diff options
| -rw-r--r-- | drivers/reset/core.c | 84 | ||||
| -rw-r--r-- | include/linux/reset-controller.h | 2 |
2 files changed, 65 insertions, 21 deletions
diff --git a/drivers/reset/core.c b/drivers/reset/core.c index bdf1763da87a..957750600ff3 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -18,19 +18,23 @@ #include <linux/reset-controller.h> #include <linux/slab.h> -static DEFINE_MUTEX(reset_controller_list_mutex); +static DEFINE_MUTEX(reset_list_mutex); static LIST_HEAD(reset_controller_list); /** * struct reset_control - a reset control * @rcdev: a pointer to the reset controller device * this reset control belongs to + * @list: list entry for the rcdev's reset controller list * @id: ID of the reset controller in the reset * controller device + * @refcnt: Number of gets of this reset_control */ struct reset_control { struct reset_controller_dev *rcdev; + struct list_head list; unsigned int id; + unsigned int refcnt; }; /** @@ -62,9 +66,11 @@ int reset_controller_register(struct reset_controller_dev *rcdev) rcdev->of_xlate = of_reset_simple_xlate; } - mutex_lock(&reset_controller_list_mutex); + INIT_LIST_HEAD(&rcdev->reset_control_head); + + mutex_lock(&reset_list_mutex); list_add(&rcdev->list, &reset_controller_list); - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); return 0; } @@ -76,9 +82,9 @@ EXPORT_SYMBOL_GPL(reset_controller_register); */ void reset_controller_unregister(struct reset_controller_dev *rcdev) { - mutex_lock(&reset_controller_list_mutex); + mutex_lock(&reset_list_mutex); list_del(&rcdev->list); - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); } EXPORT_SYMBOL_GPL(reset_controller_unregister); @@ -136,6 +142,48 @@ int reset_control_status(struct reset_control *rstc) } EXPORT_SYMBOL_GPL(reset_control_status); +static struct reset_control *__reset_control_get( + struct reset_controller_dev *rcdev, + unsigned int index) +{ + struct reset_control *rstc; + + lockdep_assert_held(&reset_list_mutex); + + list_for_each_entry(rstc, &rcdev->reset_control_head, list) { + if (rstc->id == index) { + rstc->refcnt++; + return rstc; + } + } + + rstc = kzalloc(sizeof(*rstc), GFP_KERNEL); + if (!rstc) + return ERR_PTR(-ENOMEM); + + try_module_get(rcdev->owner); + + rstc->rcdev = rcdev; + list_add(&rstc->list, &rcdev->reset_control_head); + rstc->id = index; + rstc->refcnt = 1; + + return rstc; +} + +static void __reset_control_put(struct reset_control *rstc) +{ + lockdep_assert_held(&reset_list_mutex); + + if (--rstc->refcnt) + return; + + module_put(rstc->rcdev->owner); + + list_del(&rstc->list); + kfree(rstc); +} + struct reset_control *__of_reset_control_get(struct device_node *node, const char *id, int index) { @@ -160,7 +208,7 @@ struct reset_control *__of_reset_control_get(struct device_node *node, if (ret) return ERR_PTR(ret); - mutex_lock(&reset_controller_list_mutex); + mutex_lock(&reset_list_mutex); rcdev = NULL; list_for_each_entry(r, &reset_controller_list, list) { if (args.np == r->of_node) { @@ -171,32 +219,25 @@ struct reset_control *__of_reset_control_get(struct device_node *node, of_node_put(args.np); if (!rcdev) { - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); return ERR_PTR(-EPROBE_DEFER); } if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) { - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); return ERR_PTR(-EINVAL); } rstc_id = rcdev->of_xlate(rcdev, &args); if (rstc_id < 0) { - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); return ERR_PTR(rstc_id); } - try_module_get(rcdev->owner); - mutex_unlock(&reset_controller_list_mutex); - - rstc = kzalloc(sizeof(*rstc), GFP_KERNEL); - if (!rstc) { - module_put(rcdev->owner); - return ERR_PTR(-ENOMEM); - } + /* reset_list_mutex also protects the rcdev's reset_control list */ + rstc = __reset_control_get(rcdev, rstc_id); - rstc->rcdev = rcdev; - rstc->id = rstc_id; + mutex_unlock(&reset_list_mutex); return rstc; } @@ -212,8 +253,9 @@ void reset_control_put(struct reset_control *rstc) if (IS_ERR(rstc)) return; - module_put(rstc->rcdev->owner); - kfree(rstc); + mutex_lock(&reset_list_mutex); + __reset_control_put(rstc); + mutex_unlock(&reset_list_mutex); } EXPORT_SYMBOL_GPL(reset_control_put); diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h index a3a5bcdb1d02..b91ba932bbd4 100644 --- a/include/linux/reset-controller.h +++ b/include/linux/reset-controller.h @@ -31,6 +31,7 @@ struct of_phandle_args; * @ops: a pointer to device specific struct reset_control_ops * @owner: kernel module of the reset controller driver * @list: internal list of reset controller devices + * @reset_control_head: head of internal list of requested reset controls * @of_node: corresponding device tree node as phandle target * @of_reset_n_cells: number of cells in reset line specifiers * @of_xlate: translation function to translate from specifier as found in the @@ -41,6 +42,7 @@ struct reset_controller_dev { const struct reset_control_ops *ops; struct module *owner; struct list_head list; + struct list_head reset_control_head; struct device_node *of_node; int of_reset_n_cells; int (*of_xlate)(struct reset_controller_dev *rcdev, |