diff options
| -rw-r--r-- | Documentation/hwspinlock.txt | 58 | ||||
| -rw-r--r-- | drivers/hwspinlock/hwspinlock_core.c | 165 | ||||
| -rw-r--r-- | drivers/hwspinlock/hwspinlock_internal.h | 38 | ||||
| -rw-r--r-- | drivers/hwspinlock/omap_hwspinlock.c | 86 | ||||
| -rw-r--r-- | include/linux/hwspinlock.h | 8 |
5 files changed, 211 insertions, 144 deletions
diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt index 9171f9120143..a903ee5e9776 100644 --- a/Documentation/hwspinlock.txt +++ b/Documentation/hwspinlock.txt @@ -227,42 +227,62 @@ int hwspinlock_example2(void) 4. API for implementors - int hwspin_lock_register(struct hwspinlock *hwlock); + int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, + const struct hwspinlock_ops *ops, int base_id, int num_locks); - to be called from the underlying platform-specific implementation, in - order to register a new hwspinlock instance. Should be called from - a process context (this function might sleep). + order to register a new hwspinlock device (which is usually a bank of + numerous locks). Should be called from a process context (this function + might sleep). Returns 0 on success, or appropriate error code on failure. - struct hwspinlock *hwspin_lock_unregister(unsigned int id); + int hwspin_lock_unregister(struct hwspinlock_device *bank); - to be called from the underlying vendor-specific implementation, in order - to unregister an existing (and unused) hwspinlock instance. + to unregister an hwspinlock device (which is usually a bank of numerous + locks). Should be called from a process context (this function might sleep). Returns the address of hwspinlock on success, or NULL on error (e.g. if the hwspinlock is sill in use). -5. struct hwspinlock +5. Important structs -This struct represents an hwspinlock instance. It is registered by the -underlying hwspinlock implementation using the hwspin_lock_register() API. +struct hwspinlock_device is a device which usually contains a bank +of hardware locks. It is registered by the underlying hwspinlock +implementation using the hwspin_lock_register() API. /** - * struct hwspinlock - vendor-specific hwspinlock implementation - * - * @dev: underlying device, will be used with runtime PM api - * @ops: vendor-specific hwspinlock handlers - * @id: a global, unique, system-wide, index of the lock. - * @lock: initialized and used by hwspinlock core + * struct hwspinlock_device - a device which usually spans numerous hwspinlocks + * @dev: underlying device, will be used to invoke runtime PM api + * @ops: platform-specific hwspinlock handlers + * @base_id: id index of the first lock in this device + * @num_locks: number of locks in this device + * @lock: dynamically allocated array of 'struct hwspinlock' */ -struct hwspinlock { +struct hwspinlock_device { struct device *dev; const struct hwspinlock_ops *ops; - int id; + int base_id; + int num_locks; + struct hwspinlock lock[0]; +}; + +struct hwspinlock_device contains an array of hwspinlock structs, each +of which represents a single hardware lock: + +/** + * struct hwspinlock - this struct represents a single hwspinlock instance + * @bank: the hwspinlock_device structure which owns this lock + * @lock: initialized and used by hwspinlock core + * @priv: private data, owned by the underlying platform-specific hwspinlock drv + */ +struct hwspinlock { + struct hwspinlock_device *bank; spinlock_t lock; + void *priv; }; -The underlying implementation is responsible to assign the dev, ops and id -members. The lock member, OTOH, is initialized and used by the hwspinlock -core. +When registering a bank of locks, the hwspinlock driver only needs to +set the priv members of the locks. The rest of the members are set and +initialized by the hwspinlock core itself. 6. Implementation callbacks diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 0d20b82df0a7..61c9cf15fa52 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -117,7 +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) { @@ -199,8 +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; @@ -245,7 +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) @@ -257,63 +257,32 @@ 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. - * - * 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 *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); - mutex_lock(&hwspinlock_tree_lock); - ret = radix_tree_insert(&hwspinlock_tree, hwlock->id, hwlock); - if (ret == -EEXIST) - pr_err("hwspinlock id %d already exists!\n", hwlock->id); - 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: mutex_unlock(&hwspinlock_tree_lock); - return ret; + 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. - * - * Should be called from a process context (might sleep) - * - * 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; @@ -337,6 +306,88 @@ out: 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); /** @@ -351,24 +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->dev->driver->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 */ @@ -390,7 +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); @@ -465,7 +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); @@ -500,6 +552,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_request_specific); */ int hwspin_lock_free(struct hwspinlock *hwlock) { + struct device *dev = hwlock->bank->dev; struct hwspinlock *tmp; int ret; @@ -511,28 +564,28 @@ int hwspin_lock_free(struct hwspinlock *hwlock) 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->dev->driver->owner); + module_put(dev->driver->owner); out: mutex_unlock(&hwspinlock_tree_lock); diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h index fb25830c2ee7..d26f78b8f214 100644 --- a/drivers/hwspinlock/hwspinlock_internal.h +++ b/drivers/hwspinlock/hwspinlock_internal.h @@ -21,6 +21,8 @@ #include <linux/spinlock.h> #include <linux/device.h> +struct hwspinlock_device; + /** * struct hwspinlock_ops - platform-specific hwspinlock handlers * @@ -39,21 +41,37 @@ struct hwspinlock_ops { /** * 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. + * @bank: the hwspinlock_device structure which owns this lock * @lock: initialized and used by hwspinlock core - * - * Note: currently simplicity was opted for, but later we can squeeze some - * memory bytes by grouping dev, ops in a single - * per-platform struct, and have all hwspinlocks point at it. + * @priv: private data, owned by the underlying platform-specific hwspinlock drv */ struct hwspinlock { + struct hwspinlock_device *bank; + spinlock_t lock; + void *priv; +}; + +/** + * struct hwspinlock_device - a device which usually spans numerous hwspinlocks + * @dev: underlying device, will be used to invoke runtime PM api + * @ops: platform-specific hwspinlock handlers + * @base_id: id index of the first lock in this device + * @num_locks: number of locks in this device + * @lock: dynamically allocated array of 'struct hwspinlock' + */ +struct hwspinlock_device { struct device *dev; const struct hwspinlock_ops *ops; - int id; - spinlock_t lock; + int base_id; + int num_locks; + struct hwspinlock lock[0]; }; +static inline int hwlock_to_id(struct hwspinlock *hwlock) +{ + int local_id = hwlock - &hwlock->bank->lock[0]; + + return hwlock->bank->base_id + local_id; +} + #endif /* __HWSPINLOCK_HWSPINLOCK_H */ diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c index 2044d181e49d..aec30064a466 100644 --- a/drivers/hwspinlock/omap_hwspinlock.c +++ b/drivers/hwspinlock/omap_hwspinlock.c @@ -41,34 +41,20 @@ #define SPINLOCK_NOTTAKEN (0) /* free */ #define SPINLOCK_TAKEN (1) /* locked */ -#define to_omap_hwspinlock(lock) \ - container_of(lock, struct omap_hwspinlock, lock) - -struct omap_hwspinlock { - struct hwspinlock lock; - void __iomem *addr; -}; - -struct omap_hwspinlock_state { - int num_locks; /* Total number of locks in system */ - void __iomem *io_base; /* Mapped base address */ - struct omap_hwspinlock lock[0]; /* Array of 'num_locks' locks */ -}; - static int omap_hwspinlock_trylock(struct hwspinlock *lock) { - struct omap_hwspinlock *omap_lock = to_omap_hwspinlock(lock); + void __iomem *lock_addr = lock->priv; /* attempt to acquire the lock by reading its value */ - return (SPINLOCK_NOTTAKEN == readl(omap_lock->addr)); + return (SPINLOCK_NOTTAKEN == readl(lock_addr)); } static void omap_hwspinlock_unlock(struct hwspinlock *lock) { - struct omap_hwspinlock *omap_lock = to_omap_hwspinlock(lock); + void __iomem *lock_addr = lock->priv; /* release the lock by writing 0 to it */ - writel(SPINLOCK_NOTTAKEN, omap_lock->addr); + writel(SPINLOCK_NOTTAKEN, lock_addr); } /* @@ -95,11 +81,11 @@ static const struct hwspinlock_ops omap_hwspinlock_ops = { static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) { struct hwspinlock_pdata *pdata = pdev->dev.platform_data; - struct omap_hwspinlock *omap_lock; - struct omap_hwspinlock_state *state; + struct hwspinlock_device *bank; + struct hwspinlock *hwlock; struct resource *res; void __iomem *io_base; - int i, ret; + int num_locks, i, ret; if (!pdata) return -ENODEV; @@ -122,18 +108,18 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) goto iounmap_base; } - i *= 32; /* actual number of locks in this device */ + num_locks = i * 32; /* actual number of locks in this device */ - state = kzalloc(sizeof(*state) + i * sizeof(*omap_lock), GFP_KERNEL); - if (!state) { + bank = kzalloc(sizeof(*bank) + num_locks * sizeof(*hwlock), GFP_KERNEL); + if (!bank) { ret = -ENOMEM; goto iounmap_base; } - state->num_locks = i; - state->io_base = io_base; + platform_set_drvdata(pdev, bank); - platform_set_drvdata(pdev, state); + for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++) + hwlock->priv = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i; /* * runtime PM will make sure the clock of this module is @@ -141,26 +127,16 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) */ pm_runtime_enable(&pdev->dev); - for (i = 0; i < state->num_locks; i++) { - omap_lock = &state->lock[i]; - - omap_lock->lock.dev = &pdev->dev; - omap_lock->lock.id = pdata->base_id + i; - omap_lock->lock.ops = &omap_hwspinlock_ops; - omap_lock->addr = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i; - - ret = hwspin_lock_register(&omap_lock->lock); - if (ret) - goto free_locks; - } + ret = hwspin_lock_register(bank, &pdev->dev, &omap_hwspinlock_ops, + pdata->base_id, num_locks); + if (ret) + goto reg_fail; return 0; -free_locks: - while (--i >= 0) - hwspin_lock_unregister(i); +reg_fail: pm_runtime_disable(&pdev->dev); - kfree(state); + kfree(bank); iounmap_base: iounmap(io_base); return ret; @@ -168,23 +144,19 @@ iounmap_base: static int omap_hwspinlock_remove(struct platform_device *pdev) { - struct omap_hwspinlock_state *state = platform_get_drvdata(pdev); - struct hwspinlock *lock; - int i; - - for (i = 0; i < state->num_locks; i++) { - lock = hwspin_lock_unregister(i); - /* this shouldn't happen at this point. if it does, at least - * don't continue with the remove */ - if (!lock) { - dev_err(&pdev->dev, "%s: failed on %d\n", __func__, i); - return -EBUSY; - } + struct hwspinlock_device *bank = platform_get_drvdata(pdev); + void __iomem *io_base = bank->lock[0].priv - LOCK_BASE_OFFSET; + int ret; + + ret = hwspin_lock_unregister(bank); + if (ret) { + dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret); + return ret; } pm_runtime_disable(&pdev->dev); - iounmap(state->io_base); - kfree(state); + iounmap(io_base); + kfree(bank); return 0; } diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h index c246522a9551..08a2fee40659 100644 --- a/include/linux/hwspinlock.h +++ b/include/linux/hwspinlock.h @@ -20,12 +20,15 @@ #include <linux/err.h> #include <linux/sched.h> +#include <linux/device.h> /* hwspinlock mode argument */ #define HWLOCK_IRQSTATE 0x01 /* Disable interrupts, save state */ #define HWLOCK_IRQ 0x02 /* Disable interrupts, don't save state */ struct hwspinlock; +struct hwspinlock_device; +struct hwspinlock_ops; /** * struct hwspinlock_pdata - platform data for hwspinlock drivers @@ -57,8 +60,9 @@ struct hwspinlock_pdata { #if defined(CONFIG_HWSPINLOCK) || defined(CONFIG_HWSPINLOCK_MODULE) -int hwspin_lock_register(struct hwspinlock *lock); -struct hwspinlock *hwspin_lock_unregister(unsigned int id); +int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, + const struct hwspinlock_ops *ops, int base_id, int num_locks); +int hwspin_lock_unregister(struct hwspinlock_device *bank); struct hwspinlock *hwspin_lock_request(void); struct hwspinlock *hwspin_lock_request_specific(unsigned int id); int hwspin_lock_free(struct hwspinlock *hwlock); |