lkml.org 
[lkml]   [2013]   [Mar]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v7 1/3] VFIO: Wrapper for getting reference to vfio_device from device
Date

- 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 <vijaymohan.pandarathil@hp.com>
---
drivers/vfio/vfio.c | 30 +++++++++++++++++++++++++++++-
include/linux/vfio.h | 3 +++
2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index fcc12f3..21eddd9 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -392,12 +392,13 @@ 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)
{
@@ -627,6 +628,33 @@ int vfio_add_group_dev(struct device *dev,
}
EXPORT_SYMBOL_GPL(vfio_add_group_dev);

+/**
+ * Get a reference to the vfio_device for a device that is known to
+ * be bound to a vfio driver. The driver implicitly holds a
+ * vfio_device reference between vfio_add_group_dev and
+ * vfio_del_group_dev. We can therefore use drvdata to increment
+ * that reference from the struct device. This additional
+ * reference must be released by calling vfio_device_put.
+ */
+struct vfio_device *vfio_device_get_from_dev(struct device *dev)
+{
+ struct vfio_device *device = dev_get_drvdata(dev);
+
+ vfio_device_get(device);
+
+ return device;
+}
+EXPORT_SYMBOL_GPL(vfio_device_get_from_dev);
+
+/*
+ * Caller must hold a reference to the vfio_device
+ */
+void *vfio_device_data(struct vfio_device *device)
+{
+ return device->device_data;
+}
+EXPORT_SYMBOL_GPL(vfio_device_data);
+
/* Given a referenced group, check if it contains the device */
static bool vfio_dev_present(struct vfio_group *group, struct device *dev)
{
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
--
1.7.11.3


\
 
 \ /
  Last update: 2013-03-09 09:41    [W:0.105 / U:0.220 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site