> From: Christoph Hellwig <hch@xxxxxx>
> Sent: Thursday, August 26, 2021 12:19 AM
>
> We don't need to hold a reference to the group in the driver as well as
> obtain a reference to the same group as the first thing
> vfio_register_group_dev() does.
>
> Since the drivers never use the group move this all into the core code.
>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> drivers/vfio/fsl-mc/vfio_fsl_mc.c | 17 ++-----------
> drivers/vfio/pci/vfio_pci_core.c | 13 ++--------
> drivers/vfio/platform/vfio_platform_common.c | 13 +---------
> drivers/vfio/vfio.c | 25 ++++++--------------
> include/linux/vfio.h | 3 ---
> 5 files changed, 12 insertions(+), 59 deletions(-)
>
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-
> mc/vfio_fsl_mc.c
> index 0ead91bfa83867..9e838fed560339 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> @@ -505,22 +505,13 @@ static void vfio_fsl_uninit_device(struct
> vfio_fsl_mc_device *vdev)
>
> static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
> {
> - struct iommu_group *group;
> struct vfio_fsl_mc_device *vdev;
> struct device *dev = &mc_dev->dev;
> int ret;
>
> - group = vfio_iommu_group_get(dev);
> - if (!group) {
> - dev_err(dev, "VFIO_FSL_MC: No IOMMU group\n");
> - return -EINVAL;
> - }
> -
> vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
> - if (!vdev) {
> - ret = -ENOMEM;
> - goto out_group_put;
> - }
> + if (!vdev)
> + return -ENOMEM;
>
> vfio_init_group_dev(&vdev->vdev, dev, &vfio_fsl_mc_ops);
> vdev->mc_dev = mc_dev;
> @@ -556,8 +547,6 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device
> *mc_dev)
> out_uninit:
> vfio_uninit_group_dev(&vdev->vdev);
> kfree(vdev);
> -out_group_put:
> - vfio_iommu_group_put(group, dev);
> return ret;
> }
>
> @@ -574,8 +563,6 @@ static int vfio_fsl_mc_remove(struct fsl_mc_device
> *mc_dev)
>
> vfio_uninit_group_dev(&vdev->vdev);
> kfree(vdev);
> - vfio_iommu_group_put(mc_dev->dev.iommu_group, dev);
> -
> return 0;
> }
>
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index c67751948504af..4134dceab3f73b 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -1807,7 +1807,6 @@
> EXPORT_SYMBOL_GPL(vfio_pci_core_uninit_device);
> int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
> {
> struct pci_dev *pdev = vdev->pdev;
> - struct iommu_group *group;
> int ret;
>
> if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
> @@ -1826,10 +1825,6 @@ int vfio_pci_core_register_device(struct
> vfio_pci_core_device *vdev)
> return -EBUSY;
> }
>
> - group = vfio_iommu_group_get(&pdev->dev);
> - if (!group)
> - return -EINVAL;
> -
> if (pci_is_root_bus(pdev->bus)) {
> ret = vfio_assign_device_set(&vdev->vdev, vdev);
> } else if (!pci_probe_reset_slot(pdev->slot)) {
> @@ -1843,10 +1838,10 @@ int vfio_pci_core_register_device(struct
> vfio_pci_core_device *vdev)
> }
>
> if (ret)
> - goto out_group_put;
> + return ret;
> ret = vfio_pci_vf_init(vdev);
> if (ret)
> - goto out_group_put;
> + return ret;
> ret = vfio_pci_vga_init(vdev);
> if (ret)
> goto out_vf;
> @@ -1877,8 +1872,6 @@ int vfio_pci_core_register_device(struct
> vfio_pci_core_device *vdev)
> vfio_pci_set_power_state(vdev, PCI_D0);
> out_vf:
> vfio_pci_vf_uninit(vdev);
> -out_group_put:
> - vfio_iommu_group_put(group, &pdev->dev);
> return ret;
> }
> EXPORT_SYMBOL_GPL(vfio_pci_core_register_device);
> @@ -1894,8 +1887,6 @@ void vfio_pci_core_unregister_device(struct
> vfio_pci_core_device *vdev)
> vfio_pci_vf_uninit(vdev);
> vfio_pci_vga_uninit(vdev);
>
> - vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
> -
> if (!disable_idle_d3)
> vfio_pci_set_power_state(vdev, PCI_D0);
> }
> diff --git a/drivers/vfio/platform/vfio_platform_common.c
> b/drivers/vfio/platform/vfio_platform_common.c
> index 6af7ce7d619c25..256f55b84e70a0 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -642,7 +642,6 @@ static int vfio_platform_of_probe(struct
> vfio_platform_device *vdev,
> int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> struct device *dev)
> {
> - struct iommu_group *group;
> int ret;
>
> vfio_init_group_dev(&vdev->vdev, dev, &vfio_platform_ops);
> @@ -663,24 +662,15 @@ int vfio_platform_probe_common(struct
> vfio_platform_device *vdev,
> goto out_uninit;
> }
>
> - group = vfio_iommu_group_get(dev);
> - if (!group) {
> - dev_err(dev, "No IOMMU group for device %s\n", vdev-
> >name);
> - ret = -EINVAL;
> - goto put_reset;
> - }
> -
> ret = vfio_register_group_dev(&vdev->vdev);
> if (ret)
> - goto put_iommu;
> + goto put_reset;
>
> mutex_init(&vdev->igate);
>
> pm_runtime_enable(dev);
> return 0;
>
> -put_iommu:
> - vfio_iommu_group_put(group, dev);
> put_reset:
> vfio_platform_put_reset(vdev);
> out_uninit:
> @@ -696,7 +686,6 @@ void vfio_platform_remove_common(struct
> vfio_platform_device *vdev)
> pm_runtime_disable(vdev->device);
> vfio_platform_put_reset(vdev);
> vfio_uninit_group_dev(&vdev->vdev);
> - vfio_iommu_group_put(vdev->vdev.dev->iommu_group, vdev-
> >vdev.dev);
> }
> EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
>
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 3c034fe14ccb03..5bd520f0dc6107 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -169,15 +169,7 @@ static void vfio_release_device_set(struct
> vfio_device *device)
> xa_unlock(&vfio_device_set_xa);
> }
>
> -/*
> - * vfio_iommu_group_{get,put} are only intended for VFIO bus driver probe
> - * and remove functions, any use cases other than acquiring the first
> - * reference for the purpose of calling vfio_register_group_dev() or
> removing
> - * that symmetric reference after vfio_unregister_group_dev() should use
> the raw
> - * iommu_group_{get,put} functions. In particular, vfio_iommu_group_put()
> - * removes the device from the dummy group and cannot be nested.
> - */
> -struct iommu_group *vfio_iommu_group_get(struct device *dev)
> +static struct iommu_group *vfio_iommu_group_get(struct device *dev)
> {
> struct iommu_group *group;
> int __maybe_unused ret;
> @@ -220,9 +212,8 @@ struct iommu_group *vfio_iommu_group_get(struct
> device *dev)
>
> return group;
> }
> -EXPORT_SYMBOL_GPL(vfio_iommu_group_get);
>
> -void vfio_iommu_group_put(struct iommu_group *group, struct device
> *dev)
> +static void vfio_iommu_group_put(struct iommu_group *group, struct
> device *dev)
> {
> #ifdef CONFIG_VFIO_NOIOMMU
> if (iommu_group_get_iommudata(group) == &noiommu)
> @@ -231,7 +222,6 @@ void vfio_iommu_group_put(struct iommu_group
> *group, struct device *dev)
>
> iommu_group_put(group);
> }
> -EXPORT_SYMBOL_GPL(vfio_iommu_group_put);
>
> #ifdef CONFIG_VFIO_NOIOMMU
> static void *vfio_noiommu_open(unsigned long arg)
> @@ -841,7 +831,7 @@ int vfio_register_group_dev(struct vfio_device
> *device)
> if (!device->dev_set)
> vfio_assign_device_set(device, device);
>
> - iommu_group = iommu_group_get(device->dev);
> + iommu_group = vfio_iommu_group_get(device->dev);
> if (!iommu_group)
> return -EINVAL;
>
> @@ -849,7 +839,7 @@ int vfio_register_group_dev(struct vfio_device
> *device)
> if (!group) {
> group = vfio_create_group(iommu_group);
> if (IS_ERR(group)) {
> - iommu_group_put(iommu_group);
> + vfio_iommu_group_put(iommu_group, device->dev);
> return PTR_ERR(group);
> }
> } else {
> @@ -857,7 +847,7 @@ int vfio_register_group_dev(struct vfio_device
> *device)
> * A found vfio_group already holds a reference to the
> * iommu_group. A created vfio_group keeps the reference.
> */
> - iommu_group_put(iommu_group);
> + vfio_iommu_group_put(iommu_group, device->dev);
> }
>
> existing_device = vfio_group_get_device(group, device->dev);
> @@ -865,7 +855,7 @@ int vfio_register_group_dev(struct vfio_device
> *device)
> dev_WARN(device->dev, "Device already exists on
> group %d\n",
> iommu_group_id(iommu_group));
> vfio_device_put(existing_device);
> - vfio_group_put(group);
> + vfio_iommu_group_put(iommu_group, device->dev);
semantics change? the removed line is about vfio_group instead of
iommu_group.
> return -EBUSY;
> }
>
> @@ -1010,8 +1000,7 @@ void vfio_unregister_group_dev(struct vfio_device
> *device)
> if (list_empty(&group->device_list))
> wait_event(group->container_q, !group->container);
>
> - /* Matches the get in vfio_register_group_dev() */
> - vfio_group_put(group);
> + vfio_iommu_group_put(group->iommu_group, device->dev);
ditto
> }
> EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
>
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index b53a9557884ada..f7083c2fd0d099 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -71,9 +71,6 @@ struct vfio_device_ops {
> int (*match)(struct vfio_device *vdev, char *buf);
> };
>
> -extern struct iommu_group *vfio_iommu_group_get(struct device *dev);
> -extern void vfio_iommu_group_put(struct iommu_group *group, struct
> device *dev);
> -
> void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
> const struct vfio_device_ops *ops);
> void vfio_uninit_group_dev(struct vfio_device *device);
> --
> 2.30.2
