text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * processor_throttling.c - Throttling submodule of the ACPI processor driver
   *
   *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   *                      - Added processor hotplug support
   */
  
  #define pr_fmt(fmt) "ACPI: " fmt
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/init.h>
  #include <linux/sched.h>
  #include <linux/cpufreq.h>
  #include <linux/acpi.h>
  #include <acpi/processor.h>
  #include <asm/io.h>
  #include <linux/uaccess.h>
  
  /* ignore_tpc:
   *  0 -> acpi processor driver doesn't ignore _TPC values
   *  1 -> acpi processor driver ignores _TPC values
   */
  static int ignore_tpc;
  module_param(ignore_tpc, int, 0644);
  MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  
  struct throttling_tstate {
  	unsigned int cpu;		/* cpu nr */
  	int target_state;		/* target T-state */
  };
  
  struct acpi_processor_throttling_arg {
  	struct acpi_processor *pr;
  	int target_state;
  	bool force;
  };
  
  #define THROTTLING_PRECHANGE       (1)
  #define THROTTLING_POSTCHANGE      (2)
  
  static int acpi_processor_get_throttling(struct acpi_processor *pr);
  static int __acpi_processor_set_throttling(struct acpi_processor *pr,
  					   int state, bool force, bool direct);
  
  static int acpi_processor_update_tsd_coord(void)
  {
  	int count, count_target;
  	int retval = 0;
  	unsigned int i, j;
  	cpumask_var_t covered_cpus;
  	struct acpi_processor *pr, *match_pr;
  	struct acpi_tsd_package *pdomain, *match_pdomain;
  	struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  
  	if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  		return -ENOMEM;
  
  	/*
  	 * Now that we have _TSD data from all CPUs, lets setup T-state
  	 * coordination between all CPUs.
  	 */
  	for_each_possible_cpu(i) {
  		pr = per_cpu(processors, i);
  		if (!pr)
  			continue;
  
  		/* Basic validity check for domain info */
  		pthrottling = &(pr->throttling);
  
  		/*
  		 * If tsd package for one cpu is invalid, the coordination
  		 * among all CPUs is thought as invalid.
  		 * Maybe it is ugly.
  		 */
  		if (!pthrottling->tsd_valid_flag) {
  			retval = -EINVAL;
  			break;
  		}
  	}
  	if (retval)
  		goto err_ret;
  
  	for_each_possible_cpu(i) {
  		pr = per_cpu(processors, i);
  		if (!pr)
  			continue;
  
  		if (cpumask_test_cpu(i, covered_cpus))
  			continue;
  		pthrottling = &pr->throttling;
  
  		pdomain = &(pthrottling->domain_info);
  		cpumask_set_cpu(i, pthrottling->shared_cpu_map);
  		cpumask_set_cpu(i, covered_cpus);
  		/*
  		 * If the number of processor in the TSD domain is 1, it is
  		 * unnecessary to parse the coordination for this CPU.
  		 */
  		if (pdomain->num_processors <= 1)
  			continue;
  
  		/* Validate the Domain info */
  		count_target = pdomain->num_processors;
  		count = 1;
  
  		for_each_possible_cpu(j) {
  			if (i == j)
  				continue;
  
  			match_pr = per_cpu(processors, j);
  			if (!match_pr)
  				continue;
  
  			match_pthrottling = &(match_pr->throttling);
  			match_pdomain = &(match_pthrottling->domain_info);
  			if (match_pdomain->domain != pdomain->domain)
  				continue;
  
  			/* Here i and j are in the same domain.
  			 * If two TSD packages have the same domain, they
  			 * should have the same num_porcessors and
  			 * coordination type. Otherwise it will be regarded
  			 * as illegal.
  			 */
  			if (match_pdomain->num_processors != count_target) {
  				retval = -EINVAL;
  				goto err_ret;
  			}
  
  			if (pdomain->coord_type != match_pdomain->coord_type) {
  				retval = -EINVAL;
  				goto err_ret;
  			}
  
  			cpumask_set_cpu(j, covered_cpus);
  			cpumask_set_cpu(j, pthrottling->shared_cpu_map);
  			count++;
  		}
  		for_each_possible_cpu(j) {
  			if (i == j)
  				continue;
  
  			match_pr = per_cpu(processors, j);
  			if (!match_pr)
  				continue;
  
  			match_pthrottling = &(match_pr->throttling);
  			match_pdomain = &(match_pthrottling->domain_info);
  			if (match_pdomain->domain != pdomain->domain)
  				continue;
  
  			/*
  			 * If some CPUS have the same domain, they
  			 * will have the same shared_cpu_map.
  			 */
  			cpumask_copy(match_pthrottling->shared_cpu_map,
  				     pthrottling->shared_cpu_map);
  		}
  	}
  
  err_ret:
  	free_cpumask_var(covered_cpus);
  
  	for_each_possible_cpu(i) {
  		pr = per_cpu(processors, i);
  		if (!pr)
  			continue;
  
  		/*
  		 * Assume no coordination on any error parsing domain info.
  		 * The coordination type will be forced as SW_ALL.
  		 */
  		if (retval) {
  			pthrottling = &(pr->throttling);
  			cpumask_clear(pthrottling->shared_cpu_map);
  			cpumask_set_cpu(i, pthrottling->shared_cpu_map);
  			pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
  		}
  	}
  
  	return retval;
  }
  
  /*
   * Update the T-state coordination after the _TSD
   * data for all cpus is obtained.
   */
  void acpi_processor_throttling_init(void)
  {
  	if (acpi_processor_update_tsd_coord())
  		pr_debug("Assume no T-state coordination\n");
  }
  
  static int acpi_processor_throttling_notifier(unsigned long event, void *data)
  {
  	struct throttling_tstate *p_tstate = data;
  	struct acpi_processor *pr;
  	unsigned int cpu;
  	int target_state;
  	struct acpi_processor_limit *p_limit;
  	struct acpi_processor_throttling *p_throttling;
  
  	cpu = p_tstate->cpu;
  	pr = per_cpu(processors, cpu);
  	if (!pr) {
  		pr_debug("Invalid pr pointer\n");
  		return 0;
  	}
  	if (!pr->flags.throttling) {
  		acpi_handle_debug(pr->handle,
  				  "Throttling control unsupported on CPU %d\n",
  				  cpu);
  		return 0;
  	}
  	target_state = p_tstate->target_state;
  	p_throttling = &(pr->throttling);
  	switch (event) {
  	case THROTTLING_PRECHANGE:
  		/*
  		 * Prechange event is used to choose one proper t-state,
  		 * which meets the limits of thermal, user and _TPC.
  		 */
  		p_limit = &pr->limit;
  		if (p_limit->thermal.tx > target_state)
  			target_state = p_limit->thermal.tx;
  		if (p_limit->user.tx > target_state)
  			target_state = p_limit->user.tx;
  		if (pr->throttling_platform_limit > target_state)
  			target_state = pr->throttling_platform_limit;
  		if (target_state >= p_throttling->state_count) {
  			pr_warn("Exceed the limit of T-state \n");
  			target_state = p_throttling->state_count - 1;
  		}
  		p_tstate->target_state = target_state;
  		acpi_handle_debug(pr->handle,
  				  "PreChange Event: target T-state of CPU %d is T%d\n",
  				  cpu, target_state);
  		break;
  	case THROTTLING_POSTCHANGE:
  		/*
  		 * Postchange event is only used to update the
  		 * T-state flag of acpi_processor_throttling.
  		 */
  		p_throttling->state = target_state;
  		acpi_handle_debug(pr->handle,
  				  "PostChange Event: CPU %d is switched to T%d\n",
  				  cpu, target_state);
  		break;
  	default:
  		pr_warn("Unsupported Throttling notifier event\n");
  		break;
  	}
  
  	return 0;
  }
  
  /*
   * _TPC - Throttling Present Capabilities
   */
  static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
  {
  	acpi_status status = 0;
  	unsigned long long tpc = 0;
  
  	if (!pr)
  		return -EINVAL;
  
  	if (ignore_tpc)
  		goto end;
  
  	status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
  	if (ACPI_FAILURE(status)) {
  		if (status != AE_NOT_FOUND)
  			acpi_evaluation_failure_warn(pr->handle, "_TPC", status);
  
  		return -ENODEV;
  	}
  
  end:
  	pr->throttling_platform_limit = (int)tpc;
  	return 0;
  }
  
  int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
  {
  	int result = 0;
  	int throttling_limit;
  	int current_state;
  	struct acpi_processor_limit *limit;
  	int target_state;
  
  	if (ignore_tpc)
  		return 0;
  
  	result = acpi_processor_get_platform_limit(pr);
  	if (result) {
  		/* Throttling Limit is unsupported */
  		return result;
  	}
  
  	throttling_limit = pr->throttling_platform_limit;
  	if (throttling_limit >= pr->throttling.state_count) {
  		/* Uncorrect Throttling Limit */
  		return -EINVAL;
  	}
  
  	current_state = pr->throttling.state;
  	if (current_state > throttling_limit) {
  		/*
  		 * The current state can meet the requirement of
  		 * _TPC limit. But it is reasonable that OSPM changes
  		 * t-states from high to low for better performance.
  		 * Of course the limit condition of thermal
  		 * and user should be considered.
  		 */
  		limit = &pr->limit;
  		target_state = throttling_limit;
  		if (limit->thermal.tx > target_state)
  			target_state = limit->thermal.tx;
  		if (limit->user.tx > target_state)
  			target_state = limit->user.tx;
  	} else if (current_state == throttling_limit) {
  		/*
  		 * Unnecessary to change the throttling state
  		 */
  		return 0;
  	} else {
  		/*
  		 * If the current state is lower than the limit of _TPC, it
  		 * will be forced to switch to the throttling state defined
  		 * by throttling_platfor_limit.
  		 * Because the previous state meets with the limit condition
  		 * of thermal and user, it is unnecessary to check it again.
  		 */
  		target_state = throttling_limit;
  	}
  	return acpi_processor_set_throttling(pr, target_state, false);
  }
  
  /*
   * This function is used to reevaluate whether the T-state is valid
   * after one CPU is onlined/offlined.
   * It is noted that it won't reevaluate the following properties for
   * the T-state.
   *	1. Control method.
   *	2. the number of supported T-state
   *	3. TSD domain
   */
  void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
  					bool is_dead)
  {
  	int result = 0;
  
  	if (is_dead) {
  		/* When one CPU is offline, the T-state throttling
  		 * will be invalidated.
  		 */
  		pr->flags.throttling = 0;
  		return;
  	}
  	/* the following is to recheck whether the T-state is valid for
  	 * the online CPU
  	 */
  	if (!pr->throttling.state_count) {
  		/* If the number of T-state is invalid, it is
  		 * invalidated.
  		 */
  		pr->flags.throttling = 0;
  		return;
  	}
  	pr->flags.throttling = 1;
  
  	/* Disable throttling (if enabled).  We'll let subsequent
  	 * policy (e.g.thermal) decide to lower performance if it
  	 * so chooses, but for now we'll crank up the speed.
  	 */
  
  	result = acpi_processor_get_throttling(pr);
  	if (result)
  		goto end;
  
  	if (pr->throttling.state) {
  		result = acpi_processor_set_throttling(pr, 0, false);
  		if (result)
  			goto end;
  	}
  
  end:
  	if (result)
  		pr->flags.throttling = 0;
  }
  /*
   * _PTC - Processor Throttling Control (and status) register location
   */
  static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
  {
  	int result = 0;
  	acpi_status status = 0;
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	union acpi_object *ptc = NULL;
  	union acpi_object obj;
  	struct acpi_processor_throttling *throttling;
  
  	status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
  	if (ACPI_FAILURE(status)) {
  		if (status != AE_NOT_FOUND)
  			acpi_evaluation_failure_warn(pr->handle, "_PTC", status);
  
  		return -ENODEV;
  	}
  
  	ptc = (union acpi_object *)buffer.pointer;
  	if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
  	    || (ptc->package.count != 2)) {
  		pr_err("Invalid _PTC data\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  	/*
  	 * control_register
  	 */
  
  	obj = ptc->package.elements[0];
  
  	if ((obj.type != ACPI_TYPE_BUFFER)
  	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
  	    || (obj.buffer.pointer == NULL)) {
  		pr_err("Invalid _PTC data (control_register)\n");
  		result = -EFAULT;
  		goto end;
  	}
  	memcpy(&pr->throttling.control_register, obj.buffer.pointer,
  	       sizeof(struct acpi_ptc_register));
  
  	/*
  	 * status_register
  	 */
  
  	obj = ptc->package.elements[1];
  
  	if ((obj.type != ACPI_TYPE_BUFFER)
  	    || (obj.buffer.length < sizeof(struct acpi_ptc_register))
  	    || (obj.buffer.pointer == NULL)) {
  		pr_err("Invalid _PTC data (status_register)\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  	memcpy(&pr->throttling.status_register, obj.buffer.pointer,
  	       sizeof(struct acpi_ptc_register));
  
  	throttling = &pr->throttling;
  
  	if ((throttling->control_register.bit_width +
  		throttling->control_register.bit_offset) > 32) {
  		pr_err("Invalid _PTC control register\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  	if ((throttling->status_register.bit_width +
  		throttling->status_register.bit_offset) > 32) {
  		pr_err("Invalid _PTC status register\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  end:
  	kfree(buffer.pointer);
  
  	return result;
  }
  
  /*
   * _TSS - Throttling Supported States
   */
  static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
  {
  	int result = 0;
  	acpi_status status = AE_OK;
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
  	struct acpi_buffer state = { 0, NULL };
  	union acpi_object *tss = NULL;
  	int i;
  
  	status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
  	if (ACPI_FAILURE(status)) {
  		if (status != AE_NOT_FOUND)
  			acpi_evaluation_failure_warn(pr->handle, "_TSS", status);
  
  		return -ENODEV;
  	}
  
  	tss = buffer.pointer;
  	if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
  		pr_err("Invalid _TSS data\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  	acpi_handle_debug(pr->handle, "Found %d throttling states\n",
  			  tss->package.count);
  
  	pr->throttling.state_count = tss->package.count;
  	pr->throttling.states_tss =
  	    kmalloc_array(tss->package.count,
  			  sizeof(struct acpi_processor_tx_tss),
  			  GFP_KERNEL);
  	if (!pr->throttling.states_tss) {
  		result = -ENOMEM;
  		goto end;
  	}
  
  	for (i = 0; i < pr->throttling.state_count; i++) {
  
  		struct acpi_processor_tx_tss *tx =
  		    (struct acpi_processor_tx_tss *)&(pr->throttling.
  						      states_tss[i]);
  
  		state.length = sizeof(struct acpi_processor_tx_tss);
  		state.pointer = tx;
  
  		acpi_handle_debug(pr->handle, "Extracting state %d\n", i);
  
  		status = acpi_extract_package(&(tss->package.elements[i]),
  					      &format, &state);
  		if (ACPI_FAILURE(status)) {
  			acpi_handle_warn(pr->handle, "Invalid _TSS data: %s\n",
  					 acpi_format_exception(status));
  			result = -EFAULT;
  			kfree(pr->throttling.states_tss);
  			goto end;
  		}
  
  		if (!tx->freqpercentage) {
  			pr_err("Invalid _TSS data: freq is zero\n");
  			result = -EFAULT;
  			kfree(pr->throttling.states_tss);
  			goto end;
  		}
  	}
  
  end:
  	kfree(buffer.pointer);
  
  	return result;
  }
  
  /*
   * _TSD - T-State Dependencies
   */
  static int acpi_processor_get_tsd(struct acpi_processor *pr)
  {
  	int result = 0;
  	acpi_status status = AE_OK;
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
  	struct acpi_buffer state = { 0, NULL };
  	union acpi_object *tsd = NULL;
  	struct acpi_tsd_package *pdomain;
  	struct acpi_processor_throttling *pthrottling;
  
  	pthrottling = &pr->throttling;
  	pthrottling->tsd_valid_flag = 0;
  
  	status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
  	if (ACPI_FAILURE(status)) {
  		if (status != AE_NOT_FOUND)
  			acpi_evaluation_failure_warn(pr->handle, "_TSD", status);
  
  		return -ENODEV;
  	}
  
  	tsd = buffer.pointer;
  	if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
  		pr_err("Invalid _TSD data\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  	if (tsd->package.count != 1) {
  		pr_err("Invalid _TSD data\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  	pdomain = &(pr->throttling.domain_info);
  
  	state.length = sizeof(struct acpi_tsd_package);
  	state.pointer = pdomain;
  
  	status = acpi_extract_package(&(tsd->package.elements[0]),
  				      &format, &state);
  	if (ACPI_FAILURE(status)) {
  		pr_err("Invalid _TSD data\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  	if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
  		pr_err("Unknown _TSD:num_entries\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  	if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
  		pr_err("Unknown _TSD:revision\n");
  		result = -EFAULT;
  		goto end;
  	}
  
  	pthrottling = &pr->throttling;
  	pthrottling->tsd_valid_flag = 1;
  	pthrottling->shared_type = pdomain->coord_type;
  	cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
  	/*
  	 * If the coordination type is not defined in ACPI spec,
  	 * the tsd_valid_flag will be clear and coordination type
  	 * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
  	 */
  	if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
  		pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
  		pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
  		pthrottling->tsd_valid_flag = 0;
  		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
  	}
  
  end:
  	kfree(buffer.pointer);
  	return result;
  }
  
  /* --------------------------------------------------------------------------
                                Throttling Control
     -------------------------------------------------------------------------- */
  static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
  {
  	int state = 0;
  	u32 value = 0;
  	u32 duty_mask = 0;
  	u32 duty_value = 0;
  
  	if (!pr)
  		return -EINVAL;
  
  	if (!pr->flags.throttling)
  		return -ENODEV;
  
  	/*
  	 * We don't care about error returns - we just try to mark
  	 * these reserved so that nobody else is confused into thinking
  	 * that this region might be unused..
  	 *
  	 * (In particular, allocating the IO range for Cardbus)
  	 */
  	request_region(pr->throttling.address, 6, "ACPI CPU throttle");
  
  	pr->throttling.state = 0;
  
  	duty_mask = pr->throttling.state_count - 1;
  
  	duty_mask <<= pr->throttling.duty_offset;
  
  	local_irq_disable();
  
  	value = inl(pr->throttling.address);
  
  	/*
  	 * Compute the current throttling state when throttling is enabled
  	 * (bit 4 is on).
  	 */
  	if (value & 0x10) {
  		duty_value = value & duty_mask;
  		duty_value >>= pr->throttling.duty_offset;
  
  		if (duty_value)
  			state = pr->throttling.state_count - duty_value;
  	}
  
  	pr->throttling.state = state;
  
  	local_irq_enable();
  
  	acpi_handle_debug(pr->handle,
  			  "Throttling state is T%d (%d%% throttling applied)\n",
  			  state, pr->throttling.states[state].performance);
  
  	return 0;
  }
  
  #ifdef CONFIG_X86
  static int acpi_throttling_rdmsr(u64 *value)
  {
  	u64 msr_high, msr_low;
  	u64 msr = 0;
  	int ret = -1;
  
  	if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
  		!this_cpu_has(X86_FEATURE_ACPI)) {
  		pr_err("HARDWARE addr space,NOT supported yet\n");
  	} else {
  		msr_low = 0;
  		msr_high = 0;
  		rdmsr_safe(MSR_IA32_THERM_CONTROL,
  			(u32 *)&msr_low, (u32 *) &msr_high);
  		msr = (msr_high << 32) | msr_low;
  		*value = (u64) msr;
  		ret = 0;
  	}
  	return ret;
  }
  
  static int acpi_throttling_wrmsr(u64 value)
  {
  	int ret = -1;
  	u64 msr;
  
  	if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
  		!this_cpu_has(X86_FEATURE_ACPI)) {
  		pr_err("HARDWARE addr space,NOT supported yet\n");
  	} else {
  		msr = value;
  		wrmsr_safe(MSR_IA32_THERM_CONTROL,
  			msr & 0xffffffff, msr >> 32);
  		ret = 0;
  	}
  	return ret;
  }
  #else
  static int acpi_throttling_rdmsr(u64 *value)
  {
  	pr_err("HARDWARE addr space,NOT supported yet\n");
  	return -1;
  }
  
  static int acpi_throttling_wrmsr(u64 value)
  {
  	pr_err("HARDWARE addr space,NOT supported yet\n");
  	return -1;
  }
  #endif
  
  static int acpi_read_throttling_status(struct acpi_processor *pr,
  					u64 *value)
  {
  	u32 bit_width, bit_offset;
  	u32 ptc_value;
  	u64 ptc_mask;
  	struct acpi_processor_throttling *throttling;
  	int ret = -1;
  
  	throttling = &pr->throttling;
  	switch (throttling->status_register.space_id) {
  	case ACPI_ADR_SPACE_SYSTEM_IO:
  		bit_width = throttling->status_register.bit_width;
  		bit_offset = throttling->status_register.bit_offset;
  
  		acpi_os_read_port((acpi_io_address) throttling->status_register.
  				  address, &ptc_value,
  				  (u32) (bit_width + bit_offset));
  		ptc_mask = (1 << bit_width) - 1;
  		*value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
  		ret = 0;
  		break;
  	case ACPI_ADR_SPACE_FIXED_HARDWARE:
  		ret = acpi_throttling_rdmsr(value);
  		break;
  	default:
  		pr_err("Unknown addr space %d\n",
  		       (u32) (throttling->status_register.space_id));
  	}
  	return ret;
  }
  
  static int acpi_write_throttling_state(struct acpi_processor *pr,
  				u64 value)
  {
  	u32 bit_width, bit_offset;
  	u64 ptc_value;
  	u64 ptc_mask;
  	struct acpi_processor_throttling *throttling;
  	int ret = -1;
  
  	throttling = &pr->throttling;
  	switch (throttling->control_register.space_id) {
  	case ACPI_ADR_SPACE_SYSTEM_IO:
  		bit_width = throttling->control_register.bit_width;
  		bit_offset = throttling->control_register.bit_offset;
  		ptc_mask = (1 << bit_width) - 1;
  		ptc_value = value & ptc_mask;
  
  		acpi_os_write_port((acpi_io_address) throttling->
  					control_register.address,
  					(u32) (ptc_value << bit_offset),
  					(u32) (bit_width + bit_offset));
  		ret = 0;
  		break;
  	case ACPI_ADR_SPACE_FIXED_HARDWARE:
  		ret = acpi_throttling_wrmsr(value);
  		break;
  	default:
  		pr_err("Unknown addr space %d\n",
  		       (u32) (throttling->control_register.space_id));
  	}
  	return ret;
  }
  
  static int acpi_get_throttling_state(struct acpi_processor *pr,
  				u64 value)
  {
  	int i;
  
  	for (i = 0; i < pr->throttling.state_count; i++) {
  		struct acpi_processor_tx_tss *tx =
  		    (struct acpi_processor_tx_tss *)&(pr->throttling.
  						      states_tss[i]);
  		if (tx->control == value)
  			return i;
  	}
  	return -1;
  }
  
  static int acpi_get_throttling_value(struct acpi_processor *pr,
  			int state, u64 *value)
  {
  	int ret = -1;
  
  	if (state >= 0 && state <= pr->throttling.state_count) {
  		struct acpi_processor_tx_tss *tx =
  		    (struct acpi_processor_tx_tss *)&(pr->throttling.
  						      states_tss[state]);
  		*value = tx->control;
  		ret = 0;
  	}
  	return ret;
  }
  
  static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
  {
  	int state = 0;
  	int ret;
  	u64 value;
  
  	if (!pr)
  		return -EINVAL;
  
  	if (!pr->flags.throttling)
  		return -ENODEV;
  
  	pr->throttling.state = 0;
  
  	value = 0;
  	ret = acpi_read_throttling_status(pr, &value);
  	if (ret >= 0) {
  		state = acpi_get_throttling_state(pr, value);
  		if (state == -1) {
  			acpi_handle_debug(pr->handle,
  					  "Invalid throttling state, reset\n");
  			state = 0;
  			ret = __acpi_processor_set_throttling(pr, state, true,
  							      true);
  			if (ret)
  				return ret;
  		}
  		pr->throttling.state = state;
  	}
  
  	return 0;
  }
  
  static long __acpi_processor_get_throttling(void *data)
  {
  	struct acpi_processor *pr = data;
  
  	return pr->throttling.acpi_processor_get_throttling(pr);
  }
  
  static int acpi_processor_get_throttling(struct acpi_processor *pr)
  {
  	if (!pr)
  		return -EINVAL;
  
  	if (!pr->flags.throttling)
  		return -ENODEV;
  
  	/*
  	 * This is either called from the CPU hotplug callback of
  	 * processor_driver or via the ACPI probe function. In the latter
  	 * case the CPU is not guaranteed to be online. Both call sites are
  	 * protected against CPU hotplug.
  	 */
  	if (!cpu_online(pr->id))
  		return -ENODEV;
  
  	return call_on_cpu(pr->id, __acpi_processor_get_throttling, pr, false);
  }
  
  static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
  {
  	int i, step;
  
  	if (!pr->throttling.address) {
  		acpi_handle_debug(pr->handle, "No throttling register\n");
  		return -EINVAL;
  	} else if (!pr->throttling.duty_width) {
  		acpi_handle_debug(pr->handle, "No throttling states\n");
  		return -EINVAL;
  	}
  	/* TBD: Support duty_cycle values that span bit 4. */
  	else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
  		pr_warn("duty_cycle spans bit 4\n");
  		return -EINVAL;
  	}
  
  	pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
  
  	/*
  	 * Compute state values. Note that throttling displays a linear power
  	 * performance relationship (at 50% performance the CPU will consume
  	 * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
  	 */
  
  	step = (1000 / pr->throttling.state_count);
  
  	for (i = 0; i < pr->throttling.state_count; i++) {
  		pr->throttling.states[i].performance = 1000 - step * i;
  		pr->throttling.states[i].power = 1000 - step * i;
  	}
  	return 0;
  }
  
  static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
  					      int state, bool force)
  {
  	u32 value = 0;
  	u32 duty_mask = 0;
  	u32 duty_value = 0;
  
  	if (!pr)
  		return -EINVAL;
  
  	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
  		return -EINVAL;
  
  	if (!pr->flags.throttling)
  		return -ENODEV;
  
  	if (!force && (state == pr->throttling.state))
  		return 0;
  
  	if (state < pr->throttling_platform_limit)
  		return -EPERM;
  	/*
  	 * Calculate the duty_value and duty_mask.
  	 */
  	if (state) {
  		duty_value = pr->throttling.state_count - state;
  
  		duty_value <<= pr->throttling.duty_offset;
  
  		/* Used to clear all duty_value bits */
  		duty_mask = pr->throttling.state_count - 1;
  
  		duty_mask <<= acpi_gbl_FADT.duty_offset;
  		duty_mask = ~duty_mask;
  	}
  
  	local_irq_disable();
  
  	/*
  	 * Disable throttling by writing a 0 to bit 4.  Note that we must
  	 * turn it off before you can change the duty_value.
  	 */
  	value = inl(pr->throttling.address);
  	if (value & 0x10) {
  		value &= 0xFFFFFFEF;
  		outl(value, pr->throttling.address);
  	}
  
  	/*
  	 * Write the new duty_value and then enable throttling.  Note
  	 * that a state value of 0 leaves throttling disabled.
  	 */
  	if (state) {
  		value &= duty_mask;
  		value |= duty_value;
  		outl(value, pr->throttling.address);
  
  		value |= 0x00000010;
  		outl(value, pr->throttling.address);
  	}
  
  	pr->throttling.state = state;
  
  	local_irq_enable();
  
  	acpi_handle_debug(pr->handle,
  			  "Throttling state set to T%d (%d%%)\n", state,
  			  (pr->throttling.states[state].performance ? pr->
  			   throttling.states[state].performance / 10 : 0));
  
  	return 0;
  }
  
  static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
  					     int state, bool force)
  {
  	int ret;
  	u64 value;
  
  	if (!pr)
  		return -EINVAL;
  
  	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
  		return -EINVAL;
  
  	if (!pr->flags.throttling)
  		return -ENODEV;
  
  	if (!force && (state == pr->throttling.state))
  		return 0;
  
  	if (state < pr->throttling_platform_limit)
  		return -EPERM;
  
  	value = 0;
  	ret = acpi_get_throttling_value(pr, state, &value);
  	if (ret >= 0) {
  		acpi_write_throttling_state(pr, value);
  		pr->throttling.state = state;
  	}
  
  	return 0;
  }
  
  static long acpi_processor_throttling_fn(void *data)
  {
  	struct acpi_processor_throttling_arg *arg = data;
  	struct acpi_processor *pr = arg->pr;
  
  	return pr->throttling.acpi_processor_set_throttling(pr,
  			arg->target_state, arg->force);
  }
  
  static int __acpi_processor_set_throttling(struct acpi_processor *pr,
  					   int state, bool force, bool direct)
  {
  	int ret = 0;
  	unsigned int i;
  	struct acpi_processor *match_pr;
  	struct acpi_processor_throttling *p_throttling;
  	struct acpi_processor_throttling_arg arg;
  	struct throttling_tstate t_state;
  
  	if (!pr)
  		return -EINVAL;
  
  	if (!pr->flags.throttling)
  		return -ENODEV;
  
  	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
  		return -EINVAL;
  
  	if (cpu_is_offline(pr->id)) {
  		/*
  		 * the cpu pointed by pr->id is offline. Unnecessary to change
  		 * the throttling state any more.
  		 */
  		return -ENODEV;
  	}
  
  	t_state.target_state = state;
  	p_throttling = &(pr->throttling);
  
  	/*
  	 * The throttling notifier will be called for every
  	 * affected cpu in order to get one proper T-state.
  	 * The notifier event is THROTTLING_PRECHANGE.
  	 */
  	for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
  		t_state.cpu = i;
  		acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
  							&t_state);
  	}
  	/*
  	 * The function of acpi_processor_set_throttling will be called
  	 * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
  	 * it is necessary to call it for every affected cpu. Otherwise
  	 * it can be called only for the cpu pointed by pr.
  	 */
  	if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
  		arg.pr = pr;
  		arg.target_state = state;
  		arg.force = force;
  		ret = call_on_cpu(pr->id, acpi_processor_throttling_fn, &arg,
  				  direct);
  	} else {
  		/*
  		 * When the T-state coordination is SW_ALL or HW_ALL,
  		 * it is necessary to set T-state for every affected
  		 * cpus.
  		 */
  		for_each_cpu_and(i, cpu_online_mask,
  		    p_throttling->shared_cpu_map) {
  			match_pr = per_cpu(processors, i);
  			/*
  			 * If the pointer is invalid, we will report the
  			 * error message and continue.
  			 */
  			if (!match_pr) {
  				acpi_handle_debug(pr->handle,
  					"Invalid Pointer for CPU %d\n", i);
  				continue;
  			}
  			/*
  			 * If the throttling control is unsupported on CPU i,
  			 * we will report the error message and continue.
  			 */
  			if (!match_pr->flags.throttling) {
  				acpi_handle_debug(pr->handle,
  					"Throttling Control unsupported on CPU %d\n", i);
  				continue;
  			}
  
  			arg.pr = match_pr;
  			arg.target_state = state;
  			arg.force = force;
  			ret = call_on_cpu(pr->id, acpi_processor_throttling_fn,
  					  &arg, direct);
  		}
  	}
  	/*
  	 * After the set_throttling is called, the
  	 * throttling notifier is called for every
  	 * affected cpu to update the T-states.
  	 * The notifier event is THROTTLING_POSTCHANGE
  	 */
  	for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
  		t_state.cpu = i;
  		acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
  							&t_state);
  	}
  
  	return ret;
  }
  
  int acpi_processor_set_throttling(struct acpi_processor *pr, int state,
  				  bool force)
  {
  	return __acpi_processor_set_throttling(pr, state, force, false);
  }
  
  int acpi_processor_get_throttling_info(struct acpi_processor *pr)
  {
  	int result = 0;
  	struct acpi_processor_throttling *pthrottling;
  
  	acpi_handle_debug(pr->handle,
  			  "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
  			  pr->throttling.address,
  			  pr->throttling.duty_offset,
  			  pr->throttling.duty_width);
  
  	/*
  	 * Evaluate _PTC, _TSS and _TPC
  	 * They must all be present or none of them can be used.
  	 */
  	if (acpi_processor_get_throttling_control(pr) ||
  		acpi_processor_get_throttling_states(pr) ||
  		acpi_processor_get_platform_limit(pr)) {
  		pr->throttling.acpi_processor_get_throttling =
  		    &acpi_processor_get_throttling_fadt;
  		pr->throttling.acpi_processor_set_throttling =
  		    &acpi_processor_set_throttling_fadt;
  		if (acpi_processor_get_fadt_info(pr))
  			return 0;
  	} else {
  		pr->throttling.acpi_processor_get_throttling =
  		    &acpi_processor_get_throttling_ptc;
  		pr->throttling.acpi_processor_set_throttling =
  		    &acpi_processor_set_throttling_ptc;
  	}
  
  	/*
  	 * If TSD package for one CPU can't be parsed successfully, it means
  	 * that this CPU will have no coordination with other CPUs.
  	 */
  	if (acpi_processor_get_tsd(pr)) {
  		pthrottling = &pr->throttling;
  		pthrottling->tsd_valid_flag = 0;
  		cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
  		pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
  	}
  
  	/*
  	 * PIIX4 Errata: We don't support throttling on the original PIIX4.
  	 * This shouldn't be an issue as few (if any) mobile systems ever
  	 * used this part.
  	 */
  	if (errata.piix4.throttle) {
  		acpi_handle_debug(pr->handle,
  				  "Throttling not supported on PIIX4 A- or B-step\n");
  		return 0;
  	}
  
  	acpi_handle_debug(pr->handle, "Found %d throttling states\n",
  			  pr->throttling.state_count);
  
  	pr->flags.throttling = 1;
  
  	/*
  	 * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
  	 * thermal) decide to lower performance if it so chooses, but for now
  	 * we'll crank up the speed.
  	 */
  
  	result = acpi_processor_get_throttling(pr);
  	if (result)
  		goto end;
  
  	if (pr->throttling.state) {
  		acpi_handle_debug(pr->handle,
  				  "Disabling throttling (was T%d)\n",
  				  pr->throttling.state);
  		result = acpi_processor_set_throttling(pr, 0, false);
  		if (result)
  			goto end;
  	}
  
  end:
  	if (result)
  		pr->flags.throttling = 0;
  
  	return result;
  }
  
  