1/*
   2 * processor_throttling.c - Throttling submodule of the ACPI processor driver
   3 *
   4 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6 *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   7 *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8 *  			- Added processor hotplug support
   9 *
  10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11 *
  12 *  This program is free software; you can redistribute it and/or modify
  13 *  it under the terms of the GNU General Public License as published by
  14 *  the Free Software Foundation; either version 2 of the License, or (at
  15 *  your option) any later version.
  16 *
  17 *  This program is distributed in the hope that it will be useful, but
  18 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20 *  General Public License for more details.
  21 *
  22 *  You should have received a copy of the GNU General Public License along
  23 *  with this program; if not, write to the Free Software Foundation, Inc.,
  24 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25 *
  26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27 */
  28
  29#include <linux/kernel.h>
  30#include <linux/module.h>
  31#include <linux/slab.h>
  32#include <linux/init.h>
  33#include <linux/sched.h>
  34#include <linux/cpufreq.h>
  35
  36#include <asm/io.h>
  37#include <asm/uaccess.h>
  38
  39#include <acpi/acpi_bus.h>
  40#include <acpi/acpi_drivers.h>
  41#include <acpi/processor.h>
  42
  43#define PREFIX "ACPI: "
  44
  45#define ACPI_PROCESSOR_CLASS            "processor"
  46#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  47ACPI_MODULE_NAME("processor_throttling");
  48
  49/* ignore_tpc:
  50 *  0 -> acpi processor driver doesn't ignore _TPC values
  51 *  1 -> acpi processor driver ignores _TPC values
  52 */
  53static int ignore_tpc;
  54module_param(ignore_tpc, int, 0644);
  55MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  56
  57struct throttling_tstate {
  58	unsigned int cpu;		/* cpu nr */
  59	int target_state;		/* target T-state */
  60};
  61
  62#define THROTTLING_PRECHANGE       (1)
  63#define THROTTLING_POSTCHANGE      (2)
  64
  65static int acpi_processor_get_throttling(struct acpi_processor *pr);
  66int acpi_processor_set_throttling(struct acpi_processor *pr,
  67						int state, bool force);
  68
  69static int acpi_processor_update_tsd_coord(void)
  70{
  71	int count, count_target;
  72	int retval = 0;
  73	unsigned int i, j;
  74	cpumask_var_t covered_cpus;
  75	struct acpi_processor *pr, *match_pr;
  76	struct acpi_tsd_package *pdomain, *match_pdomain;
  77	struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  78
  79	if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  80		return -ENOMEM;
  81
  82	/*
  83	 * Now that we have _TSD data from all CPUs, lets setup T-state
  84	 * coordination between all CPUs.
  85	 */
  86	for_each_possible_cpu(i) {
  87		pr = per_cpu(processors, i);
  88		if (!pr)
  89			continue;
  90
  91		/* Basic validity check for domain info */
  92		pthrottling = &(pr->throttling);
  93
  94		/*
  95		 * If tsd package for one cpu is invalid, the coordination
  96		 * among all CPUs is thought as invalid.
  97		 * Maybe it is ugly.
  98		 */
  99		if (!pthrottling->tsd_valid_flag) {
 100			retval = -EINVAL;
 101			break;
 102		}
 103	}
 104	if (retval)
 105		goto err_ret;
 106
 107	for_each_possible_cpu(i) {
 108		pr = per_cpu(processors, i);
 109		if (!pr)
 110			continue;
 111
 112		if (cpumask_test_cpu(i, covered_cpus))
 113			continue;
 114		pthrottling = &pr->throttling;
 115
 116		pdomain = &(pthrottling->domain_info);
 117		cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 118		cpumask_set_cpu(i, covered_cpus);
 119		/*
 120		 * If the number of processor in the TSD domain is 1, it is
 121		 * unnecessary to parse the coordination for this CPU.
 122		 */
 123		if (pdomain->num_processors <= 1)
 124			continue;
 125
 126		/* Validate the Domain info */
 127		count_target = pdomain->num_processors;
 128		count = 1;
 129
 130		for_each_possible_cpu(j) {
 131			if (i == j)
 132				continue;
 133
 134			match_pr = per_cpu(processors, j);
 135			if (!match_pr)
 136				continue;
 137
 138			match_pthrottling = &(match_pr->throttling);
 139			match_pdomain = &(match_pthrottling->domain_info);
 140			if (match_pdomain->domain != pdomain->domain)
 141				continue;
 142
 143			/* Here i and j are in the same domain.
 144			 * If two TSD packages have the same domain, they
 145			 * should have the same num_porcessors and
 146			 * coordination type. Otherwise it will be regarded
 147			 * as illegal.
 148			 */
 149			if (match_pdomain->num_processors != count_target) {
 150				retval = -EINVAL;
 151				goto err_ret;
 152			}
 153
 154			if (pdomain->coord_type != match_pdomain->coord_type) {
 155				retval = -EINVAL;
 156				goto err_ret;
 157			}
 158
 159			cpumask_set_cpu(j, covered_cpus);
 160			cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 161			count++;
 162		}
 163		for_each_possible_cpu(j) {
 164			if (i == j)
 165				continue;
 166
 167			match_pr = per_cpu(processors, j);
 168			if (!match_pr)
 169				continue;
 170
 171			match_pthrottling = &(match_pr->throttling);
 172			match_pdomain = &(match_pthrottling->domain_info);
 173			if (match_pdomain->domain != pdomain->domain)
 174				continue;
 175
 176			/*
 177			 * If some CPUS have the same domain, they
 178			 * will have the same shared_cpu_map.
 179			 */
 180			cpumask_copy(match_pthrottling->shared_cpu_map,
 181				     pthrottling->shared_cpu_map);
 182		}
 183	}
 184
 185err_ret:
 186	free_cpumask_var(covered_cpus);
 187
 188	for_each_possible_cpu(i) {
 189		pr = per_cpu(processors, i);
 190		if (!pr)
 191			continue;
 192
 193		/*
 194		 * Assume no coordination on any error parsing domain info.
 195		 * The coordination type will be forced as SW_ALL.
 196		 */
 197		if (retval) {
 198			pthrottling = &(pr->throttling);
 199			cpumask_clear(pthrottling->shared_cpu_map);
 200			cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 201			pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 202		}
 203	}
 204
 205	return retval;
 206}
 207
 208/*
 209 * Update the T-state coordination after the _TSD
 210 * data for all cpus is obtained.
 211 */
 212void acpi_processor_throttling_init(void)
 213{
 214	if (acpi_processor_update_tsd_coord())
 215		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 216			"Assume no T-state coordination\n"));
 217
 218	return;
 219}
 220
 221static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 222{
 223	struct throttling_tstate *p_tstate = data;
 224	struct acpi_processor *pr;
 225	unsigned int cpu ;
 226	int target_state;
 227	struct acpi_processor_limit *p_limit;
 228	struct acpi_processor_throttling *p_throttling;
 229
 230	cpu = p_tstate->cpu;
 231	pr = per_cpu(processors, cpu);
 232	if (!pr) {
 233		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 234		return 0;
 235	}
 236	if (!pr->flags.throttling) {
 237		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
 238				"unsupported on CPU %d\n", cpu));
 239		return 0;
 240	}
 241	target_state = p_tstate->target_state;
 242	p_throttling = &(pr->throttling);
 243	switch (event) {
 244	case THROTTLING_PRECHANGE:
 245		/*
 246		 * Prechange event is used to choose one proper t-state,
 247		 * which meets the limits of thermal, user and _TPC.
 248		 */
 249		p_limit = &pr->limit;
 250		if (p_limit->thermal.tx > target_state)
 251			target_state = p_limit->thermal.tx;
 252		if (p_limit->user.tx > target_state)
 253			target_state = p_limit->user.tx;
 254		if (pr->throttling_platform_limit > target_state)
 255			target_state = pr->throttling_platform_limit;
 256		if (target_state >= p_throttling->state_count) {
 257			printk(KERN_WARNING
 258				"Exceed the limit of T-state \n");
 259			target_state = p_throttling->state_count - 1;
 260		}
 261		p_tstate->target_state = target_state;
 262		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
 263				"target T-state of CPU %d is T%d\n",
 264				cpu, target_state));
 265		break;
 266	case THROTTLING_POSTCHANGE:
 267		/*
 268		 * Postchange event is only used to update the
 269		 * T-state flag of acpi_processor_throttling.
 270		 */
 271		p_throttling->state = target_state;
 272		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
 273				"CPU %d is switched to T%d\n",
 274				cpu, target_state));
 275		break;
 276	default:
 277		printk(KERN_WARNING
 278			"Unsupported Throttling notifier event\n");
 279		break;
 280	}
 281
 282	return 0;
 283}
 284
 285/*
 286 * _TPC - Throttling Present Capabilities
 287 */
 288static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 289{
 290	acpi_status status = 0;
 291	unsigned long long tpc = 0;
 292
 293	if (!pr)
 294		return -EINVAL;
 295
 296	if (ignore_tpc)
 297		goto end;
 298
 299	status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 300	if (ACPI_FAILURE(status)) {
 301		if (status != AE_NOT_FOUND) {
 302			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 303		}
 304		return -ENODEV;
 305	}
 306
 307end:
 308	pr->throttling_platform_limit = (int)tpc;
 309	return 0;
 310}
 311
 312int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 313{
 314	int result = 0;
 315	int throttling_limit;
 316	int current_state;
 317	struct acpi_processor_limit *limit;
 318	int target_state;
 319
 320	if (ignore_tpc)
 321		return 0;
 322
 323	result = acpi_processor_get_platform_limit(pr);
 324	if (result) {
 325		/* Throttling Limit is unsupported */
 326		return result;
 327	}
 328
 329	throttling_limit = pr->throttling_platform_limit;
 330	if (throttling_limit >= pr->throttling.state_count) {
 331		/* Uncorrect Throttling Limit */
 332		return -EINVAL;
 333	}
 334
 335	current_state = pr->throttling.state;
 336	if (current_state > throttling_limit) {
 337		/*
 338		 * The current state can meet the requirement of
 339		 * _TPC limit. But it is reasonable that OSPM changes
 340		 * t-states from high to low for better performance.
 341		 * Of course the limit condition of thermal
 342		 * and user should be considered.
 343		 */
 344		limit = &pr->limit;
 345		target_state = throttling_limit;
 346		if (limit->thermal.tx > target_state)
 347			target_state = limit->thermal.tx;
 348		if (limit->user.tx > target_state)
 349			target_state = limit->user.tx;
 350	} else if (current_state == throttling_limit) {
 351		/*
 352		 * Unnecessary to change the throttling state
 353		 */
 354		return 0;
 355	} else {
 356		/*
 357		 * If the current state is lower than the limit of _TPC, it
 358		 * will be forced to switch to the throttling state defined
 359		 * by throttling_platfor_limit.
 360		 * Because the previous state meets with the limit condition
 361		 * of thermal and user, it is unnecessary to check it again.
 362		 */
 363		target_state = throttling_limit;
 364	}
 365	return acpi_processor_set_throttling(pr, target_state, false);
 366}
 367
 368/*
 369 * This function is used to reevaluate whether the T-state is valid
 370 * after one CPU is onlined/offlined.
 371 * It is noted that it won't reevaluate the following properties for
 372 * the T-state.
 373 *	1. Control method.
 374 *	2. the number of supported T-state
 375 *	3. TSD domain
 376 */
 377void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
 378					unsigned long action)
 379{
 380	int result = 0;
 381
 382	if (action == CPU_DEAD) {
 383		/* When one CPU is offline, the T-state throttling
 384		 * will be invalidated.
 385		 */
 386		pr->flags.throttling = 0;
 387		return;
 388	}
 389	/* the following is to recheck whether the T-state is valid for
 390	 * the online CPU
 391	 */
 392	if (!pr->throttling.state_count) {
 393		/* If the number of T-state is invalid, it is
 394		 * invalidated.
 395		 */
 396		pr->flags.throttling = 0;
 397		return;
 398	}
 399	pr->flags.throttling = 1;
 400
 401	/* Disable throttling (if enabled).  We'll let subsequent
 402	 * policy (e.g.thermal) decide to lower performance if it
 403	 * so chooses, but for now we'll crank up the speed.
 404	 */
 405
 406	result = acpi_processor_get_throttling(pr);
 407	if (result)
 408		goto end;
 409
 410	if (pr->throttling.state) {
 411		result = acpi_processor_set_throttling(pr, 0, false);
 412		if (result)
 413			goto end;
 414	}
 415
 416end:
 417	if (result)
 418		pr->flags.throttling = 0;
 419}
 420/*
 421 * _PTC - Processor Throttling Control (and status) register location
 422 */
 423static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 424{
 425	int result = 0;
 426	acpi_status status = 0;
 427	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 428	union acpi_object *ptc = NULL;
 429	union acpi_object obj = { 0 };
 430	struct acpi_processor_throttling *throttling;
 431
 432	status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 433	if (ACPI_FAILURE(status)) {
 434		if (status != AE_NOT_FOUND) {
 435			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 436		}
 437		return -ENODEV;
 438	}
 439
 440	ptc = (union acpi_object *)buffer.pointer;
 441	if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 442	    || (ptc->package.count != 2)) {
 443		printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 444		result = -EFAULT;
 445		goto end;
 446	}
 447
 448	/*
 449	 * control_register
 450	 */
 451
 452	obj = ptc->package.elements[0];
 453
 454	if ((obj.type != ACPI_TYPE_BUFFER)
 455	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 456	    || (obj.buffer.pointer == NULL)) {
 457		printk(KERN_ERR PREFIX
 458		       "Invalid _PTC data (control_register)\n");
 459		result = -EFAULT;
 460		goto end;
 461	}
 462	memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 463	       sizeof(struct acpi_ptc_register));
 464
 465	/*
 466	 * status_register
 467	 */
 468
 469	obj = ptc->package.elements[1];
 470
 471	if ((obj.type != ACPI_TYPE_BUFFER)
 472	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 473	    || (obj.buffer.pointer == NULL)) {
 474		printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 475		result = -EFAULT;
 476		goto end;
 477	}
 478
 479	memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 480	       sizeof(struct acpi_ptc_register));
 481
 482	throttling = &pr->throttling;
 483
 484	if ((throttling->control_register.bit_width +
 485		throttling->control_register.bit_offset) > 32) {
 486		printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 487		result = -EFAULT;
 488		goto end;
 489	}
 490
 491	if ((throttling->status_register.bit_width +
 492		throttling->status_register.bit_offset) > 32) {
 493		printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 494		result = -EFAULT;
 495		goto end;
 496	}
 497
 498      end:
 499	kfree(buffer.pointer);
 500
 501	return result;
 502}
 503
 504/*
 505 * _TSS - Throttling Supported States
 506 */
 507static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 508{
 509	int result = 0;
 510	acpi_status status = AE_OK;
 511	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 512	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 513	struct acpi_buffer state = { 0, NULL };
 514	union acpi_object *tss = NULL;
 515	int i;
 516
 517	status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 518	if (ACPI_FAILURE(status)) {
 519		if (status != AE_NOT_FOUND) {
 520			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 521		}
 522		return -ENODEV;
 523	}
 524
 525	tss = buffer.pointer;
 526	if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 527		printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 528		result = -EFAULT;
 529		goto end;
 530	}
 531
 532	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 533			  tss->package.count));
 534
 535	pr->throttling.state_count = tss->package.count;
 536	pr->throttling.states_tss =
 537	    kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 538		    GFP_KERNEL);
 539	if (!pr->throttling.states_tss) {
 540		result = -ENOMEM;
 541		goto end;
 542	}
 543
 544	for (i = 0; i < pr->throttling.state_count; i++) {
 545
 546		struct acpi_processor_tx_tss *tx =
 547		    (struct acpi_processor_tx_tss *)&(pr->throttling.
 548						      states_tss[i]);
 549
 550		state.length = sizeof(struct acpi_processor_tx_tss);
 551		state.pointer = tx;
 552
 553		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 554
 555		status = acpi_extract_package(&(tss->package.elements[i]),
 556					      &format, &state);
 557		if (ACPI_FAILURE(status)) {
 558			ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 559			result = -EFAULT;
 560			kfree(pr->throttling.states_tss);
 561			goto end;
 562		}
 563
 564		if (!tx->freqpercentage) {
 565			printk(KERN_ERR PREFIX
 566			       "Invalid _TSS data: freq is zero\n");
 567			result = -EFAULT;
 568			kfree(pr->throttling.states_tss);
 569			goto end;
 570		}
 571	}
 572
 573      end:
 574	kfree(buffer.pointer);
 575
 576	return result;
 577}
 578
 579/*
 580 * _TSD - T-State Dependencies
 581 */
 582static int acpi_processor_get_tsd(struct acpi_processor *pr)
 583{
 584	int result = 0;
 585	acpi_status status = AE_OK;
 586	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 587	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 588	struct acpi_buffer state = { 0, NULL };
 589	union acpi_object *tsd = NULL;
 590	struct acpi_tsd_package *pdomain;
 591	struct acpi_processor_throttling *pthrottling;
 592
 593	pthrottling = &pr->throttling;
 594	pthrottling->tsd_valid_flag = 0;
 595
 596	status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 597	if (ACPI_FAILURE(status)) {
 598		if (status != AE_NOT_FOUND) {
 599			ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 600		}
 601		return -ENODEV;
 602	}
 603
 604	tsd = buffer.pointer;
 605	if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 606		printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 607		result = -EFAULT;
 608		goto end;
 609	}
 610
 611	if (tsd->package.count != 1) {
 612		printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 613		result = -EFAULT;
 614		goto end;
 615	}
 616
 617	pdomain = &(pr->throttling.domain_info);
 618
 619	state.length = sizeof(struct acpi_tsd_package);
 620	state.pointer = pdomain;
 621
 622	status = acpi_extract_package(&(tsd->package.elements[0]),
 623				      &format, &state);
 624	if (ACPI_FAILURE(status)) {
 625		printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 626		result = -EFAULT;
 627		goto end;
 628	}
 629
 630	if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 631		printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 632		result = -EFAULT;
 633		goto end;
 634	}
 635
 636	if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 637		printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 638		result = -EFAULT;
 639		goto end;
 640	}
 641
 642	pthrottling = &pr->throttling;
 643	pthrottling->tsd_valid_flag = 1;
 644	pthrottling->shared_type = pdomain->coord_type;
 645	cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 646	/*
 647	 * If the coordination type is not defined in ACPI spec,
 648	 * the tsd_valid_flag will be clear and coordination type
 649	 * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 650	 */
 651	if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 652		pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 653		pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 654		pthrottling->tsd_valid_flag = 0;
 655		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 656	}
 657
 658      end:
 659	kfree(buffer.pointer);
 660	return result;
 661}
 662
 663/* --------------------------------------------------------------------------
 664                              Throttling Control
 665   -------------------------------------------------------------------------- */
 666static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 667{
 668	int state = 0;
 669	u32 value = 0;
 670	u32 duty_mask = 0;
 671	u32 duty_value = 0;
 672
 673	if (!pr)
 674		return -EINVAL;
 675
 676	if (!pr->flags.throttling)
 677		return -ENODEV;
 678
 679	pr->throttling.state = 0;
 680
 681	duty_mask = pr->throttling.state_count - 1;
 682
 683	duty_mask <<= pr->throttling.duty_offset;
 684
 685	local_irq_disable();
 686
 687	value = inl(pr->throttling.address);
 688
 689	/*
 690	 * Compute the current throttling state when throttling is enabled
 691	 * (bit 4 is on).
 692	 */
 693	if (value & 0x10) {
 694		duty_value = value & duty_mask;
 695		duty_value >>= pr->throttling.duty_offset;
 696
 697		if (duty_value)
 698			state = pr->throttling.state_count - duty_value;
 699	}
 700
 701	pr->throttling.state = state;
 702
 703	local_irq_enable();
 704
 705	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 706			  "Throttling state is T%d (%d%% throttling applied)\n",
 707			  state, pr->throttling.states[state].performance));
 708
 709	return 0;
 710}
 711
 712#ifdef CONFIG_X86
 713static int acpi_throttling_rdmsr(u64 *value)
 714{
 715	u64 msr_high, msr_low;
 716	u64 msr = 0;
 717	int ret = -1;
 718
 719	if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 720		!this_cpu_has(X86_FEATURE_ACPI)) {
 721		printk(KERN_ERR PREFIX
 722			"HARDWARE addr space,NOT supported yet\n");
 723	} else {
 724		msr_low = 0;
 725		msr_high = 0;
 726		rdmsr_safe(MSR_IA32_THERM_CONTROL,
 727			(u32 *)&msr_low , (u32 *) &msr_high);
 728		msr = (msr_high << 32) | msr_low;
 729		*value = (u64) msr;
 730		ret = 0;
 731	}
 732	return ret;
 733}
 734
 735static int acpi_throttling_wrmsr(u64 value)
 736{
 737	int ret = -1;
 738	u64 msr;
 739
 740	if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 741		!this_cpu_has(X86_FEATURE_ACPI)) {
 742		printk(KERN_ERR PREFIX
 743			"HARDWARE addr space,NOT supported yet\n");
 744	} else {
 745		msr = value;
 746		wrmsr_safe(MSR_IA32_THERM_CONTROL,
 747			msr & 0xffffffff, msr >> 32);
 748		ret = 0;
 749	}
 750	return ret;
 751}
 752#else
 753static int acpi_throttling_rdmsr(u64 *value)
 754{
 755	printk(KERN_ERR PREFIX
 756		"HARDWARE addr space,NOT supported yet\n");
 757	return -1;
 758}
 759
 760static int acpi_throttling_wrmsr(u64 value)
 761{
 762	printk(KERN_ERR PREFIX
 763		"HARDWARE addr space,NOT supported yet\n");
 764	return -1;
 765}
 766#endif
 767
 768static int acpi_read_throttling_status(struct acpi_processor *pr,
 769					u64 *value)
 770{
 771	u32 bit_width, bit_offset;
 772	u64 ptc_value;
 773	u64 ptc_mask;
 774	struct acpi_processor_throttling *throttling;
 775	int ret = -1;
 776
 777	throttling = &pr->throttling;
 778	switch (throttling->status_register.space_id) {
 779	case ACPI_ADR_SPACE_SYSTEM_IO:
 780		ptc_value = 0;
 781		bit_width = throttling->status_register.bit_width;
 782		bit_offset = throttling->status_register.bit_offset;
 783
 784		acpi_os_read_port((acpi_io_address) throttling->status_register.
 785				  address, (u32 *) &ptc_value,
 786				  (u32) (bit_width + bit_offset));
 787		ptc_mask = (1 << bit_width) - 1;
 788		*value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 789		ret = 0;
 790		break;
 791	case ACPI_ADR_SPACE_FIXED_HARDWARE:
 792		ret = acpi_throttling_rdmsr(value);
 793		break;
 794	default:
 795		printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 796		       (u32) (throttling->status_register.space_id));
 797	}
 798	return ret;
 799}
 800
 801static int acpi_write_throttling_state(struct acpi_processor *pr,
 802				u64 value)
 803{
 804	u32 bit_width, bit_offset;
 805	u64 ptc_value;
 806	u64 ptc_mask;
 807	struct acpi_processor_throttling *throttling;
 808	int ret = -1;
 809
 810	throttling = &pr->throttling;
 811	switch (throttling->control_register.space_id) {
 812	case ACPI_ADR_SPACE_SYSTEM_IO:
 813		bit_width = throttling->control_register.bit_width;
 814		bit_offset = throttling->control_register.bit_offset;
 815		ptc_mask = (1 << bit_width) - 1;
 816		ptc_value = value & ptc_mask;
 817
 818		acpi_os_write_port((acpi_io_address) throttling->
 819					control_register.address,
 820					(u32) (ptc_value << bit_offset),
 821					(u32) (bit_width + bit_offset));
 822		ret = 0;
 823		break;
 824	case ACPI_ADR_SPACE_FIXED_HARDWARE:
 825		ret = acpi_throttling_wrmsr(value);
 826		break;
 827	default:
 828		printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 829		       (u32) (throttling->control_register.space_id));
 830	}
 831	return ret;
 832}
 833
 834static int acpi_get_throttling_state(struct acpi_processor *pr,
 835				u64 value)
 836{
 837	int i;
 838
 839	for (i = 0; i < pr->throttling.state_count; i++) {
 840		struct acpi_processor_tx_tss *tx =
 841		    (struct acpi_processor_tx_tss *)&(pr->throttling.
 842						      states_tss[i]);
 843		if (tx->control == value)
 844			return i;
 845	}
 846	return -1;
 847}
 848
 849static int acpi_get_throttling_value(struct acpi_processor *pr,
 850			int state, u64 *value)
 851{
 852	int ret = -1;
 853
 854	if (state >= 0 && state <= pr->throttling.state_count) {
 855		struct acpi_processor_tx_tss *tx =
 856		    (struct acpi_processor_tx_tss *)&(pr->throttling.
 857						      states_tss[state]);
 858		*value = tx->control;
 859		ret = 0;
 860	}
 861	return ret;
 862}
 863
 864static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 865{
 866	int state = 0;
 867	int ret;
 868	u64 value;
 869
 870	if (!pr)
 871		return -EINVAL;
 872
 873	if (!pr->flags.throttling)
 874		return -ENODEV;
 875
 876	pr->throttling.state = 0;
 877
 878	value = 0;
 879	ret = acpi_read_throttling_status(pr, &value);
 880	if (ret >= 0) {
 881		state = acpi_get_throttling_state(pr, value);
 882		if (state == -1) {
 883			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 884				"Invalid throttling state, reset\n"));
 885			state = 0;
 886			ret = acpi_processor_set_throttling(pr, state, true);
 887			if (ret)
 888				return ret;
 889		}
 890		pr->throttling.state = state;
 891	}
 892
 893	return 0;
 894}
 895
 896static int acpi_processor_get_throttling(struct acpi_processor *pr)
 897{
 898	cpumask_var_t saved_mask;
 899	int ret;
 900
 901	if (!pr)
 902		return -EINVAL;
 903
 904	if (!pr->flags.throttling)
 905		return -ENODEV;
 906
 907	if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
 908		return -ENOMEM;
 909
 910	/*
 911	 * Migrate task to the cpu pointed by pr.
 912	 */
 913	cpumask_copy(saved_mask, &current->cpus_allowed);
 914	/* FIXME: use work_on_cpu() */
 915	if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
 916		/* Can't migrate to the target pr->id CPU. Exit */
 917		free_cpumask_var(saved_mask);
 918		return -ENODEV;
 919	}
 920	ret = pr->throttling.acpi_processor_get_throttling(pr);
 921	/* restore the previous state */
 922	set_cpus_allowed_ptr(current, saved_mask);
 923	free_cpumask_var(saved_mask);
 924
 925	return ret;
 926}
 927
 928static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 929{
 930	int i, step;
 931
 932	if (!pr->throttling.address) {
 933		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 934		return -EINVAL;
 935	} else if (!pr->throttling.duty_width) {
 936		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 937		return -EINVAL;
 938	}
 939	/* TBD: Support duty_cycle values that span bit 4. */
 940	else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 941		printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 942		return -EINVAL;
 943	}
 944
 945	pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 946
 947	/*
 948	 * Compute state values. Note that throttling displays a linear power
 949	 * performance relationship (at 50% performance the CPU will consume
 950	 * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 951	 */
 952
 953	step = (1000 / pr->throttling.state_count);
 954
 955	for (i = 0; i < pr->throttling.state_count; i++) {
 956		pr->throttling.states[i].performance = 1000 - step * i;
 957		pr->throttling.states[i].power = 1000 - step * i;
 958	}
 959	return 0;
 960}
 961
 962static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 963					      int state, bool force)
 964{
 965	u32 value = 0;
 966	u32 duty_mask = 0;
 967	u32 duty_value = 0;
 968
 969	if (!pr)
 970		return -EINVAL;
 971
 972	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 973		return -EINVAL;
 974
 975	if (!pr->flags.throttling)
 976		return -ENODEV;
 977
 978	if (!force && (state == pr->throttling.state))
 979		return 0;
 980
 981	if (state < pr->throttling_platform_limit)
 982		return -EPERM;
 983	/*
 984	 * Calculate the duty_value and duty_mask.
 985	 */
 986	if (state) {
 987		duty_value = pr->throttling.state_count - state;
 988
 989		duty_value <<= pr->throttling.duty_offset;
 990
 991		/* Used to clear all duty_value bits */
 992		duty_mask = pr->throttling.state_count - 1;
 993
 994		duty_mask <<= acpi_gbl_FADT.duty_offset;
 995		duty_mask = ~duty_mask;
 996	}
 997
 998	local_irq_disable();
 999
1000	/*
1001	 * Disable throttling by writing a 0 to bit 4.  Note that we must
1002	 * turn it off before you can change the duty_value.
1003	 */
1004	value = inl(pr->throttling.address);
1005	if (value & 0x10) {
1006		value &= 0xFFFFFFEF;
1007		outl(value, pr->throttling.address);
1008	}
1009
1010	/*
1011	 * Write the new duty_value and then enable throttling.  Note
1012	 * that a state value of 0 leaves throttling disabled.
1013	 */
1014	if (state) {
1015		value &= duty_mask;
1016		value |= duty_value;
1017		outl(value, pr->throttling.address);
1018
1019		value |= 0x00000010;
1020		outl(value, pr->throttling.address);
1021	}
1022
1023	pr->throttling.state = state;
1024
1025	local_irq_enable();
1026
1027	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1028			  "Throttling state set to T%d (%d%%)\n", state,
1029			  (pr->throttling.states[state].performance ? pr->
1030			   throttling.states[state].performance / 10 : 0)));
1031
1032	return 0;
1033}
1034
1035static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1036					     int state, bool force)
1037{
1038	int ret;
1039	u64 value;
1040
1041	if (!pr)
1042		return -EINVAL;
1043
1044	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1045		return -EINVAL;
1046
1047	if (!pr->flags.throttling)
1048		return -ENODEV;
1049
1050	if (!force && (state == pr->throttling.state))
1051		return 0;
1052
1053	if (state < pr->throttling_platform_limit)
1054		return -EPERM;
1055
1056	value = 0;
1057	ret = acpi_get_throttling_value(pr, state, &value);
1058	if (ret >= 0) {
1059		acpi_write_throttling_state(pr, value);
1060		pr->throttling.state = state;
1061	}
1062
1063	return 0;
1064}
1065
1066int acpi_processor_set_throttling(struct acpi_processor *pr,
1067						int state, bool force)
1068{
1069	cpumask_var_t saved_mask;
1070	int ret = 0;
1071	unsigned int i;
1072	struct acpi_processor *match_pr;
1073	struct acpi_processor_throttling *p_throttling;
1074	struct throttling_tstate t_state;
1075	cpumask_var_t online_throttling_cpus;
1076
1077	if (!pr)
1078		return -EINVAL;
1079
1080	if (!pr->flags.throttling)
1081		return -ENODEV;
1082
1083	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1084		return -EINVAL;
1085
1086	if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
1087		return -ENOMEM;
1088
1089	if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
1090		free_cpumask_var(saved_mask);
1091		return -ENOMEM;
1092	}
1093
1094	if (cpu_is_offline(pr->id)) {
1095		/*
1096		 * the cpu pointed by pr->id is offline. Unnecessary to change
1097		 * the throttling state any more.
1098		 */
1099		return -ENODEV;
1100	}
1101
1102	cpumask_copy(saved_mask, &current->cpus_allowed);
1103	t_state.target_state = state;
1104	p_throttling = &(pr->throttling);
1105	cpumask_and(online_throttling_cpus, cpu_online_mask,
1106		    p_throttling->shared_cpu_map);
1107	/*
1108	 * The throttling notifier will be called for every
1109	 * affected cpu in order to get one proper T-state.
1110	 * The notifier event is THROTTLING_PRECHANGE.
1111	 */
1112	for_each_cpu(i, online_throttling_cpus) {
1113		t_state.cpu = i;
1114		acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1115							&t_state);
1116	}
1117	/*
1118	 * The function of acpi_processor_set_throttling will be called
1119	 * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1120	 * it is necessary to call it for every affected cpu. Otherwise
1121	 * it can be called only for the cpu pointed by pr.
1122	 */
1123	if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1124		/* FIXME: use work_on_cpu() */
1125		if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
1126			/* Can't migrate to the pr->id CPU. Exit */
1127			ret = -ENODEV;
1128			goto exit;
1129		}
1130		ret = p_throttling->acpi_processor_set_throttling(pr,
1131						t_state.target_state, force);
1132	} else {
1133		/*
1134		 * When the T-state coordination is SW_ALL or HW_ALL,
1135		 * it is necessary to set T-state for every affected
1136		 * cpus.
1137		 */
1138		for_each_cpu(i, online_throttling_cpus) {
1139			match_pr = per_cpu(processors, i);
1140			/*
1141			 * If the pointer is invalid, we will report the
1142			 * error message and continue.
1143			 */
1144			if (!match_pr) {
1145				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1146					"Invalid Pointer for CPU %d\n", i));
1147				continue;
1148			}
1149			/*
1150			 * If the throttling control is unsupported on CPU i,
1151			 * we will report the error message and continue.
1152			 */
1153			if (!match_pr->flags.throttling) {
1154				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1155					"Throttling Control is unsupported "
1156					"on CPU %d\n", i));
1157				continue;
1158			}
1159			t_state.cpu = i;
1160			/* FIXME: use work_on_cpu() */
1161			if (set_cpus_allowed_ptr(current, cpumask_of(i)))
1162				continue;
1163			ret = match_pr->throttling.
1164				acpi_processor_set_throttling(
1165				match_pr, t_state.target_state, force);
1166		}
1167	}
1168	/*
1169	 * After the set_throttling is called, the
1170	 * throttling notifier is called for every
1171	 * affected cpu to update the T-states.
1172	 * The notifier event is THROTTLING_POSTCHANGE
1173	 */
1174	for_each_cpu(i, online_throttling_cpus) {
1175		t_state.cpu = i;
1176		acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1177							&t_state);
1178	}
1179	/* restore the previous state */
1180	/* FIXME: use work_on_cpu() */
1181	set_cpus_allowed_ptr(current, saved_mask);
1182exit:
1183	free_cpumask_var(online_throttling_cpus);
1184	free_cpumask_var(saved_mask);
1185	return ret;
1186}
1187
1188int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1189{
1190	int result = 0;
1191	struct acpi_processor_throttling *pthrottling;
1192
1193	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1194			  "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1195			  pr->throttling.address,
1196			  pr->throttling.duty_offset,
1197			  pr->throttling.duty_width));
1198
1199	/*
1200	 * Evaluate _PTC, _TSS and _TPC
1201	 * They must all be present or none of them can be used.
1202	 */
1203	if (acpi_processor_get_throttling_control(pr) ||
1204		acpi_processor_get_throttling_states(pr) ||
1205		acpi_processor_get_platform_limit(pr))
1206	{
1207		pr->throttling.acpi_processor_get_throttling =
1208		    &acpi_processor_get_throttling_fadt;
1209		pr->throttling.acpi_processor_set_throttling =
1210		    &acpi_processor_set_throttling_fadt;
1211		if (acpi_processor_get_fadt_info(pr))
1212			return 0;
1213	} else {
1214		pr->throttling.acpi_processor_get_throttling =
1215		    &acpi_processor_get_throttling_ptc;
1216		pr->throttling.acpi_processor_set_throttling =
1217		    &acpi_processor_set_throttling_ptc;
1218	}
1219
1220	/*
1221	 * If TSD package for one CPU can't be parsed successfully, it means
1222	 * that this CPU will have no coordination with other CPUs.
1223	 */
1224	if (acpi_processor_get_tsd(pr)) {
1225		pthrottling = &pr->throttling;
1226		pthrottling->tsd_valid_flag = 0;
1227		cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1228		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1229	}
1230
1231	/*
1232	 * PIIX4 Errata: We don't support throttling on the original PIIX4.
1233	 * This shouldn't be an issue as few (if any) mobile systems ever
1234	 * used this part.
1235	 */
1236	if (errata.piix4.throttle) {
1237		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1238				  "Throttling not supported on PIIX4 A- or B-step\n"));
1239		return 0;
1240	}
1241
1242	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1243			  pr->throttling.state_count));
1244
1245	pr->flags.throttling = 1;
1246
1247	/*
1248	 * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1249	 * thermal) decide to lower performance if it so chooses, but for now
1250	 * we'll crank up the speed.
1251	 */
1252
1253	result = acpi_processor_get_throttling(pr);
1254	if (result)
1255		goto end;
1256
1257	if (pr->throttling.state) {
1258		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1259				  "Disabling throttling (was T%d)\n",
1260				  pr->throttling.state));
1261		result = acpi_processor_set_throttling(pr, 0, false);
1262		if (result)
1263			goto end;
1264	}
1265
1266      end:
1267	if (result)
1268		pr->flags.throttling = 0;
1269
1270	return result;
1271}
1272