[v10,01/27] PM / Domains: Add generic data pointer to genpd_power_state struct
diff mbox series

Message ID 20181129174700.16585-2-ulf.hansson@linaro.org
State Changes Requested, archived
Headers show
Series
  • PM / Domains: Support hierarchical CPU arrangement (PSCI/ARM)
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Commit Message

Ulf Hansson Nov. 29, 2018, 5:46 p.m. UTC
Let's add a data pointer to the genpd_power_state struct, to allow a genpd
backend driver to store per state specific data. In order to introduce the
pointer, we also need to adopt how genpd frees the allocated data for the
default genpd_power_state struct, that it may allocate at pm_genpd_init().

More precisely, let's use an internal genpd flag to understand when the
states needs to be freed by genpd. When freeing the states data in
genpd_remove(), let's also clear the corresponding genpd->states pointer
and reset the genpd->state_count. In this way, a genpd backend driver
becomes aware of when there is state specific data for it to free.

Cc: Lina Iyer <ilina@codeaurora.org>
Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---

Changes in v10:
	- Update the patch allow backend drivers to free the states specific
	  data during genpd removal. Due to this added complexity, I decided to
	  keep the patch separate, rather than fold it into the patch that makes
	  use of the new void pointer, which was suggested by Rafael.
	- Claim authorship of the patch as lots of changes has been done since
	  the original pick up from Lina Iyer.

---
 drivers/base/power/domain.c | 8 ++++++--
 include/linux/pm_domain.h   | 3 ++-
 2 files changed, 8 insertions(+), 3 deletions(-)

Comments

Daniel Lezcano Dec. 18, 2018, 10:39 a.m. UTC | #1
On 29/11/2018 18:46, Ulf Hansson wrote:
> Let's add a data pointer to the genpd_power_state struct, to allow a genpd
> backend driver to store per state specific data. In order to introduce the
> pointer, we also need to adopt how genpd frees the allocated data for the
> default genpd_power_state struct, that it may allocate at pm_genpd_init().
> 
> More precisely, let's use an internal genpd flag to understand when the
> states needs to be freed by genpd. When freeing the states data in
> genpd_remove(), let's also clear the corresponding genpd->states pointer
> and reset the genpd->state_count. In this way, a genpd backend driver
> becomes aware of when there is state specific data for it to free.
> 
> Cc: Lina Iyer <ilina@codeaurora.org>
> Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
> 
> Changes in v10:
> 	- Update the patch allow backend drivers to free the states specific
> 	  data during genpd removal. Due to this added complexity, I decided to
> 	  keep the patch separate, rather than fold it into the patch that makes
> 	  use of the new void pointer, which was suggested by Rafael.
> 	- Claim authorship of the patch as lots of changes has been done since
> 	  the original pick up from Lina Iyer.
> 
> ---
>  drivers/base/power/domain.c | 8 ++++++--
>  include/linux/pm_domain.h   | 3 ++-
>  2 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 7f38a92b444a..e27b91d36a2a 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1620,7 +1620,7 @@ static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
>  
>  	genpd->states = state;
>  	genpd->state_count = 1;
> -	genpd->free = state;
> +	genpd->free_state = true;
>  
>  	return 0;
>  }
> @@ -1736,7 +1736,11 @@ static int genpd_remove(struct generic_pm_domain *genpd)
>  	list_del(&genpd->gpd_list_node);
>  	genpd_unlock(genpd);
>  	cancel_work_sync(&genpd->power_off_work);
> -	kfree(genpd->free);
> +	if (genpd->free_state) {
> +		kfree(genpd->states);
> +		genpd->states = NULL;
> +		genpd->state_count = 0;

Why these two initializations? After genpd_remove, this structure
shouldn't be used anymore, no ?

> +	}

Instead of a flag, replacing the 'free' pointer to a 'free' callback
will allow to keep the free path self-encapsulated in domain.c

genpd->free(genpd->states);

Patch 18/27 can fill this field with its specific free pointer.



>  	pr_debug("%s: removed %s\n", __func__, genpd->name);
>  
>  	return 0;
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index 3b5d7280e52e..f9e09bd4152c 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -69,6 +69,7 @@ struct genpd_power_state {
>  	s64 residency_ns;
>  	struct fwnode_handle *fwnode;
>  	ktime_t idle_time;
> +	void *data;
>  };
>  
>  struct genpd_lock_ops;
> @@ -110,7 +111,7 @@ struct generic_pm_domain {
>  	struct genpd_power_state *states;
>  	unsigned int state_count; /* number of states */
>  	unsigned int state_idx; /* state that genpd will go to when off */
> -	void *free; /* Free the state that was allocated for default */
> +	bool free_state; /* Free the state that was allocated for default */
>  	ktime_t on_time;
>  	ktime_t accounting_time;
>  	const struct genpd_lock_ops *lock_ops;
>
Ulf Hansson Dec. 18, 2018, 11:53 a.m. UTC | #2
On Tue, 18 Dec 2018 at 11:39, Daniel Lezcano <daniel.lezcano@linaro.org> wrote:
>
> On 29/11/2018 18:46, Ulf Hansson wrote:
> > Let's add a data pointer to the genpd_power_state struct, to allow a genpd
> > backend driver to store per state specific data. In order to introduce the
> > pointer, we also need to adopt how genpd frees the allocated data for the
> > default genpd_power_state struct, that it may allocate at pm_genpd_init().
> >
> > More precisely, let's use an internal genpd flag to understand when the
> > states needs to be freed by genpd. When freeing the states data in
> > genpd_remove(), let's also clear the corresponding genpd->states pointer
> > and reset the genpd->state_count. In this way, a genpd backend driver
> > becomes aware of when there is state specific data for it to free.
> >
> > Cc: Lina Iyer <ilina@codeaurora.org>
> > Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> > ---
> >
> > Changes in v10:
> >       - Update the patch allow backend drivers to free the states specific
> >         data during genpd removal. Due to this added complexity, I decided to
> >         keep the patch separate, rather than fold it into the patch that makes
> >         use of the new void pointer, which was suggested by Rafael.
> >       - Claim authorship of the patch as lots of changes has been done since
> >         the original pick up from Lina Iyer.
> >
> > ---
> >  drivers/base/power/domain.c | 8 ++++++--
> >  include/linux/pm_domain.h   | 3 ++-
> >  2 files changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> > index 7f38a92b444a..e27b91d36a2a 100644
> > --- a/drivers/base/power/domain.c
> > +++ b/drivers/base/power/domain.c
> > @@ -1620,7 +1620,7 @@ static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
> >
> >       genpd->states = state;
> >       genpd->state_count = 1;
> > -     genpd->free = state;
> > +     genpd->free_state = true;
> >
> >       return 0;
> >  }
> > @@ -1736,7 +1736,11 @@ static int genpd_remove(struct generic_pm_domain *genpd)
> >       list_del(&genpd->gpd_list_node);
> >       genpd_unlock(genpd);
> >       cancel_work_sync(&genpd->power_off_work);
> > -     kfree(genpd->free);
> > +     if (genpd->free_state) {
> > +             kfree(genpd->states);
> > +             genpd->states = NULL;
> > +             genpd->state_count = 0;
>
> Why these two initializations? After genpd_remove, this structure
> shouldn't be used anymore, no ?

Correct.

>
> > +     }
>
> Instead of a flag, replacing the 'free' pointer to a 'free' callback
> will allow to keep the free path self-encapsulated in domain.c
>
> genpd->free(genpd->states);

Right, I get your idea and it makes sense. Let me convert to that.

>
> Patch 18/27 can fill this field with its specific free pointer.

Yep!

[...]

Thanks for reviewing!

Kind regards
Uffe
Rafael J. Wysocki Jan. 11, 2019, 10:52 a.m. UTC | #3
On Tuesday, December 18, 2018 12:53:28 PM CET Ulf Hansson wrote:
> On Tue, 18 Dec 2018 at 11:39, Daniel Lezcano <daniel.lezcano@linaro.org> wrote:
> >
> > On 29/11/2018 18:46, Ulf Hansson wrote:
> > > Let's add a data pointer to the genpd_power_state struct, to allow a genpd
> > > backend driver to store per state specific data. In order to introduce the
> > > pointer, we also need to adopt how genpd frees the allocated data for the
> > > default genpd_power_state struct, that it may allocate at pm_genpd_init().
> > >
> > > More precisely, let's use an internal genpd flag to understand when the
> > > states needs to be freed by genpd. When freeing the states data in
> > > genpd_remove(), let's also clear the corresponding genpd->states pointer
> > > and reset the genpd->state_count. In this way, a genpd backend driver
> > > becomes aware of when there is state specific data for it to free.
> > >
> > > Cc: Lina Iyer <ilina@codeaurora.org>
> > > Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
> > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> > > ---
> > >
> > > Changes in v10:
> > >       - Update the patch allow backend drivers to free the states specific
> > >         data during genpd removal. Due to this added complexity, I decided to
> > >         keep the patch separate, rather than fold it into the patch that makes
> > >         use of the new void pointer, which was suggested by Rafael.
> > >       - Claim authorship of the patch as lots of changes has been done since
> > >         the original pick up from Lina Iyer.
> > >
> > > ---
> > >  drivers/base/power/domain.c | 8 ++++++--
> > >  include/linux/pm_domain.h   | 3 ++-
> > >  2 files changed, 8 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> > > index 7f38a92b444a..e27b91d36a2a 100644
> > > --- a/drivers/base/power/domain.c
> > > +++ b/drivers/base/power/domain.c
> > > @@ -1620,7 +1620,7 @@ static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
> > >
> > >       genpd->states = state;
> > >       genpd->state_count = 1;
> > > -     genpd->free = state;
> > > +     genpd->free_state = true;
> > >
> > >       return 0;
> > >  }
> > > @@ -1736,7 +1736,11 @@ static int genpd_remove(struct generic_pm_domain *genpd)
> > >       list_del(&genpd->gpd_list_node);
> > >       genpd_unlock(genpd);
> > >       cancel_work_sync(&genpd->power_off_work);
> > > -     kfree(genpd->free);
> > > +     if (genpd->free_state) {
> > > +             kfree(genpd->states);
> > > +             genpd->states = NULL;
> > > +             genpd->state_count = 0;
> >
> > Why these two initializations? After genpd_remove, this structure
> > shouldn't be used anymore, no ?
> 
> Correct.
> 
> >
> > > +     }
> >
> > Instead of a flag, replacing the 'free' pointer to a 'free' callback
> > will allow to keep the free path self-encapsulated in domain.c
> >
> > genpd->free(genpd->states);
> 
> Right, I get your idea and it makes sense. Let me convert to that.

OK, so I'm expecting an update here.

Patch
diff mbox series

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 7f38a92b444a..e27b91d36a2a 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1620,7 +1620,7 @@  static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
 
 	genpd->states = state;
 	genpd->state_count = 1;
-	genpd->free = state;
+	genpd->free_state = true;
 
 	return 0;
 }
@@ -1736,7 +1736,11 @@  static int genpd_remove(struct generic_pm_domain *genpd)
 	list_del(&genpd->gpd_list_node);
 	genpd_unlock(genpd);
 	cancel_work_sync(&genpd->power_off_work);
-	kfree(genpd->free);
+	if (genpd->free_state) {
+		kfree(genpd->states);
+		genpd->states = NULL;
+		genpd->state_count = 0;
+	}
 	pr_debug("%s: removed %s\n", __func__, genpd->name);
 
 	return 0;
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 3b5d7280e52e..f9e09bd4152c 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -69,6 +69,7 @@  struct genpd_power_state {
 	s64 residency_ns;
 	struct fwnode_handle *fwnode;
 	ktime_t idle_time;
+	void *data;
 };
 
 struct genpd_lock_ops;
@@ -110,7 +111,7 @@  struct generic_pm_domain {
 	struct genpd_power_state *states;
 	unsigned int state_count; /* number of states */
 	unsigned int state_idx; /* state that genpd will go to when off */
-	void *free; /* Free the state that was allocated for default */
+	bool free_state; /* Free the state that was allocated for default */
 	ktime_t on_time;
 	ktime_t accounting_time;
 	const struct genpd_lock_ops *lock_ops;