[Skiboot] [RFC PATCH v2 2/9] dts: add support to read the core temperatures

Cédric Le Goater clg at fr.ibm.com
Thu Jan 22 18:09:15 AEDT 2015


This patch adds a new sensor family for Digital Temperature Sensors
and a new resource class to capture the core temperatures.

Each core has four DTS located in different zones (LSU, ISU, FXU, L3).
The max of the four temperatures is computed and returned for the core
as well as a global trip point value. This is based on the meltbox tool.

Signed-off-by: Cédric Le Goater <clg at fr.ibm.com>
---
 core/sensor.c    |    8 +++
 hw/Makefile.inc  |    2 +-
 hw/dts.c         |  166 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/dts.h    |   24 ++++++++
 include/sensor.h |    2 +
 include/xscom.h  |    8 +++
 6 files changed, 209 insertions(+), 1 deletion(-)
 create mode 100644 hw/dts.c
 create mode 100644 include/dts.h

diff --git a/core/sensor.c b/core/sensor.c
index 2099579cee4c..b109030d8c44 100644
--- a/core/sensor.c
+++ b/core/sensor.c
@@ -19,10 +19,18 @@
 #include <skiboot.h>
 #include <opal.h>
 #include <fsp.h>
+#include <dts.h>
 
 static int64_t opal_sensor_read(uint32_t sensor_hndl, int token,
 		uint32_t *sensor_data)
 {
+	/*
+	 * Dispatch the read to other OPAL components. This is just for
+	 * the core temperature for the moment.
+	 */
+	if (sensor_is_dts(sensor_hndl))
+		return dts_sensor_read(sensor_hndl, sensor_data);
+
 	if (platform.sensor_read)
 		return platform.sensor_read(sensor_hndl, token, sensor_data);
 
diff --git a/hw/Makefile.inc b/hw/Makefile.inc
index 83125beeee7f..f55654a08792 100644
--- a/hw/Makefile.inc
+++ b/hw/Makefile.inc
@@ -4,7 +4,7 @@ SUBDIRS += hw
 HW_OBJS  = xscom.o chiptod.o gx.o cec.o lpc.o lpc-uart.o psi.o
 HW_OBJS += homer.o slw.o occ.o nx.o fsi-master.o centaur.o
 HW_OBJS += p7ioc.o p7ioc-inits.o p7ioc-phb.o p5ioc2.o p5ioc2-phb.o
-HW_OBJS += phb3.o sfc-ctrl.o fake-rtc.o bt.o p8-i2c.o
+HW_OBJS += phb3.o sfc-ctrl.o fake-rtc.o bt.o p8-i2c.o dts.o
 HW=hw/built-in.o
 
 include $(SRC)/hw/fsp/Makefile.inc
diff --git a/hw/dts.c b/hw/dts.c
new file mode 100644
index 000000000000..c94e879b192a
--- /dev/null
+++ b/hw/dts.c
@@ -0,0 +1,166 @@
+/* Copyright 2013-2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <xscom.h>
+#include <chip.h>
+#include <sensor.h>
+#include <dts.h>
+
+
+struct dts_core_temp {
+	uint8_t		valid;
+	uint8_t		trip;
+	int16_t		temp;
+};
+
+
+/* Therm mac result masking for DTS (result(0:15)
+ *  0:3   - 0x0
+ *  4:11  - Temperature in degrees C
+ *  12:13 - trip bits: 00 - no trip; 01 - warning; 10 - critical; 11 - fatal
+ *  14    - spare
+ *  15    - valid
+ */
+static void dts_decode_one_dts(uint16_t dts, struct dts_core_temp *ts)
+{
+	/*
+	 * The value is both signed and unsigned :-) 0xff could be
+	 * either 255C or -1C, so for now we treat this as unsigned
+	 * which is sufficient for our purpose. We could try to be
+	 * a bit smarter and treat it as signed for values between
+	 * -10 and 0 and unsigned to 239 or something like that...
+	 */
+	ts->valid = dts & 1;
+	if (ts->valid) {
+		ts->temp = (dts >> 4) & 0xff;
+		ts->trip = (dts >> 2) & 0x3;
+	} else {
+		ts->temp = 0;
+		ts->trip = 0;
+	}
+}
+
+/* Different sensor locations */
+#define P8_CT_ZONE_LSU	0
+#define P8_CT_ZONE_ISU	1
+#define P8_CT_ZONE_FXU	2
+#define P8_CT_ZONE_L3C	3
+#define P8_CT_ZONES	4
+
+/*
+ * Returns the temperature as the max of all 4 zones and a global trip
+ * attribute.
+ */
+static int dts_read_core_temp(uint32_t pir, struct dts_core_temp *ts)
+{
+	int32_t chip_id = pir_to_chip_id(pir);
+	int32_t core = pir_to_core_id(pir);
+	uint64_t dts0, dts1;
+	struct dts_core_temp temps[P8_CT_ZONES];
+	int i;
+	int rc;
+
+	rc = xscom_read(chip_id, XSCOM_ADDR_P8_EX(core, EX_THERM_DTS_RESULT0),
+			&dts0);
+	if (rc)
+		return rc;
+
+	rc = xscom_read(chip_id, XSCOM_ADDR_P8_EX(core, EX_THERM_DTS_RESULT1),
+			&dts1);
+	if (rc)
+		return rc;
+
+	dts_decode_one_dts(dts0 >> 48, &temps[P8_CT_ZONE_LSU]);
+	dts_decode_one_dts(dts0 >> 32, &temps[P8_CT_ZONE_ISU]);
+	dts_decode_one_dts(dts0 >> 16, &temps[P8_CT_ZONE_FXU]);
+	dts_decode_one_dts(dts1 >> 48, &temps[P8_CT_ZONE_L3C]);
+
+	for (i = 0; i < P8_CT_ZONES; i++) {
+		int16_t t = temps[i].temp;
+
+		if (!temps[i].valid)
+			continue;
+
+		/* keep the max temperature of all 4 sensors */
+		if (t > ts->temp)
+			ts->temp = t;
+
+		ts->valid++;
+		ts->trip |= temps[i].trip;
+	}
+
+	prlog(PR_TRACE, "DTS: Chip %x Core %x temp:%dC trip:%x\n",
+	      chip_id, core, ts->temp, ts->trip);
+	return 0;
+}
+
+/*
+ * DTS sensor class ids. Only one for the moment: the core
+ * temperature.
+ */
+enum sensor_dts_class {
+	SENSOR_DTS_CORE_TEMP,
+	/* To be continued */
+};
+
+/*
+ * Attributes for the core temperature sensor
+ */
+enum {
+	SENSOR_DTS_ATTR_CORE_TEMP_MAX,
+	SENSOR_DTS_ATTR_CORE_TEMP_TRIP
+};
+
+static int64_t dts_sensor_read_core_temp(uint32_t sensor_hndl,
+	uint32_t *sensor_data)
+{
+	uint8_t	attr = sensor_get_attr(sensor_hndl);
+	uint32_t pir = sensor_get_rid(sensor_hndl);
+	struct dts_core_temp ts;
+	int64_t rc;
+
+	if (attr > SENSOR_DTS_ATTR_CORE_TEMP_TRIP)
+		return OPAL_PARAMETER;
+
+	memset(&ts, 0, sizeof(struct dts_core_temp));
+
+	rc = dts_read_core_temp(pir, &ts);
+	if (rc)
+		return rc;
+
+	if (attr == SENSOR_DTS_ATTR_CORE_TEMP_MAX)
+		*sensor_data = ts.temp;
+	else if (attr == SENSOR_DTS_ATTR_CORE_TEMP_TRIP)
+		*sensor_data = ts.trip;
+
+	return 0;
+}
+
+int64_t dts_sensor_read(uint32_t sensor_hndl, uint32_t *sensor_data)
+{
+	int64_t rc;
+
+	switch (sensor_get_frc(sensor_hndl) & ~SENSOR_DTS) {
+	case SENSOR_DTS_CORE_TEMP:
+		rc = dts_sensor_read_core_temp(sensor_hndl, sensor_data);
+		break;
+	default:
+		rc = OPAL_PARAMETER;
+		break;
+	}
+
+	return rc;
+}
diff --git a/include/dts.h b/include/dts.h
new file mode 100644
index 000000000000..18933909ee08
--- /dev/null
+++ b/include/dts.h
@@ -0,0 +1,24 @@
+/* Copyright 2013-2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __DTS_H
+#define __DTS_H
+
+#include <stdint.h>
+
+extern int64_t dts_sensor_read(uint32_t sensor_hndl, uint32_t *sensor_data);
+
+#endif /* __DTS_H */
diff --git a/include/sensor.h b/include/sensor.h
index 5acc740dd459..1ed156a3398f 100644
--- a/include/sensor.h
+++ b/include/sensor.h
@@ -46,7 +46,9 @@
  * the appropriate component. FSP is the initial family.
  */
 #define SENSOR_FSP 0x0
+#define SENSOR_DTS 0x80
 
+#define sensor_is_dts(handler)	(sensor_get_frc(handler) & SENSOR_DTS)
 
 extern void sensor_init(void);
 
diff --git a/include/xscom.h b/include/xscom.h
index 5eed85f50753..e321c4535b9b 100644
--- a/include/xscom.h
+++ b/include/xscom.h
@@ -154,6 +154,14 @@
 #define EX_PM_IDLE_ST_HIST_PM_STATE_MASK	PPC_BITMASK(0, 2)
 #define EX_PM_IDLE_ST_HIST_PM_STATE_LSH		PPC_BITLSHIFT(2)
 
+/* Per core Digital Thermal Sensors */
+#define EX_THERM_DTS_RESULT0	0x10050000
+#define EX_THERM_DTS_RESULT1	0x10050001
+
+/* Per core Digital Thermal Sensors control registers */
+#define EX_THERM_MODE_REG	0x1005000F
+#define EX_THERM_CONTROL_REG	0x10050012
+#define EX_THERM_ERR_STATUS_REG	0x10050013
 
 /*
  * Error handling:
-- 
1.7.10.4



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