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path: root/drivers/hwspinlock
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2011-09-21hwspinlock/omap: omap_hwspinlock_remove should be __devexitOhad Ben-Cohen1-2/+2
Mark omap_hwspinlock_remove with __devexit (and use __devexit_p appropriately) so the function can be discarded when the conditions are met. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2011-09-21hwspinlock/u8500: add hwspinlock driverMathieu J. Poirier3-0/+210
Add hwspinlock driver for U8500's Hsem hardware. At this point only HSem's protocol 1 is used (i.e. no interrupts). Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> [ohad@wizery.com: adopt recent hwspin_lock_{un}register API changes] [ohad@wizery.com: set the owner member of the driver] [ohad@wizery.com: mark ->remove() function as __devexit] [ohad@wizery.com: write commit log] [ohad@wizery.com: small cleanups] Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2011-09-21hwspinlock/core: register a bank of hwspinlocks in a single API callOhad Ben-Cohen3-123/+166
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 Gutierrez1-25/+20
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-Cohen2-1/+7
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/omap: simplify allocation schemeOhad Ben-Cohen1-34/+17
Instead of allocating every hwspinlock separately, allocate them all in one shot. This both simplifies the driver and helps achieving better slab utilization. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2011-09-21hwspinlock/core: simplify 'owner' handlingOhad Ben-Cohen3-6/+4
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>
2011-09-21hwspinlock/core: simplify KconfigOhad Ben-Cohen1-9/+7
Simplify hwspinlock's Kconfig by making the global CONFIG_HWSPINLOCK entry invisible; users will just select it when needed. This also prepares the ground for adding hwspinlock support for other platforms (the 'depends on ARCH_OMAP4' was rather hideous, and while we're at it, a dedicated menu is added). Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2011-03-19hwspinlock: depend on OMAP4Ohad Ben-Cohen1-0/+1
Currently only OMAP4 supports hwspinlocks, so don't bother asking anyone else. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
2011-02-17drivers: hwspinlock: add OMAP implementationSimon Que3-0/+241
Add hwspinlock support for the OMAP4 Hardware Spinlock device. The Hardware Spinlock device on OMAP4 provides hardware assistance for synchronization between the multiple processors in the system (dual Cortex-A9, dual Cortex-M3 and a C64x+ DSP). [ohad@wizery.com: adapt to hwspinlock framework, tidy up] Signed-off-by: Simon Que <sque@ti.com> Signed-off-by: Hari Kanigeri <h-kanigeri2@ti.com> Signed-off-by: Krishnamoorthy, Balaji T <balajitk@ti.com> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Cc: Benoit Cousson <b-cousson@ti.com> Cc: Kevin Hilman <khilman@ti.com> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Paul Walmsley <paul@pwsan.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Tony Lindgren <tony@atomide.com>
2011-02-17drivers: hwspinlock: add frameworkOhad Ben-Cohen4-0/+627
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>