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[PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states.

Started by"Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
First post2017-01-25 09:40 +0100
Last post2017-01-30 12:50 +0100
Articles 5 — 4 participants

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  [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states. "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> - 2017-01-25 09:40 +0100
    Re: [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states. Michael Ellerman <mpe@ellerman.id.au> - 2017-01-30 04:50 +0100
      Re: [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate  powernv idle states. "Rafael J. Wysocki" <rafael@kernel.org> - 2017-01-30 08:20 +0100
        Re: [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states. Michael Ellerman <mpe@ellerman.id.au> - 2017-01-30 12:20 +0100
          Re: [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate  powernv idle states. Gautham R Shenoy <ego@linux.vnet.ibm.com> - 2017-01-30 12:50 +0100

#1566387 — [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states.

From"Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
Date2017-01-25 09:40 +0100
Subject[PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states.
Message-ID<t3rhw-7QP-23@gated-at.bofh.it>
From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>

In the current code for powernv_add_idle_states, there is a lot of code
duplication while initializing an idle state in powernv_states table.

Add an inline helper function to populate the powernv_states[] table
for a given idle state. Invoke this for populating the "Nap",
"Fastsleep" and the stop states in powernv_add_idle_states.

Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
---
 drivers/cpuidle/cpuidle-powernv.c | 89 +++++++++++++++++++++++----------------
 include/linux/cpuidle.h           |  1 +
 2 files changed, 54 insertions(+), 36 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 0835a37..6871b7f 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -20,6 +20,10 @@
 #include <asm/opal.h>
 #include <asm/runlatch.h>
 
+/*
+ * Expose only those Hardware idle states via the cpuidle framework
+ * that have latency value below POWERNV_THRESHOLD_LATENCY_NS.
+ */
 #define POWERNV_THRESHOLD_LATENCY_NS 200000
 
 static struct cpuidle_driver powernv_idle_driver = {
@@ -167,6 +171,24 @@ static int powernv_cpuidle_driver_init(void)
 	return 0;
 }
 
+static inline void add_powernv_state(int index, const char *name,
+				     unsigned int flags,
+				     int (*idle_fn)(struct cpuidle_device *,
+						    struct cpuidle_driver *,
+						    int),
+				     unsigned int target_residency,
+				     unsigned int exit_latency,
+				     u64 psscr_val)
+{
+	strlcpy(powernv_states[index].name, name, CPUIDLE_NAME_LEN);
+	strlcpy(powernv_states[index].desc, name, CPUIDLE_NAME_LEN);
+	powernv_states[index].flags = flags;
+	powernv_states[index].target_residency = target_residency;
+	powernv_states[index].exit_latency = exit_latency;
+	powernv_states[index].enter = idle_fn;
+	stop_psscr_table[index] = psscr_val;
+}
+
 static int powernv_add_idle_states(void)
 {
 	struct device_node *power_mgt;
@@ -236,6 +258,7 @@ static int powernv_add_idle_states(void)
 		"ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
 
 	for (i = 0; i < dt_idle_states; i++) {
+		unsigned int exit_latency, target_residency;
 		/*
 		 * If an idle state has exit latency beyond
 		 * POWERNV_THRESHOLD_LATENCY_NS then don't use it
@@ -243,28 +266,33 @@ static int powernv_add_idle_states(void)
 		 */
 		if (latency_ns[i] > POWERNV_THRESHOLD_LATENCY_NS)
 			continue;
+		/*
+		 * Firmware passes residency and latency values in ns.
+		 * cpuidle expects it in us.
+		 */
+		exit_latency = latency_ns[i] / 1000;
+		if (!rc)
+			target_residency = residency_ns[i] / 1000;
+		else
+			target_residency = 0;
 
 		/*
-		 * Cpuidle accepts exit_latency and target_residency in us.
-		 * Use default target_residency values if f/w does not expose it.
+		 * For nap and fastsleep, use default target_residency
+		 * values if f/w does not expose it.
 		 */
 		if (flags[i] & OPAL_PM_NAP_ENABLED) {
+			if (!rc)
+				target_residency = 100;
 			/* Add NAP state */
-			strcpy(powernv_states[nr_idle_states].name, "Nap");
-			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;
+			add_powernv_state(nr_idle_states, "Nap",
+					  CPUIDLE_FLAG_NONE, nap_loop,
+					  target_residency, exit_latency, 0);
 		} 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];
+			add_powernv_state(nr_idle_states, names[i],
+					  CPUIDLE_FLAG_NONE, stop_loop,
+					  target_residency, exit_latency,
+					  psscr_val[i]);
 		}
 
 		/*
@@ -274,32 +302,21 @@ static int powernv_add_idle_states(void)
 #ifdef CONFIG_TICK_ONESHOT
 		if (flags[i] & OPAL_PM_SLEEP_ENABLED ||
 			flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) {
+			if (!rc)
+				target_residency = 300000;
 			/* Add FASTSLEEP state */
-			strcpy(powernv_states[nr_idle_states].name, "FastSleep");
-			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;
+			add_powernv_state(nr_idle_states, "FastSleep",
+					  CPUIDLE_FLAG_TIMER_STOP,
+					  fastsleep_loop,
+					  target_residency, exit_latency, 0);
 		} 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];
+			add_powernv_state(nr_idle_states, names[i],
+					  CPUIDLE_FLAG_TIMER_STOP, stop_loop,
+					  target_residency, exit_latency,
+					  psscr_val[i]);
 		}
 #endif
-		powernv_states[nr_idle_states].exit_latency =
-				((unsigned int)latency_ns[i]) / 1000;
-
-		if (!rc) {
-			powernv_states[nr_idle_states].target_residency =
-				((unsigned int)residency_ns[i]) / 1000;
-		}
-
 		nr_idle_states++;
 	}
 out:
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index da346f2..fc1e5d7 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -62,6 +62,7 @@ struct cpuidle_state {
 };
 
 /* Idle State Flags */
+#define CPUIDLE_FLAG_NONE       (0x00)
 #define CPUIDLE_FLAG_COUPLED	(0x02) /* state applies to multiple cpus */
 #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
 
-- 
1.9.4

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#1569370

FromMichael Ellerman <mpe@ellerman.id.au>
Date2017-01-30 04:50 +0100
Message-ID<t5b8C-7pH-11@gated-at.bofh.it>
In reply to#1566387
"Gautham R. Shenoy" <ego@linux.vnet.ibm.com> writes:

> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
>
> In the current code for powernv_add_idle_states, there is a lot of code
> duplication while initializing an idle state in powernv_states table.
>
> Add an inline helper function to populate the powernv_states[] table
> for a given idle state. Invoke this for populating the "Nap",
> "Fastsleep" and the stop states in powernv_add_idle_states.
>
> Acked-by: Balbir Singh <bsingharora@gmail.com>
> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> ---
>  drivers/cpuidle/cpuidle-powernv.c | 89 +++++++++++++++++++++++----------------
>  include/linux/cpuidle.h           |  1 +

I was going to merge this, but I see you've touched cpuidle.h, so I feel
like I should get an ACK from the cpuidle folks.

It's a fairly uncontroversial change, but it's their API.

cheers


> diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
> index da346f2..fc1e5d7 100644
> --- a/include/linux/cpuidle.h
> +++ b/include/linux/cpuidle.h
> @@ -62,6 +62,7 @@ struct cpuidle_state {
>  };
>  
>  /* Idle State Flags */
> +#define CPUIDLE_FLAG_NONE       (0x00)
>  #define CPUIDLE_FLAG_COUPLED	(0x02) /* state applies to multiple cpus */
>  #define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
>  
> -- 
> 1.9.4

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#1569430 — Re: [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states.

From"Rafael J. Wysocki" <rafael@kernel.org>
Date2017-01-30 08:20 +0100
SubjectRe: [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states.
Message-ID<t5epP-15B-1@gated-at.bofh.it>
In reply to#1569370
On Mon, Jan 30, 2017 at 4:47 AM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> writes:
>
>> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
>>
>> In the current code for powernv_add_idle_states, there is a lot of code
>> duplication while initializing an idle state in powernv_states table.
>>
>> Add an inline helper function to populate the powernv_states[] table
>> for a given idle state. Invoke this for populating the "Nap",
>> "Fastsleep" and the stop states in powernv_add_idle_states.
>>
>> Acked-by: Balbir Singh <bsingharora@gmail.com>
>> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
>> ---
>>  drivers/cpuidle/cpuidle-powernv.c | 89 +++++++++++++++++++++++----------------
>>  include/linux/cpuidle.h           |  1 +
>
> I was going to merge this, but I see you've touched cpuidle.h, so I feel
> like I should get an ACK from the cpuidle folks.
>
> It's a fairly uncontroversial change, but it's their API.

OK, please add an ACK from me to it then.

Thanks,
Rafael

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#1569612

FromMichael Ellerman <mpe@ellerman.id.au>
Date2017-01-30 12:20 +0100
Message-ID<t5ia5-3jQ-1@gated-at.bofh.it>
In reply to#1569430
"Rafael J. Wysocki" <rafael@kernel.org> writes:

> On Mon, Jan 30, 2017 at 4:47 AM, Michael Ellerman <mpe@ellerman.id.au> wrote:
>> "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> writes:
>>
>>> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
>>>
>>> In the current code for powernv_add_idle_states, there is a lot of code
>>> duplication while initializing an idle state in powernv_states table.
>>>
>>> Add an inline helper function to populate the powernv_states[] table
>>> for a given idle state. Invoke this for populating the "Nap",
>>> "Fastsleep" and the stop states in powernv_add_idle_states.
>>>
>>> Acked-by: Balbir Singh <bsingharora@gmail.com>
>>> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
>>> ---
>>>  drivers/cpuidle/cpuidle-powernv.c | 89 +++++++++++++++++++++++----------------
>>>  include/linux/cpuidle.h           |  1 +
>>
>> I was going to merge this, but I see you've touched cpuidle.h, so I feel
>> like I should get an ACK from the cpuidle folks.
>>
>> It's a fairly uncontroversial change, but it's their API.
>
> OK, please add an ACK from me to it then.

Thanks.

cheers

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#1569626 — Re: [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states.

FromGautham R Shenoy <ego@linux.vnet.ibm.com>
Date2017-01-30 12:50 +0100
SubjectRe: [PATCH v6 3/5] cpuidle:powernv: Add helper function to populate powernv idle states.
Message-ID<t5iD7-3th-5@gated-at.bofh.it>
In reply to#1569612
On Mon, Jan 30, 2017 at 10:17:50PM +1100, Michael Ellerman wrote:
> "Rafael J. Wysocki" <rafael@kernel.org> writes:
> 
> > On Mon, Jan 30, 2017 at 4:47 AM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> >> "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> writes:
> >>
> >>> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
> >>>
> >>> In the current code for powernv_add_idle_states, there is a lot of code
> >>> duplication while initializing an idle state in powernv_states table.
> >>>
> >>> Add an inline helper function to populate the powernv_states[] table
> >>> for a given idle state. Invoke this for populating the "Nap",
> >>> "Fastsleep" and the stop states in powernv_add_idle_states.
> >>>
> >>> Acked-by: Balbir Singh <bsingharora@gmail.com>
> >>> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> >>> ---
> >>>  drivers/cpuidle/cpuidle-powernv.c | 89 +++++++++++++++++++++++----------------
> >>>  include/linux/cpuidle.h           |  1 +
> >>
> >> I was going to merge this, but I see you've touched cpuidle.h, so I feel
> >> like I should get an ACK from the cpuidle folks.
> >>
> >> It's a fairly uncontroversial change, but it's their API.
> >
> > OK, please add an ACK from me to it then.
> 
> Thanks.

Thanks Rafael and Michal.

> 
> cheers
> 
--
Thanks and Regards
gautham.

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