pds_vdpa: subscribe to the pds_core events

Register for the pds_core's notification events, primarily to
find out when the FW has been reset so we can pass this on
back up the chain.

Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230519215632.12343-11-shannon.nelson@amd.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/vdpa/pds/vdpa_dev.c b/drivers/vdpa/pds/vdpa_dev.c
index 5690ee6..5071a4d 100644 (file)
--- a/drivers/vdpa/pds/vdpa_dev.c
+++ b/drivers/vdpa/pds/vdpa_dev.c
@@ -23,6 +23,52 @@ static struct pds_vdpa_device *vdpa_to_pdsv(struct vdpa_device *vdpa_dev)
        return container_of(vdpa_dev, struct pds_vdpa_device, vdpa_dev);
 }
 
+static int pds_vdpa_notify_handler(struct notifier_block *nb,
+                                  unsigned long ecode,
+                                  void *data)
+{
+       struct pds_vdpa_device *pdsv = container_of(nb, struct pds_vdpa_device, nb);
+       struct device *dev = &pdsv->vdpa_aux->padev->aux_dev.dev;
+
+       dev_dbg(dev, "%s: event code %lu\n", __func__, ecode);
+
+       if (ecode == PDS_EVENT_RESET || ecode == PDS_EVENT_LINK_CHANGE) {
+               if (pdsv->config_cb.callback)
+                       pdsv->config_cb.callback(pdsv->config_cb.private);
+       }
+
+       return 0;
+}
+
+static int pds_vdpa_register_event_handler(struct pds_vdpa_device *pdsv)
+{
+       struct device *dev = &pdsv->vdpa_aux->padev->aux_dev.dev;
+       struct notifier_block *nb = &pdsv->nb;
+       int err;
+
+       if (!nb->notifier_call) {
+               nb->notifier_call = pds_vdpa_notify_handler;
+               err = pdsc_register_notify(nb);
+               if (err) {
+                       nb->notifier_call = NULL;
+                       dev_err(dev, "failed to register pds event handler: %ps\n",
+                               ERR_PTR(err));
+                       return -EINVAL;
+               }
+               dev_dbg(dev, "pds event handler registered\n");
+       }
+
+       return 0;
+}
+
+static void pds_vdpa_unregister_event_handler(struct pds_vdpa_device *pdsv)
+{
+       if (pdsv->nb.notifier_call) {
+               pdsc_unregister_notify(&pdsv->nb);
+               pdsv->nb.notifier_call = NULL;
+       }
+}
+
 static int pds_vdpa_set_vq_address(struct vdpa_device *vdpa_dev, u16 qid,
                                   u64 desc_addr, u64 driver_addr, u64 device_addr)
 {
@@ -595,6 +641,12 @@ static int pds_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 
        pdsv->vdpa_dev.mdev = &vdpa_aux->vdpa_mdev;
 
+       err = pds_vdpa_register_event_handler(pdsv);
+       if (err) {
+               dev_err(dev, "Failed to register for PDS events: %pe\n", ERR_PTR(err));
+               goto err_unmap;
+       }
+
        /* We use the _vdpa_register_device() call rather than the
         * vdpa_register_device() to avoid a deadlock because our
         * dev_add() is called with the vdpa_dev_lock already set
@@ -603,13 +655,15 @@ static int pds_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
        err = _vdpa_register_device(&pdsv->vdpa_dev, pdsv->num_vqs);
        if (err) {
                dev_err(dev, "Failed to register to vDPA bus: %pe\n", ERR_PTR(err));
-               goto err_unmap;
+               goto err_unevent;
        }
 
        pds_vdpa_debugfs_add_vdpadev(vdpa_aux);
 
        return 0;
 
+err_unevent:
+       pds_vdpa_unregister_event_handler(pdsv);
 err_unmap:
        put_device(&pdsv->vdpa_dev.dev);
        vdpa_aux->pdsv = NULL;
@@ -619,8 +673,11 @@ err_unmap:
 static void pds_vdpa_dev_del(struct vdpa_mgmt_dev *mdev,
                             struct vdpa_device *vdpa_dev)
 {
+       struct pds_vdpa_device *pdsv = vdpa_to_pdsv(vdpa_dev);
        struct pds_vdpa_aux *vdpa_aux;
 
+       pds_vdpa_unregister_event_handler(pdsv);
+
        vdpa_aux = container_of(mdev, struct pds_vdpa_aux, vdpa_mdev);
        _vdpa_unregister_device(vdpa_dev);
 

diff --git a/drivers/vdpa/pds/vdpa_dev.h b/drivers/vdpa/pds/vdpa_dev.h
index 25c1d19..a1bc37d 100644 (file)
--- a/drivers/vdpa/pds/vdpa_dev.h
+++ b/drivers/vdpa/pds/vdpa_dev.h
@@ -40,6 +40,7 @@ struct pds_vdpa_device {
        u8 vdpa_index;                  /* rsvd for future subdevice use */
        u8 num_vqs;                     /* num vqs in use */
        struct vdpa_callback config_cb;
+       struct notifier_block nb;
 };
 
 #define PDS_VDPA_PACKED_INVERT_IDX     0x8000