Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / ipxe / src / drivers / bus / virtio-ring.c

diff --git a/qemu/roms/ipxe/src/drivers/bus/virtio-ring.c b/qemu/roms/ipxe/src/drivers/bus/virtio-ring.c
new file mode 100644 (file)
index 0000000..e55b6d0
--- /dev/null
+++ b/qemu/roms/ipxe/src/drivers/bus/virtio-ring.c
@@ -0,0 +1,136 @@
+/* virtio-pci.c - virtio ring management
+ *
+ * (c) Copyright 2008 Bull S.A.S.
+ *
+ *  Author: Laurent Vivier <Laurent.Vivier@bull.net>
+ *
+ *  some parts from Linux Virtio Ring
+ *
+ *  Copyright Rusty Russell IBM Corporation 2007
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include "etherboot.h"
+#include "ipxe/io.h"
+#include "ipxe/virtio-ring.h"
+#include "ipxe/virtio-pci.h"
+
+#define BUG() do { \
+   printf("BUG: failure at %s:%d/%s()!\n", \
+          __FILE__, __LINE__, __FUNCTION__); \
+   while(1); \
+} while (0)
+#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
+
+/*
+ * vring_free
+ *
+ * put at the begin of the free list the current desc[head]
+ */
+
+void vring_detach(struct vring_virtqueue *vq, unsigned int head)
+{
+   struct vring *vr = &vq->vring;
+   unsigned int i;
+
+   /* find end of given descriptor */
+
+   i = head;
+   while (vr->desc[i].flags & VRING_DESC_F_NEXT)
+           i = vr->desc[i].next;
+
+   /* link it with free list and point to it */
+
+   vr->desc[i].next = vq->free_head;
+   wmb();
+   vq->free_head = head;
+}
+
+/*
+ * vring_get_buf
+ *
+ * get a buffer from the used list
+ *
+ */
+
+void *vring_get_buf(struct vring_virtqueue *vq, unsigned int *len)
+{
+   struct vring *vr = &vq->vring;
+   struct vring_used_elem *elem;
+   u32 id;
+   void *opaque;
+
+   BUG_ON(!vring_more_used(vq));
+
+   elem = &vr->used->ring[vq->last_used_idx % vr->num];
+   wmb();
+   id = elem->id;
+   if (len != NULL)
+           *len = elem->len;
+
+   opaque = vq->vdata[id];
+
+   vring_detach(vq, id);
+
+   vq->last_used_idx++;
+
+   return opaque;
+}
+
+void vring_add_buf(struct vring_virtqueue *vq,
+                  struct vring_list list[],
+                  unsigned int out, unsigned int in,
+                  void *opaque, int num_added)
+{
+   struct vring *vr = &vq->vring;
+   int i, avail, head, prev;
+
+   BUG_ON(out + in == 0);
+
+   prev = 0;
+   head = vq->free_head;
+   for (i = head; out; i = vr->desc[i].next, out--) {
+
+           vr->desc[i].flags = VRING_DESC_F_NEXT;
+           vr->desc[i].addr = (u64)virt_to_phys(list->addr);
+           vr->desc[i].len = list->length;
+           prev = i;
+           list++;
+   }
+   for ( ; in; i = vr->desc[i].next, in--) {
+
+           vr->desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE;
+           vr->desc[i].addr = (u64)virt_to_phys(list->addr);
+           vr->desc[i].len = list->length;
+           prev = i;
+           list++;
+   }
+   vr->desc[prev].flags &= ~VRING_DESC_F_NEXT;
+
+   vq->free_head = i;
+
+   vq->vdata[head] = opaque;
+
+   avail = (vr->avail->idx + num_added) % vr->num;
+   vr->avail->ring[avail] = head;
+   wmb();
+}
+
+void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added)
+{
+   struct vring *vr = &vq->vring;
+
+   wmb();
+   vr->avail->idx += num_added;
+
+   mb();
+   if (!(vr->used->flags & VRING_USED_F_NO_NOTIFY))
+           vp_notify(ioaddr, vq->queue_index);
+}
+