Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio updates from Rusty Russell.

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  Revert "hwrng: virtio - ensure reads happen after successful probe"
  virtio: rng: delay hwrng_register() till driver is ready
  virtio: rng: re-arrange struct elements for better packing
  virtio: rng: remove unused struct element
  virtio: Replace DEFINE_PCI_DEVICE_TABLE macro use
  virtio: console: remove unnecessary null test before debugfs_remove_recursive

2 files changed, 17 insertions, 28 deletions

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 6e02ec103cc7..aa30a25c8d49 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -81,12 +81,6 @@ static void add_early_randomness(struct hwrng *rng)
         unsigned char bytes[16];
         int bytes_read;
 
-        /*
-         * Currently only virtio-rng cannot return data during device
-         * probe, and that's handled in virtio-rng.c itself.  If there
-         * are more such devices, this call to rng_get_data can be
-         * made conditional here instead of doing it per-device.
-         */
         bytes_read = rng_get_data(rng, bytes, sizeof(bytes), 1);
         if (bytes_read > 0)
                 add_device_randomness(bytes, bytes_read);
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index e9b15bc18b4d..0027137daa56 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -28,17 +28,16 @@
 static DEFINE_IDA(rng_index_ida);
 
 struct virtrng_info {
-        struct virtio_device *vdev;
         struct hwrng hwrng;
         struct virtqueue *vq;
-        unsigned int data_avail;
         struct completion have_data;
-        bool busy;
         char name[25];
+        unsigned int data_avail;
         int index;
+        bool busy;
+        bool hwrng_register_done;
 };
 
-static bool probe_done;
 
 static void random_recv_done(struct virtqueue *vq)
 {
@@ -69,13 +68,6 @@ static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
         int ret;
         struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
 
-        /*
-         * Don't ask host for data till we're setup.  This call can
-         * happen during hwrng_register(), after commit d9e7972619.
-         */
-        if (unlikely(!probe_done))
-                return 0;
-
         if (!vi->busy) {
                 vi->busy = true;
                 init_completion(&vi->have_data);
@@ -137,25 +129,17 @@ static int probe_common(struct virtio_device *vdev)
                 return err;
         }
 
-        err = hwrng_register(&vi->hwrng);
-        if (err) {
-                vdev->config->del_vqs(vdev);
-                vi->vq = NULL;
-                kfree(vi);
-                ida_simple_remove(&rng_index_ida, index);
-                return err;
-        }
-
-        probe_done = true;
         return 0;
 }
 
 static void remove_common(struct virtio_device *vdev)
 {
         struct virtrng_info *vi = vdev->priv;
+
         vdev->config->reset(vdev);
         vi->busy = false;
-        hwrng_unregister(&vi->hwrng);
+        if (vi->hwrng_register_done)
+                hwrng_unregister(&vi->hwrng);
         vdev->config->del_vqs(vdev);
         ida_simple_remove(&rng_index_ida, vi->index);
         kfree(vi);
@@ -171,6 +155,16 @@ static void virtrng_remove(struct virtio_device *vdev)
         remove_common(vdev);
 }
 
+static void virtrng_scan(struct virtio_device *vdev)
+{
+        struct virtrng_info *vi = vdev->priv;
+        int err;
+
+        err = hwrng_register(&vi->hwrng);
+        if (!err)
+                vi->hwrng_register_done = true;
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int virtrng_freeze(struct virtio_device *vdev)
 {
@@ -195,6 +189,7 @@ static struct virtio_driver virtio_rng_driver = {
         .id_table =     id_table,
         .probe =        virtrng_probe,
         .remove =       virtrng_remove,
+        .scan =         virtrng_scan,
 #ifdef CONFIG_PM_SLEEP
         .freeze =       virtrng_freeze,
         .restore =      virtrng_restore,