[PATCH 1/9] PM / Domains: Allocate memory outside domain locks

[Ulf Hansson]

On 5 August 2015 at 01:35, Lina Iyer <lina.iyer at linaro.org> wrote:
> In preparation for supporting IRQ-safe domains, allocate domain data
> outside the domain locks. These functions are not called in an atomic
> context, so we can always allocate memory using GFP_KERNEL. By
> allocating memory before the locks, we can safely lock the domain using
> spinlocks instead of mutexes.
>
> Cc: Ulf Hansson <ulf.hansson at linaro.org>
> Cc: Rafael J. Wysocki <rjw at rjwysocki.net>
> Cc: Kevin Hilman <khilman at linaro.org>
> Cc: Geert Uytterhoeven <geert at linux-m68k.org>
> Cc: Krzysztof Kozłowski <k.kozlowski at samsung.com>
> Signed-off-by: Lina Iyer <lina.iyer at linaro.org>

Acked-by: Ulf Hansson <ulf.hansson at linaro.org>

> ---
>  drivers/base/power/domain.c | 30 +++++++++++++++---------------
>  1 file changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 7666a1c..5fd1306 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1382,13 +1382,17 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
>  int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
>                            struct generic_pm_domain *subdomain)
>  {
> -       struct gpd_link *link;
> +       struct gpd_link *link, *itr;
>         int ret = 0;
>
>         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
>             || genpd == subdomain)
>                 return -EINVAL;
>
> +       link = kzalloc(sizeof(*link), GFP_KERNEL);
> +       if (!link)
> +               return -ENOMEM;
> +
>         mutex_lock(&genpd->lock);
>         mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
>
> @@ -1398,18 +1402,13 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
>                 goto out;
>         }
>
> -       list_for_each_entry(link, &genpd->master_links, master_node) {
> -               if (link->slave == subdomain && link->master == genpd) {
> +       list_for_each_entry(itr, &genpd->master_links, master_node) {
> +               if (itr->slave == subdomain && itr->master == genpd) {
>                         ret = -EINVAL;
>                         goto out;
>                 }
>         }
>
> -       link = kzalloc(sizeof(*link), GFP_KERNEL);
> -       if (!link) {
> -               ret = -ENOMEM;
> -               goto out;
> -       }
>         link->master = genpd;
>         list_add_tail(&link->master_node, &genpd->master_links);
>         link->slave = subdomain;
> @@ -1420,7 +1419,8 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
>   out:
>         mutex_unlock(&subdomain->lock);
>         mutex_unlock(&genpd->lock);
> -
> +       if (ret)
> +               kfree(link);
>         return ret;
>  }
>
> @@ -1511,17 +1511,17 @@ int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
>         if (IS_ERR_OR_NULL(genpd) || state < 0)
>                 return -EINVAL;
>
> +       cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
> +       if (!cpuidle_data)
> +               return -ENOMEM;
> +
>         mutex_lock(&genpd->lock);
>
>         if (genpd->cpuidle_data) {
>                 ret = -EEXIST;
> -               goto out;
> -       }
> -       cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
> -       if (!cpuidle_data) {
> -               ret = -ENOMEM;
> -               goto out;
> +               goto err_drv;
>         }
> +
>         cpuidle_drv = cpuidle_driver_ref();
>         if (!cpuidle_drv) {
>                 ret = -ENODEV;
> --
> 2.1.4
>