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

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

Commit Message

Ulf Hansson Nov. 29, 2018, 5:46 p.m.
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(-)

-- 
2.17.1

Comments

Ulf Hansson Dec. 18, 2018, 11:53 a.m. | #1
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

Patch

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;