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
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) {
* 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;
*/
mb();
- hwlock->ops->unlock(hwlock);
+ hwlock->bank->ops->unlock(hwlock);
/* Undo the spin_trylock{_irq, _irqsave} called while locking */
if (mode == HWLOCK_IRQSTATE)
}
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;
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);
/**
*/
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 */
return -EINVAL;
}
- return hwlock->id;
+ return hwlock_to_id(hwlock);
}
EXPORT_SYMBOL_GPL(hwspin_lock_get_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);
*/
int hwspin_lock_free(struct hwspinlock *hwlock)
{
+ struct device *dev = hwlock->bank->dev;
struct hwspinlock *tmp;
int ret;
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);
#include <linux/spinlock.h>
#include <linux/device.h>
+struct hwspinlock_device;
+
/**
* struct hwspinlock_ops - platform-specific hwspinlock handlers
*
/**
* 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 */
#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);
}
/*
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;
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
*/
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;
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;
}
#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
#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);
projects / linux-beck.git / commitdiff