vhost: vringh: Remove unused functions

The functions:
  vringh_abandon_kern()
  vringh_abandon_user()
  vringh_iov_pull_kern() and
  vringh_iov_push_kern()
were all added in 2013 by
commit f87d0fb ("vringh: host-side implementation of virtio rings.")
but have remained unused.

Remove them and the two helper functions they used.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Message-Id: <20250617001838.114457-3-linux@treblig.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>

Author: Dr. David Alan Gilbert

drivers/vhost/vringh.c

@@ -779,22 +779,6 @@ ssize_t vringh_iov_push_user(struct vringh_iov *wiov,
 }
 EXPORT_SYMBOL(vringh_iov_push_user);
 
-/**
- * vringh_abandon_user - we've decided not to handle the descriptor(s).
- * @vrh: the vring.
- * @num: the number of descriptors to put back (ie. num
- *	 vringh_get_user() to undo).
- *
- * The next vringh_get_user() will return the old descriptor(s) again.
- */
-void vringh_abandon_user(struct vringh *vrh, unsigned int num)
-{
-	/* We only update vring_avail_event(vr) when we want to be notified,
-	 * so we haven't changed that yet. */
-	vrh->last_avail_idx -= num;
-}
-EXPORT_SYMBOL(vringh_abandon_user);
-
 /**
  * vringh_complete_user - we've finished with descriptor, publish it.
  * @vrh: the vring.
@@ -900,20 +884,6 @@ static inline int putused_kern(const struct vringh *vrh,
 	return 0;
 }
 
-static inline int xfer_kern(const struct vringh *vrh, void *src,
-			    void *dst, size_t len)
-{
-	memcpy(dst, src, len);
-	return 0;
-}
-
-static inline int kern_xfer(const struct vringh *vrh, void *dst,
-			    void *src, size_t len)
-{
-	memcpy(dst, src, len);
-	return 0;
-}
-
 /**
  * vringh_init_kern - initialize a vringh for a kernelspace vring.
  * @vrh: the vringh to initialize.
@@ -998,51 +968,6 @@ int vringh_getdesc_kern(struct vringh *vrh,
 }
 EXPORT_SYMBOL(vringh_getdesc_kern);
 
-/**
- * vringh_iov_pull_kern - copy bytes from vring_iov.
- * @riov: the riov as passed to vringh_getdesc_kern() (updated as we consume)
- * @dst: the place to copy.
- * @len: the maximum length to copy.
- *
- * Returns the bytes copied <= len or a negative errno.
- */
-ssize_t vringh_iov_pull_kern(struct vringh_kiov *riov, void *dst, size_t len)
-{
-	return vringh_iov_xfer(NULL, riov, dst, len, xfer_kern);
-}
-EXPORT_SYMBOL(vringh_iov_pull_kern);
-
-/**
- * vringh_iov_push_kern - copy bytes into vring_iov.
- * @wiov: the wiov as passed to vringh_getdesc_kern() (updated as we consume)
- * @src: the place to copy from.
- * @len: the maximum length to copy.
- *
- * Returns the bytes copied <= len or a negative errno.
- */
-ssize_t vringh_iov_push_kern(struct vringh_kiov *wiov,
-			     const void *src, size_t len)
-{
-	return vringh_iov_xfer(NULL, wiov, (void *)src, len, kern_xfer);
-}
-EXPORT_SYMBOL(vringh_iov_push_kern);
-
-/**
- * vringh_abandon_kern - we've decided not to handle the descriptor(s).
- * @vrh: the vring.
- * @num: the number of descriptors to put back (ie. num
- *	 vringh_get_kern() to undo).
- *
- * The next vringh_get_kern() will return the old descriptor(s) again.
- */
-void vringh_abandon_kern(struct vringh *vrh, unsigned int num)
-{
-	/* We only update vring_avail_event(vr) when we want to be notified,
-	 * so we haven't changed that yet. */
-	vrh->last_avail_idx -= num;
-}
-EXPORT_SYMBOL(vringh_abandon_kern);
-
 /**
  * vringh_complete_kern - we've finished with descriptor, publish it.
  * @vrh: the vring.

include/linux/vringh.h

@@ -175,9 +175,6 @@ int vringh_complete_multi_user(struct vringh *vrh,
 			       const struct vring_used_elem used[],
 			       unsigned num_used);
 
-/* Pretend we've never seen descriptor (for easy error handling). */
-void vringh_abandon_user(struct vringh *vrh, unsigned int num);
-
 /* Do we need to fire the eventfd to notify the other side? */
 int vringh_need_notify_user(struct vringh *vrh);
 
@@ -235,10 +232,6 @@ int vringh_getdesc_kern(struct vringh *vrh,
 			u16 *head,
 			gfp_t gfp);
 
-ssize_t vringh_iov_pull_kern(struct vringh_kiov *riov, void *dst, size_t len);
-ssize_t vringh_iov_push_kern(struct vringh_kiov *wiov,
-			     const void *src, size_t len);
-void vringh_abandon_kern(struct vringh *vrh, unsigned int num);
 int vringh_complete_kern(struct vringh *vrh, u16 head, u32 len);
 
 bool vringh_notify_enable_kern(struct vringh *vrh);