Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 09b4d1ee authored by Venkatesh Pallipadi's avatar Venkatesh Pallipadi Committed by Len Brown
Browse files

P-state software coordination for acpi-cpufreq 

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 3b2d9942

arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c

+197 −88
Original line number Diff line number Diff line
@@ -48,12 +48,13 @@ MODULE_LICENSE("GPL"); 




struct cpufreq_acpi_io {

	struct acpi_processor_performance	acpi_data;

	struct acpi_processor_performance	*acpi_data;

	struct cpufreq_frequency_table		*freq_table;

	unsigned int				resume;

};



static struct cpufreq_acpi_io	*acpi_io_data[NR_CPUS];

static struct acpi_processor_performance	*acpi_perf_data[NR_CPUS];



static struct cpufreq_driver acpi_cpufreq_driver;
@@ -104,64 +105,43 @@ acpi_processor_set_performance ( 
{

	u16			port = 0;

	u8			bit_width = 0;

	int			i = 0;

	int			ret = 0;

	u32			value = 0;

	int			i = 0;

	struct cpufreq_freqs    cpufreq_freqs;

	cpumask_t		saved_mask;

	int			retval;

	struct acpi_processor_performance	*perf;



	dprintk("acpi_processor_set_performance\n");



	/*

	 * TBD: Use something other than set_cpus_allowed.

	 * As set_cpus_allowed is a bit racy, 

	 * with any other set_cpus_allowed for this process.

	 */

	saved_mask = current->cpus_allowed;

	set_cpus_allowed(current, cpumask_of_cpu(cpu));

	if (smp_processor_id() != cpu) {

		return (-EAGAIN);

	}

	

	if (state == data->acpi_data.state) {

	retval = 0;

	perf = data->acpi_data;	

	if (state == perf->state) {

		if (unlikely(data->resume)) {

			dprintk("Called after resume, resetting to P%d\n", state);

			data->resume = 0;

		} else {

			dprintk("Already at target state (P%d)\n", state);

			retval = 0;

			goto migrate_end;

			return (retval);

		}

	}



	dprintk("Transitioning from P%d to P%d\n",

		data->acpi_data.state, state);



	/* cpufreq frequency struct */

	cpufreq_freqs.cpu = cpu;

	cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;

	cpufreq_freqs.new = data->freq_table[state].frequency;



	/* notify cpufreq */

	cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);

	dprintk("Transitioning from P%d to P%d\n", perf->state, state);



	/*

	 * First we write the target state's 'control' value to the

	 * control_register.

	 */



	port = data->acpi_data.control_register.address;

	bit_width = data->acpi_data.control_register.bit_width;

	value = (u32) data->acpi_data.states[state].control;

	port = perf->control_register.address;

	bit_width = perf->control_register.bit_width;

	value = (u32) perf->states[state].control;



	dprintk("Writing 0x%08x to port 0x%04x\n", value, port);



	ret = acpi_processor_write_port(port, bit_width, value);

	if (ret) {

		dprintk("Invalid port width 0x%04x\n", bit_width);

		retval = ret;

		goto migrate_end;

		return (ret);

	}



	/*
@@ -177,49 +157,36 @@ acpi_processor_set_performance ( 
		 * before giving up.

		 */



		port = data->acpi_data.status_register.address;

		bit_width = data->acpi_data.status_register.bit_width;

		port = perf->status_register.address;

		bit_width = perf->status_register.bit_width;



		dprintk("Looking for 0x%08x from port 0x%04x\n",

			(u32) data->acpi_data.states[state].status, port);

			(u32) perf->states[state].status, port);



		for (i = 0; i < 100; i++) {

			ret = acpi_processor_read_port(port, bit_width, &value);

			if (ret) {	

				dprintk("Invalid port width 0x%04x\n", bit_width);

				retval = ret;

				goto migrate_end;

				return (ret);

			}

			if (value == (u32) data->acpi_data.states[state].status)

			if (value == (u32) perf->states[state].status)

				break;

			udelay(10);

		}

	} else {

		i = 0;

		value = (u32) data->acpi_data.states[state].status;

		value = (u32) perf->states[state].status;

	}



	/* notify cpufreq */

	cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);



	if (unlikely(value != (u32) data->acpi_data.states[state].status)) {

		unsigned int tmp = cpufreq_freqs.new;

		cpufreq_freqs.new = cpufreq_freqs.old;

		cpufreq_freqs.old = tmp;

		cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);

		cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);

	if (unlikely(value != (u32) perf->states[state].status)) {

		printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");

		retval = -ENODEV;

		goto migrate_end;

		return (retval);

	}



	dprintk("Transition successful after %d microseconds\n", i * 10);



	data->acpi_data.state = state;



	retval = 0;

migrate_end:

	set_cpus_allowed(current, saved_mask);

	perf->state = state;

	return (retval);

}
@@ -231,8 +198,17 @@ acpi_cpufreq_target ( 
	unsigned int relation)

{

	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];

	struct acpi_processor_performance *perf;

	struct cpufreq_freqs freqs;

	cpumask_t online_policy_cpus;

	cpumask_t saved_mask;

	cpumask_t set_mask;

	cpumask_t covered_cpus;

	unsigned int cur_state = 0;

	unsigned int next_state = 0;

	unsigned int result = 0;

	unsigned int j;

	unsigned int tmp;



	dprintk("acpi_cpufreq_setpolicy\n");
@@ -241,11 +217,91 @@ acpi_cpufreq_target ( 
			target_freq,

			relation,

			&next_state);

	if (result)

	if (unlikely(result))

		return (result);



	result = acpi_processor_set_performance (data, policy->cpu, next_state);

	perf = data->acpi_data;

	cur_state = perf->state;

	freqs.old = data->freq_table[cur_state].frequency;

	freqs.new = data->freq_table[next_state].frequency;



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

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



	for_each_cpu_mask(j, online_policy_cpus) {

		freqs.cpu = j;

		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	}



	/*

	 * We need to call driver->target() on all or any CPU in

	 * policy->cpus, depending on policy->shared_type.

	 */

	saved_mask = current->cpus_allowed;

	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");

			result = -EAGAIN;

			break;

		}



		result = acpi_processor_set_performance (data, j, next_state);

		if (result) {

			result = -EAGAIN;

			break;

		}



		if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)

			break;

 

		cpu_set(j, covered_cpus);

	}



	for_each_cpu_mask(j, online_policy_cpus) {

		freqs.cpu = j;

		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	}



	if (unlikely(result)) {

		/*

		 * We have failed halfway through the frequency change.

		 * We have sent callbacks to online_policy_cpus and

		 * acpi_processor_set_performance() has been called on 

		 * coverd_cpus. Best effort undo..

		 */



		if (!cpus_empty(covered_cpus)) {

			for_each_cpu_mask(j, covered_cpus) {

				policy->cpu = j;

				acpi_processor_set_performance (data, 

						j, 

						cur_state);

			}

		}



		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);

		}

	}



	set_cpus_allowed(current, saved_mask);

	return (result);

}
@@ -271,29 +327,64 @@ acpi_cpufreq_guess_freq ( 
	struct cpufreq_acpi_io	*data,

	unsigned int		cpu)

{

	struct acpi_processor_performance	*perf = data->acpi_data;



	if (cpu_khz) {

		/* search the closest match to cpu_khz */

		unsigned int i;

		unsigned long freq;

		unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;

		unsigned long freqn = perf->states[0].core_frequency * 1000;



		for (i=0; i < (data->acpi_data.state_count - 1); i++) {

		for (i = 0; i < (perf->state_count - 1); i++) {

			freq = freqn;

			freqn = data->acpi_data.states[i+1].core_frequency * 1000;

			freqn = perf->states[i+1].core_frequency * 1000;

			if ((2 * cpu_khz) > (freqn + freq)) {

				data->acpi_data.state = i;

				perf->state = i;

				return (freq);

			}

		}

		data->acpi_data.state = data->acpi_data.state_count - 1;

		perf->state = perf->state_count - 1;

		return (freqn);

	} else

	} else {

		/* assume CPU is at P0... */

		data->acpi_data.state = 0;

		return data->acpi_data.states[0].core_frequency * 1000;

		perf->state = 0;

		return perf->states[0].core_frequency * 1000;

	}

}





/*

 * acpi_cpufreq_early_init - initialize ACPI P-States library

 *

 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)

 * in order to determine correct frequency and voltage pairings. We can

 * do _PDC and _PSD and find out the processor dependency for the

 * actual init that will happen later...

 */

static int acpi_cpufreq_early_init_acpi(void)

{

	struct acpi_processor_performance	*data;

	unsigned int				i, j;



	dprintk("acpi_cpufreq_early_init\n");



	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;

	}



	/* Do initialization in ACPI core */

	acpi_processor_preregister_performance(acpi_perf_data);

	return 0;

}



static int

acpi_cpufreq_cpu_init (
@@ -304,41 +395,51 @@ acpi_cpufreq_cpu_init ( 
	struct cpufreq_acpi_io	*data;

	unsigned int		result = 0;

	struct cpuinfo_x86 *c = &cpu_data[policy->cpu];

	struct acpi_processor_performance	*perf;



	dprintk("acpi_cpufreq_cpu_init\n");



	if (!acpi_perf_data[cpu])

		return (-ENODEV);



	data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);

	if (!data)

		return (-ENOMEM);



	data->acpi_data = acpi_perf_data[cpu];

	acpi_io_data[cpu] = data;



	result = acpi_processor_register_performance(&data->acpi_data, cpu);

	result = acpi_processor_register_performance(data->acpi_data, cpu);



	if (result)

		goto err_free;



	perf = data->acpi_data;

	policy->cpus = perf->shared_cpu_map;

	policy->shared_type = perf->shared_type;



	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {

		acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;

	}



	/* capability check */

	if (data->acpi_data.state_count <= 1) {

	if (perf->state_count <= 1) {

		dprintk("No P-States\n");

		result = -ENODEV;

		goto err_unreg;

	}

	if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||

	    (data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {



	if ((perf->control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||

	    (perf->status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {

		dprintk("Unsupported address space [%d, %d]\n",

			(u32) (data->acpi_data.control_register.space_id),

			(u32) (data->acpi_data.status_register.space_id));

			(u32) (perf->control_register.space_id),

			(u32) (perf->status_register.space_id));

		result = -ENODEV;

		goto err_unreg;

	}



	/* alloc freq_table */

	data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.state_count + 1), GFP_KERNEL);

	data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (perf->state_count + 1), GFP_KERNEL);

	if (!data->freq_table) {

		result = -ENOMEM;

		goto err_unreg;
@@ -346,9 +447,9 @@ acpi_cpufreq_cpu_init ( 


	/* detect transition latency */

	policy->cpuinfo.transition_latency = 0;

	for (i=0; i<data->acpi_data.state_count; i++) {

		if ((data->acpi_data.states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)

			policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000;

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

		if ((perf->states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)

			policy->cpuinfo.transition_latency = perf->states[i].transition_latency * 1000;

	}

	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
@@ -356,11 +457,11 @@ acpi_cpufreq_cpu_init ( 
	policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);



	/* table init */

	for (i=0; i<=data->acpi_data.state_count; i++)

	for (i=0; i<=perf->state_count; i++)

	{

		data->freq_table[i].index = i;

		if (i<data->acpi_data.state_count)

			data->freq_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;

		if (i<perf->state_count)

			data->freq_table[i].frequency = perf->states[i].core_frequency * 1000;

		else

			data->freq_table[i].frequency = CPUFREQ_TABLE_END;

	}
@@ -375,12 +476,12 @@ acpi_cpufreq_cpu_init ( 


	printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n",

	       cpu);

	for (i = 0; i < data->acpi_data.state_count; i++)

	for (i = 0; i < perf->state_count; i++)

		dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",

			(i == data->acpi_data.state?'*':' '), i,

			(u32) data->acpi_data.states[i].core_frequency,

			(u32) data->acpi_data.states[i].power,

			(u32) data->acpi_data.states[i].transition_latency);

			(i == perf->state?'*':' '), i,

			(u32) perf->states[i].core_frequency,

			(u32) perf->states[i].power,

			(u32) perf->states[i].transition_latency);



	cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
@@ -395,7 +496,7 @@ acpi_cpufreq_cpu_init ( 
 err_freqfree:

	kfree(data->freq_table);

 err_unreg:

	acpi_processor_unregister_performance(&data->acpi_data, cpu);

	acpi_processor_unregister_performance(perf, cpu);

 err_free:

	kfree(data);

	acpi_io_data[cpu] = NULL;
@@ -416,7 +517,7 @@ acpi_cpufreq_cpu_exit ( 
	if (data) {

		cpufreq_frequency_table_put_attr(policy->cpu);

		acpi_io_data[policy->cpu] = NULL;

		acpi_processor_unregister_performance(&data->acpi_data, policy->cpu);

		acpi_processor_unregister_performance(data->acpi_data, policy->cpu);

		kfree(data);

	}
@@ -462,6 +563,9 @@ acpi_cpufreq_init (void) 


	dprintk("acpi_cpufreq_init\n");



	result = acpi_cpufreq_early_init_acpi();



	if (!result)

 		result = cpufreq_register_driver(&acpi_cpufreq_driver);

	

	return (result);
@@ -471,10 +575,15 @@ acpi_cpufreq_init (void) 
static void __exit

acpi_cpufreq_exit (void)

{

	unsigned int	i;

	dprintk("acpi_cpufreq_exit\n");



	cpufreq_unregister_driver(&acpi_cpufreq_driver);



	for_each_cpu(i) {

		kfree(acpi_perf_data[i]);

		acpi_perf_data[i] = NULL;

	}

	return;

}