diff options
| -rw-r--r-- | drivers/char/drm/drmP.h | 3 | ||||
| -rw-r--r-- | drivers/char/drm/drm_irq.c | 76 | ||||
| -rw-r--r-- | drivers/char/drm/drm_lock.c | 11 |
3 files changed, 90 insertions, 0 deletions
diff --git a/drivers/char/drm/drmP.h b/drivers/char/drm/drmP.h index 01e1f2528659..2f18329c5eb8 100644 --- a/drivers/char/drm/drmP.h +++ b/drivers/char/drm/drmP.h @@ -715,6 +715,8 @@ typedef struct drm_device { drm_vbl_sig_t vbl_sigs; /**< signal list to send on VBLANK */ drm_vbl_sig_t vbl_sigs2; /**< signals to send on secondary VBLANK */ unsigned int vbl_pending; + spinlock_t tasklet_lock; /**< For drm_locked_tasklet */ + void (*locked_tasklet_func)(struct drm_device *dev); /*@} */ cycles_t ctx_start; @@ -966,6 +968,7 @@ extern int drm_wait_vblank(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg); extern int drm_vblank_wait(drm_device_t * dev, unsigned int *vbl_seq); extern void drm_vbl_send_signals(drm_device_t * dev); +extern void drm_locked_tasklet(drm_device_t *dev, void(*func)(drm_device_t*)); /* AGP/GART support (drm_agpsupport.h) */ extern drm_agp_head_t *drm_agp_init(drm_device_t * dev); diff --git a/drivers/char/drm/drm_irq.c b/drivers/char/drm/drm_irq.c index 3c77756aad9c..2b10e5b60cfa 100644 --- a/drivers/char/drm/drm_irq.c +++ b/drivers/char/drm/drm_irq.c @@ -119,6 +119,7 @@ static int drm_irq_install(drm_device_t * dev) init_waitqueue_head(&dev->vbl_queue); spin_lock_init(&dev->vbl_lock); + spin_lock_init(&dev->tasklet_lock); INIT_LIST_HEAD(&dev->vbl_sigs.head); INIT_LIST_HEAD(&dev->vbl_sigs2.head); @@ -176,6 +177,8 @@ int drm_irq_uninstall(drm_device_t * dev) free_irq(dev->irq, dev); + dev->locked_tasklet_func = NULL; + return 0; } @@ -399,3 +402,76 @@ void drm_vbl_send_signals(drm_device_t * dev) } EXPORT_SYMBOL(drm_vbl_send_signals); + +/** + * Tasklet wrapper function. + * + * \param data DRM device in disguise. + * + * Attempts to grab the HW lock and calls the driver callback on success. On + * failure, leave the lock marked as contended so the callback can be called + * from drm_unlock(). + */ +static void drm_locked_tasklet_func(unsigned long data) +{ + drm_device_t *dev = (drm_device_t*)data; + unsigned long irqflags; + + spin_lock_irqsave(&dev->tasklet_lock, irqflags); + + if (!dev->locked_tasklet_func || + !drm_lock_take(&dev->lock.hw_lock->lock, + DRM_KERNEL_CONTEXT)) { + spin_unlock_irqrestore(&dev->tasklet_lock, irqflags); + return; + } + + dev->lock.lock_time = jiffies; + atomic_inc(&dev->counts[_DRM_STAT_LOCKS]); + + dev->locked_tasklet_func(dev); + + drm_lock_free(dev, &dev->lock.hw_lock->lock, + DRM_KERNEL_CONTEXT); + + dev->locked_tasklet_func = NULL; + + spin_unlock_irqrestore(&dev->tasklet_lock, irqflags); +} + +/** + * Schedule a tasklet to call back a driver hook with the HW lock held. + * + * \param dev DRM device. + * \param func Driver callback. + * + * This is intended for triggering actions that require the HW lock from an + * interrupt handler. The lock will be grabbed ASAP after the interrupt handler + * completes. Note that the callback may be called from interrupt or process + * context, it must not make any assumptions about this. Also, the HW lock will + * be held with the kernel context or any client context. + */ +void drm_locked_tasklet(drm_device_t *dev, void (*func)(drm_device_t*)) +{ + unsigned long irqflags; + static DECLARE_TASKLET(drm_tasklet, drm_locked_tasklet_func, 0); + + if (test_bit(TASKLET_STATE_SCHED, &drm_tasklet.state)) + return; + + spin_lock_irqsave(&dev->tasklet_lock, irqflags); + + if (dev->locked_tasklet_func) { + spin_unlock_irqrestore(&dev->tasklet_lock, irqflags); + return; + } + + dev->locked_tasklet_func = func; + + spin_unlock_irqrestore(&dev->tasklet_lock, irqflags); + + drm_tasklet.data = (unsigned long)dev; + + tasklet_hi_schedule(&drm_tasklet); +} +EXPORT_SYMBOL(drm_locked_tasklet); diff --git a/drivers/char/drm/drm_lock.c b/drivers/char/drm/drm_lock.c index f9e45303498d..e0abe5c68423 100644 --- a/drivers/char/drm/drm_lock.c +++ b/drivers/char/drm/drm_lock.c @@ -155,6 +155,7 @@ int drm_unlock(struct inode *inode, struct file *filp, drm_file_t *priv = filp->private_data; drm_device_t *dev = priv->head->dev; drm_lock_t lock; + unsigned int irqflags; if (copy_from_user(&lock, (drm_lock_t __user *) arg, sizeof(lock))) return -EFAULT; @@ -165,6 +166,16 @@ int drm_unlock(struct inode *inode, struct file *filp, return -EINVAL; } + spin_lock_irqsave(&dev->tasklet_lock, irqflags); + + if (dev->locked_tasklet_func) { + dev->locked_tasklet_func(dev); + + dev->locked_tasklet_func = NULL; + } + + spin_unlock_irqrestore(&dev->tasklet_lock, irqflags); + atomic_inc(&dev->counts[_DRM_STAT_UNLOCKS]); /* kernel_context_switch isn't used by any of the x86 drm |