*/
#include <linux/virtio.h>
#include <linux/virtio_ring.h>
+#include <linux/virtio_config.h>
#include <linux/device.h>
#ifdef DEBUG
/* For development, we want to crash whenever the ring is screwed. */
-#define BAD_RING(vq, fmt...) \
- do { dev_err(&vq->vq.vdev->dev, fmt); BUG(); } while(0)
-#define START_USE(vq) \
- do { if ((vq)->in_use) panic("in_use = %i\n", (vq)->in_use); (vq)->in_use = __LINE__; mb(); } while(0)
-#define END_USE(vq) \
- do { BUG_ON(!(vq)->in_use); (vq)->in_use = 0; mb(); } while(0)
+#define BAD_RING(_vq, fmt...) \
+ do { dev_err(&(_vq)->vq.vdev->dev, fmt); BUG(); } while(0)
+/* Caller is supposed to guarantee no reentry. */
+#define START_USE(_vq) \
+ do { \
+ if ((_vq)->in_use) \
+ panic("in_use = %i\n", (_vq)->in_use); \
+ (_vq)->in_use = __LINE__; \
+ mb(); \
+ } while(0)
+#define END_USE(_vq) \
+ do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; mb(); } while(0)
#else
-#define BAD_RING(vq, fmt...) \
- do { dev_err(&vq->vq.vdev->dev, fmt); (vq)->broken = true; } while(0)
+#define BAD_RING(_vq, fmt...) \
+ do { dev_err(&_vq->vq.vdev->dev, fmt); (_vq)->broken = true; } while(0)
#define START_USE(vq)
#define END_USE(vq)
#endif
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);
if (vq->num_free < out + in) {
pr_debug("Can't add buf len %i - avail = %i\n",
out + in, vq->num_free);
+ /* FIXME: for historical reasons, we force a notify here if
+ * there are outgoing parts to the buffer. Presumably the
+ * host should service the ring ASAP. */
+ if (out)
+ vq->notify(&vq->vq);
END_USE(vq);
return -ENOSPC;
}
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++;
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;
START_USE(vq);
+ if (unlikely(vq->broken)) {
+ END_USE(vq);
+ return NULL;
+ }
+
if (!more_used(vq)) {
pr_debug("No more buffers in queue\n");
END_USE(vq);
return ret;
}
-static bool vring_restart(struct virtqueue *_vq)
+static void vring_disable_cb(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+}
+
+static bool vring_enable_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));
/* We optimistically turn back on interrupts, then check if there was
* more to do. */
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;
}
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,
+ unsigned int vring_align,
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, vring_align);
vq->vq.callback = callback;
vq->vq.vdev = vdev;
vq->vq.vq_ops = &vring_vq_ops;
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);
+
+/* Manipulates transport-specific feature bits. */
+void vring_transport_features(struct virtio_device *vdev)
+{
+ unsigned int i;
+
+ for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) {
+ switch (i) {
+ default:
+ /* We don't understand this bit. */
+ clear_bit(i, vdev->features);
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(vring_transport_features);
+MODULE_LICENSE("GPL");
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff