[PATCH v3 02/11] virtio: pci: add PM notification handlers for restore, freeze, thaw, poweroff

[Amit Shah]

Handle restore and freeze notification from the PM core.  Expose these
to individual virtio drivers that can quiesce and resume vq operations.

These functions also save device-specific data so that the device can be
put in pre-suspend state after resume, and disable and enable the PCI
device in the freeze and resume functions, respectively.

Signed-off-by: Amit Shah <amit.s...@redhat.com>
---
 drivers/virtio/virtio_pci.c |   50 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/virtio.h      |    4 +++
 2 files changed, 54 insertions(+), 0 deletions(-)

diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 5d36bc0..0db6f98 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -55,6 +55,10 @@ struct virtio_pci_device
        unsigned msix_vectors;
        /* Vectors allocated, excluding per-vq vectors if any */
        unsigned msix_used_vectors;
+
+       /* Status saved during hibernate/restore */
+       u8 saved_status;
+
        /* Whether we have vector per vq */
        bool per_vq_vectors;
 };
@@ -708,9 +712,55 @@ static int virtio_pci_resume(struct device *dev)
        return 0;
 }
 
+static int virtio_pci_freeze(struct device *dev)
+{
+       struct pci_dev *pci_dev = to_pci_dev(dev);
+       struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+       struct virtio_driver *drv;
+       int ret;
+
+       drv = container_of(vp_dev->vdev.dev.driver,
+                          struct virtio_driver, driver);
+
+       ret = 0;
+       vp_dev->saved_status = vp_get_status(&vp_dev->vdev);
+       if (drv && drv->freeze)
+               ret = drv->freeze(&vp_dev->vdev);
+
+       if (!ret)
+               pci_disable_device(pci_dev);
+       return ret;
+}
+
+static int virtio_pci_restore(struct device *dev)
+{
+       struct pci_dev *pci_dev = to_pci_dev(dev);
+       struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+       struct virtio_driver *drv;
+       int ret;
+
+       drv = container_of(vp_dev->vdev.dev.driver,
+                          struct virtio_driver, driver);
+
+       ret = pci_enable_device(pci_dev);
+       if (ret)
+               return ret;
+       pci_set_master(pci_dev);
+       vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
+       vp_finalize_features(&vp_dev->vdev);
+       if (drv && drv->restore)
+               ret = drv->restore(&vp_dev->vdev);
+
+       return ret;
+}
+
 static const struct dev_pm_ops virtio_pci_pm_ops = {
        .suspend = virtio_pci_suspend,
        .resume  = virtio_pci_resume,
+       .freeze  = virtio_pci_freeze,
+       .thaw    = virtio_pci_restore,
+       .restore = virtio_pci_restore,
+       .poweroff = virtio_pci_suspend,
 };
 #endif
 
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 4c069d8..1c26416 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -146,6 +146,10 @@ struct virtio_driver {
        int (*probe)(struct virtio_device *dev);
        void (*remove)(struct virtio_device *dev);
        void (*config_changed)(struct virtio_device *dev);
+#ifdef CONFIG_PM
+       int (*freeze)(struct virtio_device *dev);
+       int (*restore)(struct virtio_device *dev);
+#endif
 };
 
 int register_virtio_driver(struct virtio_driver *drv);
-- 
1.7.7.1

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