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path: root/drivers/hwspinlock/hwspinlock_core.c
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2016-05-20drivers/hwspinlock: use correct radix tree APIMatthew Wilcox
radix_tree_is_indirect_ptr() is an internal API. The correct call to use is radix_tree_deref_retry() which has the appropriate unlikely() annotation. Fixes: c6400ba7e13a ("drivers/hwspinlock: fix race between radix tree insertion and lookup") Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Jan Kara <jack@suse.com> Cc: Neil Brown <neilb@suse.de> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-03drivers/hwspinlock: fix race between radix tree insertion and lookupMatthew Wilcox
of_hwspin_lock_get_id() is protected by the RCU lock, which means that insertions can occur simultaneously with the lookup. If the radix tree transitions from a height of 0, we can see a slot with the indirect_ptr bit set, which will cause us to at least read random memory, and could cause other havoc. Fix this by using the newly introduced radix_tree_iter_retry(). Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ohad Ben-Cohen <ohad@wizery.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-02hwspinlock/core: add device tree supportSuman Anna
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 <s-anna@ti.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> [small comment clarification] Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2013-04-05hwspinlock: fix __hwspin_lock_request error pathLi Fei
Even in failed case of pm_runtime_get_sync, the usage_count is incremented. In order to keep the usage_count with correct value and runtime power management to behave correctly, call pm_runtime_put_noidle in such case. In __hwspin_lock_request, module_put is also called before return in pm_runtime_get_sync failed case. Cc: stable@vger.kernel.org Signed-off-by Liu Chuansheng <chuansheng.liu@intel.com> Signed-off-by: Li Fei <fei.li@intel.com> [edit commit log] Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-09-10hwspinlock/core: move the dereference below the NULL testWei Yongjun
The dereference should be moved below the NULL test. spatch with a semantic match is used to found this. (http://coccinelle.lip6.fr/) Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-07-07hwspinlock/core: use global ID to register hwspinlocks on multiple devicesShinya Kuribayashi
Commit 300bab9770 (hwspinlock/core: register a bank of hwspinlocks in a single API call, 2011-09-06) introduced 'hwspin_lock_register_single()' to register numerous (a bank of) hwspinlock instances in a single API, 'hwspin_lock_register()'. At which time, 'hwspin_lock_register()' accidentally passes 'local IDs' to 'hwspin_lock_register_single()', despite that ..._single() requires 'global IDs' to register hwspinlocks. We have to convert into global IDs by supplying the missing 'base_id'. Cc: stable <stable@vger.kernel.org> Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com> [ohad: fix error path of hwspin_lock_register, too] Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
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 <ohad@wizery.com>
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: <stable@kernel.org> Signed-off-by: Juan Gutierrez <jgutierrez@ti.com> [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 <ohad@wizery.com>
2011-09-21hwspinlock/core/omap: fix id issues on multiple hwspinlock devicesOhad Ben-Cohen
hwspinlock devices provide system-wide hardware locks that are used by remote processors that have no other way to achieve synchronization. To achieve that, each physical lock must have a system-wide id number that is agreed upon, otherwise remote processors can't possibly assume they're using the same hardware lock. Usually boards have a single hwspinlock device, which provides several hwspinlocks, and in this case, they can be trivially numbered 0 to (num-of-locks - 1). In case boards have several hwspinlocks devices, a different base id should be used for each hwspinlock device (they can't all use 0 as a starting id!). While this is certainly not common, it's just plain wrong to just silently use 0 as a base id whenever the hwspinlock driver is probed. This patch provides a hwspinlock_pdata structure, that boards can use to set a different base id for each of the hwspinlock devices they may have, and demonstrates how to use it with the omap hwspinlock driver. While we're at it, make sure the hwspinlock core prints an explicit error message in case an hwspinlock is registered with an id number that already exists; this will help users catch such base id issues. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Acked-by: Tony Lindgren <tony@atomide.com>
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 <ohad@wizery.com>
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 <ohad@wizery.com> Cc: Hari Kanigeri <h-kanigeri2@ti.com> Cc: Benoit Cousson <b-cousson@ti.com> Cc: Kevin Hilman <khilman@ti.com> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Paul Walmsley <paul@pwsan.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Tony Lindgren <tony@atomide.com>