From patchwork Sun Feb 3 14:10:13 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v3, 1/3] VFIO: Wrapper for getting reference to vfio_device from device From: "Pandarathil, Vijaymohan R" X-Patchwork-Id: 217789 Message-Id: To: Alex Williamson , Gleb Natapov , Bjorn Helgaas , Blue Swirl , "Ortiz, Lance E" Cc: "kvm@vger.kernel.org" , "qemu-devel@nongnu.org" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" Date: Sun, 3 Feb 2013 14:10:13 +0000 - Added vfio_device_get_from_dev() as wrapper to get reference to vfio_device from struct device. - Added vfio_device_data() as a wrapper to get device_data from vfio_device. Signed-off-by: Vijay Mohan Pandarathil --- drivers/vfio/vfio.c | 41 ++++++++++++++++++++++++++++++++--------- include/linux/vfio.h | 3 +++ 2 files changed, 35 insertions(+), 9 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 12c264d..f0a78a2 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -407,12 +407,13 @@ static void vfio_device_release(struct kref *kref) } /* Device reference always implies a group reference */ -static void vfio_device_put(struct vfio_device *device) +void vfio_device_put(struct vfio_device *device) { struct vfio_group *group = device->group; kref_put_mutex(&device->kref, vfio_device_release, &group->device_lock); vfio_group_put(group); } +EXPORT_SYMBOL_GPL(vfio_device_put); static void vfio_device_get(struct vfio_device *device) { @@ -642,8 +643,12 @@ int vfio_add_group_dev(struct device *dev, } EXPORT_SYMBOL_GPL(vfio_add_group_dev); -/* Test whether a struct device is present in our tracking */ -static bool vfio_dev_present(struct device *dev) +/** + * This does a get on the vfio_device from device. + * Callers of this function will have to call vfio_put_device() to + * remove the reference. + */ +struct vfio_device *vfio_device_get_from_dev(struct device *dev) { struct iommu_group *iommu_group; struct vfio_group *group; @@ -651,25 +656,43 @@ static bool vfio_dev_present(struct device *dev) iommu_group = iommu_group_get(dev); if (!iommu_group) - return false; + return NULL; group = vfio_group_get_from_iommu(iommu_group); if (!group) { iommu_group_put(iommu_group); - return false; + return NULL; } device = vfio_group_get_device(group, dev); if (!device) { vfio_group_put(group); iommu_group_put(iommu_group); - return false; + return NULL; } - - vfio_device_put(device); vfio_group_put(group); iommu_group_put(iommu_group); - return true; + return device; +} +EXPORT_SYMBOL_GPL(vfio_device_get_from_dev); + +void *vfio_device_data(struct vfio_device *device) +{ + return device->device_data; +} +EXPORT_SYMBOL_GPL(vfio_device_data); + +/* Test whether a struct device is present in our tracking */ +static bool vfio_dev_present(struct device *dev) +{ + struct vfio_device *device; + + device = vfio_device_get_from_dev(dev); + if (device) { + vfio_device_put(device); + return true; + } else + return false; } /* diff --git a/include/linux/vfio.h b/include/linux/vfio.h index ab9e862..ac8d488 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -45,6 +45,9 @@ extern int vfio_add_group_dev(struct device *dev, void *device_data); extern void *vfio_del_group_dev(struct device *dev); +extern struct vfio_device *vfio_device_get_from_dev(struct device *dev); +extern void vfio_device_put(struct vfio_device *device); +extern void *vfio_device_data(struct vfio_device *device); /** * struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks