pvrdma: wean code off pvrdma_ring.h kernel header

The pvrdma code relies on the pvrdma_ring.h kernel header for some
basic ring buffer handling. The content of that header isn't very
exciting, but contains some (q)atomic_*() invocations that (a)
cause manual massaging when doing a headers update, and (b) are
an indication that we probably should not be importing that header
at all.

Let's reimplement the ring buffer handling directly in the pvrdma
code instead. This arguably also improves readability of the code.

Importing the header can now be dropped.

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Yuval Shaia <yuval.shaia.ml@gmail.com>
Tested-by: Yuval Shaia <yuval.shaia.ml@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 0 insertions, 114 deletions

diff --git a/include/standard-headers/drivers/infiniband/hw/vmw_pvrdma/pvrdma_ring.h b/include/standard-headers/drivers/infiniband/hw/vmw_pvrdma/pvrdma_ring.h
deleted file mode 100644
index 7b4062a1a1..0000000000
--- a/include/standard-headers/drivers/infiniband/hw/vmw_pvrdma/pvrdma_ring.h
+++ /dev/null
@@ -1,114 +0,0 @@
-/*
- * Copyright (c) 2012-2016 VMware, Inc.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of EITHER the GNU General Public License
- * version 2 as published by the Free Software Foundation or the BSD
- * 2-Clause License. This program is distributed in the hope that it
- * will be useful, but WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED
- * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
- * See the GNU General Public License version 2 for more details at
- * http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program available in the file COPYING in the main
- * directory of this source tree.
- *
- * The BSD 2-Clause License
- *
- *     Redistribution and use in source and binary forms, with or
- *     without modification, are permitted provided that the following
- *     conditions are met:
- *
- *      - Redistributions of source code must retain the above
- *        copyright notice, this list of conditions and the following
- *        disclaimer.
- *
- *      - Redistributions in binary form must reproduce the above
- *        copyright notice, this list of conditions and the following
- *        disclaimer in the documentation and/or other materials
- *        provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
- * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef __PVRDMA_RING_H__
-#define __PVRDMA_RING_H__
-
-#include "standard-headers/linux/types.h"
-
-#define PVRDMA_INVALID_IDX	-1	/* Invalid index. */
-
-struct pvrdma_ring {
-	int prod_tail;	/* Producer tail. */
-	int cons_head;	/* Consumer head. */
-};
-
-struct pvrdma_ring_state {
-	struct pvrdma_ring tx;	/* Tx ring. */
-	struct pvrdma_ring rx;	/* Rx ring. */
-};
-
-static inline int pvrdma_idx_valid(uint32_t idx, uint32_t max_elems)
-{
-	/* Generates fewer instructions than a less-than. */
-	return (idx & ~((max_elems << 1) - 1)) == 0;
-}
-
-static inline int32_t pvrdma_idx(int *var, uint32_t max_elems)
-{
-	const unsigned int idx = qatomic_read(var);
-
-	if (pvrdma_idx_valid(idx, max_elems))
-		return idx & (max_elems - 1);
-	return PVRDMA_INVALID_IDX;
-}
-
-static inline void pvrdma_idx_ring_inc(int *var, uint32_t max_elems)
-{
-	uint32_t idx = qatomic_read(var) + 1;	/* Increment. */
-
-	idx &= (max_elems << 1) - 1;		/* Modulo size, flip gen. */
-	qatomic_set(var, idx);
-}
-
-static inline int32_t pvrdma_idx_ring_has_space(const struct pvrdma_ring *r,
-					      uint32_t max_elems, uint32_t *out_tail)
-{
-	const uint32_t tail = qatomic_read(&r->prod_tail);
-	const uint32_t head = qatomic_read(&r->cons_head);
-
-	if (pvrdma_idx_valid(tail, max_elems) &&
-	    pvrdma_idx_valid(head, max_elems)) {
-		*out_tail = tail & (max_elems - 1);
-		return tail != (head ^ max_elems);
-	}
-	return PVRDMA_INVALID_IDX;
-}
-
-static inline int32_t pvrdma_idx_ring_has_data(const struct pvrdma_ring *r,
-					     uint32_t max_elems, uint32_t *out_head)
-{
-	const uint32_t tail = qatomic_read(&r->prod_tail);
-	const uint32_t head = qatomic_read(&r->cons_head);
-
-	if (pvrdma_idx_valid(tail, max_elems) &&
-	    pvrdma_idx_valid(head, max_elems)) {
-		*out_head = head & (max_elems - 1);
-		return tail != head;
-	}
-	return PVRDMA_INVALID_IDX;
-}
-
-#endif /* __PVRDMA_RING_H__ */