]> err.no Git - linux-2.6/commitdiff
P-state software coordination for speedstep-centrino
authorVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Wed, 14 Dec 2005 20:05:00 +0000 (15:05 -0500)
committerLen Brown <len.brown@intel.com>
Thu, 9 Feb 2006 08:21:49 +0000 (03:21 -0500)
http://bugzilla.kernel.org/show_bug.cgi?id=5737

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c

index c173c0fa117a927734bf9c2ee389c1d5f7ada91d..37dee862f0d37f8c6549998472b1065c2ec8b726 100644 (file)
@@ -351,7 +351,36 @@ static unsigned int get_cur_freq(unsigned int cpu)
 
 #ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI
 
-static struct acpi_processor_performance p;
+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_cpu(i) {
+               data = kzalloc(sizeof(struct acpi_processor_performance), 
+                               GFP_KERNEL);
+               if (!data) {
+                       for_each_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;
+}
 
 /*
  * centrino_cpu_init_acpi - register with ACPI P-States library
@@ -365,46 +394,51 @@ static int centrino_cpu_init_acpi(struct cpufreq_policy *policy)
        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)) {
+       if (acpi_processor_register_performance(p, cpu)) {
                dprintk(KERN_INFO PFX "obtaining ACPI data failed\n");
                return -EIO;
        }
+       policy->cpus = p->shared_cpu_map;
+       policy->shared_type = p->shared_type;
 
        /* 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;
                }
        }
@@ -416,26 +450,26 @@ static int centrino_cpu_init_acpi(struct cpufreq_policy *policy)
        }
 
        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;
@@ -451,7 +485,7 @@ static int centrino_cpu_init_acpi(struct cpufreq_policy *policy)
                }
 
                if (cur_freq == centrino_model[cpu]->op_points[i].frequency)
-                       p.state = i;
+                       p->state = i;
        }
 
        /* notify BIOS that we exist */
@@ -464,12 +498,13 @@ static int centrino_cpu_init_acpi(struct cpufreq_policy *policy)
  err_kfree:
        kfree(centrino_model[cpu]);
  err_unreg:
-       acpi_processor_unregister_performance(&p, cpu);
+       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)
@@ -557,10 +592,15 @@ static int centrino_cpu_exit(struct cpufreq_policy *policy)
 
 #ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI
        if (!centrino_model[cpu]->model_name) {
-               dprintk("unregistering and freeing ACPI data\n");
-               acpi_processor_unregister_performance(&p, cpu);
-               kfree(centrino_model[cpu]->op_points);
-               kfree(centrino_model[cpu]);
+               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]);
+               }
        }
 #endif
 
@@ -594,63 +634,124 @@ static int centrino_target (struct cpufreq_policy *policy,
                            unsigned int relation)
 {
        unsigned int    newstate = 0;
-       unsigned int    msr, oldmsr, h, cpu = policy->cpu;
+       unsigned int    msr, oldmsr = 0, h = 0, cpu = policy->cpu;
        struct cpufreq_freqs    freqs;
+       cpumask_t               online_policy_cpus;
        cpumask_t               saved_mask;
-       int                     retval;
+       cpumask_t               set_mask;
+       cpumask_t               covered_cpus;
+       int                     retval = 0;
+       unsigned int            j, k, first_cpu, tmp;
 
-       if (centrino_model[cpu] == NULL)
+       if (unlikely(centrino_model[cpu] == NULL))
                return -ENODEV;
 
-       /*
-        * 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);
+       if (unlikely(cpufreq_frequency_table_target(policy,
+                       centrino_model[cpu]->op_points,
+                       target_freq,
+                       relation,
+                       &newstate))) {
+               return -EINVAL;
        }
 
-       if (cpufreq_frequency_table_target(policy, centrino_model[cpu]->op_points, target_freq,
-                                          relation, &newstate)) {
-               retval = -EINVAL;
-               goto migrate_end;
-       }
+       /* cpufreq holds the hotplug lock, so we are safe from here on */
+       cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
 
-       msr = centrino_model[cpu]->op_points[newstate].index;
-       rdmsr(MSR_IA32_PERF_CTL, oldmsr, h);
+       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;
+               }
 
-       if (msr == (oldmsr & 0xffff)) {
-               retval = 0;
-               dprintk("no change needed - msr was and needs to be %x\n", oldmsr);
-               goto migrate_end;
-       }
+               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;
+               }
 
-       freqs.cpu = cpu;
-       freqs.old = extract_clock(oldmsr, cpu, 0);
-       freqs.new = extract_clock(msr, cpu, 0);
+               wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
+               if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
+                       break;
 
-       dprintk("target=%dkHz old=%d new=%d msr=%04x\n",
-               target_freq, freqs.old, freqs.new, msr);
+               cpu_set(j, covered_cpus);
+       }
 
-       cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+       for_each_cpu_mask(k, online_policy_cpus) {
+               freqs.cpu = k;
+               cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+       }
 
-       /* all but 16 LSB are "reserved", so treat them with
-          care */
-       oldmsr &= ~0xffff;
-       msr &= 0xffff;
-       oldmsr |= msr;
+       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..
+                */
 
-       wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
+               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);
+                       }
+               }
 
-       cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+               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);
+               }
+       }
 
-       retval = 0;
 migrate_end:
        set_cpus_allowed(current, saved_mask);
-       return (retval);
+       return 0;
 }
 
 static struct freq_attr* centrino_attr[] = {
@@ -692,12 +793,25 @@ static int __init centrino_init(void)
        if (!cpu_has(cpu, X86_FEATURE_EST))
                return -ENODEV;
 
+       centrino_cpu_early_init_acpi();
+
        return cpufreq_register_driver(&centrino_driver);
 }
 
 static void __exit centrino_exit(void)
 {
+#ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI
+       unsigned int j;
+#endif
+       
        cpufreq_unregister_driver(&centrino_driver);
+
+#ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_ACPI
+       for_each_cpu(j) {
+               kfree(acpi_perf_data[j]);
+               acpi_perf_data[j] = NULL;
+       }
+#endif
 }
 
 MODULE_AUTHOR ("Jeremy Fitzhardinge <jeremy@goop.org>");