* cpufreq driver for Enhanced SpeedStep, as found in Intel's Pentium
* M (part of the Centrino chipset).
*
- * Since the original Pentium M, most new Intel CPUs support Enhanced
- * SpeedStep.
- *
* Despite the "SpeedStep" in the name, this is almost entirely unlike
* traditional SpeedStep.
*
* Modelled on speedstep.c
*
* Copyright (C) 2003 Jeremy Fitzhardinge <jeremy@goop.org>
+ *
+ * WARNING WARNING WARNING
+ *
+ * This driver manipulates the PERF_CTL MSR, which is only somewhat
+ * documented. While it seems to work on my laptop, it has not been
+ * tested anywhere else, and it may not work for you, do strange
+ * things or simply crash.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
+#include <linux/config.h>
#include <linux/sched.h> /* current */
#include <linux/delay.h>
#include <linux/compiler.h>
#include <asm/cpufeature.h>
#define PFX "speedstep-centrino: "
-#define MAINTAINER "cpufreq@lists.linux.org.uk"
+#define MAINTAINER "Jeremy Fitzhardinge <jeremy@goop.org>"
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-centrino", msg)
if (model->cpu_id == NULL) {
/* No match at all */
- dprintk("no support for CPU model \"%s\": "
+ dprintk(KERN_INFO PFX "no support for CPU model \"%s\": "
"send /proc/cpuinfo to " MAINTAINER "\n",
cpu->x86_model_id);
return -ENOENT;
if (model->op_points == NULL) {
/* Matched a non-match */
- dprintk("no table support for CPU model \"%s\"\n",
+ dprintk(KERN_INFO PFX "no table support for CPU model \"%s\"\n",
cpu->x86_model_id);
#ifndef CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI
- dprintk("try compiling with CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI enabled\n");
+ dprintk(KERN_INFO PFX "try compiling with CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI enabled\n");
#endif
return -ENOENT;
}
#ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI
-static struct acpi_processor_performance *acpi_perf_data[NR_CPUS];
-
-/*
- * centrino_cpu_early_init_acpi - Do the preregistering with ACPI P-States
- * library
- *
- * Before doing the actual init, we need to do _PSD related setup whenever
- * supported by the BIOS. These are handled by this early_init routine.
- */
-static int centrino_cpu_early_init_acpi(void)
-{
- unsigned int i, j;
- struct acpi_processor_performance *data;
-
- for_each_possible_cpu(i) {
- data = kzalloc(sizeof(struct acpi_processor_performance),
- GFP_KERNEL);
- if (!data) {
- for_each_possible_cpu(j) {
- kfree(acpi_perf_data[j]);
- acpi_perf_data[j] = NULL;
- }
- return (-ENOMEM);
- }
- acpi_perf_data[i] = data;
- }
-
- acpi_processor_preregister_performance(acpi_perf_data);
- return 0;
-}
+static struct acpi_processor_performance p;
/*
* centrino_cpu_init_acpi - register with ACPI P-States library
unsigned long cur_freq;
int result = 0, i;
unsigned int cpu = policy->cpu;
- struct acpi_processor_performance *p;
-
- p = acpi_perf_data[cpu];
/* register with ACPI core */
- if (acpi_processor_register_performance(p, cpu)) {
- dprintk(PFX "obtaining ACPI data failed\n");
+ if (acpi_processor_register_performance(&p, cpu)) {
+ dprintk(KERN_INFO PFX "obtaining ACPI data failed\n");
return -EIO;
}
- policy->shared_type = p->shared_type;
- /*
- * Will let policy->cpus know about dependency only when software
- * coordination is required.
- */
- if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
- policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
- policy->cpus = p->shared_cpu_map;
/* verify the acpi_data */
- if (p->state_count <= 1) {
+ if (p.state_count <= 1) {
dprintk("No P-States\n");
result = -ENODEV;
goto err_unreg;
}
- if ((p->control_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
- (p->status_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
+ if ((p.control_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
+ (p.status_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
dprintk("Invalid control/status registers (%x - %x)\n",
- p->control_register.space_id, p->status_register.space_id);
+ p.control_register.space_id, p.status_register.space_id);
result = -EIO;
goto err_unreg;
}
- for (i=0; i<p->state_count; i++) {
- if (p->states[i].control != p->states[i].status) {
+ for (i=0; i<p.state_count; i++) {
+ if (p.states[i].control != p.states[i].status) {
dprintk("Different control (%llu) and status values (%llu)\n",
- p->states[i].control, p->states[i].status);
+ p.states[i].control, p.states[i].status);
result = -EINVAL;
goto err_unreg;
}
- if (!p->states[i].core_frequency) {
+ if (!p.states[i].core_frequency) {
dprintk("Zero core frequency for state %u\n", i);
result = -EINVAL;
goto err_unreg;
}
- if (p->states[i].core_frequency > p->states[0].core_frequency) {
+ if (p.states[i].core_frequency > p.states[0].core_frequency) {
dprintk("P%u has larger frequency (%llu) than P0 (%llu), skipping\n", i,
- p->states[i].core_frequency, p->states[0].core_frequency);
- p->states[i].core_frequency = 0;
+ p.states[i].core_frequency, p.states[0].core_frequency);
+ p.states[i].core_frequency = 0;
continue;
}
}
}
centrino_model[cpu]->model_name=NULL;
- centrino_model[cpu]->max_freq = p->states[0].core_frequency * 1000;
+ centrino_model[cpu]->max_freq = p.states[0].core_frequency * 1000;
centrino_model[cpu]->op_points = kmalloc(sizeof(struct cpufreq_frequency_table) *
- (p->state_count + 1), GFP_KERNEL);
+ (p.state_count + 1), GFP_KERNEL);
if (!centrino_model[cpu]->op_points) {
result = -ENOMEM;
goto err_kfree;
}
- for (i=0; i<p->state_count; i++) {
- centrino_model[cpu]->op_points[i].index = p->states[i].control;
- centrino_model[cpu]->op_points[i].frequency = p->states[i].core_frequency * 1000;
+ for (i=0; i<p.state_count; i++) {
+ centrino_model[cpu]->op_points[i].index = p.states[i].control;
+ centrino_model[cpu]->op_points[i].frequency = p.states[i].core_frequency * 1000;
dprintk("adding state %i with frequency %u and control value %04x\n",
i, centrino_model[cpu]->op_points[i].frequency, centrino_model[cpu]->op_points[i].index);
}
- centrino_model[cpu]->op_points[p->state_count].frequency = CPUFREQ_TABLE_END;
+ centrino_model[cpu]->op_points[p.state_count].frequency = CPUFREQ_TABLE_END;
cur_freq = get_cur_freq(cpu);
- for (i=0; i<p->state_count; i++) {
- if (!p->states[i].core_frequency) {
+ for (i=0; i<p.state_count; i++) {
+ if (!p.states[i].core_frequency) {
dprintk("skipping state %u\n", i);
centrino_model[cpu]->op_points[i].frequency = CPUFREQ_ENTRY_INVALID;
continue;
}
if (cur_freq == centrino_model[cpu]->op_points[i].frequency)
- p->state = i;
+ p.state = i;
}
/* notify BIOS that we exist */
err_kfree:
kfree(centrino_model[cpu]);
err_unreg:
- acpi_processor_unregister_performance(p, cpu);
- dprintk(PFX "invalid ACPI data\n");
+ acpi_processor_unregister_performance(&p, cpu);
+ dprintk(KERN_INFO PFX "invalid ACPI data\n");
return (result);
}
#else
static inline int centrino_cpu_init_acpi(struct cpufreq_policy *policy) { return -ENODEV; }
-static inline int centrino_cpu_early_init_acpi(void) { return 0; }
#endif
static int centrino_cpu_init(struct cpufreq_policy *policy)
unsigned l, h;
int ret;
int i;
+ struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
/* Only Intel makes Enhanced Speedstep-capable CPUs */
if (cpu->x86_vendor != X86_VENDOR_INTEL || !cpu_has(cpu, X86_FEATURE_EST))
return -ENODEV;
- if (cpu_has(cpu, X86_FEATURE_CONSTANT_TSC))
+ if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
centrino_driver.flags |= CPUFREQ_CONST_LOOPS;
+ }
if (centrino_cpu_init_acpi(policy)) {
if (policy->cpu != 0)
centrino_cpu[policy->cpu] = &cpu_ids[i];
if (!centrino_cpu[policy->cpu]) {
- dprintk("found unsupported CPU with "
+ dprintk(KERN_INFO PFX "found unsupported CPU with "
"Enhanced SpeedStep: send /proc/cpuinfo to "
MAINTAINER "\n");
return -ENODEV;
#ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI
if (!centrino_model[cpu]->model_name) {
- static struct acpi_processor_performance *p;
-
- if (acpi_perf_data[cpu]) {
- p = acpi_perf_data[cpu];
- dprintk("unregistering and freeing ACPI data\n");
- acpi_processor_unregister_performance(p, cpu);
- kfree(centrino_model[cpu]->op_points);
- kfree(centrino_model[cpu]);
- }
+ dprintk("unregistering and freeing ACPI data\n");
+ acpi_processor_unregister_performance(&p, cpu);
+ kfree(centrino_model[cpu]->op_points);
+ kfree(centrino_model[cpu]);
}
#endif
unsigned int relation)
{
unsigned int newstate = 0;
- unsigned int msr, oldmsr = 0, h = 0, cpu = policy->cpu;
+ unsigned int msr, oldmsr, h, cpu = policy->cpu;
struct cpufreq_freqs freqs;
- cpumask_t online_policy_cpus;
cpumask_t saved_mask;
- cpumask_t set_mask;
- cpumask_t covered_cpus;
- int retval = 0;
- unsigned int j, k, first_cpu, tmp;
+ int retval;
- if (unlikely(centrino_model[cpu] == NULL))
+ if (centrino_model[cpu] == NULL)
return -ENODEV;
- if (unlikely(cpufreq_frequency_table_target(policy,
- centrino_model[cpu]->op_points,
- target_freq,
- relation,
- &newstate))) {
- return -EINVAL;
+ /*
+ * Support for SMP systems.
+ * Make sure we are running on the CPU that wants to change frequency
+ */
+ saved_mask = current->cpus_allowed;
+ set_cpus_allowed(current, policy->cpus);
+ if (!cpu_isset(smp_processor_id(), policy->cpus)) {
+ dprintk("couldn't limit to CPUs in this domain\n");
+ return(-EAGAIN);
}
-#ifdef CONFIG_HOTPLUG_CPU
- /* cpufreq holds the hotplug lock, so we are safe from here on */
- cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
-#else
- online_policy_cpus = policy->cpus;
-#endif
+ if (cpufreq_frequency_table_target(policy, centrino_model[cpu]->op_points, target_freq,
+ relation, &newstate)) {
+ retval = -EINVAL;
+ goto migrate_end;
+ }
- saved_mask = current->cpus_allowed;
- first_cpu = 1;
- cpus_clear(covered_cpus);
- for_each_cpu_mask(j, online_policy_cpus) {
- /*
- * Support for SMP systems.
- * Make sure we are running on CPU that wants to change freq
- */
- cpus_clear(set_mask);
- if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
- cpus_or(set_mask, set_mask, online_policy_cpus);
- else
- cpu_set(j, set_mask);
-
- set_cpus_allowed(current, set_mask);
- if (unlikely(!cpu_isset(smp_processor_id(), set_mask))) {
- dprintk("couldn't limit to CPUs in this domain\n");
- retval = -EAGAIN;
- if (first_cpu) {
- /* We haven't started the transition yet. */
- goto migrate_end;
- }
- break;
- }
+ msr = centrino_model[cpu]->op_points[newstate].index;
+ rdmsr(MSR_IA32_PERF_CTL, oldmsr, h);
- msr = centrino_model[cpu]->op_points[newstate].index;
-
- if (first_cpu) {
- rdmsr(MSR_IA32_PERF_CTL, oldmsr, h);
- if (msr == (oldmsr & 0xffff)) {
- dprintk("no change needed - msr was and needs "
- "to be %x\n", oldmsr);
- retval = 0;
- goto migrate_end;
- }
-
- freqs.old = extract_clock(oldmsr, cpu, 0);
- freqs.new = extract_clock(msr, cpu, 0);
-
- dprintk("target=%dkHz old=%d new=%d msr=%04x\n",
- target_freq, freqs.old, freqs.new, msr);
-
- for_each_cpu_mask(k, online_policy_cpus) {
- freqs.cpu = k;
- cpufreq_notify_transition(&freqs,
- CPUFREQ_PRECHANGE);
- }
-
- first_cpu = 0;
- /* all but 16 LSB are reserved, treat them with care */
- oldmsr &= ~0xffff;
- msr &= 0xffff;
- oldmsr |= msr;
- }
+ if (msr == (oldmsr & 0xffff)) {
+ retval = 0;
+ dprintk("no change needed - msr was and needs to be %x\n", oldmsr);
+ goto migrate_end;
+ }
- wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
- if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
- break;
+ freqs.cpu = cpu;
+ freqs.old = extract_clock(oldmsr, cpu, 0);
+ freqs.new = extract_clock(msr, cpu, 0);
- cpu_set(j, covered_cpus);
- }
+ dprintk("target=%dkHz old=%d new=%d msr=%04x\n",
+ target_freq, freqs.old, freqs.new, msr);
- for_each_cpu_mask(k, online_policy_cpus) {
- freqs.cpu = k;
- cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
- }
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
- if (unlikely(retval)) {
- /*
- * We have failed halfway through the frequency change.
- * We have sent callbacks to policy->cpus and
- * MSRs have already been written on coverd_cpus.
- * Best effort undo..
- */
+ /* all but 16 LSB are "reserved", so treat them with
+ care */
+ oldmsr &= ~0xffff;
+ msr &= 0xffff;
+ oldmsr |= msr;
- if (!cpus_empty(covered_cpus)) {
- for_each_cpu_mask(j, covered_cpus) {
- set_cpus_allowed(current, cpumask_of_cpu(j));
- wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
- }
- }
+ wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
- tmp = freqs.new;
- freqs.new = freqs.old;
- freqs.old = tmp;
- for_each_cpu_mask(j, online_policy_cpus) {
- freqs.cpu = j;
- cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
- cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
- }
- }
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+ retval = 0;
migrate_end:
set_cpus_allowed(current, saved_mask);
- return 0;
+ return (retval);
}
static struct freq_attr* centrino_attr[] = {
if (!cpu_has(cpu, X86_FEATURE_EST))
return -ENODEV;
- centrino_cpu_early_init_acpi();
-
return cpufreq_register_driver(¢rino_driver);
}
static void __exit centrino_exit(void)
{
-#ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI
- unsigned int j;
-#endif
-
cpufreq_unregister_driver(¢rino_driver);
-
-#ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI
- for_each_possible_cpu(j) {
- kfree(acpi_perf_data[j]);
- acpi_perf_data[j] = NULL;
- }
-#endif
}
MODULE_AUTHOR ("Jeremy Fitzhardinge <jeremy@goop.org>");
git://git.onelab.eu / linux-2.6.git / blobdiff