Re: [PATCH v3 2/3] cpuidle:powernv: Add helper function to populate powernv idle states.

[Gautham R Shenoy]

Hi Michael,

On Wed, Nov 23, 2016 at 08:49:08PM +1100, Michael Ellerman wrote:
> "Gautham R. Shenoy"  writes:
> 
> > diff --git a/drivers/cpuidle/cpuidle-powernv.c 
> > b/drivers/cpuidle/cpuidle-powernv.c
> > index 7fe442c..9240e08 100644
> > --- a/drivers/cpuidle/cpuidle-powernv.c
> > +++ b/drivers/cpuidle/cpuidle-powernv.c
> > @@ -243,28 +262,31 @@ 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 = ((unsigned int)latency_ns[i]) / 1000;
> > +   target_residency = (!rc) ? ((unsigned int)residency_ns[i]) : 0;
> > +   target_residency /= 1000;
> 
> Urk.
> 
> Can you just do it normally:
> 
>   if (rc == 0)
>   target_residency = (unsigned int)residency_ns[i] / 1000;

Wrote this in a non-standard manner since the normal way would exceed
80 chars.

> 
> I also don't see why you need the cast?

It is a remnant from the previous code. But I see your point, the cast
is redundant, and removing it will make it possible to implement this
in the normal manner without checkpatch warning about it.

> 
> cheers
> 

--
Thanks and Regards
gautham.

Re: [PATCH v3 2/3] cpuidle:powernv: Add helper function to populate powernv idle states.

[Gautham R Shenoy]

Hi Michael,

On Wed, Nov 23, 2016 at 08:49:08PM +1100, Michael Ellerman wrote:
> "Gautham R. Shenoy"  writes:
> 
> > diff --git a/drivers/cpuidle/cpuidle-powernv.c 
> > b/drivers/cpuidle/cpuidle-powernv.c
> > index 7fe442c..9240e08 100644
> > --- a/drivers/cpuidle/cpuidle-powernv.c
> > +++ b/drivers/cpuidle/cpuidle-powernv.c
> > @@ -243,28 +262,31 @@ 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 = ((unsigned int)latency_ns[i]) / 1000;
> > +   target_residency = (!rc) ? ((unsigned int)residency_ns[i]) : 0;
> > +   target_residency /= 1000;
> 
> Urk.
> 
> Can you just do it normally:
> 
>   if (rc == 0)
>   target_residency = (unsigned int)residency_ns[i] / 1000;

Wrote this in a non-standard manner since the normal way would exceed
80 chars.

> 
> I also don't see why you need the cast?

It is a remnant from the previous code. But I see your point, the cast
is redundant, and removing it will make it possible to implement this
in the normal manner without checkpatch warning about it.

> 
> cheers
> 

--
Thanks and Regards
gautham.

Re: [PATCH v3 2/3] cpuidle:powernv: Add helper function to populate powernv idle states.

[Michael Ellerman]

"Gautham R. Shenoy"  writes:

> diff --git a/drivers/cpuidle/cpuidle-powernv.c 
> b/drivers/cpuidle/cpuidle-powernv.c
> index 7fe442c..9240e08 100644
> --- a/drivers/cpuidle/cpuidle-powernv.c
> +++ b/drivers/cpuidle/cpuidle-powernv.c
> @@ -243,28 +262,31 @@ 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 = ((unsigned int)latency_ns[i]) / 1000;
> + target_residency = (!rc) ? ((unsigned int)residency_ns[i]) : 0;
> + target_residency /= 1000;

Urk.

Can you just do it normally:

if (rc == 0)
target_residency = (unsigned int)residency_ns[i] / 1000;

I also don't see why you need the cast?

cheers

Re: [PATCH v3 2/3] cpuidle:powernv: Add helper function to populate powernv idle states.

[Michael Ellerman]

"Gautham R. Shenoy"  writes:

> diff --git a/drivers/cpuidle/cpuidle-powernv.c 
> b/drivers/cpuidle/cpuidle-powernv.c
> index 7fe442c..9240e08 100644
> --- a/drivers/cpuidle/cpuidle-powernv.c
> +++ b/drivers/cpuidle/cpuidle-powernv.c
> @@ -243,28 +262,31 @@ 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 = ((unsigned int)latency_ns[i]) / 1000;
> + target_residency = (!rc) ? ((unsigned int)residency_ns[i]) : 0;
> + target_residency /= 1000;

Urk.

Can you just do it normally:

if (rc == 0)
target_residency = (unsigned int)residency_ns[i] / 1000;

I also don't see why you need the cast?

cheers

[PATCH v3 2/3] cpuidle:powernv: Add helper function to populate powernv idle states.

[Gautham R. Shenoy]

From: "Gautham R. Shenoy" 

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.

Signed-off-by: Gautham R. Shenoy 
---
 drivers/cpuidle/cpuidle-powernv.c | 83 ++-
 include/linux/cpuidle.h   |  1 +
 2 files changed, 48 insertions(+), 36 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powernv.c 
b/drivers/cpuidle/cpuidle-powernv.c
index 7fe442c..9240e08 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -167,6 +167,24 @@ 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 +254,7 @@ 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 +262,31 @@ 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 = ((unsigned int)latency_ns[i]) / 1000;
+   target_residency = (!rc) ? ((unsigned int)residency_ns[i]) : 0;
+   target_residency /= 1000;
 
/*
-* 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 +296,21 @@ static int powernv_add_idle_states(void)
 #ifdef CONFIG_TICK_ONESHOT
if (flags[i] & 

[PATCH v3 2/3] cpuidle:powernv: Add helper function to populate powernv idle states.

[Gautham R. Shenoy]

From: "Gautham R. Shenoy" 

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.

Signed-off-by: Gautham R. Shenoy 
---
 drivers/cpuidle/cpuidle-powernv.c | 83 ++-
 include/linux/cpuidle.h   |  1 +
 2 files changed, 48 insertions(+), 36 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powernv.c 
b/drivers/cpuidle/cpuidle-powernv.c
index 7fe442c..9240e08 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -167,6 +167,24 @@ 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 +254,7 @@ 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 +262,31 @@ 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 = ((unsigned int)latency_ns[i]) / 1000;
+   target_residency = (!rc) ? ((unsigned int)residency_ns[i]) : 0;
+   target_residency /= 1000;
 
/*
-* 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 +296,21 @@ static int powernv_add_idle_states(void)
 #ifdef CONFIG_TICK_ONESHOT
if (flags[i] & OPAL_PM_SLEEP_ENABLED ||
flags[i] &