diff options
author | Jason Gunthorpe <jgg@nvidia.com> | 2022-05-11 13:19:07 -0600 |
---|---|---|
committer | Alex Williamson <alex.williamson@redhat.com> | 2022-05-11 13:32:56 -0600 |
commit | ff806cbd90bd2cc3d08a026e26157e5b5a6b5e03 (patch) | |
tree | 7819b677d8ec507c30674fab9e3e1f35df74fd95 /drivers/vfio/pci/vfio_pci_core.c | |
parent | 91be0bd6c6cf21328017e990d3ceeb00f03821fd (diff) | |
download | linux-ff806cbd90bd2cc3d08a026e26157e5b5a6b5e03.tar.bz2 |
vfio/pci: Remove vfio_device_get_from_dev()
The last user of this function is in PCI callbacks that want to convert
their struct pci_dev to a vfio_device. Instead of searching use the
vfio_device available trivially through the drvdata.
When a callback in the device_driver is called, the caller must hold the
device_lock() on dev. The purpose of the device_lock is to prevent
remove() from being called (see __device_release_driver), and allow the
driver to safely interact with its drvdata without races.
The PCI core correctly follows this and holds the device_lock() when
calling error_detected (see report_error_detected) and
sriov_configure (see sriov_numvfs_store).
Further, since the drvdata holds a positive refcount on the vfio_device
any access of the drvdata, under the device_lock(), from a driver callback
needs no further protection or refcounting.
Thus the remark in the vfio_device_get_from_dev() comment does not apply
here, VFIO PCI drivers all call vfio_unregister_group_dev() from their
remove callbacks under the device_lock() and cannot race with the
remaining callers.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v4-c841817a0349+8f-vfio_get_from_dev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio/pci/vfio_pci_core.c')
-rw-r--r-- | drivers/vfio/pci/vfio_pci_core.c | 32 |
1 files changed, 6 insertions, 26 deletions
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 65587fd5c021..100ab98c7ff0 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -1894,9 +1894,7 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_register_device); void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev) { - struct pci_dev *pdev = vdev->pdev; - - vfio_pci_core_sriov_configure(pdev, 0); + vfio_pci_core_sriov_configure(vdev, 0); vfio_unregister_group_dev(&vdev->vdev); @@ -1911,14 +1909,7 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_unregister_device); pci_ers_result_t vfio_pci_core_aer_err_detected(struct pci_dev *pdev, pci_channel_state_t state) { - struct vfio_pci_core_device *vdev; - struct vfio_device *device; - - device = vfio_device_get_from_dev(&pdev->dev); - if (device == NULL) - return PCI_ERS_RESULT_DISCONNECT; - - vdev = container_of(device, struct vfio_pci_core_device, vdev); + struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev); mutex_lock(&vdev->igate); @@ -1927,26 +1918,18 @@ pci_ers_result_t vfio_pci_core_aer_err_detected(struct pci_dev *pdev, mutex_unlock(&vdev->igate); - vfio_device_put(device); - return PCI_ERS_RESULT_CAN_RECOVER; } EXPORT_SYMBOL_GPL(vfio_pci_core_aer_err_detected); -int vfio_pci_core_sriov_configure(struct pci_dev *pdev, int nr_virtfn) +int vfio_pci_core_sriov_configure(struct vfio_pci_core_device *vdev, + int nr_virtfn) { - struct vfio_pci_core_device *vdev; - struct vfio_device *device; + struct pci_dev *pdev = vdev->pdev; int ret = 0; device_lock_assert(&pdev->dev); - device = vfio_device_get_from_dev(&pdev->dev); - if (!device) - return -ENODEV; - - vdev = container_of(device, struct vfio_pci_core_device, vdev); - if (nr_virtfn) { mutex_lock(&vfio_pci_sriov_pfs_mutex); /* @@ -1964,8 +1947,7 @@ int vfio_pci_core_sriov_configure(struct pci_dev *pdev, int nr_virtfn) ret = pci_enable_sriov(pdev, nr_virtfn); if (ret) goto out_del; - ret = nr_virtfn; - goto out_put; + return nr_virtfn; } pci_disable_sriov(pdev); @@ -1975,8 +1957,6 @@ out_del: list_del_init(&vdev->sriov_pfs_item); out_unlock: mutex_unlock(&vfio_pci_sriov_pfs_mutex); -out_put: - vfio_device_put(device); return ret; } EXPORT_SYMBOL_GPL(vfio_pci_core_sriov_configure); |