1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2007-2008 Kip Macy <kmacy@freebsd.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/kernel.h>
35#include <sys/lock.h>
36#include <sys/malloc.h>
37#include <sys/mbuf.h>
38#include <sys/ktr.h>
39
40#include <vm/vm.h>
41#include <vm/pmap.h>
42
43#include <machine/bus.h>
44
45#include <cxgb_include.h>
46#include <sys/mvec.h>
47
48#ifdef INVARIANTS
49#define M_SANITY m_sanity
50#else
51#define M_SANITY(a, b)
52#endif
53
54int
55busdma_map_sg_collapse(bus_dma_tag_t tag, bus_dmamap_t map,
56	struct mbuf **m, bus_dma_segment_t *segs, int *nsegs)
57{
58	struct mbuf *n = *m;
59	int seg_count, defragged = 0, err = 0;
60	bus_dma_segment_t *psegs;
61
62	KASSERT(n->m_pkthdr.len, ("packet has zero header len"));
63	if (n->m_pkthdr.len <= PIO_LEN)
64		return (0);
65retry:
66	psegs = segs;
67	seg_count = 0;
68	err = bus_dmamap_load_mbuf_sg(tag, map, *m, segs, &seg_count, 0);
69	if (seg_count == 0) {
70		if (cxgb_debug)
71			printf("empty segment chain\n");
72		err = EFBIG;
73		goto err_out;
74	}  else if (err == EFBIG || seg_count >= TX_MAX_SEGS) {
75		if (cxgb_debug)
76			printf("mbuf chain too long: %d max allowed %d\n",
77			    seg_count, TX_MAX_SEGS);
78		if (!defragged) {
79			n = m_defrag(*m, M_NOWAIT);
80			if (n == NULL) {
81				err = ENOBUFS;
82				goto err_out;
83			}
84			*m = n;
85			defragged = 1;
86			goto retry;
87		}
88		err = EFBIG;
89		goto err_out;
90	}
91
92	*nsegs = seg_count;
93err_out:
94	return (err);
95}
96
97void
98busdma_map_sg_vec(bus_dma_tag_t tag, bus_dmamap_t map,
99    struct mbuf *m, bus_dma_segment_t *segs, int *nsegs)
100{
101	int n = 0;
102
103	for (*nsegs = 0; m != NULL; segs += n, *nsegs += n, m = m->m_nextpkt)
104		bus_dmamap_load_mbuf_sg(tag, map, m, segs, &n, 0);
105}
106
107