path: root/Documentation/hwspinlock.txt
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2013-08-27doc: documentation/hwspinlock.txt fix typoXishi Qiu
Fix a trivial typo in Documentation/hwspinlock.txt Signed-off-by: Xishi Qiu <> Acked-by: Rob Landley <> Signed-off-by: Jiri Kosina <>
2011-09-21hwspinlock/core: register a bank of hwspinlocks in a single API callOhad Ben-Cohen
Hardware Spinlock devices usually contain numerous locks (known devices today support between 32 to 256 locks). Originally hwspinlock core required drivers to register (and later, when needed, unregister) each lock separately. That worked, but required hwspinlocks drivers to do a bit extra work when they were probed/removed. This patch changes hwspin_lock_{un}register() to allow a bank of hwspinlocks to be {un}registered in a single invocation. A new 'struct hwspinlock_device', which contains an array of 'struct hwspinlock's is now being passed to the core upon registration (so instead of wrapping each struct hwspinlock, a priv member has been added to allow drivers to piggyback their private data with each hwspinlock). While at it, several per-lock members were moved to be per-device: 1. struct device *dev 2. struct hwspinlock_ops *ops In addition, now that the array of locks is handled by the core, there's no reason to maintain a per-lock 'int id' member: the id of the lock anyway equals to its index in the bank's array plus the bank's base_id. Remove this per-lock id member too, and instead use a simple pointers arithmetic to derive it. As a result of this change, hwspinlocks drivers are now simpler and smaller (about %20 code reduction) and the memory footprint of the hwspinlock framework is reduced. Signed-off-by: Ohad Ben-Cohen <>
2011-09-21hwspinlock/core: use a mutex to protect the radix treeJuan Gutierrez
Since we're using non-atomic radix tree allocations, we should be protecting the tree using a mutex and not a spinlock. Non-atomic allocations and process context locking is good enough, as the tree is manipulated only when locks are registered/ unregistered/requested/freed. The locks themselves are still protected by spinlocks of course, and mutexes are not involved in the locking/unlocking paths. Cc: <> Signed-off-by: Juan Gutierrez <> [ rewrite the commit log, #include mutex.h, add minor commentary] [ update register/unregister parts in hwspinlock.txt] Signed-off-by: Ohad Ben-Cohen <>
2011-09-21hwspinlock/core: simplify 'owner' handlingOhad Ben-Cohen
Use struct device_driver's owner member instead of asking drivers to explicitly pass the owner again. This simplifies drivers and also save some memory, since there's no point now in maintaining a separate owner pointer per hwspinlock. Signed-off-by: Ohad Ben-Cohen <>
2011-02-17drivers: hwspinlock: add frameworkOhad Ben-Cohen
Add a platform-independent hwspinlock framework. Hardware spinlock devices are needed, e.g., in order to access data that is shared between remote processors, that otherwise have no alternative mechanism to accomplish synchronization and mutual exclusion operations. Signed-off-by: Ohad Ben-Cohen <> Cc: Hari Kanigeri <> Cc: Benoit Cousson <> Cc: Kevin Hilman <> Cc: Grant Likely <> Cc: Paul Walmsley <> Cc: Russell King <> Acked-by: Arnd Bergmann <> Signed-off-by: Tony Lindgren <>