diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/drm_fops.c | 11 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_stub.c | 51 |
2 files changed, 46 insertions, 16 deletions
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index 4ce5318d14bc..8f46fe273ba3 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -39,7 +39,7 @@ #include <linux/slab.h> #include <linux/module.h> -/* from BKL pushdown: note that nothing else serializes idr_find() */ +/* from BKL pushdown */ DEFINE_MUTEX(drm_global_mutex); EXPORT_SYMBOL(drm_global_mutex); @@ -91,11 +91,6 @@ int drm_open(struct inode *inode, struct file *filp) return PTR_ERR(minor); dev = minor->dev; - if (drm_device_is_unplugged(dev)) { - retcode = -ENODEV; - goto err_release; - } - if (!dev->open_count++) need_setup = 1; mutex_lock(&dev->struct_mutex); @@ -127,7 +122,6 @@ err_undo: dev->dev_mapping = old_mapping; mutex_unlock(&dev->struct_mutex); dev->open_count--; -err_release: drm_minor_release(minor); return retcode; } @@ -157,9 +151,6 @@ int drm_stub_open(struct inode *inode, struct file *filp) goto out_unlock; dev = minor->dev; - if (drm_device_is_unplugged(dev)) - goto out_release; - new_fops = fops_get(dev->driver->fops); if (!new_fops) goto out_release; diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c index 83ef4a63358c..c23eaf6442ff 100644 --- a/drivers/gpu/drm/drm_stub.c +++ b/drivers/gpu/drm/drm_stub.c @@ -70,6 +70,7 @@ module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600); module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600); module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600); +static DEFINE_SPINLOCK(drm_minor_lock); struct idr drm_minors_idr; struct class *drm_class; @@ -240,6 +241,19 @@ int drm_dropmaster_ioctl(struct drm_device *dev, void *data, return 0; } +/* + * DRM Minors + * A DRM device can provide several char-dev interfaces on the DRM-Major. Each + * of them is represented by a drm_minor object. Depending on the capabilities + * of the device-driver, different interfaces are registered. + * + * Minors can be accessed via dev->$minor_name. This pointer is either + * NULL or a valid drm_minor pointer and stays valid as long as the device is + * valid. This means, DRM minors have the same life-time as the underlying + * device. However, this doesn't mean that the minor is active. Minors are + * registered and unregistered dynamically according to device-state. + */ + static struct drm_minor **drm_minor_get_slot(struct drm_device *dev, unsigned int type) { @@ -285,6 +299,7 @@ static void drm_minor_free(struct drm_device *dev, unsigned int type) static int drm_minor_register(struct drm_device *dev, unsigned int type) { struct drm_minor *new_minor; + unsigned long flags; int ret; int minor_id; @@ -294,19 +309,21 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type) if (!new_minor) return 0; + idr_preload(GFP_KERNEL); + spin_lock_irqsave(&drm_minor_lock, flags); minor_id = idr_alloc(&drm_minors_idr, NULL, 64 * type, 64 * (type + 1), - GFP_KERNEL); + GFP_NOWAIT); + spin_unlock_irqrestore(&drm_minor_lock, flags); + idr_preload_end(); if (minor_id < 0) return minor_id; new_minor->index = minor_id; - idr_replace(&drm_minors_idr, new_minor, minor_id); - ret = drm_debugfs_init(new_minor, minor_id, drm_debugfs_root); if (ret) { DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n"); @@ -319,27 +336,40 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type) goto err_debugfs; } + /* replace NULL with @minor so lookups will succeed from now on */ + spin_lock_irqsave(&drm_minor_lock, flags); + idr_replace(&drm_minors_idr, new_minor, new_minor->index); + spin_unlock_irqrestore(&drm_minor_lock, flags); + DRM_DEBUG("new minor assigned %d\n", minor_id); return 0; err_debugfs: drm_debugfs_cleanup(new_minor); err_id: + spin_lock_irqsave(&drm_minor_lock, flags); idr_remove(&drm_minors_idr, minor_id); + spin_unlock_irqrestore(&drm_minor_lock, flags); + new_minor->index = 0; return ret; } static void drm_minor_unregister(struct drm_device *dev, unsigned int type) { struct drm_minor *minor; + unsigned long flags; minor = *drm_minor_get_slot(dev, type); if (!minor || !minor->kdev) return; + spin_lock_irqsave(&drm_minor_lock, flags); + idr_remove(&drm_minors_idr, minor->index); + spin_unlock_irqrestore(&drm_minor_lock, flags); + minor->index = 0; + drm_debugfs_cleanup(minor); drm_sysfs_device_remove(minor); - idr_remove(&drm_minors_idr, minor->index); } /** @@ -361,12 +391,21 @@ static void drm_minor_unregister(struct drm_device *dev, unsigned int type) struct drm_minor *drm_minor_acquire(unsigned int minor_id) { struct drm_minor *minor; + unsigned long flags; + spin_lock_irqsave(&drm_minor_lock, flags); minor = idr_find(&drm_minors_idr, minor_id); - if (!minor) + if (minor) + drm_dev_ref(minor->dev); + spin_unlock_irqrestore(&drm_minor_lock, flags); + + if (!minor) { + return ERR_PTR(-ENODEV); + } else if (drm_device_is_unplugged(minor->dev)) { + drm_dev_unref(minor->dev); return ERR_PTR(-ENODEV); + } - drm_dev_ref(minor->dev); return minor; } |