[PATCH v7 00/11] powerpc/powernv/cpuidle: Add support for POWER ISA v3 idle states

[PATCH v7 00/11] powerpc/powernv/cpuidle: Add support for POWER ISA v3 idle states

[Shreyas B. Prabhu]

POWER ISA v3 defines a new idle processor core mechanism. In summary,
 a) new instruction named stop is added. This instruction replaces
	instructions like nap, sleep, rvwinkle.
 b) new per thread SPR named PSSCR is added which controls the behavior
	of stop instruction. 
		
PSSCR has following key fields
	Bits 0:3  - Power-Saving Level Status. This field indicates the
	lowest power-saving state the thread entered since stop
	instruction was last executed.
		
	Bit 42 - Enable State Loss                          
	0 - No state is lost irrespective of other fields  
	1 - Allows state loss
		
	Bits 44:47 - Power-Saving Level Limit      
	This limits the power-saving level that can be entered into.
		
	Bits 60:63 - Requested Level              
	Used to specify which power-saving level must be entered on
	executing stop instruction
		
Stop idle states and their properties like name, latency, target
residency, psscr value are exposed via device tree.

This patch series adds support for this new mechanism.

Patches 1-6 are cleanups and code movement.
Patch 7 adds platform specific support for stop and psscr handling.
Patch 8 and 9 are minor cleanup in cpuidle driver.
Patch 10 adds cpuidle driver support.
Patch 11 makes offlined cpu use deepest stop state.

Note: Documentation for the device tree bindings is posted here-
http://patchwork.ozlabs.org/patch/629125/

Changes in v7
=============
 - File renamed to idle_book3s.S instead of idle_power_common.S
 - Comment changes
 - power_stop0, power_stop renamed to power9_idle and power_idle_stop
 - PSSCR template is now a macro instead of storing in paca
 - power9_idle in C file instead of assembly
 - Fixed TOC related bug
 - Handling subcore within FTR section
 - Functions in idle.c reordered and broken into multiple functions
 - calling __restore_cpu_power8/9 via cur_cpu_spec->cpu_restore 
 - Added a minor patch with minor cleanups in cpuidle-powernv.c . This
   was mainly to make the existing code consistent with the review
   comments for new code
 - Using stack for variables while probing for idle states instead of
   kzalloc/kcalloc

Changes in v6
=============
 - Restore new POWER ISA v3 SPRS when waking up from deep idle

Changes in v5
=============
 - Use generic cpuidle constant CPUIDLE_NAME_LEN
 - Fix return code handling for of_property_read_string_array
 - Use DT flags to determine if are using stop instruction, instead of
   cpu_has_feature
 - Removed uncessary cast with names
 - &stop_loop -> stop_loop
 - Added POWERNV_THRESHOLD_LATENCY_NS to filter out idle states with high latency

Changes in v4
=============
 - Added a patch to use PNV_THREAD_WINKLE macro while requesting for winkle
 - Moved power7_powersave_common rename to more appropriate patch
 - renaming power7_enter_nap_mode to pnv_enter_arch207_idle_mode
 - Added PSSCR layout to Patch 7's commit message
 - Improved / Fixed comments
 - Fixed whitespace error in paca.h
 - Using MAX_POSSIBLE_STOP_STATE macro instead of hardcoding 0xF has
   max possible stop state

Changes in v3
=============
 - Rebased on powerpc-next
 - Dropping patch 1 since we are not adding a new file for P9 idle support
 - Improved comments in multiple places
 - Moved GET_PACA from power7_restore_hyp_resource to System Reset
 - Instead of moving few functions from idle_power7 to idle_power_common,
   renaming idle_power7.S to idle_power_common.S
 - Moved HSTATE_HWTHREAD_STATE updation to power_powersave_common
 - Dropped earlier patch 5 which moved few macros from idle_power_common to
   asm/cpuidle.h. 
 - Added a patch to rename reusable power7_* idle functions to pnv_*
 - Added new patch that creates abstraction for saving SPRs before
   entering deep idle states
 - Instead of introducing new file idle_power_stop.S, P9 idle support
   is added to idle_power_common.S using CPU_FTR sections.
 - Fixed r4 reg clobbering in power_stop0

Changes in v2
=============
 - Rebased on v4.6-rc6
 - Using CPU_FTR_ARCH_300 bit instead of CPU_FTR_STOP_INST

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-pm@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@au1.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Michael Neuling <mikey@neuling.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>

Shreyas B. Prabhu (11):
  powerpc/powernv: Use PNV_THREAD_WINKLE macro while requesting for
    winkle
  powerpc/kvm: make hypervisor state restore a function
  powerpc/powernv: Rename idle_power7.S to idle_book3s.S
  powerpc/powernv: Rename reusable idle functions to hardware agnostic
    names
  powerpc/powernv: Make pnv_powersave_common more generic
  powerpc/powernv: abstraction for saving SPRs before entering deep idle
    states
  powerpc/powernv: Add platform support for stop instruction
  cpuidle/powernv: Use CPUIDLE_STATE_MAX instead of
    MAX_POWERNV_IDLE_STATES
  cpuidle/powernv: cleanup powernv_add_idle_states
  cpuidle/powernv: Add support for POWER ISA v3 idle states
  powerpc/powernv: Use deepest stop state when cpu is offlined

 arch/powerpc/include/asm/cpuidle.h        |   2 +
 arch/powerpc/include/asm/kvm_book3s_asm.h |   2 +-
 arch/powerpc/include/asm/opal-api.h       |  11 +-
 arch/powerpc/include/asm/ppc-opcode.h     |   4 +
 arch/powerpc/include/asm/processor.h      |   2 +
 arch/powerpc/include/asm/reg.h            |  10 +
 arch/powerpc/kernel/Makefile              |   2 +-
 arch/powerpc/kernel/exceptions-64s.S      |  30 +-
 arch/powerpc/kernel/idle_book3s.S         | 664 ++++++++++++++++++++++++++++++
 arch/powerpc/kernel/idle_power7.S         | 515 -----------------------
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   |   4 +-
 arch/powerpc/platforms/powernv/idle.c     | 185 +++++++--
 arch/powerpc/platforms/powernv/powernv.h  |   1 +
 arch/powerpc/platforms/powernv/smp.c      |   4 +-
 drivers/cpuidle/cpuidle-powernv.c         |  99 ++++-
 15 files changed, 940 insertions(+), 595 deletions(-)
 create mode 100644 arch/powerpc/kernel/idle_book3s.S
 delete mode 100644 arch/powerpc/kernel/idle_power7.S

-- 
2.4.11

[PATCH v7 08/11] cpuidle/powernv: Use CPUIDLE_STATE_MAX instead of MAX_POWERNV_IDLE_STATES

[Shreyas B. Prabhu]

Use cpuidle's CPUIDLE_STATE_MAX macro instead of powernv specific
MAX_POWERNV_IDLE_STATES.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-pm@vger.kernel.org
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
---
 - No changes after v5

Changes in v5
=============
 - New in v5

 drivers/cpuidle/cpuidle-powernv.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index e12dc30..3a763a8 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -20,8 +20,6 @@
 #include <asm/opal.h>
 #include <asm/runlatch.h>
 
-#define MAX_POWERNV_IDLE_STATES	8
-
 struct cpuidle_driver powernv_idle_driver = {
 	.name             = "powernv_idle",
 	.owner            = THIS_MODULE,
@@ -96,7 +94,7 @@ static int fastsleep_loop(struct cpuidle_device *dev,
 /*
  * States for dedicated partition case.
  */
-static struct cpuidle_state powernv_states[MAX_POWERNV_IDLE_STATES] = {
+static struct cpuidle_state powernv_states[CPUIDLE_STATE_MAX] = {
 	{ /* Snooze */
 		.name = "snooze",
 		.desc = "snooze",
-- 
2.4.11

[PATCH v7 09/11] cpuidle/powernv: cleanup powernv_add_idle_states

[Shreyas B. Prabhu]

 - Use stack instead of kzalloc'ed memory for variables while probing
   device tree for idle states.
 - Set cap for number of idle states that can be added to
   cpuidle_state_table
 - Minor change in way we check of_property_read_u32_array for error
   for sake of consistency
 - Drop unnecessary "&" while assigning function pointer

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
---
 - New in v7. This was mainly to make the existing code
   consistent with the review comments for new code

 drivers/cpuidle/cpuidle-powernv.c | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 3a763a8..a89f546 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -166,7 +166,9 @@ static int powernv_add_idle_states(void)
 	struct device_node *power_mgt;
 	int nr_idle_states = 1; /* Snooze */
 	int dt_idle_states;
-	u32 *latency_ns, *residency_ns, *flags;
+	u32 latency_ns[CPUIDLE_STATE_MAX];
+	u32 residency_ns[CPUIDLE_STATE_MAX];
+	u32 flags[CPUIDLE_STATE_MAX];
 	int i, rc;
 
 	/* Currently we have snooze statically defined */
@@ -184,22 +186,28 @@ static int powernv_add_idle_states(void)
 		goto out;
 	}
 
-	flags = kzalloc(sizeof(*flags) * dt_idle_states, GFP_KERNEL);
+	/*
+	 * Since snooze is used as first idle state, max idle states allowed is
+	 * CPUIDLE_STATE_MAX -1
+	 */
+	if (dt_idle_states > CPUIDLE_STATE_MAX - 1) {
+		pr_warn("cpuidle-powernv: discovered idle states more than allowed");
+		dt_idle_states = CPUIDLE_STATE_MAX - 1;
+	}
+
 	if (of_property_read_u32_array(power_mgt,
 			"ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
 		pr_warn("cpuidle-powernv : missing ibm,cpu-idle-state-flags in DT\n");
-		goto out_free_flags;
+		goto out;
 	}
 
-	latency_ns = kzalloc(sizeof(*latency_ns) * dt_idle_states, GFP_KERNEL);
-	rc = of_property_read_u32_array(power_mgt,
-		"ibm,cpu-idle-state-latencies-ns", latency_ns, dt_idle_states);
-	if (rc) {
+	if (of_property_read_u32_array(power_mgt,
+		"ibm,cpu-idle-state-latencies-ns", latency_ns,
+		dt_idle_states)) {
 		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
-		goto out_free_latency;
+		goto out;
 	}
 
-	residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL);
 	rc = of_property_read_u32_array(power_mgt,
 		"ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
 
@@ -215,7 +223,7 @@ static int powernv_add_idle_states(void)
 			strcpy(powernv_states[nr_idle_states].desc, "Nap");
 			powernv_states[nr_idle_states].flags = 0;
 			powernv_states[nr_idle_states].target_residency = 100;
-			powernv_states[nr_idle_states].enter = &nap_loop;
+			powernv_states[nr_idle_states].enter = nap_loop;
 		}
 
 		/*
@@ -230,7 +238,7 @@ static int powernv_add_idle_states(void)
 			strcpy(powernv_states[nr_idle_states].desc, "FastSleep");
 			powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
 			powernv_states[nr_idle_states].target_residency = 300000;
-			powernv_states[nr_idle_states].enter = &fastsleep_loop;
+			powernv_states[nr_idle_states].enter = fastsleep_loop;
 		}
 #endif
 		powernv_states[nr_idle_states].exit_latency =
@@ -243,12 +251,6 @@ static int powernv_add_idle_states(void)
 
 		nr_idle_states++;
 	}
-
-	kfree(residency_ns);
-out_free_latency:
-	kfree(latency_ns);
-out_free_flags:
-	kfree(flags);
 out:
 	return nr_idle_states;
 }
-- 
2.4.11

[PATCH v7 10/11] cpuidle/powernv: Add support for POWER ISA v3 idle states

[Shreyas B. Prabhu]

POWER ISA v3 defines a new idle processor core mechanism. In summary,
 a) new instruction named stop is added.
 b) new per thread SPR named PSSCR is added which controls the behavior
	of stop instruction.

Supported idle states and value to be written to PSSCR register to enter
any idle state is exposed via ibm,cpu-idle-state-names and
ibm,cpu-idle-state-psscr respectively. To enter an idle state,
platform provided power_stop() needs to be invoked with the appropriate
PSSCR value.

This patch adds support for this new mechanism in cpuidle powernv driver.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Cc: linux-pm@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
---
Note: Documentation for the device tree bindings is posted here-
http://patchwork.ozlabs.org/patch/629125/

Changes in v7
=============
 - Using stack instead kzalloc/kcalloc 

Changes in v5
=============
 - Use generic cpuidle constant CPUIDLE_NAME_LEN
 - Fix return code handling for of_property_read_string_array
 - Use DT flags to determine if are using stop instruction, instead of
   cpu_has_feature
 - Removed uncessary cast with names
 - &stop_loop -> stop_loop
 - Added POWERNV_THRESHOLD_LATENCY_NS to filter out idle states with high latency

 drivers/cpuidle/cpuidle-powernv.c | 61 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index a89f546..d27e955 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -20,6 +20,8 @@
 #include <asm/opal.h>
 #include <asm/runlatch.h>
 
+#define POWERNV_THRESHOLD_LATENCY_NS 200000
+
 struct cpuidle_driver powernv_idle_driver = {
 	.name             = "powernv_idle",
 	.owner            = THIS_MODULE,
@@ -27,6 +29,9 @@ struct cpuidle_driver powernv_idle_driver = {
 
 static int max_idle_state;
 static struct cpuidle_state *cpuidle_state_table;
+
+static u64 stop_psscr_table[CPUIDLE_STATE_MAX];
+
 static u64 snooze_timeout;
 static bool snooze_timeout_en;
 
@@ -91,6 +96,17 @@ static int fastsleep_loop(struct cpuidle_device *dev,
 	return index;
 }
 #endif
+
+static int stop_loop(struct cpuidle_device *dev,
+		     struct cpuidle_driver *drv,
+		     int index)
+{
+	ppc64_runlatch_off();
+	power9_idle_stop(stop_psscr_table[index]);
+	ppc64_runlatch_on();
+	return index;
+}
+
 /*
  * States for dedicated partition case.
  */
@@ -169,6 +185,8 @@ static int powernv_add_idle_states(void)
 	u32 latency_ns[CPUIDLE_STATE_MAX];
 	u32 residency_ns[CPUIDLE_STATE_MAX];
 	u32 flags[CPUIDLE_STATE_MAX];
+	u64 psscr_val[CPUIDLE_STATE_MAX];
+	const char *names[CPUIDLE_STATE_MAX];
 	int i, rc;
 
 	/* Currently we have snooze statically defined */
@@ -207,11 +225,34 @@ static int powernv_add_idle_states(void)
 		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
 		goto out;
 	}
+	if (of_property_read_string_array(power_mgt,
+		"ibm,cpu-idle-state-names", names, dt_idle_states)) {
+		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-names in DT\n");
+		goto out;
+	}
+
+	/*
+	 * If the idle states use stop instruction, probe for psscr values
+	 * which are necessary to specify required stop level.
+	 */
+	if (flags[0] & (OPAL_PM_STOP_INST_FAST | OPAL_PM_STOP_INST_DEEP))
+		if (of_property_read_u64_array(power_mgt,
+		    "ibm,cpu-idle-state-psscr", psscr_val, dt_idle_states)) {
+			pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n");
+			goto out;
+		}
 
 	rc = of_property_read_u32_array(power_mgt,
 		"ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
 
 	for (i = 0; i < dt_idle_states; i++) {
+		/*
+		 * If an idle state has exit latency beyond
+		 * POWERNV_THRESHOLD_LATENCY_NS then don't use it
+		 * in cpu-idle.
+		 */
+		if (latency_ns[i] > POWERNV_THRESHOLD_LATENCY_NS)
+			continue;
 
 		/*
 		 * Cpuidle accepts exit_latency and target_residency in us.
@@ -224,6 +265,16 @@ static int powernv_add_idle_states(void)
 			powernv_states[nr_idle_states].flags = 0;
 			powernv_states[nr_idle_states].target_residency = 100;
 			powernv_states[nr_idle_states].enter = nap_loop;
+		} else if ((flags[i] & OPAL_PM_STOP_INST_FAST) &&
+				!(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
+			strncpy(powernv_states[nr_idle_states].name,
+				names[i], CPUIDLE_NAME_LEN);
+			strncpy(powernv_states[nr_idle_states].desc,
+				names[i], CPUIDLE_NAME_LEN);
+			powernv_states[nr_idle_states].flags = 0;
+
+			powernv_states[nr_idle_states].enter = stop_loop;
+			stop_psscr_table[nr_idle_states] = psscr_val[i];
 		}
 
 		/*
@@ -239,6 +290,16 @@ static int powernv_add_idle_states(void)
 			powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
 			powernv_states[nr_idle_states].target_residency = 300000;
 			powernv_states[nr_idle_states].enter = fastsleep_loop;
+		} else if ((flags[i] & OPAL_PM_STOP_INST_DEEP) &&
+				(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
+			strncpy(powernv_states[nr_idle_states].name,
+				names[i], CPUIDLE_NAME_LEN);
+			strncpy(powernv_states[nr_idle_states].desc,
+				names[i], CPUIDLE_NAME_LEN);
+
+			powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
+			powernv_states[nr_idle_states].enter = stop_loop;
+			stop_psscr_table[nr_idle_states] = psscr_val[i];
 		}
 #endif
 		powernv_states[nr_idle_states].exit_latency =
-- 
2.4.11

Re: [PATCH v7 09/11] cpuidle/powernv: cleanup powernv_add_idle_states

[Michael Neuling]

>  		/*
> @@ -230,7 +238,7 @@ static int powernv_add_idle_states(void)
>  			strcpy(powernv_states[nr_idle_states].desc, "FastSleep");
>  			powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
>  			powernv_states[nr_idle_states].target_residency = 300000;
> -			powernv_states[nr_idle_states].enter = &fastsleep_loop;
> +			powernv_states[nr_idle_states].enter = fastsleep_loop;

You can change this code too with the same thing.

static struct cpuidle_state powernv_states[CPUIDLE_STATE_MAX] = {
	{ /* Snooze */
		.name = "snooze",
		.desc = "snooze",
		.exit_latency = 0,
		.target_residency = 0,
		.enter = &snooze_loop },
};

Mikey

Re: [PATCH v7 00/11] powerpc/powernv/cpuidle: Add support for POWER ISA v3 idle states

[Michael Neuling]

Except for the issue with patch 7 I've already commented on the rest of
this series is good with me.  FWIW:

Acked-by: Michael Neuling <mikey@neuling.org>

Thanks.

On Fri, 2016-07-08 at 02:17 +0530, Shreyas B. Prabhu wrote:
> POWER ISA v3 defines a new idle processor core mechanism. In summary,
>  a) new instruction named stop is added. This instruction replaces
> 	instructions like nap, sleep, rvwinkle.
>  b) new per thread SPR named PSSCR is added which controls the behavior
> 	of stop instruction. 
> 		
> PSSCR has following key fields
> 	Bits 0:3  - Power-Saving Level Status. This field indicates the
> 	lowest power-saving state the thread entered since stop
> 	instruction was last executed.
> 		
> 	Bit 42 - Enable State Loss                          
> 	0 - No state is lost irrespective of other fields  
> 	1 - Allows state loss
> 		
> 	Bits 44:47 - Power-Saving Level Limit      
> 	This limits the power-saving level that can be entered into.
> 		
> 	Bits 60:63 - Requested Level              
> 	Used to specify which power-saving level must be entered on
> 	executing stop instruction
> 		
> Stop idle states and their properties like name, latency, target
> residency, psscr value are exposed via device tree.
> 
> This patch series adds support for this new mechanism.
> 
> Patches 1-6 are cleanups and code movement.
> Patch 7 adds platform specific support for stop and psscr handling.
> Patch 8 and 9 are minor cleanup in cpuidle driver.
> Patch 10 adds cpuidle driver support.
> Patch 11 makes offlined cpu use deepest stop state.
> 
> Note: Documentation for the device tree bindings is posted here-
> http://patchwork.ozlabs.org/patch/629125/
> 
> Changes in v7
> =============
>  - File renamed to idle_book3s.S instead of idle_power_common.S
>  - Comment changes
>  - power_stop0, power_stop renamed to power9_idle and power_idle_stop
>  - PSSCR template is now a macro instead of storing in paca
>  - power9_idle in C file instead of assembly
>  - Fixed TOC related bug
>  - Handling subcore within FTR section
>  - Functions in idle.c reordered and broken into multiple functions
>  - calling __restore_cpu_power8/9 via cur_cpu_spec->cpu_restore 
>  - Added a minor patch with minor cleanups in cpuidle-powernv.c . This
>    was mainly to make the existing code consistent with the review
>    comments for new code
>  - Using stack for variables while probing for idle states instead of
>    kzalloc/kcalloc
> 
> Changes in v6
> =============
>  - Restore new POWER ISA v3 SPRS when waking up from deep idle
> 
> Changes in v5
> =============
>  - Use generic cpuidle constant CPUIDLE_NAME_LEN
>  - Fix return code handling for of_property_read_string_array
>  - Use DT flags to determine if are using stop instruction, instead of
>    cpu_has_feature
>  - Removed uncessary cast with names
>  - &stop_loop -> stop_loop
>  - Added POWERNV_THRESHOLD_LATENCY_NS to filter out idle states with high latency
> 
> Changes in v4
> =============
>  - Added a patch to use PNV_THREAD_WINKLE macro while requesting for winkle
>  - Moved power7_powersave_common rename to more appropriate patch
>  - renaming power7_enter_nap_mode to pnv_enter_arch207_idle_mode
>  - Added PSSCR layout to Patch 7's commit message
>  - Improved / Fixed comments
>  - Fixed whitespace error in paca.h
>  - Using MAX_POSSIBLE_STOP_STATE macro instead of hardcoding 0xF has
>    max possible stop state
> 
> Changes in v3
> =============
>  - Rebased on powerpc-next
>  - Dropping patch 1 since we are not adding a new file for P9 idle support
>  - Improved comments in multiple places
>  - Moved GET_PACA from power7_restore_hyp_resource to System Reset
>  - Instead of moving few functions from idle_power7 to idle_power_common,
>    renaming idle_power7.S to idle_power_common.S
>  - Moved HSTATE_HWTHREAD_STATE updation to power_powersave_common
>  - Dropped earlier patch 5 which moved few macros from idle_power_common to
>    asm/cpuidle.h. 
>  - Added a patch to rename reusable power7_* idle functions to pnv_*
>  - Added new patch that creates abstraction for saving SPRs before
>    entering deep idle states
>  - Instead of introducing new file idle_power_stop.S, P9 idle support
>    is added to idle_power_common.S using CPU_FTR sections.
>  - Fixed r4 reg clobbering in power_stop0
> 
> Changes in v2
> =============
>  - Rebased on v4.6-rc6
>  - Using CPU_FTR_ARCH_300 bit instead of CPU_FTR_STOP_INST
> 
> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: linux-pm@vger.kernel.org
> Cc: Benjamin Herrenschmidt <benh@au1.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Paul Mackerras <paulus@ozlabs.org>
> Cc: Michael Neuling <mikey@neuling.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
> 
> Shreyas B. Prabhu (11):
>   powerpc/powernv: Use PNV_THREAD_WINKLE macro while requesting for
>     winkle
>   powerpc/kvm: make hypervisor state restore a function
>   powerpc/powernv: Rename idle_power7.S to idle_book3s.S
>   powerpc/powernv: Rename reusable idle functions to hardware agnostic
>     names
>   powerpc/powernv: Make pnv_powersave_common more generic
>   powerpc/powernv: abstraction for saving SPRs before entering deep idle
>     states
>   powerpc/powernv: Add platform support for stop instruction
>   cpuidle/powernv: Use CPUIDLE_STATE_MAX instead of
>     MAX_POWERNV_IDLE_STATES
>   cpuidle/powernv: cleanup powernv_add_idle_states
>   cpuidle/powernv: Add support for POWER ISA v3 idle states
>   powerpc/powernv: Use deepest stop state when cpu is offlined
> 
>  arch/powerpc/include/asm/cpuidle.h        |   2 +
>  arch/powerpc/include/asm/kvm_book3s_asm.h |   2 +-
>  arch/powerpc/include/asm/opal-api.h       |  11 +-
>  arch/powerpc/include/asm/ppc-opcode.h     |   4 +
>  arch/powerpc/include/asm/processor.h      |   2 +
>  arch/powerpc/include/asm/reg.h            |  10 +
>  arch/powerpc/kernel/Makefile              |   2 +-
>  arch/powerpc/kernel/exceptions-64s.S      |  30 +-
>  arch/powerpc/kernel/idle_book3s.S         | 664 ++++++++++++++++++++++++++++++
>  arch/powerpc/kernel/idle_power7.S         | 515 -----------------------
>  arch/powerpc/kvm/book3s_hv_rmhandlers.S   |   4 +-
>  arch/powerpc/platforms/powernv/idle.c     | 185 +++++++--
>  arch/powerpc/platforms/powernv/powernv.h  |   1 +
>  arch/powerpc/platforms/powernv/smp.c      |   4 +-
>  drivers/cpuidle/cpuidle-powernv.c         |  99 ++++-
>  15 files changed, 940 insertions(+), 595 deletions(-)
>  create mode 100644 arch/powerpc/kernel/idle_book3s.S
>  delete mode 100644 arch/powerpc/kernel/idle_power7.S
>