Commit 3beee86a authored by Sjur Brændeland's avatar Sjur Brændeland Committed by Rusty Russell

virtio: Introduce vringh wrappers in virtio_config

Add wrappers for the host vrings to support loose
coupling between the virtio device and driver.

A new struct vringh_config_ops with the functions
find_vrhs() and del_vrhs() is added to the virtio_device
struct. This enables virtio drivers to manage virtio
host rings without detailed knowledge of how the
vrings are created and deleted.

The function vringh_notify() is added so vringh clients
can notify the other side that buffers are added to the
used-ring.

Cc: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: default avatarSjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (constified vringh_config)
parent 1515c5ce
......@@ -8,6 +8,7 @@
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/gfp.h>
#include <linux/vringh.h>
/**
* virtqueue - a queue to register buffers for sending or receiving.
......@@ -70,6 +71,7 @@ static inline unsigned int virtqueue_get_queue_index(struct virtqueue *vq)
* @dev: underlying device.
* @id: the device type identification (used to match it with a driver).
* @config: the configuration ops for this device.
* @vringh_config: configuration ops for host vrings.
* @vqs: the list of virtqueues for this device.
* @features: the features supported by both driver and device.
* @priv: private pointer for the driver's use.
......@@ -79,6 +81,7 @@ struct virtio_device {
struct device dev;
struct virtio_device_id id;
const struct virtio_config_ops *config;
const struct vringh_config_ops *vringh_config;
struct list_head vqs;
/* Note that this is a Linux set_bit-style bitmap. */
unsigned long features[1];
......
......@@ -47,6 +47,28 @@ struct vringh {
/* The vring (note: it may contain user pointers!) */
struct vring vring;
/* The function to call to notify the guest about added buffers */
void (*notify)(struct vringh *);
};
/**
* struct vringh_config_ops - ops for creating a host vring from a virtio driver
* @find_vrhs: find the host vrings and instantiate them
* vdev: the virtio_device
* nhvrs: the number of host vrings to find
* hvrs: on success, includes new host vrings
* callbacks: array of driver callbacks, for each host vring
* include a NULL entry for vqs that do not need a callback
* Returns 0 on success or error status
* @del_vrhs: free the host vrings found by find_vrhs().
*/
struct virtio_device;
typedef void vrh_callback_t(struct virtio_device *, struct vringh *);
struct vringh_config_ops {
int (*find_vrhs)(struct virtio_device *vdev, unsigned nhvrs,
struct vringh *vrhs[], vrh_callback_t *callbacks[]);
void (*del_vrhs)(struct virtio_device *vdev);
};
/* The memory the vring can access, and what offset to apply. */
......@@ -193,4 +215,11 @@ void vringh_notify_disable_kern(struct vringh *vrh);
int vringh_need_notify_kern(struct vringh *vrh);
/* Notify the guest about buffers added to the used ring */
static inline void vringh_notify(struct vringh *vrh)
{
if (vrh->notify)
vrh->notify(vrh);
}
#endif /* _LINUX_VRINGH_H */
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