Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze

[profile/ivi/kernel-adaptation-intel-automotive.git] / drivers / virtio / virtio_mmio.c

diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 453db0c..6b1b7e1 100644 (file)
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -131,9 +131,6 @@ struct virtio_mmio_vq_info {
        /* the number of entries in the queue */
        unsigned int num;
 
-       /* the index of the queue */
-       int queue_index;
-
        /* the virtual address of the ring queue */
        void *queue;
 
@@ -225,11 +222,10 @@ static void vm_reset(struct virtio_device *vdev)
 static void vm_notify(struct virtqueue *vq)
 {
        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
-       struct virtio_mmio_vq_info *info = vq->priv;
 
        /* We write the queue's selector into the notification register to
         * signal the other end */
-       writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
+       writel(virtqueue_get_queue_index(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
 }
 
 /* Notify all virtqueues on an interrupt. */
@@ -270,6 +266,7 @@ static void vm_del_vq(struct virtqueue *vq)
        struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
        struct virtio_mmio_vq_info *info = vq->priv;
        unsigned long flags, size;
+       unsigned int index = virtqueue_get_queue_index(vq);
 
        spin_lock_irqsave(&vm_dev->lock, flags);
        list_del(&info->node);
@@ -278,7 +275,7 @@ static void vm_del_vq(struct virtqueue *vq)
        vring_del_virtqueue(vq);
 
        /* Select and deactivate the queue */
-       writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
+       writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
        writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
 
        size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN));
@@ -309,6 +306,9 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
        unsigned long flags, size;
        int err;
 
+       if (!name)
+               return NULL;
+
        /* Select the queue we're interested in */
        writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
 
@@ -324,7 +324,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
                err = -ENOMEM;
                goto error_kmalloc;
        }
-       info->queue_index = index;
 
        /* Allocate pages for the queue - start with a queue as big as
         * possible (limited by maximum size allowed by device), drop down
@@ -332,11 +331,21 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
         * and two rings (which makes it "alignment_size * 2")
         */
        info->num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
+
+       /* If the device reports a 0 entry queue, we won't be able to
+        * use it to perform I/O, and vring_new_virtqueue() can't create
+        * empty queues anyway, so don't bother to set up the device.
+        */
+       if (info->num == 0) {
+               err = -ENOENT;
+               goto error_alloc_pages;
+       }
+
        while (1) {
                size = PAGE_ALIGN(vring_size(info->num,
                                VIRTIO_MMIO_VRING_ALIGN));
-               /* Already smallest possible allocation? */
-               if (size <= VIRTIO_MMIO_VRING_ALIGN * 2) {
+               /* Did the last iter shrink the queue below minimum size? */
+               if (size < VIRTIO_MMIO_VRING_ALIGN * 2) {
                        err = -ENOMEM;
                        goto error_alloc_pages;
                }
@@ -356,7 +365,7 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
                        vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
 
        /* Create the vring */
-       vq = vring_new_virtqueue(info->num, VIRTIO_MMIO_VRING_ALIGN, vdev,
+       vq = vring_new_virtqueue(index, info->num, VIRTIO_MMIO_VRING_ALIGN, vdev,
                                 true, info->queue, vm_notify, callback, name);
        if (!vq) {
                err = -ENOMEM;