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Commit c52851b6 authored by Venkatesh Pallipadi's avatar Venkatesh Pallipadi Committed by Len Brown
Browse files

P-state software coordination for speedstep-centrino 

http://bugzilla.kernel.org/show_bug.cgi?id=5737



Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 09b4d1ee

arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c

+180 −66
Original line number Diff line number Diff line
@@ -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)
@@ -557,11 +592,16 @@ static int centrino_cpu_exit(struct cpufreq_policy *policy) 


#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);

			acpi_processor_unregister_performance(p, cpu);

			kfree(centrino_model[cpu]->op_points);

			kfree(centrino_model[cpu]);

		}

	}

#endif



	centrino_model[cpu] = NULL;
@@ -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;



	if (unlikely(cpufreq_frequency_table_target(policy,

			centrino_model[cpu]->op_points,

			target_freq,

			relation,

			&newstate))) {

		return -EINVAL;

	}



	/* cpufreq holds the hotplug lock, so we are safe from here on */

	cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);



	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 the CPU that wants to change frequency

		 * Make sure we are running on CPU that wants to change freq

		 */

	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);

	}

		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);



	if (cpufreq_frequency_table_target(policy, centrino_model[cpu]->op_points, target_freq,

					   relation, &newstate)) {

		retval = -EINVAL;

		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);



		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;

		dprintk("no change needed - msr was and needs to be %x\n", oldmsr);

				goto migrate_end;

			}



	freqs.cpu = cpu;

			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);



	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

			for_each_cpu_mask(k, online_policy_cpus) {

				freqs.cpu = k;

				cpufreq_notify_transition(&freqs,

					CPUFREQ_PRECHANGE);

			}



	/* all but 16 LSB are "reserved", so treat them with

	   care */

			first_cpu = 0;

			/* all but 16 LSB are reserved, treat them with care */

			oldmsr &= ~0xffff;

			msr &= 0xffff;

			oldmsr |= msr;

		}



		wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);

		if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)

			break;



		cpu_set(j, covered_cpus);

	}



	for_each_cpu_mask(k, online_policy_cpus) {

		freqs.cpu = k;

		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	}



	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..

		 */



		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);

			}

		}



		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>");