dptf: Add support for Passive Policies

This patch adds support for emitting the Thermal Relationship Table, as
well as _PSV Methods, which together form the basis for DPTF Passive
Policies.

BUG=b:143539650
TEST=compiles

Change-Id: I82e1c9022999b0a2a733aa6cd9c98a850e6f5408
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41886
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
This commit is contained in:
Tim Wawrzynczak 2020-05-29 14:10:53 -06:00 committed by Patrick Georgi
parent c41f7f15c1
commit 7eb1136c27
4 changed files with 131 additions and 0 deletions

View File

@ -9,6 +9,7 @@
/* Defaults */
enum {
ART_REVISION = 0,
DEFAULT_PRIORITY = 100,
DEFAULT_WEIGHT = 100,
DPTF_MAX_ART_THRESHOLDS = 10,
};
@ -19,6 +20,12 @@ static int to_acpi_temp(int deg_c)
return deg_c * 10 + 2732;
}
/* Converts ms to 1/10th second for ACPI */
static int to_acpi_time(int ms)
{
return ms / 100;
}
/* Writes out a 0-argument non-Serialized Method that returns an Integer */
static void write_simple_return_method(const char *name, int value)
{
@ -27,6 +34,13 @@ static void write_simple_return_method(const char *name, int value)
acpigen_pop_len(); /* Method */
}
/* Writes out 'count' ZEROs in a row */
static void write_zeros(int count)
{
for (; count; --count)
acpigen_write_integer(0);
}
/* Return the assigned namestring of any participant */
static const char *namestring_of(enum dptf_participant participant)
{
@ -164,3 +178,87 @@ void dptf_write_active_policies(const struct dptf_active_policy *policies, int m
write_active_relationship_table(policies, max_count);
write_active_cooling_methods(policies, max_count);
}
/*
* This writes out the Thermal Relationship Table, which describes the thermal relationships
* between participants in a thermal zone. This information is used to passively cool (i.e.,
* throttle) the Source (source of heat), in order to indirectly cool the Target (temperature
* sensor).
*/
static void write_thermal_relationship_table(const struct dptf_passive_policy *policies,
int max_count)
{
char *pkg_count;
int i;
/* Nothing to do */
if (!max_count || policies[0].source == DPTF_NONE)
return;
acpigen_write_scope(TOPLEVEL_DPTF_SCOPE);
/*
* A _TRT Revision (TRTR) of 1 means that the 'Priority' field is an arbitrary priority
* value to be used for this specific relationship. The priority value determines the
* order in which various sources are used in a passive thermal action for a given
* target.
*/
acpigen_write_name_integer("TRTR", 1);
/* Thermal Relationship Table */
acpigen_write_method("_TRT", 0);
/* Return this package */
acpigen_emit_byte(RETURN_OP);
pkg_count = acpigen_write_package(0);
for (i = 0; i < max_count; ++i) {
/* Stop writing the table once an entry is empty */
if (policies[i].source == DPTF_NONE)
break;
/* Keep track of outer package item count */
(*pkg_count)++;
acpigen_write_package(8);
/* Source, Target, Priority, Sampling Period */
acpigen_emit_namestring(namestring_of(policies[i].source));
acpigen_emit_namestring(namestring_of(policies[i].target));
acpigen_write_integer(DEFAULT_IF_0(policies[i].priority, DEFAULT_PRIORITY));
acpigen_write_integer(to_acpi_time(policies[i].period));
/* Reserved */
write_zeros(4);
acpigen_pop_len(); /* Package */
}
acpigen_pop_len(); /* Package */
acpigen_pop_len(); /* Method */
acpigen_pop_len(); /* Scope */
}
/*
* When a temperature sensor measures above its the temperature returned in its _PSV Method,
* DPTF will begin throttling Sources in order to indirectly cool the sensor.
*/
static void write_all_PSV(const struct dptf_passive_policy *policies, int max_count)
{
int i;
for (i = 0; i < max_count; ++i) {
if (policies[i].source == DPTF_NONE)
break;
dptf_write_scope(policies[i].target);
write_simple_return_method("_PSV", to_acpi_temp(policies[i].temp));
acpigen_pop_len(); /* Scope */
}
}
void dptf_write_passive_policies(const struct dptf_passive_policy *policies, int max_count)
{
write_thermal_relationship_table(policies, max_count);
write_all_PSV(policies, max_count);
}

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@ -8,6 +8,7 @@
struct drivers_intel_dptf_config {
struct {
struct dptf_active_policy active[DPTF_MAX_ACTIVE_POLICIES];
struct dptf_passive_policy passive[DPTF_MAX_PASSIVE_POLICIES];
} policies;
};

View File

@ -35,6 +35,12 @@ static bool is_participant_used(const struct drivers_intel_dptf_config *config,
if (config->policies.active[i].target == participant)
return true;
/* Passive? */
for (i = 0; i < DPTF_MAX_PASSIVE_POLICIES; ++i)
if (config->policies.passive[i].source == participant ||
config->policies.passive[i].target == participant)
return true;
/* Check fan as well (its use is implicit in the Active policy) */
if (participant == DPTF_FAN && config->policies.active[0].target != DPTF_NONE)
return true;
@ -55,6 +61,9 @@ static void dptf_fill_ssdt(const struct device *dev)
dptf_write_active_policies(config->policies.active,
DPTF_MAX_ACTIVE_POLICIES);
dptf_write_passive_policies(config->policies.passive,
DPTF_MAX_PASSIVE_POLICIES);
printk(BIOS_INFO, "\\_SB.DPTF: %s at %s\n", dev->chip_ops->name, dev_path(dev));
}

View File

@ -27,6 +27,7 @@ enum {
/* A device can only define _AC0 .. _AC9 i.e. between 0 and 10 Active Cooling Methods */
DPTF_MAX_ACX = 10,
DPTF_MAX_ACTIVE_POLICIES = (DPTF_PARTICIPANT_COUNT-1),
DPTF_MAX_PASSIVE_POLICIES = (DPTF_PARTICIPANT_COUNT-1),
};
/* Active Policy */
@ -44,6 +45,20 @@ struct dptf_active_policy {
} thresholds[DPTF_MAX_ACX];
};
/* Passive Policy */
struct dptf_passive_policy {
/* The device that can be throttled */
enum dptf_participant source;
/* The device that controls the throttling */
enum dptf_participant target;
/* How often to check the temperature for required throttling (ms) */
uint16_t period;
/* The trip point for turning on throttling (degrees C) */
uint8_t temp;
/* Relative priority between Policies */
uint8_t priority;
};
/*
* This function provides tables of temperature and corresponding fan or percent. When the
* temperature thresholds are met (_AC0 - _AC9), the fan is driven to corresponding percentage
@ -51,6 +66,14 @@ struct dptf_active_policy {
*/
void dptf_write_active_policies(const struct dptf_active_policy *policies, int max_count);
/*
* This function uses the definition of the passive policies to write out _PSV Methods on all
* participants that define it. It also writes out the Thermal Relationship Table
* (\_SB.DPTF._TRT), which describes various passive (i.e., throttling) policies that can be
* applies when temperature sensors reach the _PSV threshold.
*/
void dptf_write_passive_policies(const struct dptf_passive_policy *policies, int max_count);
/* Helper method to open the scope for a given participant. */
void dptf_write_scope(enum dptf_participant participant);