From c07dcd61a0e57c6840c23d90cb1beddad7d682a1 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 2 Aug 2017 13:56:02 +0200 Subject: [PATCH] drm: Document device unplug infrastructure While at it, also ocd and give them a consistent drm_dev_ prefix, like the other device instance functionality. Plus move the functions into the right places. Reviewed-by: Alex Deucher Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20170802115604.12734-3-daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_drv.c | 24 +++++++++++++++++++++--- drivers/gpu/drm/drm_file.c | 2 +- drivers/gpu/drm/drm_gem.c | 2 +- drivers/gpu/drm/drm_gem_cma_helper.c | 2 +- drivers/gpu/drm/drm_ioctl.c | 4 ++-- drivers/gpu/drm/drm_vm.c | 2 +- drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c | 2 +- drivers/gpu/drm/udl/udl_connector.c | 2 +- drivers/gpu/drm/udl/udl_drv.c | 2 +- drivers/gpu/drm/udl/udl_fb.c | 2 +- include/drm/drmP.h | 13 ------------- include/drm/drm_drv.h | 22 ++++++++++++++++++++-- 12 files changed, 51 insertions(+), 28 deletions(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 2ed2d91..39191e5 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -291,7 +291,7 @@ struct drm_minor *drm_minor_acquire(unsigned int minor_id) if (!minor) { return ERR_PTR(-ENODEV); - } else if (drm_device_is_unplugged(minor->dev)) { + } else if (drm_dev_is_unplugged(minor->dev)) { drm_dev_unref(minor->dev); return ERR_PTR(-ENODEV); } @@ -364,7 +364,22 @@ void drm_put_dev(struct drm_device *dev) } EXPORT_SYMBOL(drm_put_dev); -void drm_unplug_dev(struct drm_device *dev) +static void drm_device_set_unplugged(struct drm_device *dev) +{ + smp_wmb(); + atomic_set(&dev->unplugged, 1); +} + +/** + * drm_dev_unplug - unplug a DRM device + * @dev: DRM device + * + * This unplugs a hotpluggable DRM device, which makes it inaccessible to + * userspace operations. Entry-points can use drm_dev_is_unplugged(). This + * essentially unregisters the device like drm_dev_unregister(), but can be + * called while there are still open users of @dev. + */ +void drm_dev_unplug(struct drm_device *dev) { /* for a USB device */ if (drm_core_check_feature(dev, DRIVER_MODESET)) @@ -383,7 +398,7 @@ void drm_unplug_dev(struct drm_device *dev) } mutex_unlock(&drm_global_mutex); } -EXPORT_SYMBOL(drm_unplug_dev); +EXPORT_SYMBOL(drm_dev_unplug); /* * DRM internal mount @@ -835,6 +850,9 @@ EXPORT_SYMBOL(drm_dev_register); * drm_dev_register() but does not deallocate the device. The caller must call * drm_dev_unref() to drop their final reference. * + * A special form of unregistering for hotpluggable devices is drm_dev_unplug(), + * which can be called while there are still open users of @dev. + * * This should be called first in the device teardown code to make sure * userspace can't access the device instance any more. */ diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index 59b75a9..b3c6e99 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -436,7 +436,7 @@ int drm_release(struct inode *inode, struct file *filp) if (!--dev->open_count) { drm_lastclose(dev); - if (drm_device_is_unplugged(dev)) + if (drm_dev_is_unplugged(dev)) drm_put_dev(dev); } mutex_unlock(&drm_global_mutex); diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index a8d396b..ad4e9cf 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -1001,7 +1001,7 @@ int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) struct drm_vma_offset_node *node; int ret; - if (drm_device_is_unplugged(dev)) + if (drm_dev_is_unplugged(dev)) return -ENODEV; drm_vma_offset_lock_lookup(dev->vma_offset_manager); diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index 275ab87..f4e0057 100644 --- a/drivers/gpu/drm/drm_gem_cma_helper.c +++ b/drivers/gpu/drm/drm_gem_cma_helper.c @@ -390,7 +390,7 @@ unsigned long drm_gem_cma_get_unmapped_area(struct file *filp, struct drm_device *dev = priv->minor->dev; struct drm_vma_offset_node *node; - if (drm_device_is_unplugged(dev)) + if (drm_dev_is_unplugged(dev)) return -ENODEV; drm_vma_offset_lock_lookup(dev->vma_offset_manager); diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 8bfeb32..d920b21 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -716,7 +716,7 @@ long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata, struct drm_device *dev = file_priv->minor->dev; int retcode; - if (drm_device_is_unplugged(dev)) + if (drm_dev_is_unplugged(dev)) return -ENODEV; retcode = drm_ioctl_permit(flags, file_priv); @@ -765,7 +765,7 @@ long drm_ioctl(struct file *filp, dev = file_priv->minor->dev; - if (drm_device_is_unplugged(dev)) + if (drm_dev_is_unplugged(dev)) return -ENODEV; is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END; diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c index 1170b32..13a59ed 100644 --- a/drivers/gpu/drm/drm_vm.c +++ b/drivers/gpu/drm/drm_vm.c @@ -631,7 +631,7 @@ int drm_legacy_mmap(struct file *filp, struct vm_area_struct *vma) struct drm_device *dev = priv->minor->dev; int ret; - if (drm_device_is_unplugged(dev)) + if (drm_dev_is_unplugged(dev)) return -ENODEV; mutex_lock(&dev->struct_mutex); diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c b/drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c index f224b54..177e9d8 100644 --- a/drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c +++ b/drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c @@ -56,7 +56,7 @@ static const struct drm_connector_helper_funcs tinydrm_connector_hfuncs = { static enum drm_connector_status tinydrm_connector_detect(struct drm_connector *connector, bool force) { - if (drm_device_is_unplugged(connector->dev)) + if (drm_dev_is_unplugged(connector->dev)) return connector_status_disconnected; return connector->status; diff --git a/drivers/gpu/drm/udl/udl_connector.c b/drivers/gpu/drm/udl/udl_connector.c index d2f57c5..9f9a497 100644 --- a/drivers/gpu/drm/udl/udl_connector.c +++ b/drivers/gpu/drm/udl/udl_connector.c @@ -96,7 +96,7 @@ static int udl_mode_valid(struct drm_connector *connector, static enum drm_connector_status udl_detect(struct drm_connector *connector, bool force) { - if (drm_device_is_unplugged(connector->dev)) + if (drm_dev_is_unplugged(connector->dev)) return connector_status_disconnected; return connector_status_connected; } diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c index 0f02e1ac..96c44ed 100644 --- a/drivers/gpu/drm/udl/udl_drv.c +++ b/drivers/gpu/drm/udl/udl_drv.c @@ -102,7 +102,7 @@ static void udl_usb_disconnect(struct usb_interface *interface) drm_kms_helper_poll_disable(dev); udl_fbdev_unplug(dev); udl_drop_usb(dev); - drm_unplug_dev(dev); + drm_dev_unplug(dev); } /* diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c index a5c54dc..77a2c59 100644 --- a/drivers/gpu/drm/udl/udl_fb.c +++ b/drivers/gpu/drm/udl/udl_fb.c @@ -198,7 +198,7 @@ static int udl_fb_open(struct fb_info *info, int user) struct udl_device *udl = dev->dev_private; /* If the USB device is gone, we don't accept new opens */ - if (drm_device_is_unplugged(udl->ddev)) + if (drm_dev_is_unplugged(udl->ddev)) return -ENODEV; ufbdev->fb_count++; diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 3031c25..7277783a 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -320,19 +320,6 @@ static __inline__ int drm_core_check_feature(struct drm_device *dev, return ((dev->driver->driver_features & feature) ? 1 : 0); } -static inline void drm_device_set_unplugged(struct drm_device *dev) -{ - smp_wmb(); - atomic_set(&dev->unplugged, 1); -} - -static inline int drm_device_is_unplugged(struct drm_device *dev) -{ - int ret = atomic_read(&dev->unplugged); - smp_rmb(); - return ret; -} - /******************************************************************/ /** \name Internal function definitions */ /*@{*/ diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h index 505c913..71bbaae 100644 --- a/include/drm/drm_drv.h +++ b/include/drm/drm_drv.h @@ -30,7 +30,8 @@ #include #include -struct drm_device; +#include + struct drm_file; struct drm_gem_object; struct drm_master; @@ -613,7 +614,24 @@ void drm_dev_unregister(struct drm_device *dev); void drm_dev_ref(struct drm_device *dev); void drm_dev_unref(struct drm_device *dev); void drm_put_dev(struct drm_device *dev); -void drm_unplug_dev(struct drm_device *dev); +void drm_dev_unplug(struct drm_device *dev); + +/** + * drm_dev_is_unplugged - is a DRM device unplugged + * @dev: DRM device + * + * This function can be called to check whether a hotpluggable is unplugged. + * Unplugging itself is singalled through drm_dev_unplug(). If a device is + * unplugged, these two functions guarantee that any store before calling + * drm_dev_unplug() is visible to callers of this function after it completes + */ +static inline int drm_dev_is_unplugged(struct drm_device *dev) +{ + int ret = atomic_read(&dev->unplugged); + smp_rmb(); + return ret; +} + int drm_dev_set_unique(struct drm_device *dev, const char *name); -- 2.7.4