Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6

[sfrench/cifs-2.6.git] / drivers / virtio / virtio_ring.c

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 0e4baca21b8f46e02f716a07aab4605e6663f20d..aa714028641e630b068f683fc67e6707d6c6a853 100644 (file)
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -53,7 +53,7 @@ struct vring_virtqueue
        unsigned int num_added;
 
        /* Last used index we've seen. */
-       unsigned int last_used_idx;
+       u16 last_used_idx;
 
        /* How to notify other side. FIXME: commonalize hcalls! */
        void (*notify)(struct virtqueue *vq);
@@ -87,6 +87,8 @@ static int vring_add_buf(struct virtqueue *_vq,
        if (vq->num_free < out + in) {
                pr_debug("Can't add buf len %i - avail = %i\n",
                         out + in, vq->num_free);
+               /* We notify *even if* VRING_USED_F_NO_NOTIFY is set here. */
+               vq->notify(&vq->vq);
                END_USE(vq);
                return -ENOSPC;
        }
@@ -97,16 +99,14 @@ static int vring_add_buf(struct virtqueue *_vq,
        head = vq->free_head;
        for (i = vq->free_head; out; i = vq->vring.desc[i].next, out--) {
                vq->vring.desc[i].flags = VRING_DESC_F_NEXT;
-               vq->vring.desc[i].addr = (page_to_pfn(sg_page(sg))<<PAGE_SHIFT)
-                       + sg->offset;
+               vq->vring.desc[i].addr = sg_phys(sg);
                vq->vring.desc[i].len = sg->length;
                prev = i;
                sg++;
        }
        for (; in; i = vq->vring.desc[i].next, in--) {
                vq->vring.desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE;
-               vq->vring.desc[i].addr = (page_to_pfn(sg_page(sg))<<PAGE_SHIFT)
-                       + sg->offset;
+               vq->vring.desc[i].addr = sg_phys(sg);
                vq->vring.desc[i].len = sg->length;
                prev = i;
                sg++;
@@ -171,16 +171,6 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
        vq->num_free++;
 }
 
-/* FIXME: We need to tell other side about removal, to synchronize. */
-static void vring_shutdown(struct virtqueue *_vq)
-{
-       struct vring_virtqueue *vq = to_vvq(_vq);
-       unsigned int i;
-
-       for (i = 0; i < vq->vring.num; i++)
-               detach_buf(vq, i);
-}
-
 static inline bool more_used(const struct vring_virtqueue *vq)
 {
        return vq->last_used_idx != vq->vring.used->idx;
@@ -220,7 +210,17 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)
        return ret;
 }
 
-static bool vring_restart(struct virtqueue *_vq)
+static void vring_disable_cb(struct virtqueue *_vq)
+{
+       struct vring_virtqueue *vq = to_vvq(_vq);
+
+       START_USE(vq);
+       BUG_ON(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT);
+       vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+       END_USE(vq);
+}
+
+static bool vring_enable_cb(struct virtqueue *_vq)
 {
        struct vring_virtqueue *vq = to_vvq(_vq);
 
@@ -232,7 +232,6 @@ static bool vring_restart(struct virtqueue *_vq)
        vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
        mb();
        if (unlikely(more_used(vq))) {
-               vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
                END_USE(vq);
                return false;
        }
@@ -253,35 +252,49 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
        if (unlikely(vq->broken))
                return IRQ_HANDLED;
 
+       /* Other side may have missed us turning off the interrupt,
+        * but we should preserve disable semantic for virtio users. */
+       if (unlikely(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
+               pr_debug("virtqueue interrupt after disable for %p\n", vq);
+               return IRQ_HANDLED;
+       }
+
        pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
-       if (vq->vq.callback && !vq->vq.callback(&vq->vq))
-               vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+       if (vq->vq.callback)
+               vq->vq.callback(&vq->vq);
 
        return IRQ_HANDLED;
 }
+EXPORT_SYMBOL_GPL(vring_interrupt);
 
 static struct virtqueue_ops vring_vq_ops = {
        .add_buf = vring_add_buf,
        .get_buf = vring_get_buf,
        .kick = vring_kick,
-       .restart = vring_restart,
-       .shutdown = vring_shutdown,
+       .disable_cb = vring_disable_cb,
+       .enable_cb = vring_enable_cb,
 };
 
 struct virtqueue *vring_new_virtqueue(unsigned int num,
                                      struct virtio_device *vdev,
                                      void *pages,
                                      void (*notify)(struct virtqueue *),
-                                     bool (*callback)(struct virtqueue *))
+                                     void (*callback)(struct virtqueue *))
 {
        struct vring_virtqueue *vq;
        unsigned int i;
 
+       /* We assume num is a power of 2. */
+       if (num & (num - 1)) {
+               dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
+               return NULL;
+       }
+
        vq = kmalloc(sizeof(*vq) + sizeof(void *)*num, GFP_KERNEL);
        if (!vq)
                return NULL;
 
-       vring_init(&vq->vring, num, pages);
+       vring_init(&vq->vring, num, pages, PAGE_SIZE);
        vq->vq.callback = callback;
        vq->vq.vdev = vdev;
        vq->vq.vq_ops = &vring_vq_ops;
@@ -305,9 +318,12 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
 
        return &vq->vq;
 }
+EXPORT_SYMBOL_GPL(vring_new_virtqueue);
 
 void vring_del_virtqueue(struct virtqueue *vq)
 {
        kfree(to_vvq(vq));
 }
+EXPORT_SYMBOL_GPL(vring_del_virtqueue);
 
+MODULE_LICENSE("GPL");