X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=bios%2Fseabios%2Fsrc%2Fvirtio-ring.c;fp=bios%2Fseabios%2Fsrc%2Fvirtio-ring.c;h=97a3ffee519bef72d7238deecae32e6474602058;hb=ab1e08bb6653d0d65ff64ea8f42506b9fd502357;hp=0000000000000000000000000000000000000000;hpb=5c40a15de52c320b70c94331e482b25fdcf768c4;p=palacios.git

diff --git a/bios/seabios/src/virtio-ring.c b/bios/seabios/src/virtio-ring.c
new file mode 100644
index 0000000..97a3ffe
--- /dev/null
+++ b/bios/seabios/src/virtio-ring.c
@@ -0,0 +1,151 @@
+/* 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
+ *
+ *  Adopted for Seabios: Gleb Natapov <gleb@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPLv3
+ * See the COPYING file in the top-level directory.
+ *
+ *
+ */
+
+#include "virtio-ring.h"
+#include "virtio-pci.h"
+#include "biosvar.h" // GET_GLOBAL
+#include "util.h" // dprintf
+
+#define BUG() do {                                      \
+        dprintf(1, "BUG: failure at %s:%d/%s()!\n",     \
+                __FILE__, __LINE__, __func__);          \
+                while(1);                               \
+        } while (0)
+#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
+
+/*
+ * vring_more_used
+ *
+ * is there some used buffers ?
+ *
+ */
+
+int vring_more_used(struct vring_virtqueue *vq)
+{
+    struct vring_used *used = GET_FLATPTR(vq->vring.used);
+    int more = GET_FLATPTR(vq->last_used_idx) != GET_FLATPTR(used->idx);
+    /* Make sure ring reads are done after idx read above. */
+    smp_rmb();
+    return more;
+}
+
+/*
+ * 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;
+    struct vring_desc *desc = GET_FLATPTR(vr->desc);
+    unsigned int i;
+
+    /* find end of given descriptor */
+
+    i = head;
+    while (GET_FLATPTR(desc[i].flags) & VRING_DESC_F_NEXT)
+        i = GET_FLATPTR(desc[i].next);
+
+    /* link it with free list and point to it */
+
+    SET_FLATPTR(desc[i].next, GET_FLATPTR(vq->free_head));
+    SET_FLATPTR(vq->free_head, head);
+}
+
+/*
+ * vring_get_buf
+ *
+ * get a buffer from the used list
+ *
+ */
+
+int vring_get_buf(struct vring_virtqueue *vq, unsigned int *len)
+{
+    struct vring *vr = &vq->vring;
+    struct vring_used_elem *elem;
+    struct vring_used *used = GET_FLATPTR(vq->vring.used);
+    u32 id;
+    int ret;
+
+//    BUG_ON(!vring_more_used(vq));
+
+    elem = &used->ring[GET_FLATPTR(vq->last_used_idx) % GET_FLATPTR(vr->num)];
+    id = GET_FLATPTR(elem->id);
+    if (len != NULL)
+        *len = GET_FLATPTR(elem->len);
+
+    ret = GET_FLATPTR(vq->vdata[id]);
+
+    vring_detach(vq, id);
+
+    SET_FLATPTR(vq->last_used_idx, GET_FLATPTR(vq->last_used_idx) + 1);
+
+    return ret;
+}
+
+void vring_add_buf(struct vring_virtqueue *vq,
+                   struct vring_list list[],
+                   unsigned int out, unsigned int in,
+                   int index, int num_added)
+{
+    struct vring *vr = &vq->vring;
+    int i, av, head, prev;
+    struct vring_desc *desc = GET_FLATPTR(vr->desc);
+    struct vring_avail *avail = GET_FLATPTR(vr->avail);
+
+    BUG_ON(out + in == 0);
+
+    prev = 0;
+    head = GET_FLATPTR(vq->free_head);
+    for (i = head; out; i = GET_FLATPTR(desc[i].next), out--) {
+        SET_FLATPTR(desc[i].flags, VRING_DESC_F_NEXT);
+        SET_FLATPTR(desc[i].addr, (u64)virt_to_phys(list->addr));
+        SET_FLATPTR(desc[i].len, list->length);
+        prev = i;
+        list++;
+    }
+    for ( ; in; i = GET_FLATPTR(desc[i].next), in--) {
+        SET_FLATPTR(desc[i].flags, VRING_DESC_F_NEXT|VRING_DESC_F_WRITE);
+        SET_FLATPTR(desc[i].addr, (u64)virt_to_phys(list->addr));
+        SET_FLATPTR(desc[i].len, list->length);
+        prev = i;
+        list++;
+    }
+    SET_FLATPTR(desc[prev].flags,
+                GET_FLATPTR(desc[prev].flags) & ~VRING_DESC_F_NEXT);
+
+    SET_FLATPTR(vq->free_head, i);
+
+    SET_FLATPTR(vq->vdata[head], index);
+
+    av = (GET_FLATPTR(avail->idx) + num_added) % GET_FLATPTR(vr->num);
+    SET_FLATPTR(avail->ring[av], head);
+}
+
+void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added)
+{
+    struct vring *vr = &vq->vring;
+    struct vring_avail *avail = GET_FLATPTR(vr->avail);
+
+    /* Make sure idx update is done after ring write. */
+    smp_wmb();
+    SET_FLATPTR(avail->idx, GET_FLATPTR(avail->idx) + num_added);
+
+    vp_notify(ioaddr, GET_FLATPTR(vq->queue_index));
+}