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@xxxxxxxxxxxxxx>
> Co-developed-by: Lina Iyer <lina.iyer@xxxxxxxxxx>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
>
> 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;
>
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