smt-snooze-delay is a tunable that is supported on
powerpc platform to delay the entry to nap state.
This can be set either via sysfs, kernel commandline
or pp64_cpu util.
Signed-off-by: Deepthi Dharwar <deep...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/processor.h | 2 +
arch/powerpc/platforms/powernv/powernv.h | 3 ++
arch/powerpc/platforms/powernv/processor_idle.c | 36 +++++++++++++++++++++++
3 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/processor.h
b/arch/powerpc/include/asm/processor.h
index 47a35b0..5700c3c 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -426,7 +426,7 @@ enum idle_boot_override {IDLE_NO_OVERRIDE = 0,
IDLE_POWERSAVE_OFF};
extern int powersave_nap; /* set if nap mode can be used in idle loop */
extern void power7_nap(void);
-#ifdef CONFIG_PSERIES_IDLE
+#if defined(CONFIG_PSERIES_IDLE) || defined(CONFIG_POWERNV_IDLE)
extern void update_smt_snooze_delay(int cpu, int residency);
#else
static inline void update_smt_snooze_delay(int cpu, int residency) {}
diff --git a/arch/powerpc/platforms/powernv/powernv.h
b/arch/powerpc/platforms/powernv/powernv.h
index a1c6f83..558ee69 100644
--- a/arch/powerpc/platforms/powernv/powernv.h
+++ b/arch/powerpc/platforms/powernv/powernv.h
@@ -15,4 +15,7 @@ static inline void pnv_pci_init(void) { }
static inline void pnv_pci_shutdown(void) { }
#endif
+/* Idle variable */
+DECLARE_PER_CPU(long, smt_snooze_delay);
+
#endif /* _POWERNV_H */
diff --git a/arch/powerpc/platforms/powernv/processor_idle.c
b/arch/powerpc/platforms/powernv/processor_idle.c
index f43ad91a..505fea4 100644
--- a/arch/powerpc/platforms/powernv/processor_idle.c
+++ b/arch/powerpc/platforms/powernv/processor_idle.c
@@ -13,6 +13,8 @@
#include <asm/machdep.h>
#include <asm/runlatch.h>
+#include "powernv.h"
+
struct cpuidle_driver powernv_idle_driver = {
.name = "powernv_idle",
.owner = THIS_MODULE,
@@ -193,6 +195,38 @@ static int powernv_idle_probe(void)
return 0;
}
+void update_smt_snooze_delay(int cpu, int residency)
+{
+ struct cpuidle_driver *drv = cpuidle_get_driver();
+ struct cpuidle_device *dev;
+
+ if (!drv)
+ return;
+
+ if (cpu == -1) {
+ if (residency < 0) {
+ /* Disable NAP on all cpus */
+ drv->states[1].disabled = true;
+ } else {
+ drv->states[1].target_residency = residency;
+ drv->states[1].disabled = false;
+ }
+ return;
+ }
+
+ dev = per_cpu(cpuidle_devices, cpu);
+ if (!dev)
+ return;
+
+ if (residency < 0)
+ dev->states_usage[1].disable = 1;
+ else {
+ drv->states[1].target_residency = residency;
+ drv->states[1].disabled = false;
+ dev->states_usage[1].disable = 0;
+ }
+}
+
static int __init powernv_processor_idle_init(void)
{
int retval;
@@ -208,6 +242,8 @@ static int __init powernv_processor_idle_init(void)
return retval;
}
+ update_smt_snooze_delay(-1, per_cpu(smt_snooze_delay, 0));
+
retval = powernv_idle_devices_init();
if (retval) {
powernv_idle_devices_uninit();
--
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