kernel/git/stable/linux.git/Documentation/hwspinlock.txt, branch master

docs: move locking-specific documents to locking/

2020-05-15T18:05:07+00:00

Several files under Documentation/*.txt describe some type of locking API. Move them to locking/ subdir and add to the locking/index.rst index file. Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/dd833a10bbd0b2c1461d78913f5ec28a7e27f00b.1588345503.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet

hwspinlock: add the 'in_atomic' API

2019-06-30T04:08:14+00:00

Add the 'in_atomic' mode which can be called from an atomic context. This mode relies on the existing 'raw' mode (no lock, no preemption/irq disabling) with the difference that the timeout is not based on jiffies (jiffies won't increase when irq are disabled) but handled with busy-waiting udelay() calls. Signed-off-by: Fabien Dessenne Signed-off-by: Bjorn Andersson

hwspinlock: document the hwspinlock 'raw' API

2019-06-30T04:08:13+00:00

Document the hwspin_lock_timeout_raw(), hwspin_trylock_raw() and hwspin_unlock_raw() API. Signed-off-by: Fabien Dessenne Signed-off-by: Bjorn Andersson

hwspinlock.txt: standardize document format

2017-07-14T19:51:37+00:00

Each text file under Documentation follows a different format. Some doesn't even have titles! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - Adjust title markups; - remove explicit numeration from titles; - mark literal blocks as such; - replace _foo_ by **foo** for emphasis; - adjust whitespaces and add blank lines where needed. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Jonathan Corbet

hwspinlock/core: add device tree support

2015-05-02T06:54:30+00:00

This patch adds a new OF-friendly API of_hwspin_lock_get_id() for hwspinlock clients to use/request locks from a hwspinlock device instantiated through a device-tree blob. This new API can be used by hwspinlock clients to get the id for a specific lock using the phandle + args specifier, so that it can be requested using the available hwspin_lock_request_specific() API. Signed-off-by: Suman Anna Reviewed-by: Bjorn Andersson [small comment clarification] Signed-off-by: Ohad Ben-Cohen

doc: documentation/hwspinlock.txt fix typo

2013-08-27T08:46:02+00:00

Fix a trivial typo in Documentation/hwspinlock.txt Signed-off-by: Xishi Qiu Acked-by: Rob Landley Signed-off-by: Jiri Kosina

hwspinlock/core: register a bank of hwspinlocks in a single API call

2011-09-21T16:45:34+00:00

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

hwspinlock/core: use a mutex to protect the radix tree

2011-09-21T16:45:32+00:00

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 [ohad@wizery.com: rewrite the commit log, #include mutex.h, add minor commentary] [ohad@wizery.com: update register/unregister parts in hwspinlock.txt] Signed-off-by: Ohad Ben-Cohen

hwspinlock/core: simplify 'owner' handling

2011-09-21T16:45:32+00:00

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

drivers: hwspinlock: add framework

2011-02-17T17:52:03+00:00

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