iommufd/vdevice: Remove struct device reference from struct vdevice

Remove struct device *dev from struct vdevice.

The dev pointer is the Plan B for vdevice to reference the physical
device. As now vdev->idev is added without refcounting concern, just
use vdev->idev->dev when needed. To avoid exposing
struct iommufd_device in the public header, export a
iommufd_vdevice_to_device() helper.

Link: https://patch.msgid.link/r/20250716070349.1807226-6-yilun.xu@linux.intel.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
index eb90af5093d89b850aeddaaefe559e10c85c8b6c..4c86eacd36b1607288f1feb6d7d2d1123d5eef57 100644 (file)
--- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
+++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
@@ -1218,7 +1218,8 @@ static void tegra241_vintf_destroy_vsid(struct iommufd_vdevice *vdev)
 
 static int tegra241_vintf_init_vsid(struct iommufd_vdevice *vdev)
 {
-       struct arm_smmu_master *master = dev_iommu_priv_get(vdev->dev);
+       struct device *dev = iommufd_vdevice_to_device(vdev);
+       struct arm_smmu_master *master = dev_iommu_priv_get(dev);
        struct tegra241_vintf *vintf = viommu_to_vintf(vdev->viommu);
        struct tegra241_vintf_sid *vsid = vdev_to_vsid(vdev);
        struct arm_smmu_stream *stream = &master->streams[0];

diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index e4eae20bcd4e8760fc8accb85f46f761b8cef5d3..6f1010da221c91f98ef12da6d5767b493fe7b2c4 100644 (file)
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -83,6 +83,12 @@ void _iommufd_destroy_mmap(struct iommufd_ctx *ictx,
 }
 EXPORT_SYMBOL_NS_GPL(_iommufd_destroy_mmap, "IOMMUFD");
 
+struct device *iommufd_vdevice_to_device(struct iommufd_vdevice *vdev)
+{
+       return vdev->idev->dev;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_vdevice_to_device, "IOMMUFD");
+
 /* Caller should xa_lock(&viommu->vdevs) to protect the return value */
 struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
                                       unsigned long vdev_id)
@@ -92,7 +98,7 @@ struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
        lockdep_assert_held(&viommu->vdevs.xa_lock);
 
        vdev = xa_load(&viommu->vdevs, vdev_id);
-       return vdev ? vdev->dev : NULL;
+       return vdev ? iommufd_vdevice_to_device(vdev) : NULL;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_viommu_find_dev, "IOMMUFD");
 
@@ -109,7 +115,7 @@ int iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
 
        xa_lock(&viommu->vdevs);
        xa_for_each(&viommu->vdevs, index, vdev) {
-               if (vdev->dev == dev) {
+               if (iommufd_vdevice_to_device(vdev) == dev) {
                        *vdev_id = vdev->virt_id;
                        rc = 0;
                        break;

diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index ecbae5091ffe1fb8ee2fd0c8c39634677334f209..6cf0bd5d8f0887093f838505dec163786d74fb26 100644 (file)
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -125,7 +125,6 @@ void iommufd_vdevice_abort(struct iommufd_object *obj)
        xa_cmpxchg(&viommu->vdevs, vdev->virt_id, vdev, NULL, GFP_KERNEL);
        refcount_dec(&viommu->obj.users);
        idev->vdev = NULL;
-       put_device(vdev->dev);
 }
 
 void iommufd_vdevice_destroy(struct iommufd_object *obj)
@@ -203,8 +202,6 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd)
        }
 
        vdev->virt_id = virt_id;
-       vdev->dev = idev->dev;
-       get_device(idev->dev);
        vdev->viommu = viommu;
        refcount_inc(&viommu->obj.users);
        /*

diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index b88911026bc412f01661bcdf27a7ccd9fd245775..810e4d8ac91240a7039c34be1ad986032e7bf0a2 100644 (file)
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -109,7 +109,6 @@ struct iommufd_vdevice {
        struct iommufd_object obj;
        struct iommufd_viommu *viommu;
        struct iommufd_device *idev;
-       struct device *dev;
 
        /*
         * Virtual device ID per vIOMMU, e.g. vSID of ARM SMMUv3, vDeviceID of
@@ -261,6 +260,7 @@ int _iommufd_alloc_mmap(struct iommufd_ctx *ictx, struct iommufd_object *owner,
                        unsigned long *offset);
 void _iommufd_destroy_mmap(struct iommufd_ctx *ictx,
                           struct iommufd_object *owner, unsigned long offset);
+struct device *iommufd_vdevice_to_device(struct iommufd_vdevice *vdev);
 struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu,
                                       unsigned long vdev_id);
 int iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
@@ -295,6 +295,12 @@ static inline void _iommufd_destroy_mmap(struct iommufd_ctx *ictx,
 {
 }
 
+static inline struct device *
+iommufd_vdevice_to_device(struct iommufd_vdevice *vdev)
+{
+       return NULL;
+}
+
 static inline struct device *
 iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id)
 {