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Subject[PATCH V2 4/4] pinctrl: Remove pin and hogs locks from struct pinctrl_dev
Date
struct pinctrl_dev's pin_desc_tree_lock and pinctrl_hogs_lock aren't
useful; the data they protect is read-only except when registering or
unregistering a pinctrl_dev, and at those times, it doesn't make sense to
protect one part of the structure independently from the rest.

Move pinctrl_init_device_debugfs() to the end of pinctrl_register() so
that debugfs can't access the struct pinctrl_dev until it's fully
initialized, i.e. after the hogs are set up.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
v2: Extracted from previous lock rework patch.

drivers/pinctrl/core.c | 25 ++-----------------------
drivers/pinctrl/core.h | 11 ++++++-----
2 files changed, 8 insertions(+), 28 deletions(-)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 2cc8f72..633b97e 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -115,18 +115,6 @@ struct pinctrl_dev *get_pinctrl_dev_from_devname(const char *devname)
return found ? pctldev : NULL;
}

-struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, unsigned int pin)
-{
- struct pin_desc *pindesc;
- unsigned long flags;
-
- spin_lock_irqsave(&pctldev->pin_desc_tree_lock, flags);
- pindesc = radix_tree_lookup(&pctldev->pin_desc_tree, pin);
- spin_unlock_irqrestore(&pctldev->pin_desc_tree_lock, flags);
-
- return pindesc;
-}
-
/**
* pin_get_from_name() - look up a pin number from a name
* @pctldev: the pin control device to lookup the pin on
@@ -182,7 +170,6 @@ static void pinctrl_free_pindescs(struct pinctrl_dev *pctldev,
{
int i;

- spin_lock(&pctldev->pin_desc_tree_lock);
for (i = 0; i < num_pins; i++) {
struct pin_desc *pindesc;

@@ -196,7 +183,6 @@ static void pinctrl_free_pindescs(struct pinctrl_dev *pctldev,
}
kfree(pindesc);
}
- spin_unlock(&pctldev->pin_desc_tree_lock);
}

static int pinctrl_register_one_pin(struct pinctrl_dev *pctldev,
@@ -232,9 +218,7 @@ static int pinctrl_register_one_pin(struct pinctrl_dev *pctldev,
pindesc->dynamic_name = true;
}

- spin_lock(&pctldev->pin_desc_tree_lock);
radix_tree_insert(&pctldev->pin_desc_tree, number, pindesc);
- spin_unlock(&pctldev->pin_desc_tree_lock);
pr_debug("registered pin %d (%s) on %s\n",
number, pindesc->name, pctldev->desc->name);
return 0;
@@ -756,9 +740,7 @@ static int pinctrl_hog_map(struct pinctrl_dev *pctldev,

dev_info(pctldev->dev, "hogged map %s, function %s\n", map->name,
map->function);
- mutex_lock(&pctldev->pinctrl_hogs_lock);
list_add_tail(&hog->node, &pctldev->pinctrl_hogs);
- mutex_unlock(&pctldev->pinctrl_hogs_lock);

return 0;
}
@@ -781,7 +763,6 @@ static int pinctrl_hog_maps(struct pinctrl_dev *pctldev)
struct pinctrl_map const *map;

INIT_LIST_HEAD(&pctldev->pinctrl_hogs);
- mutex_init(&pctldev->pinctrl_hogs_lock);

mutex_lock(&pinctrl_maps_mutex);
for_each_maps(maps_node, i, map) {
@@ -808,7 +789,6 @@ static void pinctrl_unhog_maps(struct pinctrl_dev *pctldev)
{
struct list_head *node, *tmp;

- mutex_lock(&pctldev->pinctrl_hogs_lock);
list_for_each_safe(node, tmp, &pctldev->pinctrl_hogs) {
struct pinctrl_hog *hog =
list_entry(node, struct pinctrl_hog, node);
@@ -817,7 +797,6 @@ static void pinctrl_unhog_maps(struct pinctrl_dev *pctldev)
list_del(node);
kfree(hog);
}
- mutex_unlock(&pctldev->pinctrl_hogs_lock);
}

#ifdef CONFIG_DEBUG_FS
@@ -1171,7 +1150,6 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
pctldev->desc = pctldesc;
pctldev->driver_data = driver_data;
INIT_RADIX_TREE(&pctldev->pin_desc_tree, GFP_KERNEL);
- spin_lock_init(&pctldev->pin_desc_tree_lock);
INIT_LIST_HEAD(&pctldev->gpio_ranges);
mutex_init(&pctldev->gpio_ranges_lock);
pctldev->dev = dev;
@@ -1207,11 +1185,12 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
goto out_err;
}

- pinctrl_init_device_debugfs(pctldev);
mutex_lock(&pinctrldev_list_mutex);
list_add_tail(&pctldev->node, &pinctrldev_list);
mutex_unlock(&pinctrldev_list_mutex);
pinctrl_hog_maps(pctldev);
+ pinctrl_init_device_debugfs(pctldev);
+
return pctldev;

out_err:
diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h
index 061c57d..7551611 100644
--- a/drivers/pinctrl/core.h
+++ b/drivers/pinctrl/core.h
@@ -20,7 +20,6 @@ struct pinctrl_gpio_range;
* controller
* @pin_desc_tree: each pin descriptor for this pin controller is stored in
* this radix tree
- * @pin_desc_tree_lock: lock for the descriptor tree
* @gpio_ranges: a list of GPIO ranges that is handled by this pin controller,
* ranges are added to this list at runtime
* @gpio_ranges_lock: lock for the GPIO ranges list
@@ -28,7 +27,6 @@ struct pinctrl_gpio_range;
* @owner: module providing the pin controller, used for refcounting
* @driver_data: driver data for drivers registering to the pin controller
* subsystem
- * @pinctrl_hogs_lock: lock for the pin control hog list
* @pinctrl_hogs: list of pin control maps hogged by this device
* @device_root: debugfs root for this device
*/
@@ -36,13 +34,11 @@ struct pinctrl_dev {
struct list_head node;
struct pinctrl_desc *desc;
struct radix_tree_root pin_desc_tree;
- spinlock_t pin_desc_tree_lock;
struct list_head gpio_ranges;
struct mutex gpio_ranges_lock;
struct device *dev;
struct module *owner;
void *driver_data;
- struct mutex pinctrl_hogs_lock;
struct list_head pinctrl_hogs;
#ifdef CONFIG_DEBUG_FS
struct dentry *device_root;
@@ -99,7 +95,12 @@ struct pin_desc {
};

struct pinctrl_dev *get_pinctrl_dev_from_devname(const char *dev_name);
-struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, unsigned int pin);
int pin_get_from_name(struct pinctrl_dev *pctldev, const char *name);
int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
const char *pin_group);
+
+static inline struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev,
+ unsigned int pin)
+{
+ return radix_tree_lookup(&pctldev->pin_desc_tree, pin);
+}
--
1.7.0.4


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