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processor_perflib.c

/*
 * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
 *
 *  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
 *
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>

#ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/mutex.h>

#include <asm/uaccess.h>
#endif

#include <acpi/acpi_bus.h>
#include <acpi/processor.h>

#define ACPI_PROCESSOR_COMPONENT    0x01000000
#define ACPI_PROCESSOR_CLASS        "processor"
#define ACPI_PROCESSOR_FILE_PERFORMANCE   "performance"
#define _COMPONENT            ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_perflib");

static DEFINE_MUTEX(performance_mutex);

/*
 * _PPC support is implemented as a CPUfreq policy notifier:
 * This means each time a CPUfreq driver registered also with
 * the ACPI core is asked to change the speed policy, the maximum
 * value is adjusted so that it is within the platform limit.
 *
 * Also, when a new platform limit value is detected, the CPUfreq
 * policy is adjusted accordingly.
 */

#define PPC_REGISTERED   1
#define PPC_IN_USE       2

static int acpi_processor_ppc_status = 0;

static int acpi_processor_ppc_notifier(struct notifier_block *nb,
                               unsigned long event, void *data)
{
      struct cpufreq_policy *policy = data;
      struct acpi_processor *pr;
      unsigned int ppc = 0;

      mutex_lock(&performance_mutex);

      if (event != CPUFREQ_INCOMPATIBLE)
            goto out;

      pr = processors[policy->cpu];
      if (!pr || !pr->performance)
            goto out;

      ppc = (unsigned int)pr->performance_platform_limit;

      if (ppc >= pr->performance->state_count)
            goto out;

      cpufreq_verify_within_limits(policy, 0,
                             pr->performance->states[ppc].
                             core_frequency * 1000);

      out:
      mutex_unlock(&performance_mutex);

      return 0;
}

static struct notifier_block acpi_ppc_notifier_block = {
      .notifier_call = acpi_processor_ppc_notifier,
};

static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
{
      acpi_status status = 0;
      unsigned long ppc = 0;


      if (!pr)
            return -EINVAL;

      /*
       * _PPC indicates the maximum state currently supported by the platform
       * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
       */
      status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);

      if (status != AE_NOT_FOUND)
            acpi_processor_ppc_status |= PPC_IN_USE;

      if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
            ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PPC"));
            return -ENODEV;
      }

      pr->performance_platform_limit = (int)ppc;

      return 0;
}

int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
{
      int ret = acpi_processor_get_platform_limit(pr);
      if (ret < 0)
            return (ret);
      else
            return cpufreq_update_policy(pr->id);
}

void acpi_processor_ppc_init(void)
{
      if (!cpufreq_register_notifier
          (&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
            acpi_processor_ppc_status |= PPC_REGISTERED;
      else
            printk(KERN_DEBUG
                   "Warning: Processor Platform Limit not supported.\n");
}

void acpi_processor_ppc_exit(void)
{
      if (acpi_processor_ppc_status & PPC_REGISTERED)
            cpufreq_unregister_notifier(&acpi_ppc_notifier_block,
                                  CPUFREQ_POLICY_NOTIFIER);

      acpi_processor_ppc_status &= ~PPC_REGISTERED;
}

static int acpi_processor_get_performance_control(struct acpi_processor *pr)
{
      int result = 0;
      acpi_status status = 0;
      struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
      union acpi_object *pct = NULL;
      union acpi_object obj = { 0 };


      status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
      if (ACPI_FAILURE(status)) {
            ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PCT"));
            return -ENODEV;
      }

      pct = (union acpi_object *)buffer.pointer;
      if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
          || (pct->package.count != 2)) {
            printk(KERN_ERR PREFIX "Invalid _PCT data\n");
            result = -EFAULT;
            goto end;
      }

      /*
       * control_register
       */

      obj = pct->package.elements[0];

      if ((obj.type != ACPI_TYPE_BUFFER)
          || (obj.buffer.length < sizeof(struct acpi_pct_register))
          || (obj.buffer.pointer == NULL)) {
            printk(KERN_ERR PREFIX "Invalid _PCT data (control_register)\n");
            result = -EFAULT;
            goto end;
      }
      memcpy(&pr->performance->control_register, obj.buffer.pointer,
             sizeof(struct acpi_pct_register));

      /*
       * status_register
       */

      obj = pct->package.elements[1];

      if ((obj.type != ACPI_TYPE_BUFFER)
          || (obj.buffer.length < sizeof(struct acpi_pct_register))
          || (obj.buffer.pointer == NULL)) {
            printk(KERN_ERR PREFIX "Invalid _PCT data (status_register)\n");
            result = -EFAULT;
            goto end;
      }

      memcpy(&pr->performance->status_register, obj.buffer.pointer,
             sizeof(struct acpi_pct_register));

      end:
      kfree(buffer.pointer);

      return result;
}

static int acpi_processor_get_performance_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("NNNNNN"), "NNNNNN" };
      struct acpi_buffer state = { 0, NULL };
      union acpi_object *pss = NULL;
      int i;


      status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
      if (ACPI_FAILURE(status)) {
            ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PSS"));
            return -ENODEV;
      }

      pss = buffer.pointer;
      if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
            printk(KERN_ERR PREFIX "Invalid _PSS data\n");
            result = -EFAULT;
            goto end;
      }

      ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
                    pss->package.count));

      pr->performance->state_count = pss->package.count;
      pr->performance->states =
          kmalloc(sizeof(struct acpi_processor_px) * pss->package.count,
                GFP_KERNEL);
      if (!pr->performance->states) {
            result = -ENOMEM;
            goto end;
      }

      for (i = 0; i < pr->performance->state_count; i++) {

            struct acpi_processor_px *px = &(pr->performance->states[i]);

            state.length = sizeof(struct acpi_processor_px);
            state.pointer = px;

            ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));

            status = acpi_extract_package(&(pss->package.elements[i]),
                                    &format, &state);
            if (ACPI_FAILURE(status)) {
                  ACPI_EXCEPTION((AE_INFO, status, "Invalid _PSS data"));
                  result = -EFAULT;
                  kfree(pr->performance->states);
                  goto end;
            }

            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
                          i,
                          (u32) px->core_frequency,
                          (u32) px->power,
                          (u32) px->transition_latency,
                          (u32) px->bus_master_latency,
                          (u32) px->control, (u32) px->status));

            if (!px->core_frequency) {
                  printk(KERN_ERR PREFIX
                            "Invalid _PSS data: freq is zero\n");
                  result = -EFAULT;
                  kfree(pr->performance->states);
                  goto end;
            }
      }

      end:
      kfree(buffer.pointer);

      return result;
}

static int acpi_processor_get_performance_info(struct acpi_processor *pr)
{
      int result = 0;
      acpi_status status = AE_OK;
      acpi_handle handle = NULL;


      if (!pr || !pr->performance || !pr->handle)
            return -EINVAL;

      status = acpi_get_handle(pr->handle, "_PCT", &handle);
      if (ACPI_FAILURE(status)) {
            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "ACPI-based processor performance control unavailable\n"));
            return -ENODEV;
      }

      result = acpi_processor_get_performance_control(pr);
      if (result)
            return result;

      result = acpi_processor_get_performance_states(pr);
      if (result)
            return result;

      return 0;
}

int acpi_processor_notify_smm(struct module *calling_module)
{
      acpi_status status;
      static int is_done = 0;


      if (!(acpi_processor_ppc_status & PPC_REGISTERED))
            return -EBUSY;

      if (!try_module_get(calling_module))
            return -EINVAL;

      /* is_done is set to negative if an error occured,
       * and to postitive if _no_ error occured, but SMM
       * was already notified. This avoids double notification
       * which might lead to unexpected results...
       */
      if (is_done > 0) {
            module_put(calling_module);
            return 0;
      } else if (is_done < 0) {
            module_put(calling_module);
            return is_done;
      }

      is_done = -EIO;

      /* Can't write pstate_control to smi_command if either value is zero */
      if ((!acpi_gbl_FADT.smi_command) || (!acpi_gbl_FADT.pstate_control)) {
            ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_control\n"));
            module_put(calling_module);
            return 0;
      }

      ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                    "Writing pstate_control [0x%x] to smi_command [0x%x]\n",
                    acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command));

      status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
                            (u32) acpi_gbl_FADT.pstate_control, 8);
      if (ACPI_FAILURE(status)) {
            ACPI_EXCEPTION((AE_INFO, status,
                        "Failed to write pstate_control [0x%x] to "
                        "smi_command [0x%x]", acpi_gbl_FADT.pstate_control,
                        acpi_gbl_FADT.smi_command));
            module_put(calling_module);
            return status;
      }

      /* Success. If there's no _PPC, we need to fear nothing, so
       * we can allow the cpufreq driver to be rmmod'ed. */
      is_done = 1;

      if (!(acpi_processor_ppc_status & PPC_IN_USE))
            module_put(calling_module);

      return 0;
}

EXPORT_SYMBOL(acpi_processor_notify_smm);

#ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
/* /proc/acpi/processor/../performance interface (DEPRECATED) */

static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_processor_perf_fops = {
      .open = acpi_processor_perf_open_fs,
      .read = seq_read,
      .llseek = seq_lseek,
      .release = single_release,
};

static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
{
      struct acpi_processor *pr = seq->private;
      int i;


      if (!pr)
            goto end;

      if (!pr->performance) {
            seq_puts(seq, "<not supported>\n");
            goto end;
      }

      seq_printf(seq, "state count:             %d\n"
               "active state:            P%d\n",
               pr->performance->state_count, pr->performance->state);

      seq_puts(seq, "states:\n");
      for (i = 0; i < pr->performance->state_count; i++)
            seq_printf(seq,
                     "   %cP%d:                  %d MHz, %d mW, %d uS\n",
                     (i == pr->performance->state ? '*' : ' '), i,
                     (u32) pr->performance->states[i].core_frequency,
                     (u32) pr->performance->states[i].power,
                     (u32) pr->performance->states[i].transition_latency);

      end:
      return 0;
}

static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
{
      return single_open(file, acpi_processor_perf_seq_show,
                     PDE(inode)->data);
}

static void acpi_cpufreq_add_file(struct acpi_processor *pr)
{
      struct proc_dir_entry *entry = NULL;
      struct acpi_device *device = NULL;


      if (acpi_bus_get_device(pr->handle, &device))
            return;

      /* add file 'performance' [R/W] */
      entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
                          S_IFREG | S_IRUGO,
                          acpi_device_dir(device));
      if (entry){
            entry->proc_fops = &acpi_processor_perf_fops;
            entry->data = acpi_driver_data(device);
            entry->owner = THIS_MODULE;
      }
      return;
}

static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
{
      struct acpi_device *device = NULL;


      if (acpi_bus_get_device(pr->handle, &device))
            return;

      /* remove file 'performance' */
      remove_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
                    acpi_device_dir(device));

      return;
}

#else
static void acpi_cpufreq_add_file(struct acpi_processor *pr)
{
      return;
}
static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
{
      return;
}
#endif                        /* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */

static int acpi_processor_get_psd(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  *psd = NULL;
      struct acpi_psd_package *pdomain;

      status = acpi_evaluate_object(pr->handle, "_PSD", NULL, &buffer);
      if (ACPI_FAILURE(status)) {
            return -ENODEV;
      }

      psd = buffer.pointer;
      if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) {
            ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSD data\n"));
            result = -EFAULT;
            goto end;
      }

      if (psd->package.count != 1) {
            ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSD data\n"));
            result = -EFAULT;
            goto end;
      }

      pdomain = &(pr->performance->domain_info);

      state.length = sizeof(struct acpi_psd_package);
      state.pointer = pdomain;

      status = acpi_extract_package(&(psd->package.elements[0]),
            &format, &state);
      if (ACPI_FAILURE(status)) {
            ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSD data\n"));
            result = -EFAULT;
            goto end;
      }

      if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
            ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _PSD:num_entries\n"));
            result = -EFAULT;
            goto end;
      }

      if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
            ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _PSD:revision\n"));
            result = -EFAULT;
            goto end;
      }

end:
      kfree(buffer.pointer);
      return result;
}

int acpi_processor_preregister_performance(
            struct acpi_processor_performance *performance)
{
      int count, count_target;
      int retval = 0;
      unsigned int i, j;
      cpumask_t covered_cpus;
      struct acpi_processor *pr;
      struct acpi_psd_package *pdomain;
      struct acpi_processor *match_pr;
      struct acpi_psd_package *match_pdomain;

      mutex_lock(&performance_mutex);

      retval = 0;

      /* Call _PSD for all CPUs */
      for_each_possible_cpu(i) {
            pr = processors[i];
            if (!pr) {
                  /* Look only at processors in ACPI namespace */
                  continue;
            }

            if (pr->performance) {
                  retval = -EBUSY;
                  continue;
            }

            if (!performance || !percpu_ptr(performance, i)) {
                  retval = -EINVAL;
                  continue;
            }

            pr->performance = percpu_ptr(performance, i);
            cpu_set(i, pr->performance->shared_cpu_map);
            if (acpi_processor_get_psd(pr)) {
                  retval = -EINVAL;
                  continue;
            }
      }
      if (retval)
            goto err_ret;

      /*
       * Now that we have _PSD data from all CPUs, lets setup P-state 
       * domain info.
       */
      for_each_possible_cpu(i) {
            pr = processors[i];
            if (!pr)
                  continue;

            /* Basic validity check for domain info */
            pdomain = &(pr->performance->domain_info);
            if ((pdomain->revision != ACPI_PSD_REV0_REVISION) ||
                (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES)) {
                  retval = -EINVAL;
                  goto err_ret;
            }
            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) {
                  retval = -EINVAL;
                  goto err_ret;
            }
      }

      cpus_clear(covered_cpus);
      for_each_possible_cpu(i) {
            pr = processors[i];
            if (!pr)
                  continue;

            if (cpu_isset(i, covered_cpus))
                  continue;

            pdomain = &(pr->performance->domain_info);
            cpu_set(i, pr->performance->shared_cpu_map);
            cpu_set(i, covered_cpus);
            if (pdomain->num_processors <= 1)
                  continue;

            /* Validate the Domain info */
            count_target = pdomain->num_processors;
            count = 1;
            if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
                  pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
            else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
                  pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
            else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
                  pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;

            for_each_possible_cpu(j) {
                  if (i == j)
                        continue;

                  match_pr = processors[j];
                  if (!match_pr)
                        continue;

                  match_pdomain = &(match_pr->performance->domain_info);
                  if (match_pdomain->domain != pdomain->domain)
                        continue;

                  /* Here i and j are in the same domain */

                  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;
                  }

                  cpu_set(j, covered_cpus);
                  cpu_set(j, pr->performance->shared_cpu_map);
                  count++;
            }

            for_each_possible_cpu(j) {
                  if (i == j)
                        continue;

                  match_pr = processors[j];
                  if (!match_pr)
                        continue;

                  match_pdomain = &(match_pr->performance->domain_info);
                  if (match_pdomain->domain != pdomain->domain)
                        continue;

                  match_pr->performance->shared_type = 
                              pr->performance->shared_type;
                  match_pr->performance->shared_cpu_map =
                        pr->performance->shared_cpu_map;
            }
      }

err_ret:
      for_each_possible_cpu(i) {
            pr = processors[i];
            if (!pr || !pr->performance)
                  continue;

            /* Assume no coordination on any error parsing domain info */
            if (retval) {
                  cpus_clear(pr->performance->shared_cpu_map);
                  cpu_set(i, pr->performance->shared_cpu_map);
                  pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
            }
            pr->performance = NULL; /* Will be set for real in register */
      }

      mutex_unlock(&performance_mutex);
      return retval;
}
EXPORT_SYMBOL(acpi_processor_preregister_performance);


int
acpi_processor_register_performance(struct acpi_processor_performance
                            *performance, unsigned int cpu)
{
      struct acpi_processor *pr;


      if (!(acpi_processor_ppc_status & PPC_REGISTERED))
            return -EINVAL;

      mutex_lock(&performance_mutex);

      pr = processors[cpu];
      if (!pr) {
            mutex_unlock(&performance_mutex);
            return -ENODEV;
      }

      if (pr->performance) {
            mutex_unlock(&performance_mutex);
            return -EBUSY;
      }

      WARN_ON(!performance);

      pr->performance = performance;

      if (acpi_processor_get_performance_info(pr)) {
            pr->performance = NULL;
            mutex_unlock(&performance_mutex);
            return -EIO;
      }

      acpi_cpufreq_add_file(pr);

      mutex_unlock(&performance_mutex);
      return 0;
}

EXPORT_SYMBOL(acpi_processor_register_performance);

void
acpi_processor_unregister_performance(struct acpi_processor_performance
                              *performance, unsigned int cpu)
{
      struct acpi_processor *pr;


      mutex_lock(&performance_mutex);

      pr = processors[cpu];
      if (!pr) {
            mutex_unlock(&performance_mutex);
            return;
      }

      if (pr->performance)
            kfree(pr->performance->states);
      pr->performance = NULL;

      acpi_cpufreq_remove_file(pr);

      mutex_unlock(&performance_mutex);

      return;
}

EXPORT_SYMBOL(acpi_processor_unregister_performance);

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