[i].transition_latency); 263 } 264 } else if (ret != -EINVAL) 265 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI 266 * table is referencing a non-existing CPU - which can happen 267 * with broken ACPI tables. */ 268 pr_warn(DRV_NAME "(_PXX): Hypervisor error (%d) for ACPI CPU%u\n", 269 ret, _pr->acpi_id); 270 err_free: 271 if (!IS_ERR_OR_NULL(dst_states)) 272 kfree(dst_states); 273 274 return ret; 275 } 276 static int upload_pm_data(struct acpi_processor *_pr) 277 { 278 int err = 0; 279 280 mutex_lock(&acpi_ids_mutex); 281 if (__test_and_set_bit(_pr->acpi_id, acpi_ids_done)) { 282 mutex_unlock(&acpi_ids_mutex); 283 return -EBUSY; 284 } 285 if (_pr->flags.power) 286 err = push_cxx_to_hypervisor(_pr); 287 288 if (_pr->performance && _pr->performance->states) 289 err |= push_pxx_to_hypervisor(_pr); 290 291 mutex_unlock(&acpi_ids_mutex); 292 return err; 293 } 294 static unsigned int __init get_max_acpi_id(void) 295 { 296 struct xenpf_pcpuinfo *info; 297 struct xen_platform_op op = { 298 .cmd = XENPF_get_cpuinfo, 299 .interface_version = XENPF_INTERFACE_VERSION, 300 }; 301 int ret = 0; 302 unsigned int i, last_cpu, max_acpi_id = 0; 303 304 info = &op.u.pcpu_info; 305 info->xen_cpuid = 0; 306 307 ret = HYPERVISOR_dom0_op(&op); 308 if (ret) 309 return NR_CPUS; 310 311 /* The max_present is the same irregardless of the xen_cpuid */ 312 last_cpu = op.u.pcpu_info.max_present; 313 for (i = 0; i <= last_cpu; i++) { 314 info->xen_cpuid = i; 315 ret = HYPERVISOR_dom0_op(&op); 316 if (ret) 317 continue; 318 max_acpi_id = max(info->acpi_id, max_acpi_id); 319 } 320 max_acpi_id *= 2; /* Slack for CPU hotplug support. */ 321 pr_debug(DRV_NAME "Max ACPI ID: %u\n", max_acpi_id); 322 return max_acpi_id; 323 } 324 /* 325 * The read_acpi_id and check_acpi_ids are there to support the Xen 326 * oddity of virtual CPUs != physical CPUs in the initial domain. 327 * The user can supply 'xen_max_vcpus=X' on the Xen hypervisor line 328 * which will band the amount of CPUs the initial domain can see. 329 * In general that is OK, except it plays havoc with any of the 330 * for_each_[present|online]_cpu macros which are banded to the virtual 331 * CPU amount. 332 */ 333 static acpi_status 334 read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv) 335 { 336 u32 acpi_id; 337 acpi_status status; 338 acpi_object_type acpi_type; 339 unsigned long long tmp; 340 union acpi_object object = { 0 }; 341 struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; 342 acpi_io_address pblk = 0; 343 344 status = acpi_get_type(handle, &acpi_type); 345 if (ACPI_FAILURE(status)) 346 return AE_OK; 347 348 switch (acpi_type) { 349 case ACPI_TYPE_PROCESSOR: 350 status = acpi_evaluate_object(handle, NULL, NULL, &buffer); 351 if (ACPI_FAILURE(status)) 352 return AE_OK; 353 acpi_id = object.processor.proc_id; 354 pblk = object.processor.pblk_address; 355 break; 356 case ACPI_TYPE_DEVICE: 357 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp); 358 if (ACPI_FAILURE(status)) 359 return AE_OK; 360 acpi_id = tmp; 361 break; 362 default: 363 return AE_OK; 364 } 365 /* There are more ACPI Processor objects than in x2APIC or MADT. 366 * This can happen with incorrect ACPI SSDT declerations. */ 367 if (acpi_id > nr_acpi_bits) { 368 pr_debug(DRV_NAME "We only have %u, trying to set %u\n", 369 nr_acpi_bits, acpi_id); 370 return AE_OK; 371 } 372 /* OK, There is a ACPI Processor object */ 373 __set_bit(acpi_id, acpi_id_present); 374 375 pr_debug(DRV_NAME "ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, 376 (unsigned long)pblk); 377 378 status = acpi_evaluate_object(handle, "_CST", NULL, &buffer); 379 if (ACPI_FAILURE(status)) { 380 if (!pblk) 381 return AE_OK; 382 } 383 /* .. and it has a C-state */ 384 __set_bit(acpi_id, acpi_id_cst_present); 385 386 return AE_OK; 387 } 388 static int check_acpi_ids(struct acpi_processor *pr_backup) 389 { 390 391 if (!pr_backup) 392 return -ENODEV; 393 394 if (acpi_id_present && acpi_id_cst_present) 395 /* OK, done this once .. skip to uploading */ 396 goto upload; 397 398 /* All online CPUs have been processed at this stage. Now verify 399 * whether in fact "online CPUs" == physical CPUs. 400 */ 401 acpi_id_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL); 402 if (!acpi_id_present) 403 return -ENOMEM; 404 405 acpi_id_cst_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL); 406 if (!acpi_id_cst_present) { 407 kfree(acpi_id_present); 408 return -ENOMEM; 409 } 410 411 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, 412 ACPI_UINT32_MAX, 413 read_acpi_id, NULL, NULL, NULL); 414 acpi_get_devices("ACPI0007", read_acpi_id, NULL, NULL); 415 416 upload: 417 if (!bitmap_equal(acpi_id_present, acpi_ids_done, nr_acpi_bits)) { 418 unsigned int i; 419 for_each_set_bit(i, acpi_id_present, nr_acpi_bits) { 420 pr_backup->acpi_id = i; 421 /* Mask out C-states if there are no _CST or PBLK */ 422 pr_backup->flags.power = test_bit(i, acpi_id_cst_present); 423 (void)upload_pm_data(pr_backup); 424 } 425 } 426 427 return 0; 428 } 429 static int __init check_prereq(void) 430 { 431 struct cpuinfo_x86 *c = &cpu_data(0); 432 433 if (!xen_initial_domain()) 434 return -ENODEV; 435 436 if (!acpi_gbl_FADT.smi_command) 437 return -ENODEV; 438 439 if (c->x86_vendor == X86_VENDOR_INTEL) { 440 if (!cpu_has(c, X86_FEATURE_EST)) 441 return -ENODEV; 442 443 return 0; 444 } 445 if (c->x86_vendor == X86_VENDOR_AMD) { 446 /* Copied from powernow-k8.h, can't include ../cpufreq/powernow 447 * as we get compile warnings for the static functions. 448 */ 449 #define CPUID_FREQ_VOLT_CAPABILITIES 0x80000007 450 #define USE_HW_PSTATE 0x00000080 451 u32 eax, ebx, ecx, edx; 452 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx); 453 if ((edx & USE_HW_PSTATE) != USE_HW_PSTATE) 454 return -ENODEV; 455 return 0; 456 } 457 return -ENODEV; 458 } 459 /* acpi_perf_data is a pointer to percpu data. */ 460 static struct acpi_processor_performance __percpu *acpi_perf_data; 461 462 static void free_acpi_perf_data(void) 463 { 464 unsigned int i; 465 466 /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */ 467 for_each_possible_cpu(i) 468 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i) 469 ->shared_cpu_map); 470 free_percpu(acpi_perf_data); 471 } 472 473 static int xen_upload_processor_pm_data(void) 474 { 475 struct acpi_processor *pr_backup = NULL; 476 unsigned int i; 477 int rc = 0; 478 479 pr_info(DRV_NAME "Uploading Xen processor PM info\n"); 480 481 for_each_possible_cpu(i) { 482 struct acpi_processor *_pr; 483 _pr = per_cpu(processors, i /* APIC ID */); 484 if (!_pr) 485 continue; 486 487 if (!pr_backup) { 488 pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL); 489 if (pr_backup) 490 memcpy(pr_backup, _pr, sizeof(struct acpi_processor)); 491 } 492 (void)upload_pm_data(_pr); 493 } 494 495 rc = check_acpi_ids(pr_backup); 496 kfree(pr_backup); 497 498 return rc; 499 } 500 501 static void xen_acpi_processor_resume(void) 502 { 503 bitmap_zero(acpi_ids_done, nr_acpi_bits); 504 xen_upload_processor_pm_data(); 505 } 506 507 static struct syscore_ops xap_syscore_ops = { 508 .resume = xen_acpi_processor_resume, 509 }; 510 511 static int __init xen_acpi_processor_init(void) 512 { 513 unsigned int i; 514 int rc = check_prereq(); 515 516 if (rc) 517 return rc; 518 519 nr_acpi_bits = get_max_acpi_id() + 1; 520 acpi_ids_done = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL); 521 if (!acpi_ids_done) 522 return -ENOMEM; 523 524 acpi_perf_data = alloc_percpu(struct acpi_processor_performance); 525 if (!acpi_perf_data) { 526 pr_debug(DRV_NAME "Memory allocation error for acpi_perf_data.\n"); 527 kfree(acpi_ids_done); 528 return -ENOMEM; 529 } 530 for_each_possible_cpu(i) { 531 if (!zalloc_cpumask_var_node( 532 &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map, 533 GFP_KERNEL, cpu_to_node(i))) { 534 rc = -ENOMEM; 535 goto err_out; 536 } 537 } 538 539 /* Do initialization in ACPI core. It is OK to fail here. */ 540 (void)acpi_processor_preregister_performance(acpi_perf_data); 541 542 for_each_possible_cpu(i) { 543 struct acpi_processor *pr; 544 struct acpi_processor_performance *perf; 545 546 pr = per_cpu(processors, i); 547 perf = per_cpu_ptr(acpi_perf_data, i); 548 if (!pr) 549 continue; 550 551 pr->performance = perf; 552 rc = acpi_processor_get_performance_info(pr); 553 if (rc) 554 goto err_out; 555 } 556 557 rc = xen_upload_processor_pm_data(); 558 if (rc) 559 goto err_unregister; 560 561 register_syscore_ops(&xap_syscore_ops); 562 563 return 0; 564 err_unregister: 565 for_each_possible_cpu(i) { 566 struct acpi_processor_performance *perf; 567 perf = per_cpu_ptr(acpi_perf_data, i); 568 acpi_processor_unregister_performance(perf, i); 569 } 570 err_out: 571 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */ 572 free_acpi_perf_data(); 573 kfree(acpi_ids_done); 574 return rc; 575 } 576 static void __exit xen_acpi_processor_exit(void) 577 { 578 int i; 579 580 unregister_syscore_ops(&xap_syscore_ops); 581 kfree(acpi_ids_done); 582 kfree(acpi_id_present); 583 kfree(acpi_id_cst_present); 584 for_each_possible_cpu(i) { 585 struct acpi_processor_performance *perf; 586 perf = per_cpu_ptr(acpi_perf_data, i); 587 acpi_processor_unregister_performance(perf, i); 588 } 589 free_acpi_perf_data(); 590 } 591 592 MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>"); 593 MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor"); 594 MODULE_LICENSE("GPL"); 595 596 /* We want to be loaded before the CPU freq scaling drivers are loaded. 597 * They are loaded in late_initcall. */ 598 device_initcall(xen_acpi_processor_init); 599 module_exit(xen_acpi_processor_exit); 600