[RFC PATCH v2 02/13] hwspinlock: add callback to fill private data of a hwspinlock

[Wolfram Sang]

To hide internal core structures from providers, a callback is added to
the ops which allows to set the 'priv' field of a hwspinlock. It is
called when a hwspinlock device is registered and, thus, iterated over
all locks. The register-functions are also extended to pass a data
pointer to this callback, so it can do necessary calculations for the
priv field of each hwspinlock. Providers are converted separately
because these changes need dedicated reviews.

Signed-off-by: Wolfram Sang <wsa+renesas at sang-engineering.com>
---
 drivers/hwspinlock/hwspinlock_core.c     | 19 +++++++++++++++----
 drivers/hwspinlock/hwspinlock_internal.h | 19 +++++++++++--------
 include/linux/hwspinlock.h               |  4 ++--
 3 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c
index 2c9eceba7fe8..afe1e7ce2829 100644
--- a/drivers/hwspinlock/hwspinlock_core.c
+++ b/drivers/hwspinlock/hwspinlock_core.c
@@ -507,6 +507,7 @@ static struct hwspinlock *hwspin_lock_unregister_single(unsigned int id)
  * @ops: hwspinlock handlers for this device
  * @base_id: id of the first hardware spinlock in this bank
  * @num_locks: number of hwspinlocks provided by this device
+ * @init_data: additional data passed on to the init_priv callback
  *
  * This function should be called from the underlying platform-specific
  * implementation, to register a new hwspinlock device instance.
@@ -516,10 +517,11 @@ static struct hwspinlock *hwspin_lock_unregister_single(unsigned int id)
  * Returns: %0 on success, or an appropriate error code on failure
  */
 int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,
-		const struct hwspinlock_ops *ops, int base_id, int num_locks)
+		const struct hwspinlock_ops *ops, int base_id, int num_locks,
+		void *init_data)
 {
 	struct hwspinlock *hwlock;
-	int ret = 0, i;
+	int ret, i;
 
 	if (!bank || !ops || !dev || !num_locks || !ops->trylock ||
 							!ops->unlock) {
@@ -538,6 +540,14 @@ int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,
 		spin_lock_init(&hwlock->lock);
 		hwlock->bank = bank;
 
+		if (ops->init_priv) {
+			hwlock->priv = ops->init_priv(i, init_data);
+			if (IS_ERR(hwlock->priv)) {
+				ret = PTR_ERR(hwlock->priv);
+				goto reg_failed;
+			}
+		}
+
 		ret = hwspin_lock_register_single(hwlock, base_id + i);
 		if (ret)
 			goto reg_failed;
@@ -633,6 +643,7 @@ EXPORT_SYMBOL_GPL(devm_hwspin_lock_unregister);
  * @ops: hwspinlock handlers for this device
  * @base_id: id of the first hardware spinlock in this bank
  * @num_locks: number of hwspinlocks provided by this device
+ * @init_data: additional data passed on to the init_priv callback
  *
  * This function should be called from the underlying platform-specific
  * implementation, to register a new hwspinlock device instance.
@@ -644,7 +655,7 @@ EXPORT_SYMBOL_GPL(devm_hwspin_lock_unregister);
 int devm_hwspin_lock_register(struct device *dev,
 			      struct hwspinlock_device *bank,
 			      const struct hwspinlock_ops *ops,
-			      int base_id, int num_locks)
+			      int base_id, int num_locks, void *init_data)
 {
 	struct hwspinlock_device **ptr;
 	int ret;
@@ -653,7 +664,7 @@ int devm_hwspin_lock_register(struct device *dev,
 	if (!ptr)
 		return -ENOMEM;
 
-	ret = hwspin_lock_register(bank, dev, ops, base_id, num_locks);
+	ret = hwspin_lock_register(bank, dev, ops, base_id, num_locks, init_data);
 	if (!ret) {
 		*ptr = bank;
 		devres_add(dev, ptr);
diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h
index f298fc0ee5ad..3c835d96bf86 100644
--- a/drivers/hwspinlock/hwspinlock_internal.h
+++ b/drivers/hwspinlock/hwspinlock_internal.h
@@ -18,20 +18,23 @@ struct hwspinlock_device;
 /**
  * struct hwspinlock_ops - platform-specific hwspinlock handlers
  *
- * @trylock: make a single attempt to take the lock. returns 0 on
- *	     failure and true on success. may _not_ sleep.
- * @unlock:  release the lock. always succeed. may _not_ sleep.
- * @bust:    optional, platform-specific bust handler, called by hwspinlock
- *	     core to bust a specific lock.
- * @relax:   optional, platform-specific relax handler, called by hwspinlock
- *	     core while spinning on a lock, between two successive
- *	     invocations of @trylock. may _not_ sleep.
+ * @trylock:	make a single attempt to take the lock. returns 0 on
+ *		failure and true on success. may _not_ sleep.
+ * @unlock:	release the lock. always succeed. may _not_ sleep.
+ * @bust:	optional, platform-specific bust handler, called by hwspinlock
+ *		core to bust a specific lock.
+ * @relax:	optional, platform-specific relax handler, called by hwspinlock
+ *		core while spinning on a lock, between two successive
+ *		invocations of @trylock. may _not_ sleep.
+ * @init_priv:	optional, callback used when registering the hwspinlock device.
+ *		Its return value will be used to fill the per-lock 'priv' data.
  */
 struct hwspinlock_ops {
 	int (*trylock)(struct hwspinlock *lock);
 	void (*unlock)(struct hwspinlock *lock);
 	int (*bust)(struct hwspinlock *lock, unsigned int id);
 	void (*relax)(struct hwspinlock *lock);
+	void *(*init_priv)(int local_id, void *init_data);
 };
 
 /**
diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h
index dffa1dff7289..094a6d0d39d6 100644
--- a/include/linux/hwspinlock.h
+++ b/include/linux/hwspinlock.h
@@ -30,7 +30,7 @@ struct hwspinlock_ops;
 void *hwspin_lock_get_priv(struct hwspinlock *hwlock);
 struct device *hwspin_lock_get_dev(struct hwspinlock *hwlock);
 int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,
-		const struct hwspinlock_ops *ops, int base_id, int num_locks);
+		const struct hwspinlock_ops *ops, int base_id, int num_locks, void *init_data);
 int hwspin_lock_unregister(struct hwspinlock_device *bank);
 struct hwspinlock *hwspin_lock_request_specific(unsigned int id);
 int hwspin_lock_free(struct hwspinlock *hwlock);
@@ -49,7 +49,7 @@ int devm_hwspin_lock_unregister(struct device *dev,
 int devm_hwspin_lock_register(struct device *dev,
 			      struct hwspinlock_device *bank,
 			      const struct hwspinlock_ops *ops,
-			      int base_id, int num_locks);
+			      int base_id, int num_locks, void *init_data);
 
 #else /* !CONFIG_HWSPINLOCK */
 
-- 
2.51.0