From: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Subject: powercap: Add Power Limit4 support
References: jsc#INTEL-549
Patch-Mainline: v5.9-rc1
Git-commit: 8365a898fe53f85529566501d3b3d88640b3975e
Modern Intel Mobile platforms support power limit4 (PL4), which is
the SoC package level maximum power limit (in Watts). It can be used
to preemptively limits potential SoC power to prevent power spikes
from tripping the power adapter and battery over-current protection.
This patch enables this feature by exposing package level peak power
capping control to userspace via RAPL sysfs interface. With this,
application like DTPF can modify PL4 power limit, the similar way
of other package power limit (PL1).
As this feature is not tested on previous generations, here it is
enabled only for the platform that has been verified to work,
for safety concerns.
Signed-off-by: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Co-developed-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: <trenn@suse.com>
---
Documentation/power/powercap/powercap.rst | 15 +++++---
drivers/powercap/intel_rapl_common.c | 54 ++++++++++++++++++++++++++++--
drivers/powercap/intel_rapl_msr.c | 15 ++++++++
include/linux/intel_rapl.h | 5 ++
4 files changed, 81 insertions(+), 8 deletions(-)
--- a/Documentation/power/powercap/powercap.rst
+++ b/Documentation/power/powercap/powercap.rst
@@ -167,11 +167,13 @@
package-0
---------
-The Intel RAPL technology allows two constraints, short term and long term,
-with two different time windows to be applied to each power zone. Thus for
-each zone there are 2 attributes representing the constraint names, 2 power
-limits and 2 attributes representing the sizes of the time windows. Such that,
-constraint_j_* attributes correspond to the jth constraint (j = 0,1).
+Depending on different power zones, the Intel RAPL technology allows
+one or multiple constraints like short term, long term and peak power,
+with different time windows to be applied to each power zone.
+All the zones contain attributes representing the constraint names,
+power limits and the sizes of the time windows. Note that time window
+is not applicable to peak power. Here, constraint_j_* attributes
+correspond to the jth constraint (j = 0,1,2).
For example::
@@ -181,6 +183,9 @@
constraint_1_name
constraint_1_power_limit_uw
constraint_1_time_window_us
+ constraint_2_name
+ constraint_2_power_limit_uw
+ constraint_2_time_window_us
Power Zone Attributes
=====================
--- a/drivers/powercap/intel_rapl_common.c
+++ b/drivers/powercap/intel_rapl_common.c
@@ -42,6 +42,8 @@
#define POWER_HIGH_LOCK BIT_ULL(63)
#define POWER_LOW_LOCK BIT(31)
+#define POWER_LIMIT4_MASK 0x1FFF
+
#define TIME_WINDOW1_MASK (0x7FULL<<17)
#define TIME_WINDOW2_MASK (0x7FULL<<49)
@@ -85,6 +87,7 @@
static const char pl1_name[] = "long_term";
static const char pl2_name[] = "short_term";
+static const char pl4_name[] = "peak_power";
#define power_zone_to_rapl_domain(_zone) \
container_of(_zone, struct rapl_domain, power_zone)
@@ -341,6 +344,9 @@
case PL2_ENABLE:
rapl_write_data_raw(rd, POWER_LIMIT2, power_limit);
break;
+ case PL4_ENABLE:
+ rapl_write_data_raw(rd, POWER_LIMIT4, power_limit);
+ break;
default:
ret = -EINVAL;
}
@@ -375,6 +381,9 @@
case PL2_ENABLE:
prim = POWER_LIMIT2;
break;
+ case PL4_ENABLE:
+ prim = POWER_LIMIT4;
+ break;
default:
put_online_cpus();
return -EINVAL;
@@ -444,6 +453,13 @@
case PL2_ENABLE:
ret = rapl_read_data_raw(rd, TIME_WINDOW2, true, &val);
break;
+ case PL4_ENABLE:
+ /*
+ * Time window parameter is not applicable for PL4 entry
+ * so assigining '0' as default value.
+ */
+ val = 0;
+ break;
default:
put_online_cpus();
return -EINVAL;
@@ -487,6 +503,9 @@
case PL2_ENABLE:
prim = MAX_POWER;
break;
+ case PL4_ENABLE:
+ prim = MAX_POWER;
+ break;
default:
put_online_cpus();
return -EINVAL;
@@ -496,6 +515,10 @@
else
*data = val;
+ /* As a generalization rule, PL4 would be around two times PL2. */
+ if (rd->rpl[id].prim_id == PL4_ENABLE)
+ *data = *data * 2;
+
put_online_cpus();
return ret;
@@ -528,12 +551,22 @@
rd->id = i;
rd->rpl[0].prim_id = PL1_ENABLE;
rd->rpl[0].name = pl1_name;
- /* some domain may support two power limits */
- if (rp->priv->limits[i] == 2) {
+
+ /*
+ * The PL2 power domain is applicable for limits two
+ * and limits three
+ */
+ if (rp->priv->limits[i] >= 2) {
rd->rpl[1].prim_id = PL2_ENABLE;
rd->rpl[1].name = pl2_name;
}
+ /* Enable PL4 domain if the total power limits are three */
+ if (rp->priv->limits[i] == 3) {
+ rd->rpl[2].prim_id = PL4_ENABLE;
+ rd->rpl[2].name = pl4_name;
+ }
+
for (j = 0; j < RAPL_DOMAIN_REG_MAX; j++)
rd->regs[j] = rp->priv->regs[i][j];
@@ -602,6 +635,8 @@
RAPL_DOMAIN_REG_LIMIT, POWER_UNIT, 0),
PRIMITIVE_INFO_INIT(POWER_LIMIT2, POWER_LIMIT2_MASK, 32,
RAPL_DOMAIN_REG_LIMIT, POWER_UNIT, 0),
+ PRIMITIVE_INFO_INIT(POWER_LIMIT4, POWER_LIMIT4_MASK, 0,
+ RAPL_DOMAIN_REG_PL4, POWER_UNIT, 0),
PRIMITIVE_INFO_INIT(FW_LOCK, POWER_LOW_LOCK, 31,
RAPL_DOMAIN_REG_LIMIT, ARBITRARY_UNIT, 0),
PRIMITIVE_INFO_INIT(PL1_ENABLE, POWER_LIMIT1_ENABLE, 15,
@@ -612,6 +647,8 @@
RAPL_DOMAIN_REG_LIMIT, ARBITRARY_UNIT, 0),
PRIMITIVE_INFO_INIT(PL2_CLAMP, POWER_LIMIT2_CLAMP, 48,
RAPL_DOMAIN_REG_LIMIT, ARBITRARY_UNIT, 0),
+ PRIMITIVE_INFO_INIT(PL4_ENABLE, POWER_LIMIT4_MASK, 0,
+ RAPL_DOMAIN_REG_PL4, ARBITRARY_UNIT, 0),
PRIMITIVE_INFO_INIT(TIME_WINDOW1, TIME_WINDOW1_MASK, 17,
RAPL_DOMAIN_REG_LIMIT, TIME_UNIT, 0),
PRIMITIVE_INFO_INIT(TIME_WINDOW2, TIME_WINDOW2_MASK, 49,
@@ -1276,6 +1313,7 @@
if (find_nr_power_limit(rd) > 1) {
rapl_write_data_raw(rd, PL2_ENABLE, 0);
rapl_write_data_raw(rd, PL2_CLAMP, 0);
+ rapl_write_data_raw(rd, PL4_ENABLE, 0);
}
if (rd->id == RAPL_DOMAIN_PACKAGE) {
rd_package = rd;
@@ -1384,6 +1422,13 @@
if (ret)
rd->rpl[i].last_power_limit = 0;
break;
+ case PL4_ENABLE:
+ ret = rapl_read_data_raw(rd,
+ POWER_LIMIT4, true,
+ &rd->rpl[i].last_power_limit);
+ if (ret)
+ rd->rpl[i].last_power_limit = 0;
+ break;
}
}
}
@@ -1414,6 +1459,11 @@
rapl_write_data_raw(rd, POWER_LIMIT2,
rd->rpl[i].last_power_limit);
break;
+ case PL4_ENABLE:
+ if (rd->rpl[i].last_power_limit)
+ rapl_write_data_raw(rd, POWER_LIMIT4,
+ rd->rpl[i].last_power_limit);
+ break;
}
}
}
--- a/drivers/powercap/intel_rapl_msr.c
+++ b/drivers/powercap/intel_rapl_msr.c
@@ -28,6 +28,7 @@
/* Local defines */
#define MSR_PLATFORM_POWER_LIMIT 0x0000065C
+#define MSR_VR_CURRENT_CONFIG 0x00000601
/* private data for RAPL MSR Interface */
static struct rapl_if_priv rapl_msr_priv = {
@@ -123,13 +124,27 @@
return ra->err;
}
+/* List of verified CPUs. */
+static const struct x86_cpu_id pl4_support_ids[] = {
+ { X86_VENDOR_INTEL, 6, INTEL_FAM6_TIGERLAKE_L, X86_FEATURE_ANY },
+ {}
+};
+
static int rapl_msr_probe(struct platform_device *pdev)
{
+ const struct x86_cpu_id *id = x86_match_cpu(pl4_support_ids);
int ret;
rapl_msr_priv.read_raw = rapl_msr_read_raw;
rapl_msr_priv.write_raw = rapl_msr_write_raw;
+ if (id) {
+ rapl_msr_priv.limits[RAPL_DOMAIN_PACKAGE] = 3;
+ rapl_msr_priv.regs[RAPL_DOMAIN_PACKAGE][RAPL_DOMAIN_REG_PL4] =
+ MSR_VR_CURRENT_CONFIG;
+ pr_info("PL4 support detected.\n");
+ }
+
rapl_msr_priv.control_type = powercap_register_control_type(NULL, "intel-rapl", NULL);
if (IS_ERR(rapl_msr_priv.control_type)) {
pr_debug("failed to register powercap control_type.\n");
--- a/include/linux/intel_rapl.h
+++ b/include/linux/intel_rapl.h
@@ -29,6 +29,7 @@
RAPL_DOMAIN_REG_PERF,
RAPL_DOMAIN_REG_POLICY,
RAPL_DOMAIN_REG_INFO,
+ RAPL_DOMAIN_REG_PL4,
RAPL_DOMAIN_REG_MAX,
};
@@ -38,12 +39,14 @@
ENERGY_COUNTER,
POWER_LIMIT1,
POWER_LIMIT2,
+ POWER_LIMIT4,
FW_LOCK,
PL1_ENABLE, /* power limit 1, aka long term */
PL1_CLAMP, /* allow frequency to go below OS request */
PL2_ENABLE, /* power limit 2, aka short term, instantaneous */
PL2_CLAMP,
+ PL4_ENABLE, /* power limit 4, aka max peak power */
TIME_WINDOW1, /* long term */
TIME_WINDOW2, /* short term */
@@ -65,7 +68,7 @@
unsigned long timestamp;
};
-#define NR_POWER_LIMITS (2)
+#define NR_POWER_LIMITS (3)
struct rapl_power_limit {
struct powercap_zone_constraint *constraint;
int prim_id; /* primitive ID used to enable */