diff options
author | David Howells <dhowells@redhat.com> | 2012-10-13 05:46:48 -0400 |
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committer | David Howells <dhowells@redhat.com> | 2012-10-13 05:46:48 -0400 |
commit | 607ca46e97a1b6594b29647d98a32d545c24bdff (patch) | |
tree | 30f4c0784bfddb57332cdc0678bd06d1e77fa185 /include/linux/virtio_ring.h | |
parent | 08cce05c5a91f5017f4edc9866cf026908c73f9f (diff) |
UAPI: (Scripted) Disintegrate include/linux
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'include/linux/virtio_ring.h')
-rw-r--r-- | include/linux/virtio_ring.h | 163 |
1 files changed, 2 insertions, 161 deletions
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h index c2d793a06ad7..63c6ea199519 100644 --- a/include/linux/virtio_ring.h +++ b/include/linux/virtio_ring.h | |||
@@ -1,167 +1,9 @@ | |||
1 | #ifndef _LINUX_VIRTIO_RING_H | 1 | #ifndef _LINUX_VIRTIO_RING_H |
2 | #define _LINUX_VIRTIO_RING_H | 2 | #define _LINUX_VIRTIO_RING_H |
3 | /* An interface for efficient virtio implementation, currently for use by KVM | ||
4 | * and lguest, but hopefully others soon. Do NOT change this since it will | ||
5 | * break existing servers and clients. | ||
6 | * | ||
7 | * This header is BSD licensed so anyone can use the definitions to implement | ||
8 | * compatible drivers/servers. | ||
9 | * | ||
10 | * Redistribution and use in source and binary forms, with or without | ||
11 | * modification, are permitted provided that the following conditions | ||
12 | * are met: | ||
13 | * 1. Redistributions of source code must retain the above copyright | ||
14 | * notice, this list of conditions and the following disclaimer. | ||
15 | * 2. Redistributions in binary form must reproduce the above copyright | ||
16 | * notice, this list of conditions and the following disclaimer in the | ||
17 | * documentation and/or other materials provided with the distribution. | ||
18 | * 3. Neither the name of IBM nor the names of its contributors | ||
19 | * may be used to endorse or promote products derived from this software | ||
20 | * without specific prior written permission. | ||
21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND | ||
22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
24 | * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE | ||
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
31 | * SUCH DAMAGE. | ||
32 | * | ||
33 | * Copyright Rusty Russell IBM Corporation 2007. */ | ||
34 | #include <linux/types.h> | ||
35 | 3 | ||
36 | /* This marks a buffer as continuing via the next field. */ | ||
37 | #define VRING_DESC_F_NEXT 1 | ||
38 | /* This marks a buffer as write-only (otherwise read-only). */ | ||
39 | #define VRING_DESC_F_WRITE 2 | ||
40 | /* This means the buffer contains a list of buffer descriptors. */ | ||
41 | #define VRING_DESC_F_INDIRECT 4 | ||
42 | |||
43 | /* The Host uses this in used->flags to advise the Guest: don't kick me when | ||
44 | * you add a buffer. It's unreliable, so it's simply an optimization. Guest | ||
45 | * will still kick if it's out of buffers. */ | ||
46 | #define VRING_USED_F_NO_NOTIFY 1 | ||
47 | /* The Guest uses this in avail->flags to advise the Host: don't interrupt me | ||
48 | * when you consume a buffer. It's unreliable, so it's simply an | ||
49 | * optimization. */ | ||
50 | #define VRING_AVAIL_F_NO_INTERRUPT 1 | ||
51 | |||
52 | /* We support indirect buffer descriptors */ | ||
53 | #define VIRTIO_RING_F_INDIRECT_DESC 28 | ||
54 | |||
55 | /* The Guest publishes the used index for which it expects an interrupt | ||
56 | * at the end of the avail ring. Host should ignore the avail->flags field. */ | ||
57 | /* The Host publishes the avail index for which it expects a kick | ||
58 | * at the end of the used ring. Guest should ignore the used->flags field. */ | ||
59 | #define VIRTIO_RING_F_EVENT_IDX 29 | ||
60 | |||
61 | /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ | ||
62 | struct vring_desc { | ||
63 | /* Address (guest-physical). */ | ||
64 | __u64 addr; | ||
65 | /* Length. */ | ||
66 | __u32 len; | ||
67 | /* The flags as indicated above. */ | ||
68 | __u16 flags; | ||
69 | /* We chain unused descriptors via this, too */ | ||
70 | __u16 next; | ||
71 | }; | ||
72 | |||
73 | struct vring_avail { | ||
74 | __u16 flags; | ||
75 | __u16 idx; | ||
76 | __u16 ring[]; | ||
77 | }; | ||
78 | |||
79 | /* u32 is used here for ids for padding reasons. */ | ||
80 | struct vring_used_elem { | ||
81 | /* Index of start of used descriptor chain. */ | ||
82 | __u32 id; | ||
83 | /* Total length of the descriptor chain which was used (written to) */ | ||
84 | __u32 len; | ||
85 | }; | ||
86 | |||
87 | struct vring_used { | ||
88 | __u16 flags; | ||
89 | __u16 idx; | ||
90 | struct vring_used_elem ring[]; | ||
91 | }; | ||
92 | |||
93 | struct vring { | ||
94 | unsigned int num; | ||
95 | |||
96 | struct vring_desc *desc; | ||
97 | |||
98 | struct vring_avail *avail; | ||
99 | |||
100 | struct vring_used *used; | ||
101 | }; | ||
102 | |||
103 | /* The standard layout for the ring is a continuous chunk of memory which looks | ||
104 | * like this. We assume num is a power of 2. | ||
105 | * | ||
106 | * struct vring | ||
107 | * { | ||
108 | * // The actual descriptors (16 bytes each) | ||
109 | * struct vring_desc desc[num]; | ||
110 | * | ||
111 | * // A ring of available descriptor heads with free-running index. | ||
112 | * __u16 avail_flags; | ||
113 | * __u16 avail_idx; | ||
114 | * __u16 available[num]; | ||
115 | * __u16 used_event_idx; | ||
116 | * | ||
117 | * // Padding to the next align boundary. | ||
118 | * char pad[]; | ||
119 | * | ||
120 | * // A ring of used descriptor heads with free-running index. | ||
121 | * __u16 used_flags; | ||
122 | * __u16 used_idx; | ||
123 | * struct vring_used_elem used[num]; | ||
124 | * __u16 avail_event_idx; | ||
125 | * }; | ||
126 | */ | ||
127 | /* We publish the used event index at the end of the available ring, and vice | ||
128 | * versa. They are at the end for backwards compatibility. */ | ||
129 | #define vring_used_event(vr) ((vr)->avail->ring[(vr)->num]) | ||
130 | #define vring_avail_event(vr) (*(__u16 *)&(vr)->used->ring[(vr)->num]) | ||
131 | |||
132 | static inline void vring_init(struct vring *vr, unsigned int num, void *p, | ||
133 | unsigned long align) | ||
134 | { | ||
135 | vr->num = num; | ||
136 | vr->desc = p; | ||
137 | vr->avail = p + num*sizeof(struct vring_desc); | ||
138 | vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__u16) | ||
139 | + align-1) & ~(align - 1)); | ||
140 | } | ||
141 | |||
142 | static inline unsigned vring_size(unsigned int num, unsigned long align) | ||
143 | { | ||
144 | return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (3 + num) | ||
145 | + align - 1) & ~(align - 1)) | ||
146 | + sizeof(__u16) * 3 + sizeof(struct vring_used_elem) * num; | ||
147 | } | ||
148 | |||
149 | /* The following is used with USED_EVENT_IDX and AVAIL_EVENT_IDX */ | ||
150 | /* Assuming a given event_idx value from the other size, if | ||
151 | * we have just incremented index from old to new_idx, | ||
152 | * should we trigger an event? */ | ||
153 | static inline int vring_need_event(__u16 event_idx, __u16 new_idx, __u16 old) | ||
154 | { | ||
155 | /* Note: Xen has similar logic for notification hold-off | ||
156 | * in include/xen/interface/io/ring.h with req_event and req_prod | ||
157 | * corresponding to event_idx + 1 and new_idx respectively. | ||
158 | * Note also that req_event and req_prod in Xen start at 1, | ||
159 | * event indexes in virtio start at 0. */ | ||
160 | return (__u16)(new_idx - event_idx - 1) < (__u16)(new_idx - old); | ||
161 | } | ||
162 | |||
163 | #ifdef __KERNEL__ | ||
164 | #include <linux/irqreturn.h> | 4 | #include <linux/irqreturn.h> |
5 | #include <uapi/linux/virtio_ring.h> | ||
6 | |||
165 | struct virtio_device; | 7 | struct virtio_device; |
166 | struct virtqueue; | 8 | struct virtqueue; |
167 | 9 | ||
@@ -179,5 +21,4 @@ void vring_del_virtqueue(struct virtqueue *vq); | |||
179 | void vring_transport_features(struct virtio_device *vdev); | 21 | void vring_transport_features(struct virtio_device *vdev); |
180 | 22 | ||
181 | irqreturn_t vring_interrupt(int irq, void *_vq); | 23 | irqreturn_t vring_interrupt(int irq, void *_vq); |
182 | #endif /* __KERNEL__ */ | ||
183 | #endif /* _LINUX_VIRTIO_RING_H */ | 24 | #endif /* _LINUX_VIRTIO_RING_H */ |