[Skiboot] [PATCH V4 1/4] sensors: dts: Assert special wakeup on idle cores while reading temperature
Shilpasri G Bhat
shilpa.bhat at linux.vnet.ibm.com
Mon Nov 20 17:09:37 AEDT 2017
In P9, when a core enters a stop state, its clocks will be stopped
to save power and hence we will not be able to perform a scom
operation to read the DTS temperature sensor. Hence, assert
a special wakeup on cores that have entered a stop state in order to
successfully complete the scom operation.
Signed-off-by: Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com>
[rlippert at google.com: Clear special wakeup only when it succeeds]
---
Changes from V3:
- Add per-cpu DTS timer and flag
core/direct-controls.c | 4 +--
core/sensor.c | 2 +-
hw/dts.c | 74 +++++++++++++++++++++++++++++++++++++++++---------
include/cpu.h | 14 ++++++++++
include/dts.h | 2 +-
5 files changed, 79 insertions(+), 17 deletions(-)
diff --git a/core/direct-controls.c b/core/direct-controls.c
index 512cb36..fcb9350 100644
--- a/core/direct-controls.c
+++ b/core/direct-controls.c
@@ -220,7 +220,7 @@ static int p9_sreset_thread(struct cpu_thread *cpu)
return 0;
}
-static int dctl_set_special_wakeup(struct cpu_thread *t)
+int dctl_set_special_wakeup(struct cpu_thread *t)
{
struct cpu_thread *c = t->primary;
int rc = OPAL_SUCCESS;
@@ -238,7 +238,7 @@ static int dctl_set_special_wakeup(struct cpu_thread *t)
return rc;
}
-static int dctl_clear_special_wakeup(struct cpu_thread *t)
+int dctl_clear_special_wakeup(struct cpu_thread *t)
{
struct cpu_thread *c = t->primary;
int rc = OPAL_SUCCESS;
diff --git a/core/sensor.c b/core/sensor.c
index 57b21bc..0e2a5ca 100644
--- a/core/sensor.c
+++ b/core/sensor.c
@@ -28,7 +28,7 @@ static int64_t opal_sensor_read(uint32_t sensor_hndl, int token,
{
switch (sensor_get_family(sensor_hndl)) {
case SENSOR_DTS:
- return dts_sensor_read(sensor_hndl, sensor_data);
+ return dts_sensor_read(sensor_hndl, token, sensor_data);
case SENSOR_OCC:
return occ_sensor_read(sensor_hndl, sensor_data);
default:
diff --git a/hw/dts.c b/hw/dts.c
index a10df58..72a392b 100644
--- a/hw/dts.c
+++ b/hw/dts.c
@@ -20,6 +20,9 @@
#include <dts.h>
#include <skiboot.h>
#include <opal-api.h>
+#include <opal-msg.h>
+#include <timer.h>
+#include <timebase.h>
struct dts {
uint8_t valid;
@@ -27,6 +30,14 @@ struct dts {
int16_t temp;
};
+/*
+ * Attributes for the core temperature sensor
+ */
+enum {
+ SENSOR_DTS_ATTR_TEMP_MAX,
+ SENSOR_DTS_ATTR_TEMP_TRIP
+};
+
/* Different sensor locations */
#define P7_CT_ZONE_LSU 0
#define P7_CT_ZONE_ISU 1
@@ -225,8 +236,37 @@ static int dts_read_core_temp_p9(uint32_t pir, struct dts *dts)
return 0;
}
-static int dts_read_core_temp(uint32_t pir, struct dts *dts)
+static void dts_async_read_temp(struct timer *t __unused, void *data,
+ u64 now __unused)
+{
+ struct dts dts;
+ int rc, swkup_rc;
+ struct cpu_thread *cpu = data;
+
+ swkup_rc = dctl_set_special_wakeup(cpu);
+
+ rc = dts_read_core_temp_p9(cpu->pir, &dts);
+ if (!rc) {
+ if (cpu->sensor_attr == SENSOR_DTS_ATTR_TEMP_MAX)
+ *(u32 *)cpu->sensor_data = dts.temp;
+ else if (cpu->sensor_attr == SENSOR_DTS_ATTR_TEMP_TRIP)
+ *(u32 *)cpu->sensor_data = dts.trip;
+ }
+
+ if (!swkup_rc)
+ dctl_clear_special_wakeup(cpu);
+
+ rc = opal_queue_msg(OPAL_MSG_ASYNC_COMP, NULL, NULL, cpu->token, rc);
+ if (rc)
+ prerror("Failed to queue async message\n");
+
+ cpu->dts_read_in_progress = false;
+}
+
+static int dts_read_core_temp(u32 pir, struct dts *dts, u8 attr,
+ int token, u32 *sensor_data)
{
+ struct cpu_thread *cpu;
int rc;
switch (proc_gen) {
@@ -236,8 +276,22 @@ static int dts_read_core_temp(uint32_t pir, struct dts *dts)
case proc_gen_p8:
rc = dts_read_core_temp_p8(pir, dts);
break;
- case proc_gen_p9:
- rc = dts_read_core_temp_p9(pir, dts);
+ case proc_gen_p9: /* Asynchronus read */
+ cpu = find_cpu_by_pir(pir);
+ if (!cpu)
+ return OPAL_PARAMETER;
+ lock(&cpu->dts_lock);
+ if (cpu->dts_read_in_progress) {
+ unlock(&cpu->dts_lock);
+ return OPAL_BUSY;
+ }
+ cpu->dts_read_in_progress = true;
+ cpu->sensor_attr = attr;
+ cpu->sensor_data = sensor_data;
+ cpu->token = token;
+ schedule_timer(&cpu->dts_timer, 0);
+ rc = OPAL_ASYNC_COMPLETION;
+ unlock(&cpu->dts_lock);
break;
default:
rc = OPAL_UNSUPPORTED;
@@ -303,20 +357,12 @@ enum sensor_dts_class {
};
/*
- * Attributes for the core temperature sensor
- */
-enum {
- SENSOR_DTS_ATTR_TEMP_MAX,
- SENSOR_DTS_ATTR_TEMP_TRIP
-};
-
-/*
* Extract the centaur chip id which was truncated to fit in the
* resource identifier field of the sensor handler
*/
#define centaur_get_id(rid) (0x80000000 | ((rid) & 0x3ff))
-int64_t dts_sensor_read(uint32_t sensor_hndl, uint32_t *sensor_data)
+int64_t dts_sensor_read(u32 sensor_hndl, int token, u32 *sensor_data)
{
uint8_t attr = sensor_get_attr(sensor_hndl);
uint32_t rid = sensor_get_rid(sensor_hndl);
@@ -330,7 +376,7 @@ int64_t dts_sensor_read(uint32_t sensor_hndl, uint32_t *sensor_data)
switch (sensor_get_frc(sensor_hndl)) {
case SENSOR_DTS_CORE_TEMP:
- rc = dts_read_core_temp(rid, &dts);
+ rc = dts_read_core_temp(rid, &dts, attr, token, sensor_data);
break;
case SENSOR_DTS_MEM_TEMP:
rc = dts_read_mem_temp(centaur_get_id(rid), &dts);
@@ -403,6 +449,8 @@ bool dts_sensor_create_nodes(struct dt_node *sensors)
dt_add_property_string(node, "sensor-type", "temp");
dt_add_property_cells(node, "ibm,pir", c->pir);
dt_add_property_string(node, "label", "Core");
+ init_timer(&c->dts_timer, dts_async_read_temp, c);
+ c->dts_read_in_progress = false;
}
}
diff --git a/include/cpu.h b/include/cpu.h
index 168fa99..d4b7a42 100644
--- a/include/cpu.h
+++ b/include/cpu.h
@@ -23,6 +23,7 @@
#include <device.h>
#include <opal.h>
#include <stack.h>
+#include <timer.h>
/*
* cpu_thread is our internal structure representing each
@@ -102,6 +103,16 @@ struct cpu_thread {
struct lock dctl_lock; /* primary only */
bool dctl_stopped; /* per thread */
uint32_t special_wakeup_count; /* primary */
+
+ /*
+ * For reading DTS sensors async
+ */
+ struct lock dts_lock;
+ struct timer dts_timer;
+ void *sensor_data;
+ u32 sensor_attr;
+ u32 token;
+ bool dts_read_in_progress;
};
/* This global is set to 1 to allow secondaries to callin,
@@ -284,4 +295,7 @@ extern void cpu_idle_delay(unsigned long delay);
extern void cpu_set_radix_mode(void);
extern void cpu_fast_reboot_complete(void);
+int dctl_set_special_wakeup(struct cpu_thread *t);
+int dctl_clear_special_wakeup(struct cpu_thread *t);
+
#endif /* __CPU_H */
diff --git a/include/dts.h b/include/dts.h
index b37919f..17e2e15 100644
--- a/include/dts.h
+++ b/include/dts.h
@@ -19,7 +19,7 @@
#include <stdint.h>
-extern int64_t dts_sensor_read(uint32_t sensor_hndl, uint32_t *sensor_data);
+extern int64_t dts_sensor_read(u32 sensor_hndl, int token, u32 *sensor_data);
extern bool dts_sensor_create_nodes(struct dt_node *sensors);
#endif /* __DTS_H */
--
1.8.3.1
More information about the Skiboot
mailing list