Commit 4fcb2fcd authored by Venkatesh Pallipadi's avatar Venkatesh Pallipadi Committed by Len Brown
Browse files

ACPI, cpuidle: Clarify C-state description in sysfs 



Add a new sysfs entry under cpuidle states. desc - can be used by driver to
communicate to userspace any specific information about the state.
This helps in identifying the exact hardware C-states behind the ACPI C-state
definition.

Idea is to export this through powertop, which will help to map the C-state
reported by powertop to actual hardware C-state.

Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent e760e716

arch/x86/kernel/acpi/cstate.c

+2 −0
Original line number Diff line number Diff line
@@ -126,6 +126,8 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu, 
		printk(KERN_DEBUG "Monitor-Mwait will be used to enter C-%d "

		       "state\n", cx->type);

	}

	snprintf(cx->desc, ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x",

		 cx->address);



out:

	set_cpus_allowed(current, saved_mask);

drivers/acpi/processor_idle.c

+11 −0
Original line number Diff line number Diff line
@@ -945,11 +945,16 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) 
				 * Otherwise, ignore this info and continue.

				 */

				cx.entry_method = ACPI_CSTATE_HALT;

				snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");

			} else {

				continue;

			}

		} else {

			snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",

				 cx.address);

		}





		obj = &(element->package.elements[2]);

		if (obj->type != ACPI_TYPE_INTEGER)

			continue;
@@ -1643,6 +1648,11 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) 
		return -EINVAL;

	}



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

		dev->states[i].name[0] = '\0';

		dev->states[i].desc[0] = '\0';

	}



	for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {

		cx = &pr->power.states[i];

		state = &dev->states[count];
@@ -1659,6 +1669,7 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) 
		cpuidle_set_statedata(state, cx);



		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);

		strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);

		state->exit_latency = cx->latency;

		state->target_residency = cx->latency * latency_factor;

		state->power_usage = cx->power;

drivers/cpuidle/cpuidle.c

+2 −1
Original line number Diff line number Diff line
@@ -219,7 +219,8 @@ static void poll_idle_init(struct cpuidle_device *dev) 


	cpuidle_set_statedata(state, NULL);



	snprintf(state->name, CPUIDLE_NAME_LEN, "C0 (poll idle)");

	snprintf(state->name, CPUIDLE_NAME_LEN, "C0");

	snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");

	state->exit_latency = 0;

	state->target_residency = 0;

	state->power_usage = -1;

drivers/cpuidle/sysfs.c

+11 −3
Original line number Diff line number Diff line
@@ -218,16 +218,23 @@ static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \ 
	return sprintf(buf, "%u\n", state->_name);\

}



static ssize_t show_state_name(struct cpuidle_state *state, char *buf)

{

	return sprintf(buf, "%s\n", state->name);

#define define_show_state_str_function(_name) \

static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \

{ \

	if (state->_name[0] == '\0')\

		return sprintf(buf, "<null>\n");\

	return sprintf(buf, "%s\n", state->_name);\

}



define_show_state_function(exit_latency)

define_show_state_function(power_usage)

define_show_state_function(usage)

define_show_state_function(time)

define_show_state_str_function(name)

define_show_state_str_function(desc)



define_one_state_ro(name, show_state_name);

define_one_state_ro(desc, show_state_desc);

define_one_state_ro(latency, show_state_exit_latency);

define_one_state_ro(power, show_state_power_usage);

define_one_state_ro(usage, show_state_usage);
@@ -235,6 +242,7 @@ define_one_state_ro(time, show_state_time); 


static struct attribute *cpuidle_state_default_attrs[] = {

	&attr_name.attr,

	&attr_desc.attr,

	&attr_latency.attr,

	&attr_power.attr,

	&attr_usage.attr,

include/acpi/processor.h

+6 −3
Original line number Diff line number Diff line
@@ -32,9 +32,11 @@ 
#define DOMAIN_COORD_TYPE_SW_ANY	0xfd

#define DOMAIN_COORD_TYPE_HW_ALL	0xfe



#define ACPI_CSTATE_SYSTEMIO	(0)

#define ACPI_CSTATE_FFH		(1)

#define ACPI_CSTATE_HALT	(2)

#define ACPI_CSTATE_SYSTEMIO	0

#define ACPI_CSTATE_FFH		1

#define ACPI_CSTATE_HALT	2



#define ACPI_CX_DESC_LEN	32



/* Power Management */
@@ -74,6 +76,7 @@ struct acpi_processor_cx { 
	u64 time;

	struct acpi_processor_cx_policy promotion;

	struct acpi_processor_cx_policy demotion;

	char desc[ACPI_CX_DESC_LEN];

};



struct acpi_processor_power {

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