From bd9a4c7df256cee4e9f6a4b56baa3b89d63f0f1e Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Thu, 17 Feb 2011 09:52:03 -0800 Subject: drivers: hwspinlock: add framework 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 --- drivers/hwspinlock/hwspinlock_internal.h | 61 ++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 drivers/hwspinlock/hwspinlock_internal.h (limited to 'drivers/hwspinlock/hwspinlock_internal.h') diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h new file mode 100644 index 000000000000..69935e6b93e5 --- /dev/null +++ b/drivers/hwspinlock/hwspinlock_internal.h @@ -0,0 +1,61 @@ +/* + * Hardware spinlocks internal header + * + * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com + * + * Contact: Ohad Ben-Cohen + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef __HWSPINLOCK_HWSPINLOCK_H +#define __HWSPINLOCK_HWSPINLOCK_H + +#include +#include + +/** + * struct hwspinlock_ops - platform-specific hwspinlock handlers + * + * @trylock: make a single attempt to take the lock. returns 0 on + * failure and true on success. may _not_ sleep. + * @unlock: release the lock. always succeed. may _not_ sleep. + * @relax: optional, platform-specific relax handler, called by hwspinlock + * core while spinning on a lock, between two successive + * invocations of @trylock. may _not_ sleep. + */ +struct hwspinlock_ops { + int (*trylock)(struct hwspinlock *lock); + void (*unlock)(struct hwspinlock *lock); + void (*relax)(struct hwspinlock *lock); +}; + +/** + * struct hwspinlock - this struct represents a single hwspinlock instance + * + * @dev: underlying device, will be used to invoke runtime PM api + * @ops: platform-specific hwspinlock handlers + * @id: a global, unique, system-wide, index of the lock. + * @lock: initialized and used by hwspinlock core + * @owner: underlying implementation module, used to maintain module ref count + * + * Note: currently simplicity was opted for, but later we can squeeze some + * memory bytes by grouping the dev, ops and owner members in a single + * per-platform struct, and have all hwspinlocks point at it. + */ +struct hwspinlock { + struct device *dev; + const struct hwspinlock_ops *ops; + int id; + spinlock_t lock; + struct module *owner; +}; + +#endif /* __HWSPINLOCK_HWSPINLOCK_H */ -- cgit v1.2.3