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Rusty Russellec3d41c2007-10-22 11:03:36 +10001#ifndef _LINUX_VIRTIO_CONFIG_H
2#define _LINUX_VIRTIO_CONFIG_H
Rusty Russell674bfc22008-07-25 12:06:03 -05003
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -06004#include <linux/err.h>
Paul Gortmaker187f1882011-11-23 20:12:59 -05005#include <linux/bug.h>
Rusty Russell72e61eb2008-05-02 21:50:49 -05006#include <linux/virtio.h>
David Howells607ca462012-10-13 10:46:48 +01007#include <uapi/linux/virtio_config.h>
Rusty Russellec3d41c2007-10-22 11:03:36 +10008
9/**
10 * virtio_config_ops - operations for configuring a virtio device
Rusty Russella586d4f2008-02-04 23:49:56 -050011 * @get: read the value of a configuration field
Rusty Russellec3d41c2007-10-22 11:03:36 +100012 * vdev: the virtio_device
Rusty Russella586d4f2008-02-04 23:49:56 -050013 * offset: the offset of the configuration field
Rusty Russellec3d41c2007-10-22 11:03:36 +100014 * buf: the buffer to write the field value into.
Rusty Russella586d4f2008-02-04 23:49:56 -050015 * len: the length of the buffer
Rusty Russella586d4f2008-02-04 23:49:56 -050016 * @set: write the value of a configuration field
Rusty Russellec3d41c2007-10-22 11:03:36 +100017 * vdev: the virtio_device
Rusty Russella586d4f2008-02-04 23:49:56 -050018 * offset: the offset of the configuration field
Rusty Russellec3d41c2007-10-22 11:03:36 +100019 * buf: the buffer to read the field value from.
Rusty Russella586d4f2008-02-04 23:49:56 -050020 * len: the length of the buffer
Rusty Russellec3d41c2007-10-22 11:03:36 +100021 * @get_status: read the status byte
22 * vdev: the virtio_device
23 * Returns the status byte
24 * @set_status: write the status byte
25 * vdev: the virtio_device
26 * status: the new status byte
Rusty Russell6e5aa7e2008-02-04 23:50:03 -050027 * @reset: reset the device
28 * vdev: the virtio device
29 * After this, status and feature negotiation must be done again
Michael S. Tsirkine6af5782011-11-17 17:41:15 +020030 * Device must not be reset from its vq/config callbacks, or in
31 * parallel with being added/removed.
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -060032 * @find_vqs: find virtqueues and instantiate them.
Rusty Russellec3d41c2007-10-22 11:03:36 +100033 * vdev: the virtio_device
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -060034 * nvqs: the number of virtqueues to find
35 * vqs: on success, includes new virtqueues
36 * callbacks: array of callbacks, for each virtqueue
Michael S. Tsirkin6457f122012-09-05 21:47:45 +030037 * include a NULL entry for vqs that do not need a callback
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -060038 * names: array of virtqueue names (mainly for debugging)
Michael S. Tsirkin6457f122012-09-05 21:47:45 +030039 * include a NULL entry for vqs unused by driver
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -060040 * Returns 0 on success or error status
41 * @del_vqs: free virtqueues found by find_vqs().
Rusty Russellc45a6812008-05-02 21:50:50 -050042 * @get_features: get the array of feature bits for this device.
43 * vdev: the virtio_device
44 * Returns the first 32 feature bits (all we currently need).
Rusty Russellc6248962008-07-25 12:06:07 -050045 * @finalize_features: confirm what device features we'll be using.
Rusty Russellc45a6812008-05-02 21:50:50 -050046 * vdev: the virtio_device
Rusty Russellc6248962008-07-25 12:06:07 -050047 * This gives the final feature bits for the device: it can change
48 * the dev->feature bits if it wants.
Rick Jones66846042011-11-14 14:17:08 +000049 * @bus_name: return the bus name associated with the device
50 * vdev: the virtio_device
51 * This returns a pointer to the bus name a la pci_name from which
52 * the caller can then copy.
Jason Wang75a0a522012-08-28 13:54:14 +020053 * @set_vq_affinity: set the affinity for a virtqueue.
Rusty Russellec3d41c2007-10-22 11:03:36 +100054 */
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -060055typedef void vq_callback_t(struct virtqueue *);
Rusty Russell1842f232009-07-30 16:03:46 -060056struct virtio_config_ops {
Rusty Russella586d4f2008-02-04 23:49:56 -050057 void (*get)(struct virtio_device *vdev, unsigned offset,
Rusty Russellec3d41c2007-10-22 11:03:36 +100058 void *buf, unsigned len);
Rusty Russella586d4f2008-02-04 23:49:56 -050059 void (*set)(struct virtio_device *vdev, unsigned offset,
Rusty Russellec3d41c2007-10-22 11:03:36 +100060 const void *buf, unsigned len);
61 u8 (*get_status)(struct virtio_device *vdev);
62 void (*set_status)(struct virtio_device *vdev, u8 status);
Rusty Russell6e5aa7e2008-02-04 23:50:03 -050063 void (*reset)(struct virtio_device *vdev);
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -060064 int (*find_vqs)(struct virtio_device *, unsigned nvqs,
65 struct virtqueue *vqs[],
66 vq_callback_t *callbacks[],
67 const char *names[]);
68 void (*del_vqs)(struct virtio_device *);
Rusty Russellc45a6812008-05-02 21:50:50 -050069 u32 (*get_features)(struct virtio_device *vdev);
Rusty Russellc6248962008-07-25 12:06:07 -050070 void (*finalize_features)(struct virtio_device *vdev);
Rick Jones66846042011-11-14 14:17:08 +000071 const char *(*bus_name)(struct virtio_device *vdev);
Jason Wang75a0a522012-08-28 13:54:14 +020072 int (*set_vq_affinity)(struct virtqueue *vq, int cpu);
Rusty Russellec3d41c2007-10-22 11:03:36 +100073};
74
Rusty Russellc45a6812008-05-02 21:50:50 -050075/* If driver didn't advertise the feature, it will never appear. */
76void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
77 unsigned int fbit);
78
79/**
80 * virtio_has_feature - helper to determine if this device has this feature.
81 * @vdev: the device
82 * @fbit: the feature bit
83 */
84static inline bool virtio_has_feature(const struct virtio_device *vdev,
85 unsigned int fbit)
86{
87 /* Did you forget to fix assumptions on max features? */
Rusty Russell1765e3a2011-01-24 14:45:10 -060088 if (__builtin_constant_p(fbit))
89 BUILD_BUG_ON(fbit >= 32);
90 else
91 BUG_ON(fbit >= 32);
Rusty Russellc45a6812008-05-02 21:50:50 -050092
Mark McLoughlinee006b32009-05-11 18:11:44 +010093 if (fbit < VIRTIO_TRANSPORT_F_START)
94 virtio_check_driver_offered_feature(vdev, fbit);
95
Rusty Russellc45a6812008-05-02 21:50:50 -050096 return test_bit(fbit, vdev->features);
97}
98
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -060099static inline
100struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
101 vq_callback_t *c, const char *n)
102{
103 vq_callback_t *callbacks[] = { c };
104 const char *names[] = { n };
105 struct virtqueue *vq;
106 int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
107 if (err < 0)
108 return ERR_PTR(err);
109 return vq;
110}
Rick Jones66846042011-11-14 14:17:08 +0000111
112static inline
113const char *virtio_bus_name(struct virtio_device *vdev)
114{
115 if (!vdev->config->bus_name)
116 return "virtio";
117 return vdev->config->bus_name(vdev);
118}
119
Jason Wang75a0a522012-08-28 13:54:14 +0200120/**
121 * virtqueue_set_affinity - setting affinity for a virtqueue
122 * @vq: the virtqueue
123 * @cpu: the cpu no.
124 *
125 * Pay attention the function are best-effort: the affinity hint may not be set
126 * due to config support, irq type and sharing.
127 *
128 */
129static inline
130int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
131{
132 struct virtio_device *vdev = vq->vdev;
133 if (vdev->config->set_vq_affinity)
134 return vdev->config->set_vq_affinity(vq, cpu);
135 return 0;
136}
137
Rusty Russell0b90d062013-10-14 18:11:51 +1030138/* Config space accessors. */
139#define virtio_cread(vdev, structname, member, ptr) \
140 do { \
141 /* Must match the member's type, and be integer */ \
142 if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
143 (*ptr) = 1; \
144 \
145 switch (sizeof(*ptr)) { \
146 case 1: \
147 *(ptr) = virtio_cread8(vdev, \
148 offsetof(structname, member)); \
149 break; \
150 case 2: \
151 *(ptr) = virtio_cread16(vdev, \
152 offsetof(structname, member)); \
153 break; \
154 case 4: \
155 *(ptr) = virtio_cread32(vdev, \
156 offsetof(structname, member)); \
157 break; \
158 case 8: \
159 *(ptr) = virtio_cread64(vdev, \
160 offsetof(structname, member)); \
161 break; \
162 default: \
163 BUG(); \
164 } \
165 } while(0)
166
167/* Config space accessors. */
168#define virtio_cwrite(vdev, structname, member, ptr) \
169 do { \
170 /* Must match the member's type, and be integer */ \
171 if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
172 BUG_ON((*ptr) == 1); \
173 \
174 switch (sizeof(*ptr)) { \
175 case 1: \
176 virtio_cwrite8(vdev, \
177 offsetof(structname, member), \
178 *(ptr)); \
179 break; \
180 case 2: \
181 virtio_cwrite16(vdev, \
182 offsetof(structname, member), \
183 *(ptr)); \
184 break; \
185 case 4: \
186 virtio_cwrite32(vdev, \
187 offsetof(structname, member), \
188 *(ptr)); \
189 break; \
190 case 8: \
191 virtio_cwrite64(vdev, \
192 offsetof(structname, member), \
193 *(ptr)); \
194 break; \
195 default: \
196 BUG(); \
197 } \
198 } while(0)
199
200static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
201{
202 u8 ret;
203 vdev->config->get(vdev, offset, &ret, sizeof(ret));
204 return ret;
205}
206
207static inline void virtio_cread_bytes(struct virtio_device *vdev,
208 unsigned int offset,
209 void *buf, size_t len)
210{
211 vdev->config->get(vdev, offset, buf, len);
212}
213
214static inline void virtio_cwrite8(struct virtio_device *vdev,
215 unsigned int offset, u8 val)
216{
217 vdev->config->set(vdev, offset, &val, sizeof(val));
218}
219
220static inline u16 virtio_cread16(struct virtio_device *vdev,
221 unsigned int offset)
222{
223 u16 ret;
224 vdev->config->get(vdev, offset, &ret, sizeof(ret));
225 return ret;
226}
227
228static inline void virtio_cwrite16(struct virtio_device *vdev,
229 unsigned int offset, u16 val)
230{
231 vdev->config->set(vdev, offset, &val, sizeof(val));
232}
233
234static inline u32 virtio_cread32(struct virtio_device *vdev,
235 unsigned int offset)
236{
237 u32 ret;
238 vdev->config->get(vdev, offset, &ret, sizeof(ret));
239 return ret;
240}
241
242static inline void virtio_cwrite32(struct virtio_device *vdev,
243 unsigned int offset, u32 val)
244{
245 vdev->config->set(vdev, offset, &val, sizeof(val));
246}
247
248static inline u64 virtio_cread64(struct virtio_device *vdev,
249 unsigned int offset)
250{
251 u64 ret;
252 vdev->config->get(vdev, offset, &ret, sizeof(ret));
253 return ret;
254}
255
256static inline void virtio_cwrite64(struct virtio_device *vdev,
257 unsigned int offset, u64 val)
258{
259 vdev->config->set(vdev, offset, &val, sizeof(val));
260}
261
262/* Conditional config space accessors. */
263#define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
264 ({ \
265 int _r = 0; \
266 if (!virtio_has_feature(vdev, fbit)) \
267 _r = -ENOENT; \
268 else \
269 virtio_cread((vdev), structname, member, ptr); \
270 _r; \
271 })
Jason Wang75a0a522012-08-28 13:54:14 +0200272
Rusty Russellec3d41c2007-10-22 11:03:36 +1000273#endif /* _LINUX_VIRTIO_CONFIG_H */