diff options
Diffstat (limited to 'drivers/hwspinlock/hwspinlock_core.c')
| -rw-r--r-- | drivers/hwspinlock/hwspinlock_core.c | 45 |
1 files changed, 20 insertions, 25 deletions
diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 4eb85b4a320..0d20b82df0a 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -26,6 +26,7 @@ #include <linux/radix-tree.h> #include <linux/hwspinlock.h> #include <linux/pm_runtime.h> +#include <linux/mutex.h> #include "hwspinlock_internal.h" @@ -52,10 +53,12 @@ static RADIX_TREE(hwspinlock_tree, GFP_KERNEL); /* - * Synchronization of access to the tree is achieved using this spinlock, + * Synchronization of access to the tree is achieved using this mutex, * as the radix-tree API requires that users provide all synchronisation. + * A mutex is needed because we're using non-atomic radix tree allocations. */ -static DEFINE_SPINLOCK(hwspinlock_tree_lock); +static DEFINE_MUTEX(hwspinlock_tree_lock); + /** * __hwspin_trylock() - attempt to lock a specific hwspinlock @@ -261,8 +264,7 @@ EXPORT_SYMBOL_GPL(__hwspin_unlock); * This function should be called from the underlying platform-specific * implementation, to register a new hwspinlock instance. * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context. + * Should be called from a process context (might sleep) * * Returns 0 on success, or an appropriate error code on failure */ @@ -279,7 +281,7 @@ int hwspin_lock_register(struct hwspinlock *hwlock) spin_lock_init(&hwlock->lock); - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); ret = radix_tree_insert(&hwspinlock_tree, hwlock->id, hwlock); if (ret == -EEXIST) @@ -295,7 +297,7 @@ int hwspin_lock_register(struct hwspinlock *hwlock) WARN_ON(tmp != hwlock); out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return ret; } EXPORT_SYMBOL_GPL(hwspin_lock_register); @@ -307,8 +309,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_register); * This function should be called from the underlying platform-specific * implementation, to unregister an existing (and unused) hwspinlock. * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context. + * Should be called from a process context (might sleep) * * Returns the address of hwspinlock @id on success, or NULL on failure */ @@ -317,7 +318,7 @@ struct hwspinlock *hwspin_lock_unregister(unsigned int id) struct hwspinlock *hwlock = NULL; int ret; - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); /* make sure the hwspinlock is not in use (tag is set) */ ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); @@ -333,7 +334,7 @@ struct hwspinlock *hwspin_lock_unregister(unsigned int id) } out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return hwlock; } EXPORT_SYMBOL_GPL(hwspin_lock_unregister); @@ -402,9 +403,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_get_id); * to the remote core before it can be used for synchronization (to get the * id of a given hwlock, use hwspin_lock_get_id()). * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context (simply because there is no use case for - * that yet). + * Should be called from a process context (might sleep) * * Returns the address of the assigned hwspinlock, or NULL on error */ @@ -413,7 +412,7 @@ struct hwspinlock *hwspin_lock_request(void) struct hwspinlock *hwlock; int ret; - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); /* look for an unused lock */ ret = radix_tree_gang_lookup_tag(&hwspinlock_tree, (void **)&hwlock, @@ -433,7 +432,7 @@ struct hwspinlock *hwspin_lock_request(void) hwlock = NULL; out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return hwlock; } EXPORT_SYMBOL_GPL(hwspin_lock_request); @@ -447,9 +446,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_request); * Usually early board code will be calling this function in order to * reserve specific hwspinlock ids for predefined purposes. * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context (simply because there is no use case for - * that yet). + * Should be called from a process context (might sleep) * * Returns the address of the assigned hwspinlock, or NULL on error */ @@ -458,7 +455,7 @@ struct hwspinlock *hwspin_lock_request_specific(unsigned int id) struct hwspinlock *hwlock; int ret; - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); /* make sure this hwspinlock exists */ hwlock = radix_tree_lookup(&hwspinlock_tree, id); @@ -484,7 +481,7 @@ struct hwspinlock *hwspin_lock_request_specific(unsigned int id) hwlock = NULL; out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return hwlock; } EXPORT_SYMBOL_GPL(hwspin_lock_request_specific); @@ -497,9 +494,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_request_specific); * Should only be called with an @hwlock that was retrieved from * an earlier call to omap_hwspin_lock_request{_specific}. * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context (simply because there is no use case for - * that yet). + * Should be called from a process context (might sleep) * * Returns 0 on success, or an appropriate error code on failure */ @@ -513,7 +508,7 @@ int hwspin_lock_free(struct hwspinlock *hwlock) return -EINVAL; } - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); /* make sure the hwspinlock is used */ ret = radix_tree_tag_get(&hwspinlock_tree, hwlock->id, @@ -540,7 +535,7 @@ int hwspin_lock_free(struct hwspinlock *hwlock) module_put(hwlock->dev->driver->owner); out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return ret; } EXPORT_SYMBOL_GPL(hwspin_lock_free); |