diff options
Diffstat (limited to 'drivers/hwspinlock/hwspinlock_core.c')
| -rw-r--r-- | drivers/hwspinlock/hwspinlock_core.c | 204 |
1 files changed, 127 insertions, 77 deletions
diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 43a62714b4f..61c9cf15fa5 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 @@ -114,7 +117,7 @@ int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags) return -EBUSY; /* try to take the hwspinlock device */ - ret = hwlock->ops->trylock(hwlock); + ret = hwlock->bank->ops->trylock(hwlock); /* if hwlock is already taken, undo spin_trylock_* and exit */ if (!ret) { @@ -196,8 +199,8 @@ int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to, * Allow platform-specific relax handlers to prevent * hogging the interconnect (no sleeping, though) */ - if (hwlock->ops->relax) - hwlock->ops->relax(hwlock); + if (hwlock->bank->ops->relax) + hwlock->bank->ops->relax(hwlock); } return ret; @@ -242,7 +245,7 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) */ mb(); - hwlock->ops->unlock(hwlock); + hwlock->bank->ops->unlock(hwlock); /* Undo the spin_trylock{_irq, _irqsave} called while locking */ if (mode == HWLOCK_IRQSTATE) @@ -254,68 +257,37 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) } EXPORT_SYMBOL_GPL(__hwspin_unlock); -/** - * hwspin_lock_register() - register a new hw spinlock - * @hwlock: hwspinlock to register. - * - * 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. - * - * Returns 0 on success, or an appropriate error code on failure - */ -int hwspin_lock_register(struct hwspinlock *hwlock) +static int hwspin_lock_register_single(struct hwspinlock *hwlock, int id) { struct hwspinlock *tmp; int ret; - if (!hwlock || !hwlock->ops || - !hwlock->ops->trylock || !hwlock->ops->unlock) { - pr_err("invalid parameters\n"); - return -EINVAL; - } - - 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) + ret = radix_tree_insert(&hwspinlock_tree, id, hwlock); + if (ret) { + if (ret == -EEXIST) + pr_err("hwspinlock id %d already exists!\n", id); goto out; + } /* mark this hwspinlock as available */ - tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock->id, - HWSPINLOCK_UNUSED); + tmp = radix_tree_tag_set(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); /* self-sanity check which should never fail */ WARN_ON(tmp != hwlock); out: - spin_unlock(&hwspinlock_tree_lock); - return ret; + mutex_unlock(&hwspinlock_tree_lock); + return 0; } -EXPORT_SYMBOL_GPL(hwspin_lock_register); -/** - * hwspin_lock_unregister() - unregister an hw spinlock - * @id: index of the specific hwspinlock to unregister - * - * 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. - * - * Returns the address of hwspinlock @id on success, or NULL on failure - */ -struct hwspinlock *hwspin_lock_unregister(unsigned int id) +static struct hwspinlock *hwspin_lock_unregister_single(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); @@ -331,9 +303,91 @@ struct hwspinlock *hwspin_lock_unregister(unsigned int id) } out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return hwlock; } + +/** + * hwspin_lock_register() - register a new hw spinlock device + * @bank: the hwspinlock device, which usually provides numerous hw locks + * @dev: the backing device + * @ops: hwspinlock handlers for this device + * @base_id: id of the first hardware spinlock in this bank + * @num_locks: number of hwspinlocks provided by this device + * + * This function should be called from the underlying platform-specific + * implementation, to register a new hwspinlock device instance. + * + * Should be called from a process context (might sleep) + * + * Returns 0 on success, or an appropriate error code on failure + */ +int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, + const struct hwspinlock_ops *ops, int base_id, int num_locks) +{ + struct hwspinlock *hwlock; + int ret = 0, i; + + if (!bank || !ops || !dev || !num_locks || !ops->trylock || + !ops->unlock) { + pr_err("invalid parameters\n"); + return -EINVAL; + } + + bank->dev = dev; + bank->ops = ops; + bank->base_id = base_id; + bank->num_locks = num_locks; + + for (i = 0; i < num_locks; i++) { + hwlock = &bank->lock[i]; + + spin_lock_init(&hwlock->lock); + hwlock->bank = bank; + + ret = hwspin_lock_register_single(hwlock, i); + if (ret) + goto reg_failed; + } + + return 0; + +reg_failed: + while (--i >= 0) + hwspin_lock_unregister_single(i); + return ret; +} +EXPORT_SYMBOL_GPL(hwspin_lock_register); + +/** + * hwspin_lock_unregister() - unregister an hw spinlock device + * @bank: the hwspinlock device, which usually provides numerous hw locks + * + * This function should be called from the underlying platform-specific + * implementation, to unregister an existing (and unused) hwspinlock. + * + * Should be called from a process context (might sleep) + * + * Returns 0 on success, or an appropriate error code on failure + */ +int hwspin_lock_unregister(struct hwspinlock_device *bank) +{ + struct hwspinlock *hwlock, *tmp; + int i; + + for (i = 0; i < bank->num_locks; i++) { + hwlock = &bank->lock[i]; + + tmp = hwspin_lock_unregister_single(bank->base_id + i); + if (!tmp) + return -EBUSY; + + /* self-sanity check that should never fail */ + WARN_ON(tmp != hwlock); + } + + return 0; +} EXPORT_SYMBOL_GPL(hwspin_lock_unregister); /** @@ -348,24 +402,25 @@ EXPORT_SYMBOL_GPL(hwspin_lock_unregister); */ static int __hwspin_lock_request(struct hwspinlock *hwlock) { + struct device *dev = hwlock->bank->dev; struct hwspinlock *tmp; int ret; /* prevent underlying implementation from being removed */ - if (!try_module_get(hwlock->owner)) { - dev_err(hwlock->dev, "%s: can't get owner\n", __func__); + if (!try_module_get(dev->driver->owner)) { + dev_err(dev, "%s: can't get owner\n", __func__); return -EINVAL; } /* notify PM core that power is now needed */ - ret = pm_runtime_get_sync(hwlock->dev); + ret = pm_runtime_get_sync(dev); if (ret < 0) { - dev_err(hwlock->dev, "%s: can't power on device\n", __func__); + dev_err(dev, "%s: can't power on device\n", __func__); return ret; } /* mark hwspinlock as used, should not fail */ - tmp = radix_tree_tag_clear(&hwspinlock_tree, hwlock->id, + tmp = radix_tree_tag_clear(&hwspinlock_tree, hwlock_to_id(hwlock), HWSPINLOCK_UNUSED); /* self-sanity check that should never fail */ @@ -387,7 +442,7 @@ int hwspin_lock_get_id(struct hwspinlock *hwlock) return -EINVAL; } - return hwlock->id; + return hwlock_to_id(hwlock); } EXPORT_SYMBOL_GPL(hwspin_lock_get_id); @@ -400,9 +455,7 @@ 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 */ @@ -411,7 +464,7 @@ 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, @@ -431,7 +484,7 @@ 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); @@ -445,9 +498,7 @@ 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 */ @@ -456,7 +507,7 @@ 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); @@ -466,7 +517,7 @@ struct hwspinlock *hwspin_lock_request_specific(unsigned int id) } /* sanity check (this shouldn't happen) */ - WARN_ON(hwlock->id != id); + WARN_ON(hwlock_to_id(hwlock) != id); /* make sure this hwspinlock is unused */ ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); @@ -482,7 +533,7 @@ 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); @@ -495,14 +546,13 @@ 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 */ int hwspin_lock_free(struct hwspinlock *hwlock) { + struct device *dev = hwlock->bank->dev; struct hwspinlock *tmp; int ret; @@ -511,34 +561,34 @@ 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, + ret = radix_tree_tag_get(&hwspinlock_tree, hwlock_to_id(hwlock), HWSPINLOCK_UNUSED); if (ret == 1) { - dev_err(hwlock->dev, "%s: hwlock is already free\n", __func__); + dev_err(dev, "%s: hwlock is already free\n", __func__); dump_stack(); ret = -EINVAL; goto out; } /* notify the underlying device that power is not needed */ - ret = pm_runtime_put(hwlock->dev); + ret = pm_runtime_put(dev); if (ret < 0) goto out; /* mark this hwspinlock as available */ - tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock->id, + tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock_to_id(hwlock), HWSPINLOCK_UNUSED); /* sanity check (this shouldn't happen) */ WARN_ON(tmp != hwlock); - module_put(hwlock->owner); + module_put(dev->driver->owner); out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return ret; } EXPORT_SYMBOL_GPL(hwspin_lock_free); |