USB: audio: guard kernel-only code with __KERNEL__

[safe/jmp/linux-2.6] / include / linux / virtio_config.h

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index f364bbf..e547e3c 100644 (file)
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -1,5 +1,8 @@
 #ifndef _LINUX_VIRTIO_CONFIG_H
 #define _LINUX_VIRTIO_CONFIG_H
+/* This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
+ * anyone can use the definitions to implement compatible drivers/servers. */
+
 /* Virtio devices use a standardized configuration space to define their
  * features and pass configuration information, but each implementation can
  * store and access that space differently. */
@@ -15,11 +18,18 @@
 /* We've given up on this device. */
 #define VIRTIO_CONFIG_S_FAILED         0x80
 
+/* Some virtio feature bits (currently bits 28 through 31) are reserved for the
+ * transport being used (eg. virtio_ring), the rest are per-device feature
+ * bits. */
+#define VIRTIO_TRANSPORT_F_START       28
+#define VIRTIO_TRANSPORT_F_END         32
+
 /* Do we get callbacks when the ring is completely used, even if we've
  * suppressed them? */
 #define VIRTIO_F_NOTIFY_ON_EMPTY       24
 
 #ifdef __KERNEL__
+#include <linux/err.h>
 #include <linux/virtio.h>
 
 /**
@@ -40,24 +50,36 @@
  * @set_status: write the status byte
  *     vdev: the virtio_device
  *     status: the new status byte
+ * @request_vqs: request the specified number of virtqueues
+ *     vdev: the virtio_device
+ *     max_vqs: the max number of virtqueues we want
+ *      If supplied, must call before any virtqueues are instantiated.
+ *      To modify the max number of virtqueues after request_vqs has been
+ *      called, call free_vqs and then request_vqs with a new value.
+ * @free_vqs: cleanup resources allocated by request_vqs
+ *     vdev: the virtio_device
+ *      If supplied, must call after all virtqueues have been deleted.
  * @reset: reset the device
  *     vdev: the virtio device
  *     After this, status and feature negotiation must be done again
- * @find_vq: find a virtqueue and instantiate it.
+ * @find_vqs: find virtqueues and instantiate them.
  *     vdev: the virtio_device
- *     index: the 0-based virtqueue number in case there's more than one.
- *     callback: the virqtueue callback
- *     Returns the new virtqueue or ERR_PTR() (eg. -ENOENT).
- * @del_vq: free a virtqueue found by find_vq().
+ *     nvqs: the number of virtqueues to find
+ *     vqs: on success, includes new virtqueues
+ *     callbacks: array of callbacks, for each virtqueue
+ *     names: array of virtqueue names (mainly for debugging)
+ *     Returns 0 on success or error status
+ * @del_vqs: free virtqueues found by find_vqs().
  * @get_features: get the array of feature bits for this device.
  *     vdev: the virtio_device
  *     Returns the first 32 feature bits (all we currently need).
- * @set_features: confirm what device features we'll be using.
+ * @finalize_features: confirm what device features we'll be using.
  *     vdev: the virtio_device
- *     feature: the first 32 feature bits
+ *     This gives the final feature bits for the device: it can change
+ *     the dev->feature bits if it wants.
  */
-struct virtio_config_ops
-{
+typedef void vq_callback_t(struct virtqueue *);
+struct virtio_config_ops {
        void (*get)(struct virtio_device *vdev, unsigned offset,
                    void *buf, unsigned len);
        void (*set)(struct virtio_device *vdev, unsigned offset,
@@ -65,12 +87,13 @@ struct virtio_config_ops
        u8 (*get_status)(struct virtio_device *vdev);
        void (*set_status)(struct virtio_device *vdev, u8 status);
        void (*reset)(struct virtio_device *vdev);
-       struct virtqueue *(*find_vq)(struct virtio_device *vdev,
-                                    unsigned index,
-                                    void (*callback)(struct virtqueue *));
-       void (*del_vq)(struct virtqueue *vq);
+       int (*find_vqs)(struct virtio_device *, unsigned nvqs,
+                       struct virtqueue *vqs[],
+                       vq_callback_t *callbacks[],
+                       const char *names[]);
+       void (*del_vqs)(struct virtio_device *);
        u32 (*get_features)(struct virtio_device *vdev);
-       void (*set_features)(struct virtio_device *vdev, u32 features);
+       void (*finalize_features)(struct virtio_device *vdev);
 };
 
 /* If driver didn't advertise the feature, it will never appear. */
@@ -89,7 +112,9 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev,
        if (__builtin_constant_p(fbit))
                BUILD_BUG_ON(fbit >= 32);
 
-       virtio_check_driver_offered_feature(vdev, fbit);
+       if (fbit < VIRTIO_TRANSPORT_F_START)
+               virtio_check_driver_offered_feature(vdev, fbit);
+
        return test_bit(fbit, vdev->features);
 }
 
@@ -116,5 +141,18 @@ static inline int virtio_config_buf(struct virtio_device *vdev,
        vdev->config->get(vdev, offset, buf, len);
        return 0;
 }
+
+static inline
+struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
+                                       vq_callback_t *c, const char *n)
+{
+       vq_callback_t *callbacks[] = { c };
+       const char *names[] = { n };
+       struct virtqueue *vq;
+       int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
+       if (err < 0)
+               return ERR_PTR(err);
+       return vq;
+}
 #endif /* __KERNEL__ */
 #endif /* _LINUX_VIRTIO_CONFIG_H */