Re: [PATCH v4 03/12] vfio_pci: refine vfio_pci_driver reference in vfio_pci.c

Alex Williamson
2020-01-09T22:48:33Z

On Tue, 7 Jan 2020 20:01:40 +0800
Liu Yi L <yi.l.liu@intel.com> wrote:

> This patch replaces the vfio_pci_driver reference in vfio_pci.c with
> pci_dev_driver(vdev->pdev) which is more helpful to make the functions
> be generic to module types.
>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Cc: Lu Baolu <baolu.lu@linux.intel.com>
> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> ---
> drivers/vfio/pci/vfio_pci.c | 34 ++++++++++++++++++----------------
> 1 file changed, 18 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index 009d2df..9140f5e5 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -1463,24 +1463,25 @@ static void vfio_pci_reflck_get(struct vfio_pci_reflck *reflck)
>
> static int vfio_pci_reflck_find(struct pci_dev *pdev, void *data)
> {
> - struct vfio_pci_reflck **preflck = data;
> + struct vfio_pci_device *vdev = data;
> + struct vfio_pci_reflck **preflck = &vdev->reflck;
> struct vfio_device *device;
> - struct vfio_pci_device *vdev;
> + struct vfio_pci_device *tmp;
>
> device = vfio_device_get_from_dev(&pdev->dev);
> if (!device)
> return 0;
>
> - if (pci_dev_driver(pdev) != &vfio_pci_driver) {
> + if (pci_dev_driver(pdev) != pci_dev_driver(vdev->pdev)) {
> vfio_device_put(device);
> return 0;
> }
>
> - vdev = vfio_device_data(device);
> + tmp = vfio_device_data(device);
>
> - if (vdev->reflck) {
> - vfio_pci_reflck_get(vdev->reflck);
> - *preflck = vdev->reflck;
> + if (tmp->reflck) {
> + vfio_pci_reflck_get(tmp->reflck);
> + *preflck = tmp->reflck;

Seems we can do away with preflck entirely with this refactor, this
simply becomes vdev->reflck = tmp->reflck. Thanks,

Alex

> vfio_device_put(device);
> return 1;
> }
> @@ -1497,7 +1498,7 @@ static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev)
>
> if (pci_is_root_bus(vdev->pdev->bus) ||
> vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_reflck_find,
> - &vdev->reflck, slot) <= 0)
> + vdev, slot) <= 0)
> vdev->reflck = vfio_pci_reflck_alloc();
>
> mutex_unlock(&reflck_lock);
> @@ -1522,6 +1523,7 @@ static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck)
>
> struct vfio_devices {
> struct vfio_device **devices;
> + struct vfio_pci_device *vdev;
> int cur_index;
> int max_index;
> };
> @@ -1530,7 +1532,7 @@ static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data)
> {
> struct vfio_devices *devs = data;
> struct vfio_device *device;
> - struct vfio_pci_device *vdev;
> + struct vfio_pci_device *tmp;
>
> if (devs->cur_index == devs->max_index)
> return -ENOSPC;
> @@ -1539,15 +1541,15 @@ static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data)
> if (!device)
> return -EINVAL;
>
> - if (pci_dev_driver(pdev) != &vfio_pci_driver) {
> + if (pci_dev_driver(pdev) != pci_dev_driver(devs->vdev->pdev)) {
> vfio_device_put(device);
> return -EBUSY;
> }
>
> - vdev = vfio_device_data(device);
> + tmp = vfio_device_data(device);
>
> /* Fault if the device is not unused */
> - if (vdev->refcnt) {
> + if (tmp->refcnt) {
> vfio_device_put(device);
> return -EBUSY;
> }
> @@ -1574,7 +1576,7 @@ static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data)
> */
> static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
> {
> - struct vfio_devices devs = { .cur_index = 0 };
> + struct vfio_devices devs = { .vdev = vdev, .cur_index = 0 };
> int i = 0, ret = -EINVAL;
> bool slot = false;
> struct vfio_pci_device *tmp;
> @@ -1637,7 +1639,7 @@ static void __exit vfio_pci_cleanup(void)
> vfio_pci_uninit_perm_bits();
> }
>
> -static void __init vfio_pci_fill_ids(char *ids)
> +static void __init vfio_pci_fill_ids(char *ids, struct pci_driver *driver)
> {
> char *p, *id;
> int rc;
> @@ -1665,7 +1667,7 @@ static void __init vfio_pci_fill_ids(char *ids)
> continue;
> }
>
> - rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
> + rc = pci_add_dynid(driver, vendor, device,
> subvendor, subdevice, class, class_mask, 0);
> if (rc)
> pr_warn("failed to add dynamic id [%04x:%04x[%04x:%04x]] class %#08x/%08x (%d)\n",
> @@ -1692,7 +1694,7 @@ static int __init vfio_pci_init(void)
> if (ret)
> goto out_driver;
>
> - vfio_pci_fill_ids(ids);
> + vfio_pci_fill_ids(ids, &vfio_pci_driver);
>
> return 0;
>