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Commit 4f1acd75 authored Jun 22, 2018 by Baolin Wang Committed by Bjorn Andersson Jun 26, 2018

hwspinlock: Add devm_xxx() APIs to request/free hwlock



This patch introduces some devm_xxx() APIs to help to request or free
the hwlocks, which will help to simplify the cleanup code for drivers
requesting one hwlock, ensuring that the hwlock is automatically freed
whenever the device is unbound.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

parent 5560f70c

drivers/hwspinlock/hwspinlock_core.c

+110 −0

Original line number	Diff line number	Diff line
		@@ -735,6 +735,116 @@ int hwspin_lock_free(struct hwspinlock *hwlock)
		}
		EXPORT_SYMBOL_GPL(hwspin_lock_free);

		static int devm_hwspin_lock_match(struct device dev, void res, void *data)
		{
		struct hwspinlock **hwlock = res;

		if (WARN_ON(!hwlock \|\| !*hwlock))
		return 0;

		return *hwlock == data;
		}

		static void devm_hwspin_lock_release(struct device dev, void res)
		{
		hwspin_lock_free((struct hwspinlock *)res);
		}

		/**
		* devm_hwspin_lock_free() - free a specific hwspinlock for a managed device
		* @dev: the device to free the specific hwspinlock
		* @hwlock: the specific hwspinlock to free
		*
		* This function mark @hwlock as free again.
		* Should only be called with an @hwlock that was retrieved from
		* an earlier call to hwspin_lock_request{_specific}.
		*
		* Should be called from a process context (might sleep)
		*
		* Returns 0 on success, or an appropriate error code on failure
		*/
		int devm_hwspin_lock_free(struct device dev, struct hwspinlock hwlock)
		{
		int ret;

		ret = devres_release(dev, devm_hwspin_lock_release,
		devm_hwspin_lock_match, hwlock);
		WARN_ON(ret);

		return ret;
		}
		EXPORT_SYMBOL_GPL(devm_hwspin_lock_free);

		/**
		* devm_hwspin_lock_request() - request an hwspinlock for a managed device
		* @dev: the device to request an hwspinlock
		*
		* This function should be called by users of the hwspinlock device,
		* in order to dynamically assign them an unused hwspinlock.
		* Usually the user of this lock will then have to communicate the lock's id
		* to the remote core before it can be used for synchronization (to get the
		* id of a given hwlock, use hwspin_lock_get_id()).
		*
		* Should be called from a process context (might sleep)
		*
		* Returns the address of the assigned hwspinlock, or NULL on error
		*/
		struct hwspinlock devm_hwspin_lock_request(struct device dev)
		{
		struct hwspinlock *ptr, hwlock;

		ptr = devres_alloc(devm_hwspin_lock_release, sizeof(*ptr), GFP_KERNEL);
		if (!ptr)
		return ERR_PTR(-ENOMEM);

		hwlock = hwspin_lock_request();
		if (!IS_ERR(hwlock)) {
		*ptr = hwlock;
		devres_add(dev, ptr);
		} else {
		devres_free(ptr);
		}

		return hwlock;
		}
		EXPORT_SYMBOL_GPL(devm_hwspin_lock_request);

		/**
		* devm_hwspin_lock_request_specific() - request for a specific hwspinlock for
		* a managed device
		* @dev: the device to request the specific hwspinlock
		* @id: index of the specific hwspinlock that is requested
		*
		* This function should be called by users of the hwspinlock module,
		* in order to assign them a specific hwspinlock.
		* Usually early board code will be calling this function in order to
		* reserve specific hwspinlock ids for predefined purposes.
		*
		* Should be called from a process context (might sleep)
		*
		* Returns the address of the assigned hwspinlock, or NULL on error
		*/
		struct hwspinlock devm_hwspin_lock_request_specific(struct device dev,
		unsigned int id)
		{
		struct hwspinlock *ptr, hwlock;

		ptr = devres_alloc(devm_hwspin_lock_release, sizeof(*ptr), GFP_KERNEL);
		if (!ptr)
		return ERR_PTR(-ENOMEM);

		hwlock = hwspin_lock_request_specific(id);
		if (!IS_ERR(hwlock)) {
		*ptr = hwlock;
		devres_add(dev, ptr);
		} else {
		devres_free(ptr);
		}

		return hwlock;
		}
		EXPORT_SYMBOL_GPL(devm_hwspin_lock_request_specific);

		MODULE_LICENSE("GPL v2");
		MODULE_DESCRIPTION("Hardware spinlock interface");
		MODULE_AUTHOR("Ohad Ben-Cohen <ohad@wizery.com>");

include/linux/hwspinlock.h

+22 −0

Original line number	Diff line number	Diff line
		@@ -67,6 +67,10 @@ int __hwspin_lock_timeout(struct hwspinlock *, unsigned int, int,
		int __hwspin_trylock(struct hwspinlock , int, unsigned long );
		void __hwspin_unlock(struct hwspinlock , int, unsigned long );
		int of_hwspin_lock_get_id_byname(struct device_node np, const char name);
		int devm_hwspin_lock_free(struct device dev, struct hwspinlock hwlock);
		struct hwspinlock devm_hwspin_lock_request(struct device dev);
		struct hwspinlock devm_hwspin_lock_request_specific(struct device dev,
		unsigned int id);

		#else /* !CONFIG_HWSPINLOCK */

		@@ -132,6 +136,24 @@ int of_hwspin_lock_get_id_byname(struct device_node np, const char name)
		return 0;
		}

		static inline
		int devm_hwspin_lock_free(struct device dev, struct hwspinlock hwlock)
		{
		return 0;
		}

		static inline struct hwspinlock devm_hwspin_lock_request(struct device dev)
		{
		return ERR_PTR(-ENODEV);
		}

		static inline
		struct hwspinlock devm_hwspin_lock_request_specific(struct device dev,
		unsigned int id)
		{
		return ERR_PTR(-ENODEV);
		}

		#endif /* !CONFIG_HWSPINLOCK */

		/**