[PATCH v8 0/7] POWER/cpuidle: Generic POWERPC-BOOK3S cpuidle driver enabled for PSERIES and POWERNV platforms

[PATCH v8 0/7] POWER/cpuidle: Generic POWERPC-BOOK3S cpuidle driver enabled for PSERIES and POWERNV platforms

[Deepthi Dharwar]

This patch series consolidates the backend cpuidle driver for pSeries
and powernv platforms with minimal code duplication.

Current existing backend driver for pseries has been moved to drivers/cpuidle 
and has been extended to accommodate powernv idle power mgmt states. 
As seen in V1 of this patch series, having a separate powernv backend driver 
results in too much code duplication, which is less elegant and can pose 
maintenance problems going further.

Using the cpuidle framework to exploit platform low power idle states
management can take advantage of advanced heuristics, tunables and features 
provided by framework. The statistics and tracing infrastructure provided 
by the cpuidle framework also helps in enabling power management 
related tools and help tune the system and applications.

Earlier in 3.3 kernel, pSeries idle state management was modified to 
exploit the cpuidle framework and the end goal of this patch is to have powernv
platform also to hook its idle states into cpuidle framework with minimal 
code duplication between both platforms.  

This series aims to maintain compatibility and functionality to existing pseries 
and powernv idle cpu management code. There are no new functions or idle 
states added as part of this series. This can be extended by adding more 
states to this existing framework.

With this patch series, the powernv cpuidle functionalities are on-par with 
pSeries idle management.  

V1 -> http://lkml.org/lkml/2013/7/23/143
V2 -> https://lkml.org/lkml/2013/7/30/872
V3 -> http://comments.gmane.org/gmane.linux.ports.ppc.embedded/63093 
V4 -> https://lkml.org/lkml/2013/8/22/25
V5 -> http://lkml.org/lkml/2013/8/22/184
V6 -> https://lkml.org/lkml/2013/8/27/432 
v7 -> https://lkml.org/lkml/2013/10/29/216

Changes in V8:
============
* Renaming driver and related files from
  ibm-power-idle to powerpc-book3s-idle
  for clarity and to avoid confusing between ibm-power
  systems and power mgmt.

Changes in V7:
============
* Rebased to the latest kernel 3.12-rc7

* Default idle routine to be called on POWERNV
  is power7_idle() instead of HMT_low() routines.

Changes in V6:
=============
* Made changes in Patch3: Generic POWER cpuidle driver in V5 by
  breaking down to multiple patches, as there were multiple changes
  including moving the file location.

* Remove MAX_IDLE_STATE macro and kernel command line for
  IBM-POWER systems.

* Make backend driver a built-in, instead of a module.
  As building this as a module is currently not possible. 

* Generic backend driver minor cleanups.

* First two patches in V5 are not a part of the series, as
  they are generic cleanups, already pushed into the tree.

Changes in V5:
=============

* As per the discussions in the community, this patch series
  enables cpuidle backend driver only for IBM-POWER 
  platforms. File is re-named from drivers/cpuidle/cpuidle-powerpc.c
  to drivers/cpuidle/cpuildle-ibm-power.c
  New back-end cpuidle driver is called IBM-POWER-Idle.

* General cleanups on the accessors front that was introduced in 
  previous version.

Changes in V4:
=============

* This patch series includes generic backend driver cpuidle cleanups 
  including, replacing the driver and device initialisation
  routines with cpuidle_register function.

* Enable CPUIDLE framework only for POWER and POWERNV platforms.

Changes in V3:
=============

* This patch series does not include smt-snooze-delay fixes. 
  This will be taken up later on.

* Integrated POWERPC driver in drivers/cpuidle.  Enabled for all of 
  POWERPC platform.  Currently has PSERIES and POWERNV support.
  No compile time flags in .c file. This  will be one consolidated 
  binary that does a run time detection based on platform and take 
  decisions accordingly.

* Enabled CPUIDLE framwork for all of PPC64.

Changes in V2:
=============

* Merged the backend driver posted out for powernv in V1 with
  pSeries to create a single powerpc driver but this had compile
  time flags.

 Deepthi Dharwar (7):
      pseries/cpuidle: Move processor_idle.c to drivers/cpuidle.
      pseries/cpuidle: Use cpuidle_register() for initialisation.
      pseries/cpuidle: Make pseries_idle backend driver a  non-module.
      pseries/cpuidle: Remove MAX_IDLE_STATE macro.
      POWER/cpuidle: Generic POWERPC-BOOK3S CPUIDLE driver supporting PSERIES.
      POWER/cpuidle: Enable powernv cpuidle support.
      powernv/cpuidle: Enable idle powernv cpu to call into the cpuidle framework.


 arch/powerpc/include/asm/processor.h            |    2 
 arch/powerpc/platforms/powernv/setup.c          |   13 +
 arch/powerpc/platforms/pseries/Kconfig          |    9 -
 arch/powerpc/platforms/pseries/Makefile         |    1 
 arch/powerpc/platforms/pseries/processor_idle.c |  364 -----------------------
 drivers/cpuidle/Kconfig                         |    5 
 drivers/cpuidle/Kconfig.powerpc                 |   10 +
 drivers/cpuidle/Makefile                        |    4 
 drivers/cpuidle/cpuidle-powerpc-book3s.c        |  320 ++++++++++++++++++++
 9 files changed, 352 insertions(+), 376 deletions(-)
 delete mode 100644 arch/powerpc/platforms/pseries/processor_idle.c
 create mode 100644 drivers/cpuidle/Kconfig.powerpc
 create mode 100644 drivers/cpuidle/cpuidle-powerpc-book3s.c


-- Deepthi

[PATCH v8 1/7] pseries/cpuidle: Move processor_idle.c to drivers/cpuidle.

[Deepthi Dharwar]

Move the file from arch specific pseries/processor_idle.c
to drivers/cpuidle/cpuidle-powerpc-book3s.c
Make the relevant Makefile and Kconfig changes.
This will enable having a common backend cpuidle driver
for POWERPC-BOOK3S platform going forward.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 arch/powerpc/include/asm/processor.h            |    2 
 arch/powerpc/platforms/pseries/Kconfig          |    9 -
 arch/powerpc/platforms/pseries/Makefile         |    1 
 arch/powerpc/platforms/pseries/processor_idle.c |  364 -----------------------
 drivers/cpuidle/Kconfig                         |    5 
 drivers/cpuidle/Kconfig.powerpc                 |   10 +
 drivers/cpuidle/Makefile                        |    4 
 drivers/cpuidle/cpuidle-powerpc-book3s.c        |  364 +++++++++++++++++++++++
 8 files changed, 384 insertions(+), 375 deletions(-)
 delete mode 100644 arch/powerpc/platforms/pseries/processor_idle.c
 create mode 100644 drivers/cpuidle/Kconfig.powerpc
 create mode 100644 drivers/cpuidle/cpuidle-powerpc-book3s.c

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index ce4de5a..826360c 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -428,7 +428,7 @@ 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
+#ifdef CONFIG_CPU_IDLE_POWERPC_BOOK3S
 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/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index 62b4f80..bb59bb0 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -119,12 +119,3 @@ config DTL
 	  which are accessible through a debugfs file.
 
 	  Say N if you are unsure.
-
-config PSERIES_IDLE
-	bool "Cpuidle driver for pSeries platforms"
-	depends on CPU_IDLE
-	depends on PPC_PSERIES
-	default y
-	help
-	  Select this option to enable processor idle state management
-	  through cpuidle subsystem.
diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
index 6c61ec5..6f2500b 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -21,7 +21,6 @@ obj-$(CONFIG_HCALL_STATS)	+= hvCall_inst.o
 obj-$(CONFIG_CMM)		+= cmm.o
 obj-$(CONFIG_DTL)		+= dtl.o
 obj-$(CONFIG_IO_EVENT_IRQ)	+= io_event_irq.o
-obj-$(CONFIG_PSERIES_IDLE)	+= processor_idle.o
 obj-$(CONFIG_LPARCFG)		+= lparcfg.o
 
 ifeq ($(CONFIG_PPC_PSERIES),y)
diff --git a/arch/powerpc/platforms/pseries/processor_idle.c b/arch/powerpc/platforms/pseries/processor_idle.c
deleted file mode 100644
index a166e38..0000000
--- a/arch/powerpc/platforms/pseries/processor_idle.c
+++ /dev/null
@@ -1,364 +0,0 @@
-/*
- *  processor_idle - idle state cpuidle driver.
- *  Adapted from drivers/idle/intel_idle.c and
- *  drivers/acpi/processor_idle.c
- *
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/moduleparam.h>
-#include <linux/cpuidle.h>
-#include <linux/cpu.h>
-#include <linux/notifier.h>
-
-#include <asm/paca.h>
-#include <asm/reg.h>
-#include <asm/machdep.h>
-#include <asm/firmware.h>
-#include <asm/runlatch.h>
-#include <asm/plpar_wrappers.h>
-
-struct cpuidle_driver pseries_idle_driver = {
-	.name             = "pseries_idle",
-	.owner            = THIS_MODULE,
-};
-
-#define MAX_IDLE_STATE_COUNT	2
-
-static int max_idle_state = MAX_IDLE_STATE_COUNT - 1;
-static struct cpuidle_device __percpu *pseries_cpuidle_devices;
-static struct cpuidle_state *cpuidle_state_table;
-
-static inline void idle_loop_prolog(unsigned long *in_purr)
-{
-	*in_purr = mfspr(SPRN_PURR);
-	/*
-	 * Indicate to the HV that we are idle. Now would be
-	 * a good time to find other work to dispatch.
-	 */
-	get_lppaca()->idle = 1;
-}
-
-static inline void idle_loop_epilog(unsigned long in_purr)
-{
-	u64 wait_cycles;
-
-	wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
-	wait_cycles += mfspr(SPRN_PURR) - in_purr;
-	get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
-	get_lppaca()->idle = 0;
-}
-
-static int snooze_loop(struct cpuidle_device *dev,
-			struct cpuidle_driver *drv,
-			int index)
-{
-	unsigned long in_purr;
-	int cpu = dev->cpu;
-
-	idle_loop_prolog(&in_purr);
-	local_irq_enable();
-	set_thread_flag(TIF_POLLING_NRFLAG);
-
-	while ((!need_resched()) && cpu_online(cpu)) {
-		ppc64_runlatch_off();
-		HMT_low();
-		HMT_very_low();
-	}
-
-	HMT_medium();
-	clear_thread_flag(TIF_POLLING_NRFLAG);
-	smp_mb();
-
-	idle_loop_epilog(in_purr);
-
-	return index;
-}
-
-static void check_and_cede_processor(void)
-{
-	/*
-	 * Ensure our interrupt state is properly tracked,
-	 * also checks if no interrupt has occurred while we
-	 * were soft-disabled
-	 */
-	if (prep_irq_for_idle()) {
-		cede_processor();
-#ifdef CONFIG_TRACE_IRQFLAGS
-		/* Ensure that H_CEDE returns with IRQs on */
-		if (WARN_ON(!(mfmsr() & MSR_EE)))
-			__hard_irq_enable();
-#endif
-	}
-}
-
-static int dedicated_cede_loop(struct cpuidle_device *dev,
-				struct cpuidle_driver *drv,
-				int index)
-{
-	unsigned long in_purr;
-
-	idle_loop_prolog(&in_purr);
-	get_lppaca()->donate_dedicated_cpu = 1;
-
-	ppc64_runlatch_off();
-	HMT_medium();
-	check_and_cede_processor();
-
-	get_lppaca()->donate_dedicated_cpu = 0;
-
-	idle_loop_epilog(in_purr);
-
-	return index;
-}
-
-static int shared_cede_loop(struct cpuidle_device *dev,
-			struct cpuidle_driver *drv,
-			int index)
-{
-	unsigned long in_purr;
-
-	idle_loop_prolog(&in_purr);
-
-	/*
-	 * Yield the processor to the hypervisor.  We return if
-	 * an external interrupt occurs (which are driven prior
-	 * to returning here) or if a prod occurs from another
-	 * processor. When returning here, external interrupts
-	 * are enabled.
-	 */
-	check_and_cede_processor();
-
-	idle_loop_epilog(in_purr);
-
-	return index;
-}
-
-/*
- * States for dedicated partition case.
- */
-static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = {
-	{ /* Snooze */
-		.name = "snooze",
-		.desc = "snooze",
-		.flags = CPUIDLE_FLAG_TIME_VALID,
-		.exit_latency = 0,
-		.target_residency = 0,
-		.enter = &snooze_loop },
-	{ /* CEDE */
-		.name = "CEDE",
-		.desc = "CEDE",
-		.flags = CPUIDLE_FLAG_TIME_VALID,
-		.exit_latency = 10,
-		.target_residency = 100,
-		.enter = &dedicated_cede_loop },
-};
-
-/*
- * States for shared partition case.
- */
-static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = {
-	{ /* Shared Cede */
-		.name = "Shared Cede",
-		.desc = "Shared Cede",
-		.flags = CPUIDLE_FLAG_TIME_VALID,
-		.exit_latency = 0,
-		.target_residency = 0,
-		.enter = &shared_cede_loop },
-};
-
-void update_smt_snooze_delay(int cpu, int residency)
-{
-	struct cpuidle_driver *drv = cpuidle_get_driver();
-	struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu);
-
-	if (cpuidle_state_table != dedicated_states)
-		return;
-
-	if (residency < 0) {
-		/* Disable the Nap state on that cpu */
-		if (dev)
-			dev->states_usage[1].disable = 1;
-	} else
-		if (drv)
-			drv->states[1].target_residency = residency;
-}
-
-static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
-			unsigned long action, void *hcpu)
-{
-	int hotcpu = (unsigned long)hcpu;
-	struct cpuidle_device *dev =
-			per_cpu_ptr(pseries_cpuidle_devices, hotcpu);
-
-	if (dev && cpuidle_get_driver()) {
-		switch (action) {
-		case CPU_ONLINE:
-		case CPU_ONLINE_FROZEN:
-			cpuidle_pause_and_lock();
-			cpuidle_enable_device(dev);
-			cpuidle_resume_and_unlock();
-			break;
-
-		case CPU_DEAD:
-		case CPU_DEAD_FROZEN:
-			cpuidle_pause_and_lock();
-			cpuidle_disable_device(dev);
-			cpuidle_resume_and_unlock();
-			break;
-
-		default:
-			return NOTIFY_DONE;
-		}
-	}
-	return NOTIFY_OK;
-}
-
-static struct notifier_block setup_hotplug_notifier = {
-	.notifier_call = pseries_cpuidle_add_cpu_notifier,
-};
-
-/*
- * pseries_cpuidle_driver_init()
- */
-static int pseries_cpuidle_driver_init(void)
-{
-	int idle_state;
-	struct cpuidle_driver *drv = &pseries_idle_driver;
-
-	drv->state_count = 0;
-
-	for (idle_state = 0; idle_state < MAX_IDLE_STATE_COUNT; ++idle_state) {
-
-		if (idle_state > max_idle_state)
-			break;
-
-		/* is the state not enabled? */
-		if (cpuidle_state_table[idle_state].enter == NULL)
-			continue;
-
-		drv->states[drv->state_count] =	/* structure copy */
-			cpuidle_state_table[idle_state];
-
-		drv->state_count += 1;
-	}
-
-	return 0;
-}
-
-/* pseries_idle_devices_uninit(void)
- * unregister cpuidle devices and de-allocate memory
- */
-static void pseries_idle_devices_uninit(void)
-{
-	int i;
-	struct cpuidle_device *dev;
-
-	for_each_possible_cpu(i) {
-		dev = per_cpu_ptr(pseries_cpuidle_devices, i);
-		cpuidle_unregister_device(dev);
-	}
-
-	free_percpu(pseries_cpuidle_devices);
-	return;
-}
-
-/* pseries_idle_devices_init()
- * allocate, initialize and register cpuidle device
- */
-static int pseries_idle_devices_init(void)
-{
-	int i;
-	struct cpuidle_driver *drv = &pseries_idle_driver;
-	struct cpuidle_device *dev;
-
-	pseries_cpuidle_devices = alloc_percpu(struct cpuidle_device);
-	if (pseries_cpuidle_devices == NULL)
-		return -ENOMEM;
-
-	for_each_possible_cpu(i) {
-		dev = per_cpu_ptr(pseries_cpuidle_devices, i);
-		dev->state_count = drv->state_count;
-		dev->cpu = i;
-		if (cpuidle_register_device(dev)) {
-			printk(KERN_DEBUG \
-				"cpuidle_register_device %d failed!\n", i);
-			return -EIO;
-		}
-	}
-
-	return 0;
-}
-
-/*
- * pseries_idle_probe()
- * Choose state table for shared versus dedicated partition
- */
-static int pseries_idle_probe(void)
-{
-
-	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
-		return -ENODEV;
-
-	if (cpuidle_disable != IDLE_NO_OVERRIDE)
-		return -ENODEV;
-
-	if (max_idle_state == 0) {
-		printk(KERN_DEBUG "pseries processor idle disabled.\n");
-		return -EPERM;
-	}
-
-	if (lppaca_shared_proc(get_lppaca()))
-		cpuidle_state_table = shared_states;
-	else
-		cpuidle_state_table = dedicated_states;
-
-	return 0;
-}
-
-static int __init pseries_processor_idle_init(void)
-{
-	int retval;
-
-	retval = pseries_idle_probe();
-	if (retval)
-		return retval;
-
-	pseries_cpuidle_driver_init();
-	retval = cpuidle_register_driver(&pseries_idle_driver);
-	if (retval) {
-		printk(KERN_DEBUG "Registration of pseries driver failed.\n");
-		return retval;
-	}
-
-	retval = pseries_idle_devices_init();
-	if (retval) {
-		pseries_idle_devices_uninit();
-		cpuidle_unregister_driver(&pseries_idle_driver);
-		return retval;
-	}
-
-	register_cpu_notifier(&setup_hotplug_notifier);
-	printk(KERN_DEBUG "pseries_idle_driver registered\n");
-
-	return 0;
-}
-
-static void __exit pseries_processor_idle_exit(void)
-{
-
-	unregister_cpu_notifier(&setup_hotplug_notifier);
-	pseries_idle_devices_uninit();
-	cpuidle_unregister_driver(&pseries_idle_driver);
-
-	return;
-}
-
-module_init(pseries_processor_idle_init);
-module_exit(pseries_processor_idle_exit);
-
-MODULE_AUTHOR("Deepthi Dharwar <deepthi@linux.vnet.ibm.com>");
-MODULE_DESCRIPTION("Cpuidle driver for POWER");
-MODULE_LICENSE("GPL");
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index b3fb81d..f04e25f 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -35,6 +35,11 @@ depends on ARM
 source "drivers/cpuidle/Kconfig.arm"
 endmenu
 
+menu "POWERPC CPU Idle Drivers"
+depends on PPC
+source "drivers/cpuidle/Kconfig.powerpc"
+endmenu
+
 endif
 
 config ARCH_NEEDS_CPU_IDLE_COUPLED
diff --git a/drivers/cpuidle/Kconfig.powerpc b/drivers/cpuidle/Kconfig.powerpc
new file mode 100644
index 0000000..689c0d4
--- /dev/null
+++ b/drivers/cpuidle/Kconfig.powerpc
@@ -0,0 +1,10 @@
+#
+# POWERPC CPU Idle Drivers
+#
+config CPU_IDLE_POWERPC_BOOK3S
+	bool "CPU Idle driver for POWERPC-BOOK3S platforms"
+	depends on PPC_PSERIES
+	default y
+	help
+	Select this option to enable processor idle state management
+	on POWERPC-BOOK3S platform.
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index cea5ef5..6adb81c 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -12,3 +12,7 @@ obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE)	+= cpuidle-kirkwood.o
 obj-$(CONFIG_ARM_ZYNQ_CPUIDLE)		+= cpuidle-zynq.o
 obj-$(CONFIG_ARM_U8500_CPUIDLE)         += cpuidle-ux500.o
 obj-$(CONFIG_CPU_IDLE_BIG_LITTLE)	+= cpuidle-big_little.o
+
+###############################################################################
+# POWERPC drivers
+obj-$(CONFIG_CPU_IDLE_POWERPC_BOOK3S) += cpuidle-powerpc-book3s.o
diff --git a/drivers/cpuidle/cpuidle-powerpc-book3s.c b/drivers/cpuidle/cpuidle-powerpc-book3s.c
new file mode 100644
index 0000000..a166e38
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-powerpc-book3s.c
@@ -0,0 +1,364 @@
+/*
+ *  processor_idle - idle state cpuidle driver.
+ *  Adapted from drivers/idle/intel_idle.c and
+ *  drivers/acpi/processor_idle.c
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/cpuidle.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+
+#include <asm/paca.h>
+#include <asm/reg.h>
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+#include <asm/runlatch.h>
+#include <asm/plpar_wrappers.h>
+
+struct cpuidle_driver pseries_idle_driver = {
+	.name             = "pseries_idle",
+	.owner            = THIS_MODULE,
+};
+
+#define MAX_IDLE_STATE_COUNT	2
+
+static int max_idle_state = MAX_IDLE_STATE_COUNT - 1;
+static struct cpuidle_device __percpu *pseries_cpuidle_devices;
+static struct cpuidle_state *cpuidle_state_table;
+
+static inline void idle_loop_prolog(unsigned long *in_purr)
+{
+	*in_purr = mfspr(SPRN_PURR);
+	/*
+	 * Indicate to the HV that we are idle. Now would be
+	 * a good time to find other work to dispatch.
+	 */
+	get_lppaca()->idle = 1;
+}
+
+static inline void idle_loop_epilog(unsigned long in_purr)
+{
+	u64 wait_cycles;
+
+	wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
+	wait_cycles += mfspr(SPRN_PURR) - in_purr;
+	get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
+	get_lppaca()->idle = 0;
+}
+
+static int snooze_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	unsigned long in_purr;
+	int cpu = dev->cpu;
+
+	idle_loop_prolog(&in_purr);
+	local_irq_enable();
+	set_thread_flag(TIF_POLLING_NRFLAG);
+
+	while ((!need_resched()) && cpu_online(cpu)) {
+		ppc64_runlatch_off();
+		HMT_low();
+		HMT_very_low();
+	}
+
+	HMT_medium();
+	clear_thread_flag(TIF_POLLING_NRFLAG);
+	smp_mb();
+
+	idle_loop_epilog(in_purr);
+
+	return index;
+}
+
+static void check_and_cede_processor(void)
+{
+	/*
+	 * Ensure our interrupt state is properly tracked,
+	 * also checks if no interrupt has occurred while we
+	 * were soft-disabled
+	 */
+	if (prep_irq_for_idle()) {
+		cede_processor();
+#ifdef CONFIG_TRACE_IRQFLAGS
+		/* Ensure that H_CEDE returns with IRQs on */
+		if (WARN_ON(!(mfmsr() & MSR_EE)))
+			__hard_irq_enable();
+#endif
+	}
+}
+
+static int dedicated_cede_loop(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	unsigned long in_purr;
+
+	idle_loop_prolog(&in_purr);
+	get_lppaca()->donate_dedicated_cpu = 1;
+
+	ppc64_runlatch_off();
+	HMT_medium();
+	check_and_cede_processor();
+
+	get_lppaca()->donate_dedicated_cpu = 0;
+
+	idle_loop_epilog(in_purr);
+
+	return index;
+}
+
+static int shared_cede_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	unsigned long in_purr;
+
+	idle_loop_prolog(&in_purr);
+
+	/*
+	 * Yield the processor to the hypervisor.  We return if
+	 * an external interrupt occurs (which are driven prior
+	 * to returning here) or if a prod occurs from another
+	 * processor. When returning here, external interrupts
+	 * are enabled.
+	 */
+	check_and_cede_processor();
+
+	idle_loop_epilog(in_purr);
+
+	return index;
+}
+
+/*
+ * States for dedicated partition case.
+ */
+static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = {
+	{ /* Snooze */
+		.name = "snooze",
+		.desc = "snooze",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &snooze_loop },
+	{ /* CEDE */
+		.name = "CEDE",
+		.desc = "CEDE",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 10,
+		.target_residency = 100,
+		.enter = &dedicated_cede_loop },
+};
+
+/*
+ * States for shared partition case.
+ */
+static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = {
+	{ /* Shared Cede */
+		.name = "Shared Cede",
+		.desc = "Shared Cede",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &shared_cede_loop },
+};
+
+void update_smt_snooze_delay(int cpu, int residency)
+{
+	struct cpuidle_driver *drv = cpuidle_get_driver();
+	struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu);
+
+	if (cpuidle_state_table != dedicated_states)
+		return;
+
+	if (residency < 0) {
+		/* Disable the Nap state on that cpu */
+		if (dev)
+			dev->states_usage[1].disable = 1;
+	} else
+		if (drv)
+			drv->states[1].target_residency = residency;
+}
+
+static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
+			unsigned long action, void *hcpu)
+{
+	int hotcpu = (unsigned long)hcpu;
+	struct cpuidle_device *dev =
+			per_cpu_ptr(pseries_cpuidle_devices, hotcpu);
+
+	if (dev && cpuidle_get_driver()) {
+		switch (action) {
+		case CPU_ONLINE:
+		case CPU_ONLINE_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_enable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		case CPU_DEAD:
+		case CPU_DEAD_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_disable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		default:
+			return NOTIFY_DONE;
+		}
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block setup_hotplug_notifier = {
+	.notifier_call = pseries_cpuidle_add_cpu_notifier,
+};
+
+/*
+ * pseries_cpuidle_driver_init()
+ */
+static int pseries_cpuidle_driver_init(void)
+{
+	int idle_state;
+	struct cpuidle_driver *drv = &pseries_idle_driver;
+
+	drv->state_count = 0;
+
+	for (idle_state = 0; idle_state < MAX_IDLE_STATE_COUNT; ++idle_state) {
+
+		if (idle_state > max_idle_state)
+			break;
+
+		/* is the state not enabled? */
+		if (cpuidle_state_table[idle_state].enter == NULL)
+			continue;
+
+		drv->states[drv->state_count] =	/* structure copy */
+			cpuidle_state_table[idle_state];
+
+		drv->state_count += 1;
+	}
+
+	return 0;
+}
+
+/* pseries_idle_devices_uninit(void)
+ * unregister cpuidle devices and de-allocate memory
+ */
+static void pseries_idle_devices_uninit(void)
+{
+	int i;
+	struct cpuidle_device *dev;
+
+	for_each_possible_cpu(i) {
+		dev = per_cpu_ptr(pseries_cpuidle_devices, i);
+		cpuidle_unregister_device(dev);
+	}
+
+	free_percpu(pseries_cpuidle_devices);
+	return;
+}
+
+/* pseries_idle_devices_init()
+ * allocate, initialize and register cpuidle device
+ */
+static int pseries_idle_devices_init(void)
+{
+	int i;
+	struct cpuidle_driver *drv = &pseries_idle_driver;
+	struct cpuidle_device *dev;
+
+	pseries_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+	if (pseries_cpuidle_devices == NULL)
+		return -ENOMEM;
+
+	for_each_possible_cpu(i) {
+		dev = per_cpu_ptr(pseries_cpuidle_devices, i);
+		dev->state_count = drv->state_count;
+		dev->cpu = i;
+		if (cpuidle_register_device(dev)) {
+			printk(KERN_DEBUG \
+				"cpuidle_register_device %d failed!\n", i);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * pseries_idle_probe()
+ * Choose state table for shared versus dedicated partition
+ */
+static int pseries_idle_probe(void)
+{
+
+	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+		return -ENODEV;
+
+	if (cpuidle_disable != IDLE_NO_OVERRIDE)
+		return -ENODEV;
+
+	if (max_idle_state == 0) {
+		printk(KERN_DEBUG "pseries processor idle disabled.\n");
+		return -EPERM;
+	}
+
+	if (lppaca_shared_proc(get_lppaca()))
+		cpuidle_state_table = shared_states;
+	else
+		cpuidle_state_table = dedicated_states;
+
+	return 0;
+}
+
+static int __init pseries_processor_idle_init(void)
+{
+	int retval;
+
+	retval = pseries_idle_probe();
+	if (retval)
+		return retval;
+
+	pseries_cpuidle_driver_init();
+	retval = cpuidle_register_driver(&pseries_idle_driver);
+	if (retval) {
+		printk(KERN_DEBUG "Registration of pseries driver failed.\n");
+		return retval;
+	}
+
+	retval = pseries_idle_devices_init();
+	if (retval) {
+		pseries_idle_devices_uninit();
+		cpuidle_unregister_driver(&pseries_idle_driver);
+		return retval;
+	}
+
+	register_cpu_notifier(&setup_hotplug_notifier);
+	printk(KERN_DEBUG "pseries_idle_driver registered\n");
+
+	return 0;
+}
+
+static void __exit pseries_processor_idle_exit(void)
+{
+
+	unregister_cpu_notifier(&setup_hotplug_notifier);
+	pseries_idle_devices_uninit();
+	cpuidle_unregister_driver(&pseries_idle_driver);
+
+	return;
+}
+
+module_init(pseries_processor_idle_init);
+module_exit(pseries_processor_idle_exit);
+
+MODULE_AUTHOR("Deepthi Dharwar <deepthi@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("Cpuidle driver for POWER");
+MODULE_LICENSE("GPL");

[PATCH v8 2/7] pseries/cpuidle: Use cpuidle_register() for initialisation.

[Deepthi Dharwar]

This patch replaces the cpuidle driver and devices initialisation
calls with a single generic cpuidle_register() call
and also includes minor refactoring of the code around it.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/cpuidle/cpuidle-powerpc-book3s.c |   80 +++++-------------------------
 1 file changed, 12 insertions(+), 68 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powerpc-book3s.c b/drivers/cpuidle/cpuidle-powerpc-book3s.c
index a166e38..51f6cda 100644
--- a/drivers/cpuidle/cpuidle-powerpc-book3s.c
+++ b/drivers/cpuidle/cpuidle-powerpc-book3s.c
@@ -1,5 +1,5 @@
 /*
- *  processor_idle - idle state cpuidle driver.
+ *  cpuidle-powerpc-book3s - idle state cpuidle driver.
  *  Adapted from drivers/idle/intel_idle.c and
  *  drivers/acpi/processor_idle.c
  *
@@ -28,7 +28,6 @@ struct cpuidle_driver pseries_idle_driver = {
 #define MAX_IDLE_STATE_COUNT	2
 
 static int max_idle_state = MAX_IDLE_STATE_COUNT - 1;
-static struct cpuidle_device __percpu *pseries_cpuidle_devices;
 static struct cpuidle_state *cpuidle_state_table;
 
 static inline void idle_loop_prolog(unsigned long *in_purr)
@@ -56,13 +55,12 @@ static int snooze_loop(struct cpuidle_device *dev,
 			int index)
 {
 	unsigned long in_purr;
-	int cpu = dev->cpu;
 
 	idle_loop_prolog(&in_purr);
 	local_irq_enable();
 	set_thread_flag(TIF_POLLING_NRFLAG);
 
-	while ((!need_resched()) && cpu_online(cpu)) {
+	while (!need_resched()) {
 		ppc64_runlatch_off();
 		HMT_low();
 		HMT_very_low();
@@ -191,7 +189,7 @@ static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
 {
 	int hotcpu = (unsigned long)hcpu;
 	struct cpuidle_device *dev =
-			per_cpu_ptr(pseries_cpuidle_devices, hotcpu);
+			per_cpu(cpuidle_devices, hotcpu);
 
 	if (dev && cpuidle_get_driver()) {
 		switch (action) {
@@ -248,50 +246,6 @@ static int pseries_cpuidle_driver_init(void)
 	return 0;
 }
 
-/* pseries_idle_devices_uninit(void)
- * unregister cpuidle devices and de-allocate memory
- */
-static void pseries_idle_devices_uninit(void)
-{
-	int i;
-	struct cpuidle_device *dev;
-
-	for_each_possible_cpu(i) {
-		dev = per_cpu_ptr(pseries_cpuidle_devices, i);
-		cpuidle_unregister_device(dev);
-	}
-
-	free_percpu(pseries_cpuidle_devices);
-	return;
-}
-
-/* pseries_idle_devices_init()
- * allocate, initialize and register cpuidle device
- */
-static int pseries_idle_devices_init(void)
-{
-	int i;
-	struct cpuidle_driver *drv = &pseries_idle_driver;
-	struct cpuidle_device *dev;
-
-	pseries_cpuidle_devices = alloc_percpu(struct cpuidle_device);
-	if (pseries_cpuidle_devices == NULL)
-		return -ENOMEM;
-
-	for_each_possible_cpu(i) {
-		dev = per_cpu_ptr(pseries_cpuidle_devices, i);
-		dev->state_count = drv->state_count;
-		dev->cpu = i;
-		if (cpuidle_register_device(dev)) {
-			printk(KERN_DEBUG \
-				"cpuidle_register_device %d failed!\n", i);
-			return -EIO;
-		}
-	}
-
-	return 0;
-}
-
 /*
  * pseries_idle_probe()
  * Choose state table for shared versus dedicated partition
@@ -299,9 +253,6 @@ static int pseries_idle_devices_init(void)
 static int pseries_idle_probe(void)
 {
 
-	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
-		return -ENODEV;
-
 	if (cpuidle_disable != IDLE_NO_OVERRIDE)
 		return -ENODEV;
 
@@ -310,10 +261,13 @@ static int pseries_idle_probe(void)
 		return -EPERM;
 	}
 
-	if (lppaca_shared_proc(get_lppaca()))
-		cpuidle_state_table = shared_states;
-	else
-		cpuidle_state_table = dedicated_states;
+	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
+		if (lppaca_shared_proc(get_lppaca()))
+			cpuidle_state_table = shared_states;
+		else
+			cpuidle_state_table = dedicated_states;
+	} else
+		return -ENODEV;
 
 	return 0;
 }
@@ -327,22 +281,14 @@ static int __init pseries_processor_idle_init(void)
 		return retval;
 
 	pseries_cpuidle_driver_init();
-	retval = cpuidle_register_driver(&pseries_idle_driver);
+	retval = cpuidle_register(&pseries_idle_driver, NULL);
 	if (retval) {
 		printk(KERN_DEBUG "Registration of pseries driver failed.\n");
 		return retval;
 	}
 
-	retval = pseries_idle_devices_init();
-	if (retval) {
-		pseries_idle_devices_uninit();
-		cpuidle_unregister_driver(&pseries_idle_driver);
-		return retval;
-	}
-
 	register_cpu_notifier(&setup_hotplug_notifier);
 	printk(KERN_DEBUG "pseries_idle_driver registered\n");
-
 	return 0;
 }
 
@@ -350,9 +296,7 @@ static void __exit pseries_processor_idle_exit(void)
 {
 
 	unregister_cpu_notifier(&setup_hotplug_notifier);
-	pseries_idle_devices_uninit();
-	cpuidle_unregister_driver(&pseries_idle_driver);
-
+	cpuidle_unregister(&pseries_idle_driver);
 	return;
 }
 

[PATCH v8 3/7] pseries/cpuidle: Make pseries_idle backend driver a non-module.

[Deepthi Dharwar]

Currently pseries_idle cpuidle backend driver cannot be
built as a module due to dependencies. Therefore the driver has
to be built in. The dependency is around update_snooze_delay() defined
in cpuidle driver and called from kernel/sysfs.c.
This patch is removes all the module related code.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/cpuidle/cpuidle-powerpc-book3s.c |   15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powerpc-book3s.c b/drivers/cpuidle/cpuidle-powerpc-book3s.c
index 51f6cda..82c9e15 100644
--- a/drivers/cpuidle/cpuidle-powerpc-book3s.c
+++ b/drivers/cpuidle/cpuidle-powerpc-book3s.c
@@ -292,17 +292,4 @@ static int __init pseries_processor_idle_init(void)
 	return 0;
 }
 
-static void __exit pseries_processor_idle_exit(void)
-{
-
-	unregister_cpu_notifier(&setup_hotplug_notifier);
-	cpuidle_unregister(&pseries_idle_driver);
-	return;
-}
-
-module_init(pseries_processor_idle_init);
-module_exit(pseries_processor_idle_exit);
-
-MODULE_AUTHOR("Deepthi Dharwar <deepthi@linux.vnet.ibm.com>");
-MODULE_DESCRIPTION("Cpuidle driver for POWER");
-MODULE_LICENSE("GPL");
+device_initcall(pseries_processor_idle_init);

[PATCH v8 4/7] pseries/cpuidle: Remove MAX_IDLE_STATE macro.

[Deepthi Dharwar]

This patch removes the usage of MAX_IDLE_STATE macro
and dead code around it. The number of states
are determined at run time based on the cpuidle
state table selected on a given platform

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/cpuidle/cpuidle-powerpc-book3s.c |   26 +++++++++-----------------
 1 file changed, 9 insertions(+), 17 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powerpc-book3s.c b/drivers/cpuidle/cpuidle-powerpc-book3s.c
index 82c9e15..fe8ea0c 100644
--- a/drivers/cpuidle/cpuidle-powerpc-book3s.c
+++ b/drivers/cpuidle/cpuidle-powerpc-book3s.c
@@ -25,9 +25,7 @@ struct cpuidle_driver pseries_idle_driver = {
 	.owner            = THIS_MODULE,
 };
 
-#define MAX_IDLE_STATE_COUNT	2
-
-static int max_idle_state = MAX_IDLE_STATE_COUNT - 1;
+static int max_idle_state;
 static struct cpuidle_state *cpuidle_state_table;
 
 static inline void idle_loop_prolog(unsigned long *in_purr)
@@ -137,7 +135,7 @@ static int shared_cede_loop(struct cpuidle_device *dev,
 /*
  * States for dedicated partition case.
  */
-static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = {
+static struct cpuidle_state dedicated_states[] = {
 	{ /* Snooze */
 		.name = "snooze",
 		.desc = "snooze",
@@ -157,7 +155,7 @@ static struct cpuidle_state dedicated_states[MAX_IDLE_STATE_COUNT] = {
 /*
  * States for shared partition case.
  */
-static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = {
+static struct cpuidle_state shared_states[] = {
 	{ /* Shared Cede */
 		.name = "Shared Cede",
 		.desc = "Shared Cede",
@@ -227,11 +225,7 @@ static int pseries_cpuidle_driver_init(void)
 	struct cpuidle_driver *drv = &pseries_idle_driver;
 
 	drv->state_count = 0;
-
-	for (idle_state = 0; idle_state < MAX_IDLE_STATE_COUNT; ++idle_state) {
-
-		if (idle_state > max_idle_state)
-			break;
+	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
 
 		/* is the state not enabled? */
 		if (cpuidle_state_table[idle_state].enter == NULL)
@@ -256,16 +250,14 @@ static int pseries_idle_probe(void)
 	if (cpuidle_disable != IDLE_NO_OVERRIDE)
 		return -ENODEV;
 
-	if (max_idle_state == 0) {
-		printk(KERN_DEBUG "pseries processor idle disabled.\n");
-		return -EPERM;
-	}
-
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
-		if (lppaca_shared_proc(get_lppaca()))
+		if (lppaca_shared_proc(get_lppaca())) {
 			cpuidle_state_table = shared_states;
-		else
+			max_idle_state = ARRAY_SIZE(shared_states);
+		} else {
 			cpuidle_state_table = dedicated_states;
+			max_idle_state = ARRAY_SIZE(dedicated_states);
+		}
 	} else
 		return -ENODEV;
 

[PATCH v8 5/7] POWER/cpuidle: Generic POWERPC-BOOK3S CPUIDLE driver supporting PSERIES.

[Deepthi Dharwar]

This patch includes cleanup and refactoring of the
existing code to make the driver POWERPC-BOOK3S generic.
* Re-naming the functions from pseries to generic powerpc-book3s.
* Re-naming the backend driver from pseries_idle to
  powerpc_book3s_idle.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/cpuidle/cpuidle-powerpc-book3s.c |   32 +++++++++++++++---------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powerpc-book3s.c b/drivers/cpuidle/cpuidle-powerpc-book3s.c
index fe8ea0c..7b785ff 100644
--- a/drivers/cpuidle/cpuidle-powerpc-book3s.c
+++ b/drivers/cpuidle/cpuidle-powerpc-book3s.c
@@ -20,8 +20,8 @@
 #include <asm/runlatch.h>
 #include <asm/plpar_wrappers.h>
 
-struct cpuidle_driver pseries_idle_driver = {
-	.name             = "pseries_idle",
+struct cpuidle_driver powerpc_book3s_idle_driver = {
+	.name             = "powerpc_book3s_idle",
 	.owner            = THIS_MODULE,
 };
 
@@ -182,7 +182,7 @@ void update_smt_snooze_delay(int cpu, int residency)
 			drv->states[1].target_residency = residency;
 }
 
-static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
+static int powerpc_book3s_cpuidle_add_cpu_notifier(struct notifier_block *n,
 			unsigned long action, void *hcpu)
 {
 	int hotcpu = (unsigned long)hcpu;
@@ -213,16 +213,16 @@ static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
 }
 
 static struct notifier_block setup_hotplug_notifier = {
-	.notifier_call = pseries_cpuidle_add_cpu_notifier,
+	.notifier_call = powerpc_book3s_cpuidle_add_cpu_notifier,
 };
 
 /*
- * pseries_cpuidle_driver_init()
+ * powerpc_book3s_cpuidle_driver_init()
  */
-static int pseries_cpuidle_driver_init(void)
+static int powerpc_book3s_cpuidle_driver_init(void)
 {
 	int idle_state;
-	struct cpuidle_driver *drv = &pseries_idle_driver;
+	struct cpuidle_driver *drv = &powerpc_book3s_idle_driver;
 
 	drv->state_count = 0;
 	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
@@ -241,10 +241,10 @@ static int pseries_cpuidle_driver_init(void)
 }
 
 /*
- * pseries_idle_probe()
+ * powerpc_book3s_idle_probe()
  * Choose state table for shared versus dedicated partition
  */
-static int pseries_idle_probe(void)
+static int powerpc_book3s_idle_probe(void)
 {
 
 	if (cpuidle_disable != IDLE_NO_OVERRIDE)
@@ -264,24 +264,24 @@ static int pseries_idle_probe(void)
 	return 0;
 }
 
-static int __init pseries_processor_idle_init(void)
+static int __init powerpc_book3s_processor_idle_init(void)
 {
 	int retval;
 
-	retval = pseries_idle_probe();
+	retval = powerpc_book3s_idle_probe();
 	if (retval)
 		return retval;
 
-	pseries_cpuidle_driver_init();
-	retval = cpuidle_register(&pseries_idle_driver, NULL);
+	powerpc_book3s_cpuidle_driver_init();
+	retval = cpuidle_register(&powerpc_book3s_idle_driver, NULL);
 	if (retval) {
-		printk(KERN_DEBUG "Registration of pseries driver failed.\n");
+		printk(KERN_DEBUG "Registration of powerpc_book3s_idle driver failed.\n");
 		return retval;
 	}
 
 	register_cpu_notifier(&setup_hotplug_notifier);
-	printk(KERN_DEBUG "pseries_idle_driver registered\n");
+	printk(KERN_DEBUG "powerpc_book3s_idle registered\n");
 	return 0;
 }
 
-device_initcall(pseries_processor_idle_init);
+device_initcall(powerpc_book3s_processor_idle_init);

[PATCH v8 6/7] POWER/cpuidle: Enable powernv cpuidle support.

[Deepthi Dharwar]

The following patch extends the current powerpc-book3s backend
idle driver to the powernv platform.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/cpuidle/cpuidle-powerpc-book3s.c |   39 ++++++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powerpc-book3s.c b/drivers/cpuidle/cpuidle-powerpc-book3s.c
index 7b785ff..25e8a99 100644
--- a/drivers/cpuidle/cpuidle-powerpc-book3s.c
+++ b/drivers/cpuidle/cpuidle-powerpc-book3s.c
@@ -52,9 +52,10 @@ static int snooze_loop(struct cpuidle_device *dev,
 			struct cpuidle_driver *drv,
 			int index)
 {
-	unsigned long in_purr;
+	unsigned long in_purr = 0;
 
-	idle_loop_prolog(&in_purr);
+	if (firmware_has_feature(FW_FEATURE_SPLPAR))
+		idle_loop_prolog(&in_purr);
 	local_irq_enable();
 	set_thread_flag(TIF_POLLING_NRFLAG);
 
@@ -68,7 +69,8 @@ static int snooze_loop(struct cpuidle_device *dev,
 	clear_thread_flag(TIF_POLLING_NRFLAG);
 	smp_mb();
 
-	idle_loop_epilog(in_purr);
+	if (firmware_has_feature(FW_FEATURE_SPLPAR))
+		idle_loop_epilog(in_purr);
 
 	return index;
 }
@@ -132,6 +134,15 @@ static int shared_cede_loop(struct cpuidle_device *dev,
 	return index;
 }
 
+static int nap_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	ppc64_runlatch_off();
+	power7_idle();
+	return index;
+}
+
 /*
  * States for dedicated partition case.
  */
@@ -165,6 +176,23 @@ static struct cpuidle_state shared_states[] = {
 		.enter = &shared_cede_loop },
 };
 
+static struct cpuidle_state powernv_states[] = {
+	{ /* Snooze */
+		.name = "snooze",
+		.desc = "snooze",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &snooze_loop },
+	{ /* NAP */
+		.name = "NAP",
+		.desc = "NAP",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 10,
+		.target_residency = 100,
+		.enter = &nap_loop },
+};
+
 void update_smt_snooze_delay(int cpu, int residency)
 {
 	struct cpuidle_driver *drv = cpuidle_get_driver();
@@ -258,6 +286,11 @@ static int powerpc_book3s_idle_probe(void)
 			cpuidle_state_table = dedicated_states;
 			max_idle_state = ARRAY_SIZE(dedicated_states);
 		}
+
+	} else if (firmware_has_feature(FW_FEATURE_OPALv3)) {
+		cpuidle_state_table = powernv_states;
+		max_idle_state = ARRAY_SIZE(powernv_states);
+
 	} else
 		return -ENODEV;
 

[PATCH v8 7/7] powernv/cpuidle: Enable idle powernv cpu to call into the cpuidle framework.

[Deepthi Dharwar]

This patch enables idle cpu on the powernv platform  to hook on to the cpuidle
framework, if available, else call on to default idle platform
code.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 arch/powerpc/platforms/powernv/setup.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index e239dcf..42a6ba0 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -25,6 +25,7 @@
 #include <linux/of.h>
 #include <linux/interrupt.h>
 #include <linux/bug.h>
+#include <linux/cpuidle.h>
 
 #include <asm/machdep.h>
 #include <asm/firmware.h>
@@ -192,6 +193,16 @@ static void __init pnv_setup_machdep_rtas(void)
 }
 #endif /* CONFIG_PPC_POWERNV_RTAS */
 
+void powernv_idle(void)
+{
+	/* Hook to cpuidle framework if available, else
+	 * call on default platform idle code
+	 */
+	if (cpuidle_idle_call()) {
+		power7_idle();
+	}
+}
+
 static int __init pnv_probe(void)
 {
 	unsigned long root = of_get_flat_dt_root();
@@ -222,7 +233,7 @@ define_machine(powernv) {
 	.show_cpuinfo		= pnv_show_cpuinfo,
 	.progress		= pnv_progress,
 	.machine_shutdown	= pnv_shutdown,
-	.power_save             = power7_idle,
+	.power_save             = powernv_idle,
 	.calibrate_decr		= generic_calibrate_decr,
 #ifdef CONFIG_KEXEC
 	.kexec_cpu_down		= pnv_kexec_cpu_down,