content.tex: split virtio-ring out

Split virtio_ring.h out to a separate file.
Required by OASIS (though not a strict requirement
for non-normative definitions like this one).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

git-svn-id: https://tools.oasis-open.org/version-control/svn/virtio@130 0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652

1 files changed, 5 insertions, 167 deletions

diff --git a/content.tex b/content.tex
index 8a1759a..37c8257 100644
--- a/content.tex
+++ b/content.tex
@@ -3857,174 +3857,12 @@ VIRTIO_F_ANY_LAYOUT (27) This feature indicates that the device
 
 \chapter{virtio_ring.h}\label{sec:virtio-ring.h}
 
-\begin{lstlisting}
-#ifndef VIRTIO_RING_H
-#define VIRTIO_RING_H
-/* An interface for efficient virtio implementation.
- *
- * This header is BSD licensed so anyone can use the definitions
- * to implement compatible drivers/servers.
- *
- * Copyright 2007, 2009, IBM Corporation
- * Copyright 2011, Red Hat, Inc
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. Neither the name of IBM nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-#include <stdint.h>
-
-/* This marks a buffer as continuing via the next field. */
-#define VRING_DESC_F_NEXT       1
-/* This marks a buffer as write-only (otherwise read-only). */
-#define VRING_DESC_F_WRITE      2
-/* This means the buffer contains a list of buffer descriptors. */
-#define VRING_DESC_F_INDIRECT   4
-
-/* The Host uses this in used->flags to advise the Guest: don't kick me
- * when you add a buffer.  It's unreliable, so it's simply an
- * optimization.  Guest will still kick if it's out of buffers. */
-#define VRING_USED_F_NO_NOTIFY  1
-/* The Guest uses this in avail->flags to advise the Host: don't
- * interrupt me when you consume a buffer.  It's unreliable, so it's
- * simply an optimization.  */
-#define VRING_AVAIL_F_NO_INTERRUPT      1
-
-/* Support for indirect descriptors */
-#define VIRTIO_RING_F_INDIRECT_DESC    28
-
-/* Support for avail_idx and used_idx fields */
-#define VIRTIO_RING_F_EVENT_IDX        29
-
-/* Arbitrary descriptor layouts. */
-#define VIRTIO_F_ANY_LAYOUT            27
-
-/* Virtio ring descriptors: 16 bytes.
- * These can chain together via "next". */
-struct vring_desc {
-        /* Address (guest-physical). */
-        le64 addr;
-        /* Length. */
-        le32 len;
-        /* The flags as indicated above. */
-        le16 flags;
-        /* We chain unused descriptors via this, too */
-        le16 next;
-};
-
-struct vring_avail {
-        le16 flags;
-        le16 idx;
-        le16 ring[];
-        /* Only if VIRTIO_RING_F_EVENT_IDX: le16 used_event; */
-};
-
-/* le32 is used here for ids for padding reasons. */
-struct vring_used_elem {
-        /* Index of start of used descriptor chain. */
-        le32 id;
-        /* Total length of the descriptor chain which was written to. */
-        le32 len;
-};
-
-struct vring_used {
-        le16 flags;
-        le16 idx;
-        struct vring_used_elem ring[];
-        /* Only if VIRTIO_RING_F_EVENT_IDX: le16 avail_event; */
-};
-
-struct vring {
-        unsigned int num;
-
-        struct vring_desc *desc;
-        struct vring_avail *avail;
-        struct vring_used *used;
-};
-
-/* The standard layout for the ring is a continuous chunk of memory which
- * looks like this.  We assume num is a power of 2.
- *
- * struct vring {
- *      // The actual descriptors (16 bytes each)
- *      struct vring_desc desc[num];
- *
- *      // A ring of available descriptor heads with free-running index.
- *      le16 avail_flags;
- *      le16 avail_idx;
- *      le16 available[num];
- *      le16 used_event_idx; // Only if VIRTIO_RING_F_EVENT_IDX
- *
- *      // Padding to the next align boundary.
- *      char pad[];
- *
- *      // A ring of used descriptor heads with free-running index.
- *      le16 used_flags;
- *      le16 used_idx;
- *      struct vring_used_elem used[num];
- *      le16 avail_event_idx; // Only if VIRTIO_RING_F_EVENT_IDX
- * };
- * Note: for virtio PCI, align is 4096.
- */
-static inline void vring_init(struct vring *vr, unsigned int num, void *p,
-                              unsigned long align)
-{
-        vr->num = num;
-        vr->desc = p;
-        vr->avail = p + num*sizeof(struct vring_desc);
-        vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(le16)
-                              + align-1)
-                            & ~(align - 1));
-}
-
-static inline unsigned vring_size(unsigned int num, unsigned long align)
-{
-        return ((sizeof(struct vring_desc)*num + sizeof(le16)*(3+num)
-                 + align - 1) & ~(align - 1))
-                + sizeof(le16)*3 + sizeof(struct vring_used_elem)*num;
-}
-
-static inline int vring_need_event(uint16_t event_idx, uint16_t new_idx, uint16_t old_idx)
-{
-         return (uint16_t)(new_idx - event_idx - 1) < (uint16_t)(new_idx - old_idx);
-}
-
-/* Get location of event indices (only with VIRTIO_RING_F_EVENT_IDX) */
-static inline le16 *vring_used_event(struct vring *vr)
-{
-        /* For backwards compat, used event index is at *end* of avail ring. */
-        return &vr->avail->ring[vr->num];
-}
-
-static inline le16 *vring_avail_event(struct vring *vr)
-{
-        /* For backwards compat, avail event index is at *end* of used ring. */
-        return (le16 *)&vr->used->ring[vr->num];
-}
-#endif /* VIRTIO_RING_H */
-\end{lstlisting}
-
+This file is also available at the link
+\url{\virtiourlbase/listings/virtio_ring.h}.
+All definitions in this section are for non-normative reference
+only.
 
+\lstinputlisting{virtio-ring.h}
 
 \chapter{Creating New Device Types}\label{sec:Creating New Device Types}